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| 6 <title>WebGL Specification</title> | |
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| 14 <!--begin-logo--> | |
| 15 <div class=head> | |
| 16 <p> | |
| 17 <a href="http://khronos.org/"> | |
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| 19 </a> | |
| 20 </p> | |
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| 22 <div class=head> | |
| 23 <p> | |
| 24 <a href="http://webgl.org/"> | |
| 25 <img alt=WebGL height=72 src="../../resources/WebGL-Logo.png" wi
dth=156> | |
| 26 </a> | |
| 27 </p> | |
| 28 </div> | |
| 29 <!--end-logo--> | |
| 30 | |
| 31 <h1>WebGL 1.0 Specification</h1> | |
| 32 <h2 class="no-toc">23 December 2010 (r13288)</h2> | |
| 33 <dl> | |
| 34 <dt>This version: | |
| 35 <dd> | |
| 36 <a href="https://cvs.khronos.org/svn/repos/registry/trunk/public
/webgl/doc/spec/WebGL-spec.html"> | |
| 37 https://cvs.khronos.org/svn/repos/registry/trunk/public/webg
l/doc/spec/WebGL-spec.html | |
| 38 </a> | |
| 39 <br> | |
| 40 <a href="https://cvs.khronos.org/svn/repos/registry/trunk/public
/webgl/doc/spec/webgl.idl"> | |
| 41 <b>WebIDL:</b> https://cvs.khronos.org/svn/repos/registry/tr
unk/public/webgl/doc/spec/webgl.idl | |
| 42 </a> | |
| 43 </dd> | |
| 44 <dt>Latest version: | |
| 45 <dd> | |
| 46 <a href="https://cvs.khronos.org/svn/repos/registry/trunk/public
/webgl/doc/spec/WebGL-spec.html"> | |
| 47 https://cvs.khronos.org/svn/repos/registry/trunk/public/webg
l/doc/spec/WebGL-spec.html | |
| 48 </a> | |
| 49 <br> | |
| 50 <a href="https://cvs.khronos.org/svn/repos/registry/trunk/public
/webgl/doc/spec/webgl.idl"> | |
| 51 <b>WebIDL:</b> https://cvs.khronos.org/svn/repos/registry/tr
unk/public/webgl/doc/spec/webgl.idl | |
| 52 </a> | |
| 53 </dd> | |
| 54 <dt>Previous version: | |
| 55 <dd> | |
| 56 none | |
| 57 </dd> | |
| 58 <dt>Editor: | |
| 59 <dd> | |
| 60 <a href="mailto:cmarrin@apple.com">Chris Marrin</a> | |
| 61 <a href="http://www.apple.com/">(Apple Inc.)</a> | |
| 62 </dd> | |
| 63 </dl> | |
| 64 | |
| 65 <span style="font-size: x-small; font-style: oblique">Copyright © 2010
Khronos Group</span> | |
| 66 | |
| 67 <hr /> | |
| 68 | |
| 69 <h2 class="no-toc">Abstract</h2> | |
| 70 <p> | |
| 71 This specification describes an additional rendering context and support | |
| 72 objects for the | |
| 73 <a | |
| 74 href="http://www.whatwg.org/specs/web-apps/current-work/multipage/th
e-canvas-element.html" | |
| 75 title="HTML 5 Canvas Element"> | |
| 76 HTML 5 <span class="prop-name">canvas</span> element. | |
| 77 </a> | |
| 78 This context allows rendering using an API that conforms closely to the
OpenGL ES 2.0 API. | |
| 79 </p> | |
| 80 | |
| 81 <h2 class="no-toc">Status of this document</h2> | |
| 82 | |
| 83 <!--begin-status--> | |
| 84 <p> | |
| 85 Discussion and questions about this specification are | |
| 86 welcome on the (<a | |
| 87 href="https://www.khronos.org/webgl/public-mailing-list/archives/">a
rchived</a>) | |
| 88 WebGL mailing list <a href="mailto:public_webgl@khronos.org">public_webg
l@khronos.org</a> (see | |
| 89 <a href="http://www.khronos.org/webgl/public-mailing-list/">instructions
</a>). | |
| 90 </p> | |
| 91 <!--end-status--> | |
| 92 | |
| 93 <h2 class="no-toc">Table of contents</h2> | |
| 94 <div id="toc"></div> | |
| 95 | |
| 96 <h2>Introduction</h2> | |
| 97 <div class="note"> | |
| 98 <p> | |
| 99 WebGL is an immediate mode 3D rendering API designed for the | |
| 100 web. It is derived from OpenGL ES 2.0, and provides similar | |
| 101 rendering functionality, but in a HTML context. WebGL is | |
| 102 designed as a rendering context for the HTML Canvas element. | |
| 103 The HTML Canvas provides a destination for programmatic | |
| 104 rendering in web pages, and allows for performing that rendering | |
| 105 using different rendering APIs. The only such interface | |
| 106 described as part of the Canvas specification is the 2D canvas | |
| 107 rendering context, CanvasRenderingContext2D. This document | |
| 108 describes another such interface, WebGLRenderingContext, which | |
| 109 presents the WebGL API. | |
| 110 </p> | |
| 111 | |
| 112 <p> | |
| 113 The immediate mode nature of the API is a divergence from most | |
| 114 web APIs. Given the many use cases of 3D graphics, WebGL | |
| 115 chooses the approach of providing flexible primitives that can | |
| 116 be applied to any use case. Libraries can provide an API on top | |
| 117 of WebGL that is more tailored to specific areas, thus adding a | |
| 118 convenience layer to WebGL that can accelerate and simplify development. | |
| 119 However, because of its OpenGL ES 2.0 heritage, it should be | |
| 120 straightforward for developers familiar with modern desktop | |
| 121 OpenGL or OpenGL ES 2.0 development to transition to WebGL | |
| 122 development. | |
| 123 </p> | |
| 124 | |
| 125 <p> | |
| 126 Many functions described in this document contain links to OpenGL ES | |
| 127 man pages. While every effort is made to make these pages match the | |
| 128 OpenGL ES 2.0 spec <a href="#refsGLES20">[GLES20]</a>, | |
| 129 they may contain errors. In cases where a man page | |
| 130 contradicts the spec, the spec is the final authority. | |
| 131 </p> | |
| 132 | |
| 133 <p> | |
| 134 The remaining sections of this document are intended to be read in conjunc
tion | |
| 135 with the OpenGL ES 2.0 specification (2.0.24 at the time of this writing,
available | |
| 136 from the <a href="http://www.khronos.org/registry/gles/">Khronos OpenGL ES
API Regsitry</a>). | |
| 137 Unless otherwise specified, the behaviour of each method is defined by the | |
| 138 OpenGL ES 2.0 specification. This specification may diverge from OpenGL E
S 2.0 | |
| 139 in order to ensure interoperability or security, often defining areas that | |
| 140 OpenGL ES 2.0 leaves implementation-defined. These differences are summar
ized in the | |
| 141 <a href="#webgl_gl_differences">Differences Between WebGL and OpenGL ES 2.
0</a> section. | |
| 142 </p> | |
| 143 </div> | |
| 144 | |
| 145 <!-- ===========================================================================
============================ --> | |
| 146 | |
| 147 <h2>Context Creation and Drawing Buffer Presentation</h2> | |
| 148 | |
| 149 <p> | |
| 150 Before using the WebGL API, the author must obtain a WebGLRenderingConte
xt object | |
| 151 for a given HTMLCanvasElement as described below. This object is used to
manage | |
| 152 OpenGL state and render to the drawing buffer, which must also be create
d at the time of | |
| 153 context creation. The author may supply configuration options for this d
rawing buffer, otherwise | |
| 154 default values shall be used as specified elsewhere in this document. Th
is drawing buffer | |
| 155 is presented to the HTML page compositor immediately before an HTML page
compositing operation, | |
| 156 but only if the drawing buffer has been modified since the last composit
ing operation. | |
| 157 </p> | |
| 158 | |
| 159 <!-- ===========================================================================
============================ --> | |
| 160 | |
| 161 <h3>The <span class=prop-name>‘<code class=property>canvas</code>&rsqu
o;</span> Element</h3> | |
| 162 | |
| 163 <p> | |
| 164 A WebGLRenderingContext object shall be created by calling the <code>get
Context()</code> | |
| 165 method of a given HTMLCanvasElement object with the exact string | |
| 166 ‘<code class=property>webgl</code>’. This string is case se
nsitive. When called | |
| 167 for the first time, a WebGLRenderingContext object is created and return
ed. Also at this | |
| 168 time a drawing buffer shall be created. Subsequent calls to <code>getCon
text()</code> with | |
| 169 the same string shall return the same object. If <code>getContext()</co
de> is subsequently | |
| 170 called with any other string, the WebGLRenderingContext shall be detache
d from its Canvas | |
| 171 object (the <code>canvas</code> attribute will be null). API calls may s
till be made on the | |
| 172 WebGLRenderingContext object and readPixels() may be used to obtain the
contents of the | |
| 173 drawing buffer, but the contents shall no longer be shown on the page. | |
| 174 </p> | |
| 175 <p> | |
| 176 A second parameter may be passed to the <code>getContext()</code> method
. If passed, this | |
| 177 parameter shall be a WebGLContextAttributes object containing configurat
ion parameters to be | |
| 178 used in creating the drawing buffer. | |
| 179 See <a href="#WEBGLCONTEXTATTRIBUTES">WebGLContextAttributes</a> for mor
e details. | |
| 180 </p> | |
| 181 <p> | |
| 182 The passed attributes are requests, not requirements. The WebGL implemen
tation does not | |
| 183 guarantee that they will be obeyed, but should make a best effort to hon
or them. | |
| 184 Combinations of attributes not supported by the WebGL implementation or
graphics hardware | |
| 185 shall not cause a failure to create a WebGLRenderingContext. The attribu
tes actually used to | |
| 186 create the context may be queried by the <code>getContextAttributes()</c
ode> method on the | |
| 187 WebGLRenderingContext. | |
| 188 </p> | |
| 189 <p> | |
| 190 On subsequent calls to getContext() with the ‘<code class=property
>webgl</code>’ | |
| 191 string, the passed WebGLContextAttributes object, if any, shall be ignor
ed. | |
| 192 <p> | |
| 193 </p> | |
| 194 | |
| 195 <!-- ===========================================================================
============================ --> | |
| 196 | |
| 197 <h3><a name="THE_DRAWING_BUFFER">The Drawing Buffer</a></h3> | |
| 198 | |
| 199 <p> | |
| 200 The drawing buffer into which the API calls are rendered shall be define
d upon creation of | |
| 201 the WebGLRenderingContext object. The table below shows all the buffers
which make up | |
| 202 the drawing buffer, along with their minimum sizes and whether they are
defined or not by | |
| 203 default. The size of this drawing buffer shall be determined by the <cod
e>width</code> | |
| 204 and <code>height</code> attributes of the HTMLCanvasElement. The table b
elow also shows | |
| 205 the value to which these buffers shall be cleared when first created or
when the size is | |
| 206 changed. | |
| 207 </p> | |
| 208 <table class="foo"> | |
| 209 <tr><th>Buffer</th><th>Clear value</th><th>Minimum size</th><th>Defined
By default?</th></tr> | |
| 210 <tr><td>Color</td><td>(0, 0, 0, 0)</td><td>8 bits per component</td><td>
yes</td></tr> | |
| 211 <tr><td>Depth</td><td>1.0</td><td>16 bit integer</td><td>yes</td></tr> | |
| 212 <tr><td>Stencil</td><td>0</td><td>8 bits</td><td>no</td></tr> | |
| 213 </table> | |
| 214 <br> | |
| 215 <p> | |
| 216 If the requested width or height cannot be satisfied, either when the dr
awing buffer is first | |
| 217 created or when the <code>width</code> and <code>height</code> attribute
s of the | |
| 218 <code>HTMLCanvasElement</code> are changed, a drawing buffer with smalle
r dimensions shall | |
| 219 be created. The dimensions actually used are implementation dependent an
d there is no | |
| 220 guarantee that a buffer with the same aspect ratio will be created. The
actual drawing | |
| 221 buffer size can be obtained from the <code>drawingBufferWidth</code> and
| |
| 222 <code>drawingBufferHeight</code> attributes. | |
| 223 </p> | |
| 224 <p> | |
| 225 By default, the buffers shall be the size shown below. The optional <a h
ref="#WEBGLCONTEXTATTRIBUTES">WebGLContextAttributes</a> | |
| 226 object may be used to change whether or not the buffers are defined. It
can also be used | |
| 227 to define whether the color buffer will include an alpha channel. If def
ined, the | |
| 228 alpha channel is used by the HTML compositor to combine the color buffer
with the rest | |
| 229 of the page. The WebGLContextAttributes object is only used on the first
call to | |
| 230 <code>getContext</code>. No facility is provided to change the attribute
s of the drawing | |
| 231 buffer after its creation. | |
| 232 </p> | |
| 233 <p> | |
| 234 WebGL presents its drawing buffer to the HTML page compositor immediatel
y before a compositing | |
| 235 operation, but only if the drawing buffer has been modified since the la
st compositing operation. | |
| 236 Before the drawing buffer is presented for compositing the implementatio
n shall ensure that all | |
| 237 rendering operations have been flushed to the drawing buffer. By default
, after compositing the | |
| 238 contents of the drawing buffer shall be cleared to its default values, a
s shown in the table | |
| 239 above. | |
| 240 </p> | |
| 241 <p> | |
| 242 This default behavior can be changed by setting the <code>preserveDrawin
gBuffer</code> | |
| 243 attribute of the <a href="#WEBGLCONTEXTATTRIBUTES">WebGLContextAttribute
s</a> object to | |
| 244 true, the contents of the drawing buffer can be preserved until the auth
or either clears | |
| 245 or overwrites them. If this flag is false attempting to perform operatio
ns using this | |
| 246 context as a source image after the rendering function has returned can
lead to undefined | |
| 247 behavior. This includes <code>readPixels</code> or <code>toDataURL</code
> calls, or using | |
| 248 this context as the source image of another context's <code>texImage2D</
code> or | |
| 249 <code>drawImage</code> call. | |
| 250 </p> | |
| 251 <div class="note"> | |
| 252 <p> | |
| 253 While it is sometimes desirable to preserve the drawing buffer, it c
an cause significant | |
| 254 performance loss on some platforms. Whenever possible this flag shou
ld remain false | |
| 255 and other techniques used. Techniques like synchronous drawing buffe
r access (e.g., | |
| 256 calling <code>readPixels</code> or <code>toDataURL</code> in the sam
e function that | |
| 257 renders to the drawing buffer) can be used to get the contents of th
e drawing buffer. | |
| 258 If the author needs to render to the same drawing buffer over a seri
es of calls, a | |
| 259 <a href="#WEBGL_FRAMEBUFFER">Framebuffer Object</a> can be used. | |
| 260 </p> | |
| 261 <p> | |
| 262 One way for an implementation to guarantee buffers do not contain in
formation from another | |
| 263 process is to clear the buffer to the default values specified in th
e OpenGL ES 2.0 | |
| 264 specification <a href="#refsGLES20">[GLES20]</a>. | |
| 265 </p> | |
| 266 </div> | |
| 267 | |
| 268 <!-- ===========================================================================
============================ --> | |
| 269 | |
| 270 <h3>The WebGL Viewport</h3> | |
| 271 | |
| 272 <p> | |
| 273 OpenGL manages a rectangular viewport as part of its state which defines
the placement of the | |
| 274 rendering results in the drawing buffer. Upon creation of the WebGL cont
ext, the viewport is | |
| 275 initialized to a rectangle with origin at (0, 0) and width and height eq
ual to (canvas.width, | |
| 276 canvas.height). | |
| 277 </p> | |
| 278 <p> | |
| 279 A WebGL implementation <em>shall not</em> affect the state of the OpenGL
viewport in response to | |
| 280 resizing of the canvas element. | |
| 281 </p> | |
| 282 <div class="example"> | |
| 283 Note that if a WebGL program does not contain logic to set the viewport,
it will not properly | |
| 284 handle the case where the canvas is resized. The following ECMAScript ex
ample illustrates how | |
| 285 a WebGL program might resize the canvas programmatically. | |
| 286 | |
| 287 <pre> | |
| 288 var canvas = document.getElementById('canvas1'); | |
| 289 var gl = canvas.getContext('webgl'); | |
| 290 canvas.width = newWidth; | |
| 291 canvas.height = newHeight; | |
| 292 gl.viewport(0, 0, canvas.width, canvas.height); | |
| 293 </pre> | |
| 294 </div> | |
| 295 <p> | |
| 296 <em>Rationale</em>: automatically setting the viewport will interfere wi
th applications that set | |
| 297 it manually. Applications are expected to use <code>onresize</code> hand
lers to respond to | |
| 298 changes in size of the canvas and set the OpenGL viewport in turn. | |
| 299 </p> | |
| 300 | |
| 301 <!-- ===========================================================================
============================ --> | |
| 302 | |
| 303 <h3><a name="PREMULTIPLIED_ALPHA">Premultiplied Alpha, Canvas APIs and texIm
age2D</a></h3> | |
| 304 | |
| 305 <p> | |
| 306 The OpenGL API allows the application to modify the blending modes used
during rendering, | |
| 307 and for this reason allows control over how alpha values in the drawing
buffer are | |
| 308 interpreted; see the <code>premultipliedAlpha</code> parameter in | |
| 309 the <a href="#WEBGLCONTEXTATTRIBUTES">WebGLContextAttributes</a> section
. | |
| 310 </p> | |
| 311 <p> | |
| 312 The HTML Canvas APIs <code>toDataURL</code> and <code>drawImage</code> m
ust respect | |
| 313 the <code>premultipliedAlpha</code> context creation parameter. When <co
de>toDataURL</code> | |
| 314 is called against a Canvas into which WebGL content is being rendered, t
hen if the requested | |
| 315 image format does not specify premultiplied alpha and the WebGL context
has | |
| 316 the <code>premultipliedAlpha</code> parameter set to true, then the pixe
l values must be | |
| 317 de-multiplied; i.e., the color channels are divided by the alpha channel
. <b>Note</b> that | |
| 318 this operation is lossy. | |
| 319 </p> | |
| 320 <p> | |
| 321 Passing a WebGL-rendered Canvas to the <code>drawImage</code> method | |
| 322 of <code>CanvasRenderingContext2D</code> may or may not need to modify t
he the rendered | |
| 323 WebGL content during the drawing operation, depending on the premultipli
cation needs of the | |
| 324 <code>CanvasRenderingContext2D</code> implementation. | |
| 325 </p> | |
| 326 <p> | |
| 327 When passing a WebGL-rendered Canvas to the <code>texImage2D</code> API,
then depending on | |
| 328 the setting of the <code>premultipliedAlpha</code> context creation para
meter of the passed | |
| 329 canvas and the <code>UNPACK_PREMULTIPLY_ALPHA_WEBGL</code> pixel store p
arameter of the | |
| 330 destination WebGL context, the pixel data may need to be changed to or f
rom premultiplied | |
| 331 form. | |
| 332 </p> | |
| 333 | |
| 334 <!-- ===========================================================================
============================ --> | |
| 335 | |
| 336 <h2>WebGL Resources</h2> | |
| 337 | |
| 338 <p> | |
| 339 OpenGL manages several types of resources as part of its state. These ar
e identified | |
| 340 by integer object names and are obtained from OpenGL by various creation
calls. | |
| 341 In contrast WebGL represents these resources as DOM objects. Each object
is derived | |
| 342 from the WebGLObject interface. Currently supported resources are: | |
| 343 textures, buffers (i.e., VBOs), framebuffers, renderbuffers, shaders and | |
| 344 programs. The WebGLRenderingContext interface has a method to create a | |
| 345 WebGLObject subclass for each type. Data from the underlying graphics li
brary are | |
| 346 stored in these objects and are fully managed by them. The resources rep
resented | |
| 347 by these objects are guaranteed to exist as long as the object exists. | |
| 348 Furthermore, the DOM object is guaranteed to exist as long as the author
has an explicit | |
| 349 valid reference to it OR as long as it is bound by the underlying graphi
cs library. | |
| 350 When none of these conditions exist the user agent can, at any point, de
lete the object | |
| 351 using the equivalent of a delete call (e.g., deleteTexture). If authors
wish to control | |
| 352 when the underlying resource is released then the delete call can be mad
e explicitly. | |
| 353 </p> | |
| 354 | |
| 355 <!-- ===========================================================================
============================ --> | |
| 356 | |
| 357 <h2>Security</h2> | |
| 358 | |
| 359 <p> | |
| 360 </p> | |
| 361 | |
| 362 <!-- ===========================================================================
============================ --> | |
| 363 | |
| 364 <h3>Resource Restrictions</h3> | |
| 365 | |
| 366 <p> | |
| 367 WebGL resources such as textures and vertex buffer objects (VBOs) must a
lways | |
| 368 contain initialized data, even if they were created without initial user
| |
| 369 data values. Creating a resource without initial values is commonly use
d to | |
| 370 reserve space for a texture or VBO, which is then modified using <code>t
exSubImage</code> or | |
| 371 <code>bufferSubData</code> calls. If initial data is not provided to th
ese calls, the WebGL | |
| 372 implementation must initialize their contents to 0; depth renderbuffers
must be cleared to | |
| 373 the default 1.0 clear depth. For example, this may require creating a t
emporary buffer of 0 | |
| 374 values the size of a requested VBO, so that it can be initialized correc
tly. All other | |
| 375 forms of loading data into a texture or VBO involve either ArrayBuffers
or DOM objects such | |
| 376 as images, and are therefore already required to be initialized. | |
| 377 </p> | |
| 378 | |
| 379 <p> | |
| 380 When WebGL resources are accessed by shaders through a call such as | |
| 381 <code>drawElements</code> or <code>drawArrays</code>, the WebGL implemen
tation must ensure | |
| 382 that the shader cannot access either out of bounds or uninitialized data
. | |
| 383 See <a href="#ATTRIBS_AND_RANGE_CHECKING">Enabled Vertex Attributes and
Range Checking</a> | |
| 384 for restrictions which must be enforced by the WebGL implementation. | |
| 385 </p> | |
| 386 | |
| 387 <!-- ===========================================================================
============================ --> | |
| 388 | |
| 389 <h3>Origin Restrictions</h3> | |
| 390 | |
| 391 <p> | |
| 392 In order to prevent information leakage, the HTML5 canvas element has | |
| 393 a <i>origin-clean</i> flag. (See HTML5, section 4.8.11.3, "Security wit
h canvas | |
| 394 elements".) For a WebGL context, the <i>origin-clean</i> flag must be s
et to false | |
| 395 if any of the following actions occur: | |
| 396 </p> | |
| 397 <ul> | |
| 398 <li>The <code>texImage2D</code> method is called with an <code>HTMLI
mageElement</code> or | |
| 399 <code>HTMLVideoElement</code> whose origin is not the same as th
at of the Document | |
| 400 object that owns the canvas element. | |
| 401 <li>The <code>texImage2D</code> method is called with an <code>HTMLC
anvasElement</code> | |
| 402 whose <i>origin-clean</i> flag is set to false. | |
| 403 </ul> | |
| 404 <p> | |
| 405 Whenever the <code>readPixels</code> method of the 2D context of a <code
>canvas</code> | |
| 406 element whose <i>origin-clean</i> flag is set to false is called with ot
herwise correct | |
| 407 arguments, the method must raise a <code>SECURITY_ERR</code> exception. | |
| 408 </p> | |
| 409 | |
| 410 <!-- ===========================================================================
============================ --> | |
| 411 | |
| 412 <h3><a name="SUPPORTED_GLSL_CONSTRUCTS">Supported GLSL Constructs</a></h3> | |
| 413 | |
| 414 <p> | |
| 415 A WebGL implementation must only accept shaders which conform to The Ope
nGL ES Shading | |
| 416 Language, Version 1.00 <a href="#refsGLES20GLSL">[GLES20GLSL]</a>, and w
hich do not exceed | |
| 417 the minimum functionality mandated in Sections 4 and 5 of Appendix A. I
n particular, a shader | |
| 418 referencing state variables or functions that are available in other ver
sions of GLSL (such | |
| 419 as that found in versions of OpenGL for the desktop), must not be allowe
d to load. | |
| 420 </p> | |
| 421 <p> | |
| 422 In addition to the reserved identifiers in the aforementioned specificat
ion, identifiers | |
| 423 starting with "webgl_" and "_webgl_" are reserved for use by WebGL. A sh
ader which declares | |
| 424 a function, variable, structure name, or structure field starting with t
hese prefixes must | |
| 425 not be allowed to load. | |
| 426 </p> | |
| 427 | |
| 428 <!-- ===========================================================================
============================ --> | |
| 429 | |
| 430 <h3>Defense Against Denial of Service</h3> | |
| 431 <div class="note"> | |
| 432 <p> | |
| 433 It is possible to create, either intentionally or unintentionally, combinati
ons of shaders and | |
| 434 geometry that take an undesirably long time to render. This issue is analogo
us to that of | |
| 435 long-running scripts, for which user agents already have safeguards. However
, long-running draw | |
| 436 calls can cause loss of interactivity for the entire window system, not just
the user agent. | |
| 437 </p> | |
| 438 | |
| 439 <p> | |
| 440 In the general case it is not possible to impose limits on the structure of
incoming shaders to | |
| 441 guard against this problem. Experimentation has shown that even very strict
structural limits | |
| 442 are insufficient to prevent long rendering times, and such limits would prev
ent shader authors | |
| 443 from implementing common algorithms. | |
| 444 </p> | |
| 445 | |
| 446 <p> | |
| 447 User agents should implement safeguards to prevent excessively long renderin
g times and | |
| 448 associated loss of interactivity. Suggested safeguards include: | |
| 449 </p> | |
| 450 | |
| 451 <ul> | |
| 452 | |
| 453 <li> Splitting up draw calls with large numbers of elements into smaller dra
w calls. | |
| 454 | |
| 455 <li> Timing individual draw calls and forbidding further rendering from a pa
ge if a certain | |
| 456 timeout is exceeded. | |
| 457 | |
| 458 <li> Using any watchdog facilities available at the user level, graphics API
level, or operating | |
| 459 system level to limit the duration of draw calls. | |
| 460 | |
| 461 <li> Separating the graphics rendering of the user agent into a distinct ope
rating system | |
| 462 process which can be terminated and restarted without losing applicatio
n state. | |
| 463 | |
| 464 </ul> | |
| 465 | |
| 466 <p> | |
| 467 The supporting infrastructure at the OS and graphics API layer is expected t
o improve over time, | |
| 468 which is why the exact nature of these safeguards is not specified. | |
| 469 </p> | |
| 470 </div> | |
| 471 <!-- ===========================================================================
============================ --> | |
| 472 | |
| 473 <h2>DOM Interfaces</h2> | |
| 474 | |
| 475 <p> | |
| 476 This section describes the interfaces and functionality added to the | |
| 477 DOM to support runtime access to the functionality described above. | |
| 478 </p> | |
| 479 | |
| 480 <!-- ===========================================================================
============================ --> | |
| 481 | |
| 482 <h3>Types</h3> | |
| 483 | |
| 484 <p> | |
| 485 The following types are used in all interfaces in the following section. | |
| 486 </p> | |
| 487 <pre class="idl"> | |
| 488 typedef events::Event Event; | |
| 489 typedef html::HTMLCanvasElement HTMLCanvasElement; | |
| 490 typedef html::HTMLImageElement HTMLImageElement; | |
| 491 typedef html::HTMLVideoElement HTMLVideoElement; | |
| 492 typedef html::ImageData ImageData; | |
| 493 | |
| 494 typedef unsigned long GLenum; | |
| 495 typedef boolean GLboolean; | |
| 496 typedef unsigned long GLbitfield; | |
| 497 typedef byte GLbyte; /* 'byte' should be a signed 8 bit type.
*/ | |
| 498 typedef short GLshort; | |
| 499 typedef long GLint; | |
| 500 typedef long GLsizei; | |
| 501 typedef long GLsizeiptr; | |
| 502 typedef unsigned byte GLubyte; /* 'unsigned byte' should be an unsigned
8 bit type. */ | |
| 503 typedef unsigned short GLushort; | |
| 504 typedef unsigned long GLuint; | |
| 505 typedef float GLfloat; | |
| 506 typedef float GLclampf; | |
| 507 </pre> | |
| 508 | |
| 509 <!-- ===========================================================================
============================ --> | |
| 510 | |
| 511 <h3><a name="WEBGLCONTEXTATTRIBUTES">WebGLContextAttributes</a></h3> | |
| 512 | |
| 513 <p> | |
| 514 The <code>WebGLContextAttributes</code> interface contains drawing surfa
ce attributes and is | |
| 515 passed as the second parameter to <code>getContext</code>. A native obje
ct may be supplied | |
| 516 as this parameter; the specified attributes will be queried from this ob
ject. | |
| 517 </p> | |
| 518 <pre class="idl">[Callback] interface <dfn id="WebGLContextAttributes">WebGL
ContextAttributes</dfn> { | |
| 519 attribute boolean alpha; | |
| 520 attribute boolean depth; | |
| 521 attribute boolean stencil; | |
| 522 attribute boolean antialias; | |
| 523 attribute boolean premultipliedAlpha; | |
| 524 attribute boolean preserveDrawingBuffer; | |
| 525 };</pre> | |
| 526 | |
| 527 <h4>Context creation parameters</h4> | |
| 528 | |
| 529 <p> | |
| 530 The following list describes each attribute in the WebGLContextAttribute
s object and its | |
| 531 use. For each attribute the default value is shown. The default value is
used either if no | |
| 532 second parameter is passed to <code>getContext</code>, or if a native ob
ject is passed which | |
| 533 has no attribute of the given name. | |
| 534 </p> | |
| 535 <dl> | |
| 536 <dt><span class=prop-value>alpha</span></dt> | |
| 537 <dd> | |
| 538 <em>Default: true</em>. If the value is true, the drawing buffer
has an alpha | |
| 539 channel for the purposes of performing OpenGL destination alpha
operations and | |
| 540 compositing with the page. If the value is false, no alpha buffe
r is available. | |
| 541 </dd> | |
| 542 <dt> <span class=prop-value>depth</span> | |
| 543 <dd> | |
| 544 <em>Default: true</em>. If the value is true, the drawing buffer
has a depth | |
| 545 buffer of at least 16 bits. If the value is false, no depth buff
er is | |
| 546 available. | |
| 547 </dd> | |
| 548 <dt> <span class=prop-value>stencil</span> | |
| 549 <dd> | |
| 550 <em>Default: false</em>. If the value is true, the drawing buffe
r has a stencil | |
| 551 buffer of at least 8 bits. If the value is false, no stencil buf
fer is | |
| 552 available. | |
| 553 </dd> | |
| 554 <dt> <span class=prop-value>antialias</span> | |
| 555 <dd> | |
| 556 <em>Default: true</em>. If the value is true and the implementat
ion supports | |
| 557 antialiasing the drawing buffer will perform antialiasing using
its choice of | |
| 558 technique (multisample/supersample) and quality. If the value is
false or the | |
| 559 implementation does not support antialiasing, no antialiasing is
performed. | |
| 560 </dd> | |
| 561 <dt> <span class=prop-value>premultipliedAlpha</span> | |
| 562 <dd> | |
| 563 <em>Default: true</em>. If the value is true the page compositor
will assume the | |
| 564 drawing buffer contains colors with premultiplied alpha. If the
value is false the | |
| 565 page compositor will assume that colors in the drawing buffer ar
e not | |
| 566 premultiplied. This flag is ignored if the <strong>alpha</strong
> flag is | |
| 567 false. See <a href="#PREMULTIPLIED_ALPHA">Premultiplied Alpha</a
> for more | |
| 568 information on the effects of the <code>premultipliedAlpha</code
> flag. | |
| 569 </dd> | |
| 570 <dt> <span class=prop-value>preserveDrawingBuffer</span> | |
| 571 <dd> | |
| 572 <em>Default: false</em>. If false, once the drawing buffer is pr
esented | |
| 573 as described in the<a href="#THE_DRAWING_BUFFER">Drawing Buffer<
/a> section, | |
| 574 the contents of the drawing buffer are cleared to their default
values. | |
| 575 All elements of the drawing buffer (color, depth and stencil) ar
e cleared. | |
| 576 If the value is true the buffers will not be cleared and will pr
eserve | |
| 577 their values until cleared or overwritten by the author. | |
| 578 <blockquote> | |
| 579 <em> | |
| 580 On some hardware setting the <code>preserveDrawingBuffer</co
de> flag | |
| 581 to true can have significant performance implications. | |
| 582 </em> | |
| 583 </blockquote> | |
| 584 </dd> | |
| 585 </dl> | |
| 586 <div class="example"> | |
| 587 Here is an ECMAScript example which passes a WebGLContextAttributes argument | |
| 588 to <code>getContext</code>. It assumes the presence of a canvas element nam
ed "canvas1" on the | |
| 589 page. | |
| 590 | |
| 591 <pre> | |
| 592 var canvas = document.getElementById('canvas1'); | |
| 593 var context = canvas.getContext('webgl', | |
| 594 { antialias: false, | |
| 595 stencil: true }); | |
| 596 </pre> | |
| 597 </div> | |
| 598 | |
| 599 <!-- ===========================================================================
============================ --> | |
| 600 | |
| 601 <h3>WebGLObject</h3> | |
| 602 | |
| 603 <p> | |
| 604 The <code>WebGLObject</code> interface is the parent interface for all G
L objects. | |
| 605 </p> | |
| 606 <pre class="idl">interface <dfn id="WebGLObject">WebGLObject</dfn> { | |
| 607 };</pre> | |
| 608 | |
| 609 <!-- ===========================================================================
============================ --> | |
| 610 | |
| 611 <h3>WebGLBuffer</h3> | |
| 612 | |
| 613 <p> | |
| 614 The <code>WebGLBuffer</code> interface represents an OpenGL Buffer Objec
t. The | |
| 615 underlying object is created as if by calling glGenBuffers | |
| 616 <span class="gl-spec">(OpenGL ES 2.0 §2.9, <a href="http://www.khro
nos.org/opengles/sdk/2.0/docs/man/glGenBuffers.xml">man page</a>)</span> | |
| 617 , bound as if by calling glBindBuffer | |
| 618 <span class="gl-spec">(OpenGL ES 2.0 §2.9, <a href="http://www.khro
nos.org/opengles/sdk/2.0/docs/man/glBindBuffer.xml">man page</a>)</span> | |
| 619 and destroyed as if by calling glDeleteBuffers | |
| 620 <span class="gl-spec">(OpenGL ES 2.0 §2.9, <a href="http://www.khro
nos.org/opengles/sdk/2.0/docs/man/glDeleteBuffers.xml">man page</a>)</span> | |
| 621 . | |
| 622 </p> | |
| 623 <pre class="idl">interface <dfn id="WebGLBuffer">WebGLBuffer</dfn> : WebGLOb
ject { | |
| 624 };</pre> | |
| 625 | |
| 626 <!-- ===========================================================================
============================ --> | |
| 627 | |
| 628 <h3><a name="WEBGL_FRAMEBUFFER">WebGLFramebuffer</a></h3> | |
| 629 | |
| 630 <p> | |
| 631 The <code>WebGLFramebuffer</code> interface represents an OpenGL Framebu
ffer Object. The | |
| 632 underlying object is created as if by calling glGenFramebuffers | |
| 633 <span class="gl-spec">(OpenGL ES 2.0 §4.4.1, <a href="http://www.kh
ronos.org/opengles/sdk/2.0/docs/man/glGenFramebuffers.xml">man page</a>)</span> | |
| 634 , bound as if by calling glBindFramebuffer | |
| 635 <span class="gl-spec">(OpenGL ES 2.0 §4.4.1, <a href="http://www.kh
ronos.org/opengles/sdk/2.0/docs/man/glBindFramebuffer.xml">man page</a>)</span> | |
| 636 and destroyed as if by calling glDeleteFramebuffers | |
| 637 <span class="gl-spec">(OpenGL ES 2.0 §4.4.1, <a href="http://www.kh
ronos.org/opengles/sdk/2.0/docs/man/glDeleteFramebuffers.xml">man page</a>)</spa
n> | |
| 638 . | |
| 639 </p> | |
| 640 <pre class="idl">interface <dfn id="WebGLFramebuffer">WebGLFramebuffer</dfn>
: WebGLObject { | |
| 641 };</pre> | |
| 642 | |
| 643 <!-- ===========================================================================
============================ --> | |
| 644 | |
| 645 <h3>WebGLProgram</h3> | |
| 646 | |
| 647 <p> | |
| 648 The <code>WebGLProgram</code> interface represents an OpenGL Program Obj
ect. The | |
| 649 underlying object is created as if by calling glCreateProgram | |
| 650 <span class="gl-spec">(OpenGL ES 2.0 §2.10.3, <a href="http://www.k
hronos.org/opengles/sdk/2.0/docs/man/glCreateProgram.xml">man page</a>)</span> | |
| 651 , used as if by calling glUseProgram | |
| 652 <span class="gl-spec">(OpenGL ES 2.0 §2.10.3, <a href="http://www.k
hronos.org/opengles/sdk/2.0/docs/man/glUseProgram.xml">man page</a>)</span> | |
| 653 and destroyed as if by calling glDeleteProgram | |
| 654 <span class="gl-spec">(OpenGL ES 2.0 §2.10.3, <a href="http://www.k
hronos.org/opengles/sdk/2.0/docs/man/glDeleteProgram.xml">man page</a>)</span> | |
| 655 . | |
| 656 </p> | |
| 657 <pre class="idl">interface <dfn id="WebGLProgram">WebGLProgram</dfn> : WebGL
Object { | |
| 658 };</pre> | |
| 659 | |
| 660 <!-- ===========================================================================
============================ --> | |
| 661 | |
| 662 <h3>WebGLRenderbuffer</h3> | |
| 663 | |
| 664 <p> | |
| 665 The <code>WebGLRenderbuffer</code> interface represents an OpenGL Render
buffer Object. The | |
| 666 underlying object is created as if by calling glGenRenderbuffers | |
| 667 <span class="gl-spec">(OpenGL ES 2.0 §4.4.3, <a href="http://www.kh
ronos.org/opengles/sdk/2.0/docs/man/glGenRenderbuffers.xml">man page</a>)</span> | |
| 668 , bound as if by calling glBindRenderbuffer | |
| 669 <span class="gl-spec">(OpenGL ES 2.0 §4.4.3, <a href="http://www.kh
ronos.org/opengles/sdk/2.0/docs/man/glBindRenderbuffer.xml">man page</a>)</span> | |
| 670 and destroyed as if by calling glDeleteRenderbuffers | |
| 671 <span class="gl-spec">(OpenGL ES 2.0 §4.4.3, <a href="http://www.kh
ronos.org/opengles/sdk/2.0/docs/man/glDeleteRenderbuffers.xml">man page</a>)</sp
an> | |
| 672 . | |
| 673 </p> | |
| 674 <pre class="idl">interface <dfn id="WebGLRenderbuffer">WebGLRenderbuffer</df
n> : WebGLObject { | |
| 675 };</pre> | |
| 676 | |
| 677 <!-- ===========================================================================
============================ --> | |
| 678 | |
| 679 <h3>WebGLShader</h3> | |
| 680 | |
| 681 <p> | |
| 682 The <code>WebGLShader</code> interface represents an OpenGL Shader Objec
t. The | |
| 683 underlying object is created as if by calling glCreateShader | |
| 684 <span class="gl-spec">(OpenGL ES 2.0 §2.10.1, <a href="http://www.k
hronos.org/opengles/sdk/2.0/docs/man/glCreateShader.xml">man page</a>)</span> | |
| 685 , attached to a Program as if by calling glAttachShader | |
| 686 <span class="gl-spec">(OpenGL ES 2.0 §2.10.3, <a href="http://www.k
hronos.org/opengles/sdk/2.0/docs/man/glAttachShader.xml">man page</a>)</span> | |
| 687 and destroyed as if by calling glDeleteShader | |
| 688 <span class="gl-spec">(OpenGL ES 2.0 §2.10.1, <a href="http://www.k
hronos.org/opengles/sdk/2.0/docs/man/glDeleteShader.xml">man page</a>)</span> | |
| 689 . | |
| 690 </p> | |
| 691 <pre class="idl">interface <dfn id="WebGLShader">WebGLShader</dfn> : WebGLOb
ject { | |
| 692 };</pre> | |
| 693 | |
| 694 <!-- ===========================================================================
============================ --> | |
| 695 | |
| 696 <h3>WebGLTexture</h3> | |
| 697 | |
| 698 <p> | |
| 699 The <code>WebGLTexture</code> interface represents an OpenGL Texture Obj
ect. The | |
| 700 underlying object is created as if by calling glGenTextures | |
| 701 <span class="gl-spec">(OpenGL ES 2.0 §3.7.13, <a href="http://www.k
hronos.org/opengles/sdk/2.0/docs/man/glGenTextures.xml">man page</a>)</span> | |
| 702 , bound as if by calling glBindTexture | |
| 703 <span class="gl-spec">(OpenGL ES 2.0 §3.7.13, <a href="http://www.k
hronos.org/opengles/sdk/2.0/docs/man/glBindTexture.xml">man page</a>)</span> | |
| 704 and destroyed as if by calling glDeleteTextures | |
| 705 <span class="gl-spec">(OpenGL ES 2.0 §3.7.13, <a href="http://www.k
hronos.org/opengles/sdk/2.0/docs/man/glDeleteTextures.xml">man page</a>)</span> | |
| 706 . | |
| 707 </p> | |
| 708 <pre class="idl">interface <dfn id="WebGLTexture">WebGLTexture</dfn> : WebGL
Object { | |
| 709 };</pre> | |
| 710 | |
| 711 <!-- ===========================================================================
============================ --> | |
| 712 | |
| 713 <h3>WebGLUniformLocation</h3> | |
| 714 | |
| 715 <p> | |
| 716 The <code>WebGLUniformLocation</code> interface represents the location
of a uniform variable | |
| 717 in a shader program. | |
| 718 </p> | |
| 719 <pre class="idl">interface <dfn id="WebGLUniformLocation">WebGLUniformLocati
on</dfn> { | |
| 720 };</pre> | |
| 721 | |
| 722 <!-- ===========================================================================
============================ --> | |
| 723 | |
| 724 <h3>WebGLActiveInfo</h3> | |
| 725 | |
| 726 <p> | |
| 727 The <code>WebGLActiveInfo</code> interface represents the information re
turned | |
| 728 from the getActiveAttrib and getActiveUniform calls. | |
| 729 </p> | |
| 730 <pre class="idl">interface <dfn id="WebGLActiveInfo">WebGLActiveInfo</dfn> { | |
| 731 readonly attribute GLint size; | |
| 732 readonly attribute GLenum type; | |
| 733 readonly attribute DOMString name; | |
| 734 };</pre> | |
| 735 | |
| 736 <h4>Attributes</h4> | |
| 737 | |
| 738 <p> | |
| 739 The following attributes are available: | |
| 740 </p> | |
| 741 | |
| 742 <dl class="methods"> | |
| 743 <dt> | |
| 744 <code class=attribute-name> | |
| 745 <a id="DOM-WebGLActiveInfo-size"> | |
| 746 size | |
| 747 </a> | |
| 748 </code> | |
| 749 of type <code>GLint</code> | |
| 750 <dd> | |
| 751 The size of the requested variable. | |
| 752 <dt> | |
| 753 <code class=attribute-name> | |
| 754 <a id="DOM-WebGLActiveInfo-type"> | |
| 755 type | |
| 756 </a> | |
| 757 </code> | |
| 758 of type <code>GLenum</code> | |
| 759 <dd> | |
| 760 The data type of the requested variable. | |
| 761 <dt> | |
| 762 <code class=attribute-name> | |
| 763 <a id="DOM-WebGLActiveInfo-name"> | |
| 764 name | |
| 765 </a> | |
| 766 </code> | |
| 767 of type <code>DOMString</code> | |
| 768 <dd> | |
| 769 The name of the requested variable. | |
| 770 </dl> | |
| 771 | |
| 772 <!-- ===========================================================================
============================ --> | |
| 773 | |
| 774 <h3><a name="ARRAYBUFFER">ArrayBuffer</a> and <a name="TYPEDARRAY">Typed Arr
ays</a></h3> | |
| 775 | |
| 776 <p> | |
| 777 Vertex, index, texture, and other data is transferred to the WebGL imple
mentation using | |
| 778 the <a href="TypedArray-spec.html#ARRAYBUFFER">ArrayBuffer</a> | |
| 779 and <a href="TypedArray-spec.html#TYPEDARRAYS">views</a> defined in | |
| 780 the <a href="TypedArray-spec.html">Typed Array</a> | |
| 781 specification <a href="#refsTYPEDARRAYS">[TYPEDARRAYS]</a>. All of the t
yped array views | |
| 782 except <tt>Float64Array</tt> may be used in conjunction with WebGL; Open
GL ES 2.0, and | |
| 783 therefore WebGL, does not support double-precision floating-point data. | |
| 784 </p> | |
| 785 <p> | |
| 786 Typed Arrays support the creation of interleaved, heterogeneous vertex d
ata; uploading of | |
| 787 distinct blocks of data into a large vertex buffer object; and most othe
r use cases required | |
| 788 by OpenGL programs. | |
| 789 </p> | |
| 790 | |
| 791 <div class="example"> | |
| 792 Here is an ECMAScript example showing access to the same ArrayBuffer using d
ifferent types of | |
| 793 typed arrays. In this case the buffer contains a floating point vertex posit
ion (x, y, z) | |
| 794 followed by a color as 4 unsigned bytes (r, g, b, a). | |
| 795 | |
| 796 <pre> | |
| 797 var numVertices = 100; // for example | |
| 798 | |
| 799 // Compute the size needed for the buffer, in bytes and floats | |
| 800 var vertexSize = 3 * Float32Array.BYTES_PER_ELEMENT + | |
| 801 4 * Uint8Array.BYTES_PER_ELEMENT; | |
| 802 var vertexSizeInFloats = vertexSize / Float32Array.BYTES_PER_ELEMENT; | |
| 803 | |
| 804 // Allocate the buffer | |
| 805 var buf = new ArrayBuffer(numVertices * vertexSize); | |
| 806 | |
| 807 // Map this buffer to a Float32Array to access the positions | |
| 808 var positionArray = new Float32Array(buf); | |
| 809 | |
| 810 // Map the same buffer to a Uint8Array to access the color | |
| 811 var colorArray = new Uint8Array(buf); | |
| 812 | |
| 813 // Set up the initial offset of the vertices and colors within the buffer | |
| 814 var positionIdx = 0; | |
| 815 var colorIdx = 3 * Float32Array.BYTES_PER_ELEMENT; | |
| 816 | |
| 817 // Initialize the buffer | |
| 818 for (var i = 0; i < numVertices; i++) { | |
| 819 positionArray[positionIdx] = ...; | |
| 820 positionArray[positionIdx + 1] = ...; | |
| 821 positionArray[positionIdx + 2] = ...; | |
| 822 colorArray[colorIdx] = ...; | |
| 823 colorArray[colorIdx + 1] = ...; | |
| 824 colorArray[colorIdx + 2] = ...; | |
| 825 colorArray[colorIdx + 3] = ...; | |
| 826 positionIdx += vertexSizeInFloats; | |
| 827 colorIdx += vertexSize; | |
| 828 } | |
| 829 </pre> | |
| 830 </div> | |
| 831 | |
| 832 <!-- ===========================================================================
============================ --> | |
| 833 | |
| 834 <h3><a name="WEBGLRENDERINGCONTEXT">The WebGL context</a></h3> | |
| 835 | |
| 836 <p> | |
| 837 The <code>WebGLRenderingContext</code> represents the API allowing | |
| 838 OpenGL ES 2.0 style rendering into the canvas element. | |
| 839 </p> | |
| 840 <pre class="idl">interface <dfn id="WebGLRenderingContext">WebGLRenderingCon
text</dfn> { | |
| 841 | |
| 842 /* ClearBufferMask */ | |
| 843 const GLenum DEPTH_BUFFER_BIT = 0x00000100; | |
| 844 const GLenum STENCIL_BUFFER_BIT = 0x00000400; | |
| 845 const GLenum COLOR_BUFFER_BIT = 0x00004000; | |
| 846 | |
| 847 /* BeginMode */ | |
| 848 const GLenum POINTS = 0x0000; | |
| 849 const GLenum LINES = 0x0001; | |
| 850 const GLenum LINE_LOOP = 0x0002; | |
| 851 const GLenum LINE_STRIP = 0x0003; | |
| 852 const GLenum TRIANGLES = 0x0004; | |
| 853 const GLenum TRIANGLE_STRIP = 0x0005; | |
| 854 const GLenum TRIANGLE_FAN = 0x0006; | |
| 855 | |
| 856 /* AlphaFunction (not supported in ES20) */ | |
| 857 /* NEVER */ | |
| 858 /* LESS */ | |
| 859 /* EQUAL */ | |
| 860 /* LEQUAL */ | |
| 861 /* GREATER */ | |
| 862 /* NOTEQUAL */ | |
| 863 /* GEQUAL */ | |
| 864 /* ALWAYS */ | |
| 865 | |
| 866 /* BlendingFactorDest */ | |
| 867 const GLenum ZERO = 0; | |
| 868 const GLenum ONE = 1; | |
| 869 const GLenum SRC_COLOR = 0x0300; | |
| 870 const GLenum ONE_MINUS_SRC_COLOR = 0x0301; | |
| 871 const GLenum SRC_ALPHA = 0x0302; | |
| 872 const GLenum ONE_MINUS_SRC_ALPHA = 0x0303; | |
| 873 const GLenum DST_ALPHA = 0x0304; | |
| 874 const GLenum ONE_MINUS_DST_ALPHA = 0x0305; | |
| 875 | |
| 876 /* BlendingFactorSrc */ | |
| 877 /* ZERO */ | |
| 878 /* ONE */ | |
| 879 const GLenum DST_COLOR = 0x0306; | |
| 880 const GLenum ONE_MINUS_DST_COLOR = 0x0307; | |
| 881 const GLenum SRC_ALPHA_SATURATE = 0x0308; | |
| 882 /* SRC_ALPHA */ | |
| 883 /* ONE_MINUS_SRC_ALPHA */ | |
| 884 /* DST_ALPHA */ | |
| 885 /* ONE_MINUS_DST_ALPHA */ | |
| 886 | |
| 887 /* BlendEquationSeparate */ | |
| 888 const GLenum FUNC_ADD = 0x8006; | |
| 889 const GLenum BLEND_EQUATION = 0x8009; | |
| 890 const GLenum BLEND_EQUATION_RGB = 0x8009; /* same as BLEND_EQU
ATION */ | |
| 891 const GLenum BLEND_EQUATION_ALPHA = 0x883D; | |
| 892 | |
| 893 /* BlendSubtract */ | |
| 894 const GLenum FUNC_SUBTRACT = 0x800A; | |
| 895 const GLenum FUNC_REVERSE_SUBTRACT = 0x800B; | |
| 896 | |
| 897 /* Separate Blend Functions */ | |
| 898 const GLenum BLEND_DST_RGB = 0x80C8; | |
| 899 const GLenum BLEND_SRC_RGB = 0x80C9; | |
| 900 const GLenum BLEND_DST_ALPHA = 0x80CA; | |
| 901 const GLenum BLEND_SRC_ALPHA = 0x80CB; | |
| 902 const GLenum CONSTANT_COLOR = 0x8001; | |
| 903 const GLenum ONE_MINUS_CONSTANT_COLOR = 0x8002; | |
| 904 const GLenum CONSTANT_ALPHA = 0x8003; | |
| 905 const GLenum ONE_MINUS_CONSTANT_ALPHA = 0x8004; | |
| 906 const GLenum BLEND_COLOR = 0x8005; | |
| 907 | |
| 908 /* Buffer Objects */ | |
| 909 const GLenum ARRAY_BUFFER = 0x8892; | |
| 910 const GLenum ELEMENT_ARRAY_BUFFER = 0x8893; | |
| 911 const GLenum ARRAY_BUFFER_BINDING = 0x8894; | |
| 912 const GLenum ELEMENT_ARRAY_BUFFER_BINDING = 0x8895; | |
| 913 | |
| 914 const GLenum STREAM_DRAW = 0x88E0; | |
| 915 const GLenum STATIC_DRAW = 0x88E4; | |
| 916 const GLenum DYNAMIC_DRAW = 0x88E8; | |
| 917 | |
| 918 const GLenum BUFFER_SIZE = 0x8764; | |
| 919 const GLenum BUFFER_USAGE = 0x8765; | |
| 920 | |
| 921 const GLenum CURRENT_VERTEX_ATTRIB = 0x8626; | |
| 922 | |
| 923 /* CullFaceMode */ | |
| 924 const GLenum FRONT = 0x0404; | |
| 925 const GLenum BACK = 0x0405; | |
| 926 const GLenum FRONT_AND_BACK = 0x0408; | |
| 927 | |
| 928 /* DepthFunction */ | |
| 929 /* NEVER */ | |
| 930 /* LESS */ | |
| 931 /* EQUAL */ | |
| 932 /* LEQUAL */ | |
| 933 /* GREATER */ | |
| 934 /* NOTEQUAL */ | |
| 935 /* GEQUAL */ | |
| 936 /* ALWAYS */ | |
| 937 | |
| 938 /* EnableCap */ | |
| 939 /* TEXTURE_2D */ | |
| 940 const GLenum CULL_FACE = 0x0B44; | |
| 941 const GLenum BLEND = 0x0BE2; | |
| 942 const GLenum DITHER = 0x0BD0; | |
| 943 const GLenum STENCIL_TEST = 0x0B90; | |
| 944 const GLenum DEPTH_TEST = 0x0B71; | |
| 945 const GLenum SCISSOR_TEST = 0x0C11; | |
| 946 const GLenum POLYGON_OFFSET_FILL = 0x8037; | |
| 947 const GLenum SAMPLE_ALPHA_TO_COVERAGE = 0x809E; | |
| 948 const GLenum SAMPLE_COVERAGE = 0x80A0; | |
| 949 | |
| 950 /* ErrorCode */ | |
| 951 const GLenum NO_ERROR = 0; | |
| 952 const GLenum INVALID_ENUM = 0x0500; | |
| 953 const GLenum INVALID_VALUE = 0x0501; | |
| 954 const GLenum INVALID_OPERATION = 0x0502; | |
| 955 const GLenum OUT_OF_MEMORY = 0x0505; | |
| 956 | |
| 957 /* FrontFaceDirection */ | |
| 958 const GLenum CW = 0x0900; | |
| 959 const GLenum CCW = 0x0901; | |
| 960 | |
| 961 /* GetPName */ | |
| 962 const GLenum LINE_WIDTH = 0x0B21; | |
| 963 const GLenum ALIASED_POINT_SIZE_RANGE = 0x846D; | |
| 964 const GLenum ALIASED_LINE_WIDTH_RANGE = 0x846E; | |
| 965 const GLenum CULL_FACE_MODE = 0x0B45; | |
| 966 const GLenum FRONT_FACE = 0x0B46; | |
| 967 const GLenum DEPTH_RANGE = 0x0B70; | |
| 968 const GLenum DEPTH_WRITEMASK = 0x0B72; | |
| 969 const GLenum DEPTH_CLEAR_VALUE = 0x0B73; | |
| 970 const GLenum DEPTH_FUNC = 0x0B74; | |
| 971 const GLenum STENCIL_CLEAR_VALUE = 0x0B91; | |
| 972 const GLenum STENCIL_FUNC = 0x0B92; | |
| 973 const GLenum STENCIL_FAIL = 0x0B94; | |
| 974 const GLenum STENCIL_PASS_DEPTH_FAIL = 0x0B95; | |
| 975 const GLenum STENCIL_PASS_DEPTH_PASS = 0x0B96; | |
| 976 const GLenum STENCIL_REF = 0x0B97; | |
| 977 const GLenum STENCIL_VALUE_MASK = 0x0B93; | |
| 978 const GLenum STENCIL_WRITEMASK = 0x0B98; | |
| 979 const GLenum STENCIL_BACK_FUNC = 0x8800; | |
| 980 const GLenum STENCIL_BACK_FAIL = 0x8801; | |
| 981 const GLenum STENCIL_BACK_PASS_DEPTH_FAIL = 0x8802; | |
| 982 const GLenum STENCIL_BACK_PASS_DEPTH_PASS = 0x8803; | |
| 983 const GLenum STENCIL_BACK_REF = 0x8CA3; | |
| 984 const GLenum STENCIL_BACK_VALUE_MASK = 0x8CA4; | |
| 985 const GLenum STENCIL_BACK_WRITEMASK = 0x8CA5; | |
| 986 const GLenum VIEWPORT = 0x0BA2; | |
| 987 const GLenum SCISSOR_BOX = 0x0C10; | |
| 988 /* SCISSOR_TEST */ | |
| 989 const GLenum COLOR_CLEAR_VALUE = 0x0C22; | |
| 990 const GLenum COLOR_WRITEMASK = 0x0C23; | |
| 991 const GLenum UNPACK_ALIGNMENT = 0x0CF5; | |
| 992 const GLenum PACK_ALIGNMENT = 0x0D05; | |
| 993 const GLenum MAX_TEXTURE_SIZE = 0x0D33; | |
| 994 const GLenum MAX_VIEWPORT_DIMS = 0x0D3A; | |
| 995 const GLenum SUBPIXEL_BITS = 0x0D50; | |
| 996 const GLenum RED_BITS = 0x0D52; | |
| 997 const GLenum GREEN_BITS = 0x0D53; | |
| 998 const GLenum BLUE_BITS = 0x0D54; | |
| 999 const GLenum ALPHA_BITS = 0x0D55; | |
| 1000 const GLenum DEPTH_BITS = 0x0D56; | |
| 1001 const GLenum STENCIL_BITS = 0x0D57; | |
| 1002 const GLenum POLYGON_OFFSET_UNITS = 0x2A00; | |
| 1003 /* POLYGON_OFFSET_FILL */ | |
| 1004 const GLenum POLYGON_OFFSET_FACTOR = 0x8038; | |
| 1005 const GLenum TEXTURE_BINDING_2D = 0x8069; | |
| 1006 const GLenum SAMPLE_BUFFERS = 0x80A8; | |
| 1007 const GLenum SAMPLES = 0x80A9; | |
| 1008 const GLenum SAMPLE_COVERAGE_VALUE = 0x80AA; | |
| 1009 const GLenum SAMPLE_COVERAGE_INVERT = 0x80AB; | |
| 1010 | |
| 1011 /* GetTextureParameter */ | |
| 1012 /* TEXTURE_MAG_FILTER */ | |
| 1013 /* TEXTURE_MIN_FILTER */ | |
| 1014 /* TEXTURE_WRAP_S */ | |
| 1015 /* TEXTURE_WRAP_T */ | |
| 1016 | |
| 1017 const GLenum NUM_COMPRESSED_TEXTURE_FORMATS = 0x86A2; | |
| 1018 const GLenum COMPRESSED_TEXTURE_FORMATS = 0x86A3; | |
| 1019 | |
| 1020 /* HintMode */ | |
| 1021 const GLenum DONT_CARE = 0x1100; | |
| 1022 const GLenum FASTEST = 0x1101; | |
| 1023 const GLenum NICEST = 0x1102; | |
| 1024 | |
| 1025 /* HintTarget */ | |
| 1026 const GLenum GENERATE_MIPMAP_HINT = 0x8192; | |
| 1027 | |
| 1028 /* DataType */ | |
| 1029 const GLenum BYTE = 0x1400; | |
| 1030 const GLenum UNSIGNED_BYTE = 0x1401; | |
| 1031 const GLenum SHORT = 0x1402; | |
| 1032 const GLenum UNSIGNED_SHORT = 0x1403; | |
| 1033 const GLenum INT = 0x1404; | |
| 1034 const GLenum UNSIGNED_INT = 0x1405; | |
| 1035 const GLenum FLOAT = 0x1406; | |
| 1036 | |
| 1037 /* PixelFormat */ | |
| 1038 const GLenum DEPTH_COMPONENT = 0x1902; | |
| 1039 const GLenum ALPHA = 0x1906; | |
| 1040 const GLenum RGB = 0x1907; | |
| 1041 const GLenum RGBA = 0x1908; | |
| 1042 const GLenum LUMINANCE = 0x1909; | |
| 1043 const GLenum LUMINANCE_ALPHA = 0x190A; | |
| 1044 | |
| 1045 /* PixelType */ | |
| 1046 /* UNSIGNED_BYTE */ | |
| 1047 const GLenum UNSIGNED_SHORT_4_4_4_4 = 0x8033; | |
| 1048 const GLenum UNSIGNED_SHORT_5_5_5_1 = 0x8034; | |
| 1049 const GLenum UNSIGNED_SHORT_5_6_5 = 0x8363; | |
| 1050 | |
| 1051 /* Shaders */ | |
| 1052 const GLenum FRAGMENT_SHADER = 0x8B30; | |
| 1053 const GLenum VERTEX_SHADER = 0x8B31; | |
| 1054 const GLenum MAX_VERTEX_ATTRIBS = 0x8869; | |
| 1055 const GLenum MAX_VERTEX_UNIFORM_VECTORS = 0x8DFB; | |
| 1056 const GLenum MAX_VARYING_VECTORS = 0x8DFC; | |
| 1057 const GLenum MAX_COMBINED_TEXTURE_IMAGE_UNITS = 0x8B4D; | |
| 1058 const GLenum MAX_VERTEX_TEXTURE_IMAGE_UNITS = 0x8B4C; | |
| 1059 const GLenum MAX_TEXTURE_IMAGE_UNITS = 0x8872; | |
| 1060 const GLenum MAX_FRAGMENT_UNIFORM_VECTORS = 0x8DFD; | |
| 1061 const GLenum SHADER_TYPE = 0x8B4F; | |
| 1062 const GLenum DELETE_STATUS = 0x8B80; | |
| 1063 const GLenum LINK_STATUS = 0x8B82; | |
| 1064 const GLenum VALIDATE_STATUS = 0x8B83; | |
| 1065 const GLenum ATTACHED_SHADERS = 0x8B85; | |
| 1066 const GLenum ACTIVE_UNIFORMS = 0x8B86; | |
| 1067 const GLenum ACTIVE_UNIFORM_MAX_LENGTH = 0x8B87; | |
| 1068 const GLenum ACTIVE_ATTRIBUTES = 0x8B89; | |
| 1069 const GLenum ACTIVE_ATTRIBUTE_MAX_LENGTH = 0x8B8A; | |
| 1070 const GLenum SHADING_LANGUAGE_VERSION = 0x8B8C; | |
| 1071 const GLenum CURRENT_PROGRAM = 0x8B8D; | |
| 1072 | |
| 1073 /* StencilFunction */ | |
| 1074 const GLenum NEVER = 0x0200; | |
| 1075 const GLenum LESS = 0x0201; | |
| 1076 const GLenum EQUAL = 0x0202; | |
| 1077 const GLenum LEQUAL = 0x0203; | |
| 1078 const GLenum GREATER = 0x0204; | |
| 1079 const GLenum NOTEQUAL = 0x0205; | |
| 1080 const GLenum GEQUAL = 0x0206; | |
| 1081 const GLenum ALWAYS = 0x0207; | |
| 1082 | |
| 1083 /* StencilOp */ | |
| 1084 /* ZERO */ | |
| 1085 const GLenum KEEP = 0x1E00; | |
| 1086 const GLenum REPLACE = 0x1E01; | |
| 1087 const GLenum INCR = 0x1E02; | |
| 1088 const GLenum DECR = 0x1E03; | |
| 1089 const GLenum INVERT = 0x150A; | |
| 1090 const GLenum INCR_WRAP = 0x8507; | |
| 1091 const GLenum DECR_WRAP = 0x8508; | |
| 1092 | |
| 1093 /* StringName */ | |
| 1094 const GLenum VENDOR = 0x1F00; | |
| 1095 const GLenum RENDERER = 0x1F01; | |
| 1096 const GLenum VERSION = 0x1F02; | |
| 1097 | |
| 1098 /* TextureMagFilter */ | |
| 1099 const GLenum NEAREST = 0x2600; | |
| 1100 const GLenum LINEAR = 0x2601; | |
| 1101 | |
| 1102 /* TextureMinFilter */ | |
| 1103 /* NEAREST */ | |
| 1104 /* LINEAR */ | |
| 1105 const GLenum NEAREST_MIPMAP_NEAREST = 0x2700; | |
| 1106 const GLenum LINEAR_MIPMAP_NEAREST = 0x2701; | |
| 1107 const GLenum NEAREST_MIPMAP_LINEAR = 0x2702; | |
| 1108 const GLenum LINEAR_MIPMAP_LINEAR = 0x2703; | |
| 1109 | |
| 1110 /* TextureParameterName */ | |
| 1111 const GLenum TEXTURE_MAG_FILTER = 0x2800; | |
| 1112 const GLenum TEXTURE_MIN_FILTER = 0x2801; | |
| 1113 const GLenum TEXTURE_WRAP_S = 0x2802; | |
| 1114 const GLenum TEXTURE_WRAP_T = 0x2803; | |
| 1115 | |
| 1116 /* TextureTarget */ | |
| 1117 const GLenum TEXTURE_2D = 0x0DE1; | |
| 1118 const GLenum TEXTURE = 0x1702; | |
| 1119 | |
| 1120 const GLenum TEXTURE_CUBE_MAP = 0x8513; | |
| 1121 const GLenum TEXTURE_BINDING_CUBE_MAP = 0x8514; | |
| 1122 const GLenum TEXTURE_CUBE_MAP_POSITIVE_X = 0x8515; | |
| 1123 const GLenum TEXTURE_CUBE_MAP_NEGATIVE_X = 0x8516; | |
| 1124 const GLenum TEXTURE_CUBE_MAP_POSITIVE_Y = 0x8517; | |
| 1125 const GLenum TEXTURE_CUBE_MAP_NEGATIVE_Y = 0x8518; | |
| 1126 const GLenum TEXTURE_CUBE_MAP_POSITIVE_Z = 0x8519; | |
| 1127 const GLenum TEXTURE_CUBE_MAP_NEGATIVE_Z = 0x851A; | |
| 1128 const GLenum MAX_CUBE_MAP_TEXTURE_SIZE = 0x851C; | |
| 1129 | |
| 1130 /* TextureUnit */ | |
| 1131 const GLenum TEXTURE0 = 0x84C0; | |
| 1132 const GLenum TEXTURE1 = 0x84C1; | |
| 1133 const GLenum TEXTURE2 = 0x84C2; | |
| 1134 const GLenum TEXTURE3 = 0x84C3; | |
| 1135 const GLenum TEXTURE4 = 0x84C4; | |
| 1136 const GLenum TEXTURE5 = 0x84C5; | |
| 1137 const GLenum TEXTURE6 = 0x84C6; | |
| 1138 const GLenum TEXTURE7 = 0x84C7; | |
| 1139 const GLenum TEXTURE8 = 0x84C8; | |
| 1140 const GLenum TEXTURE9 = 0x84C9; | |
| 1141 const GLenum TEXTURE10 = 0x84CA; | |
| 1142 const GLenum TEXTURE11 = 0x84CB; | |
| 1143 const GLenum TEXTURE12 = 0x84CC; | |
| 1144 const GLenum TEXTURE13 = 0x84CD; | |
| 1145 const GLenum TEXTURE14 = 0x84CE; | |
| 1146 const GLenum TEXTURE15 = 0x84CF; | |
| 1147 const GLenum TEXTURE16 = 0x84D0; | |
| 1148 const GLenum TEXTURE17 = 0x84D1; | |
| 1149 const GLenum TEXTURE18 = 0x84D2; | |
| 1150 const GLenum TEXTURE19 = 0x84D3; | |
| 1151 const GLenum TEXTURE20 = 0x84D4; | |
| 1152 const GLenum TEXTURE21 = 0x84D5; | |
| 1153 const GLenum TEXTURE22 = 0x84D6; | |
| 1154 const GLenum TEXTURE23 = 0x84D7; | |
| 1155 const GLenum TEXTURE24 = 0x84D8; | |
| 1156 const GLenum TEXTURE25 = 0x84D9; | |
| 1157 const GLenum TEXTURE26 = 0x84DA; | |
| 1158 const GLenum TEXTURE27 = 0x84DB; | |
| 1159 const GLenum TEXTURE28 = 0x84DC; | |
| 1160 const GLenum TEXTURE29 = 0x84DD; | |
| 1161 const GLenum TEXTURE30 = 0x84DE; | |
| 1162 const GLenum TEXTURE31 = 0x84DF; | |
| 1163 const GLenum ACTIVE_TEXTURE = 0x84E0; | |
| 1164 | |
| 1165 /* TextureWrapMode */ | |
| 1166 const GLenum REPEAT = 0x2901; | |
| 1167 const GLenum CLAMP_TO_EDGE = 0x812F; | |
| 1168 const GLenum MIRRORED_REPEAT = 0x8370; | |
| 1169 | |
| 1170 /* Uniform Types */ | |
| 1171 const GLenum FLOAT_VEC2 = 0x8B50; | |
| 1172 const GLenum FLOAT_VEC3 = 0x8B51; | |
| 1173 const GLenum FLOAT_VEC4 = 0x8B52; | |
| 1174 const GLenum INT_VEC2 = 0x8B53; | |
| 1175 const GLenum INT_VEC3 = 0x8B54; | |
| 1176 const GLenum INT_VEC4 = 0x8B55; | |
| 1177 const GLenum BOOL = 0x8B56; | |
| 1178 const GLenum BOOL_VEC2 = 0x8B57; | |
| 1179 const GLenum BOOL_VEC3 = 0x8B58; | |
| 1180 const GLenum BOOL_VEC4 = 0x8B59; | |
| 1181 const GLenum FLOAT_MAT2 = 0x8B5A; | |
| 1182 const GLenum FLOAT_MAT3 = 0x8B5B; | |
| 1183 const GLenum FLOAT_MAT4 = 0x8B5C; | |
| 1184 const GLenum SAMPLER_2D = 0x8B5E; | |
| 1185 const GLenum SAMPLER_CUBE = 0x8B60; | |
| 1186 | |
| 1187 /* Vertex Arrays */ | |
| 1188 const GLenum VERTEX_ATTRIB_ARRAY_ENABLED = 0x8622; | |
| 1189 const GLenum VERTEX_ATTRIB_ARRAY_SIZE = 0x8623; | |
| 1190 const GLenum VERTEX_ATTRIB_ARRAY_STRIDE = 0x8624; | |
| 1191 const GLenum VERTEX_ATTRIB_ARRAY_TYPE = 0x8625; | |
| 1192 const GLenum VERTEX_ATTRIB_ARRAY_NORMALIZED = 0x886A; | |
| 1193 const GLenum VERTEX_ATTRIB_ARRAY_POINTER = 0x8645; | |
| 1194 const GLenum VERTEX_ATTRIB_ARRAY_BUFFER_BINDING = 0x889F; | |
| 1195 | |
| 1196 /* Shader Source */ | |
| 1197 const GLenum COMPILE_STATUS = 0x8B81; | |
| 1198 const GLenum INFO_LOG_LENGTH = 0x8B84; | |
| 1199 const GLenum SHADER_SOURCE_LENGTH = 0x8B88; | |
| 1200 | |
| 1201 /* Shader Precision-Specified Types */ | |
| 1202 const GLenum LOW_FLOAT = 0x8DF0; | |
| 1203 const GLenum MEDIUM_FLOAT = 0x8DF1; | |
| 1204 const GLenum HIGH_FLOAT = 0x8DF2; | |
| 1205 const GLenum LOW_INT = 0x8DF3; | |
| 1206 const GLenum MEDIUM_INT = 0x8DF4; | |
| 1207 const GLenum HIGH_INT = 0x8DF5; | |
| 1208 | |
| 1209 /* Framebuffer Object. */ | |
| 1210 const GLenum FRAMEBUFFER = 0x8D40; | |
| 1211 const GLenum RENDERBUFFER = 0x8D41; | |
| 1212 | |
| 1213 const GLenum RGBA4 = 0x8056; | |
| 1214 const GLenum RGB5_A1 = 0x8057; | |
| 1215 const GLenum RGB565 = 0x8D62; | |
| 1216 const GLenum DEPTH_COMPONENT16 = 0x81A5; | |
| 1217 const GLenum STENCIL_INDEX = 0x1901; | |
| 1218 const GLenum STENCIL_INDEX8 = 0x8D48; | |
| 1219 const GLenum DEPTH_STENCIL = 0x84F9; | |
| 1220 | |
| 1221 const GLenum RENDERBUFFER_WIDTH = 0x8D42; | |
| 1222 const GLenum RENDERBUFFER_HEIGHT = 0x8D43; | |
| 1223 const GLenum RENDERBUFFER_INTERNAL_FORMAT = 0x8D44; | |
| 1224 const GLenum RENDERBUFFER_RED_SIZE = 0x8D50; | |
| 1225 const GLenum RENDERBUFFER_GREEN_SIZE = 0x8D51; | |
| 1226 const GLenum RENDERBUFFER_BLUE_SIZE = 0x8D52; | |
| 1227 const GLenum RENDERBUFFER_ALPHA_SIZE = 0x8D53; | |
| 1228 const GLenum RENDERBUFFER_DEPTH_SIZE = 0x8D54; | |
| 1229 const GLenum RENDERBUFFER_STENCIL_SIZE = 0x8D55; | |
| 1230 | |
| 1231 const GLenum FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE = 0x8CD0; | |
| 1232 const GLenum FRAMEBUFFER_ATTACHMENT_OBJECT_NAME = 0x8CD1; | |
| 1233 const GLenum FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL = 0x8CD2; | |
| 1234 const GLenum FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE = 0x8CD3; | |
| 1235 | |
| 1236 const GLenum COLOR_ATTACHMENT0 = 0x8CE0; | |
| 1237 const GLenum DEPTH_ATTACHMENT = 0x8D00; | |
| 1238 const GLenum STENCIL_ATTACHMENT = 0x8D20; | |
| 1239 const GLenum DEPTH_STENCIL_ATTACHMENT = 0x821A; | |
| 1240 | |
| 1241 const GLenum NONE = 0; | |
| 1242 | |
| 1243 const GLenum FRAMEBUFFER_COMPLETE = 0x8CD5; | |
| 1244 const GLenum FRAMEBUFFER_INCOMPLETE_ATTACHMENT = 0x8CD6; | |
| 1245 const GLenum FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT = 0x8CD7; | |
| 1246 const GLenum FRAMEBUFFER_INCOMPLETE_DIMENSIONS = 0x8CD9; | |
| 1247 const GLenum FRAMEBUFFER_UNSUPPORTED = 0x8CDD; | |
| 1248 | |
| 1249 const GLenum FRAMEBUFFER_BINDING = 0x8CA6; | |
| 1250 const GLenum RENDERBUFFER_BINDING = 0x8CA7; | |
| 1251 const GLenum MAX_RENDERBUFFER_SIZE = 0x84E8; | |
| 1252 | |
| 1253 const GLenum INVALID_FRAMEBUFFER_OPERATION = 0x0506; | |
| 1254 | |
| 1255 /* WebGL-specific enums */ | |
| 1256 const GLenum UNPACK_FLIP_Y_WEBGL = 0x9240; | |
| 1257 const GLenum UNPACK_PREMULTIPLY_ALPHA_WEBGL = 0x9241; | |
| 1258 const GLenum CONTEXT_LOST_WEBGL = 0x9242; | |
| 1259 const GLenum UNPACK_COLORSPACE_CONVERSION_WEBGL = 0x9243; | |
| 1260 const GLenum BROWSER_DEFAULT_WEBGL = 0x9244; | |
| 1261 | |
| 1262 readonly attribute HTMLCanvasElement canvas; | |
| 1263 readonly attribute GLsizei drawingBufferWidth; | |
| 1264 readonly attribute GLsizei drawingBufferHeight; | |
| 1265 | |
| 1266 WebGLContextAttributes getContextAttributes(); | |
| 1267 boolean isContextLost(); | |
| 1268 | |
| 1269 DOMString[ ] getSupportedExtensions(); | |
| 1270 object getExtension(DOMString name); | |
| 1271 | |
| 1272 void activeTexture(GLenum texture); | |
| 1273 void attachShader(WebGLProgram program, WebGLShader shader); | |
| 1274 void bindAttribLocation(WebGLProgram program, GLuint index, DOMString name); | |
| 1275 void bindBuffer(GLenum target, WebGLBuffer buffer); | |
| 1276 void bindFramebuffer(GLenum target, WebGLFramebuffer framebuffer); | |
| 1277 void bindRenderbuffer(GLenum target, WebGLRenderbuffer renderbuffer); | |
| 1278 void bindTexture(GLenum target, WebGLTexture texture); | |
| 1279 void blendColor(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha)
; | |
| 1280 void blendEquation(GLenum mode); | |
| 1281 void blendEquationSeparate(GLenum modeRGB, GLenum modeAlpha); | |
| 1282 void blendFunc(GLenum sfactor, GLenum dfactor); | |
| 1283 void blendFuncSeparate(GLenum srcRGB, GLenum dstRGB, | |
| 1284 GLenum srcAlpha, GLenum dstAlpha); | |
| 1285 | |
| 1286 void bufferData(GLenum target, GLsizei size, GLenum usage); | |
| 1287 void bufferData(GLenum target, ArrayBufferView data, GLenum usage); | |
| 1288 void bufferData(GLenum target, ArrayBuffer data, GLenum usage); | |
| 1289 void bufferSubData(GLenum target, GLsizeiptr offset, ArrayBufferView data); | |
| 1290 void bufferSubData(GLenum target, GLsizeiptr offset, ArrayBuffer data); | |
| 1291 | |
| 1292 GLenum checkFramebufferStatus(GLenum target); | |
| 1293 void clear(GLbitfield mask); | |
| 1294 void clearColor(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha)
; | |
| 1295 void clearDepth(GLclampf depth); | |
| 1296 void clearStencil(GLint s); | |
| 1297 void colorMask(GLboolean red, GLboolean green, GLboolean blue, GLboolean alp
ha); | |
| 1298 void compileShader(WebGLShader shader); | |
| 1299 | |
| 1300 void copyTexImage2D(GLenum target, GLint level, GLenum internalformat, | |
| 1301 GLint x, GLint y, GLsizei width, GLsizei height, | |
| 1302 GLint border); | |
| 1303 void copyTexSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoff
set, | |
| 1304 GLint x, GLint y, GLsizei width, GLsizei height); | |
| 1305 | |
| 1306 WebGLBuffer createBuffer(); | |
| 1307 WebGLFramebuffer createFramebuffer(); | |
| 1308 WebGLProgram createProgram(); | |
| 1309 WebGLRenderbuffer createRenderbuffer(); | |
| 1310 WebGLShader createShader(GLenum type); | |
| 1311 WebGLTexture createTexture(); | |
| 1312 | |
| 1313 void cullFace(GLenum mode); | |
| 1314 | |
| 1315 void deleteBuffer(WebGLBuffer buffer); | |
| 1316 void deleteFramebuffer(WebGLFramebuffer framebuffer); | |
| 1317 void deleteProgram(WebGLProgram program); | |
| 1318 void deleteRenderbuffer(WebGLRenderbuffer renderbuffer); | |
| 1319 void deleteShader(WebGLShader shader); | |
| 1320 void deleteTexture(WebGLTexture texture); | |
| 1321 | |
| 1322 void depthFunc(GLenum func); | |
| 1323 void depthMask(GLboolean flag); | |
| 1324 void depthRange(GLclampf zNear, GLclampf zFar); | |
| 1325 void detachShader(WebGLProgram program, WebGLShader shader); | |
| 1326 void disable(GLenum cap); | |
| 1327 void disableVertexAttribArray(GLuint index); | |
| 1328 void drawArrays(GLenum mode, GLint first, GLsizei count); | |
| 1329 void drawElements(GLenum mode, GLsizei count, GLenum type, GLsizeiptr offset
); | |
| 1330 | |
| 1331 void enable(GLenum cap); | |
| 1332 void enableVertexAttribArray(GLuint index); | |
| 1333 void finish(); | |
| 1334 void flush(); | |
| 1335 void framebufferRenderbuffer(GLenum target, GLenum attachment, | |
| 1336 GLenum renderbuffertarget, | |
| 1337 WebGLRenderbuffer renderbuffer); | |
| 1338 void framebufferTexture2D(GLenum target, GLenum attachment, GLenum textarget
, | |
| 1339 WebGLTexture texture, GLint level); | |
| 1340 void frontFace(GLenum mode); | |
| 1341 | |
| 1342 void generateMipmap(GLenum target); | |
| 1343 | |
| 1344 WebGLActiveInfo getActiveAttrib(WebGLProgram program, GLuint index); | |
| 1345 WebGLActiveInfo getActiveUniform(WebGLProgram program, GLuint index); | |
| 1346 WebGLShader[ ] getAttachedShaders(WebGLProgram program); | |
| 1347 | |
| 1348 GLint getAttribLocation(WebGLProgram program, DOMString name); | |
| 1349 | |
| 1350 any getParameter(GLenum pname); | |
| 1351 any getBufferParameter(GLenum target, GLenum pname); | |
| 1352 | |
| 1353 GLenum getError(); | |
| 1354 | |
| 1355 any getFramebufferAttachmentParameter(GLenum target, GLenum attachment, | |
| 1356 GLenum pname); | |
| 1357 any getProgramParameter(WebGLProgram program, GLenum pname); | |
| 1358 DOMString getProgramInfoLog(WebGLProgram program); | |
| 1359 any getRenderbufferParameter(GLenum target, GLenum pname); | |
| 1360 any getShaderParameter(WebGLShader shader, GLenum pname); | |
| 1361 DOMString getShaderInfoLog(WebGLShader shader); | |
| 1362 | |
| 1363 DOMString getShaderSource(WebGLShader shader); | |
| 1364 | |
| 1365 any getTexParameter(GLenum target, GLenum pname); | |
| 1366 | |
| 1367 any getUniform(WebGLProgram program, WebGLUniformLocation location); | |
| 1368 | |
| 1369 WebGLUniformLocation getUniformLocation(WebGLProgram program, DOMString name
); | |
| 1370 | |
| 1371 any getVertexAttrib(GLuint index, GLenum pname); | |
| 1372 | |
| 1373 GLsizeiptr getVertexAttribOffset(GLuint index, GLenum pname); | |
| 1374 | |
| 1375 void hint(GLenum target, GLenum mode); | |
| 1376 GLboolean isBuffer(WebGLBuffer buffer); | |
| 1377 GLboolean isEnabled(GLenum cap); | |
| 1378 GLboolean isFramebuffer(WebGLFramebuffer framebuffer); | |
| 1379 GLboolean isProgram(WebGLProgram program); | |
| 1380 GLboolean isRenderbuffer(WebGLRenderbuffer renderbuffer); | |
| 1381 GLboolean isShader(WebGLShader shader); | |
| 1382 GLboolean isTexture(WebGLTexture texture); | |
| 1383 void lineWidth(GLfloat width); | |
| 1384 void linkProgram(WebGLProgram program); | |
| 1385 void pixelStorei(GLenum pname, GLint param); | |
| 1386 void polygonOffset(GLfloat factor, GLfloat units); | |
| 1387 | |
| 1388 void readPixels(GLint x, GLint y, GLsizei width, GLsizei height, | |
| 1389 GLenum format, GLenum type, ArrayBufferView pixels); | |
| 1390 | |
| 1391 void renderbufferStorage(GLenum target, GLenum internalformat, | |
| 1392 GLsizei width, GLsizei height); | |
| 1393 void sampleCoverage(GLclampf value, GLboolean invert); | |
| 1394 void scissor(GLint x, GLint y, GLsizei width, GLsizei height); | |
| 1395 | |
| 1396 void shaderSource(WebGLShader shader, DOMString source); | |
| 1397 | |
| 1398 void stencilFunc(GLenum func, GLint ref, GLuint mask); | |
| 1399 void stencilFuncSeparate(GLenum face, GLenum func, GLint ref, GLuint mask); | |
| 1400 void stencilMask(GLuint mask); | |
| 1401 void stencilMaskSeparate(GLenum face, GLuint mask); | |
| 1402 void stencilOp(GLenum fail, GLenum zfail, GLenum zpass); | |
| 1403 void stencilOpSeparate(GLenum face, GLenum fail, GLenum zfail, GLenum zpass)
; | |
| 1404 | |
| 1405 void texImage2D(GLenum target, GLint level, GLenum internalformat, | |
| 1406 GLsizei width, GLsizei height, GLint border, GLenum format, | |
| 1407 GLenum type, ArrayBufferView pixels); | |
| 1408 void texImage2D(GLenum target, GLint level, GLenum internalformat, | |
| 1409 GLenum format, GLenum type, ImageData pixels); | |
| 1410 void texImage2D(GLenum target, GLint level, GLenum internalformat, | |
| 1411 GLenum format, GLenum type, HTMLImageElement image); | |
| 1412 void texImage2D(GLenum target, GLint level, GLenum internalformat, | |
| 1413 GLenum format, GLenum type, HTMLCanvasElement canvas); | |
| 1414 void texImage2D(GLenum target, GLint level, GLenum internalformat, | |
| 1415 GLenum format, GLenum type, HTMLVideoElement video); | |
| 1416 | |
| 1417 void texParameterf(GLenum target, GLenum pname, GLfloat param); | |
| 1418 void texParameteri(GLenum target, GLenum pname, GLint param); | |
| 1419 | |
| 1420 void texSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset,
| |
| 1421 GLsizei width, GLsizei height, | |
| 1422 GLenum format, GLenum type, ArrayBufferView pixels); | |
| 1423 void texSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset,
| |
| 1424 GLenum format, GLenum type, ImageData pixels); | |
| 1425 void texSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset,
| |
| 1426 GLenum format, GLenum type, HTMLImageElement image); | |
| 1427 void texSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset,
| |
| 1428 GLenum format, GLenum type, HTMLCanvasElement canvas); | |
| 1429 void texSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset,
| |
| 1430 GLenum format, GLenum type, HTMLVideoElement video); | |
| 1431 | |
| 1432 void uniform1f(WebGLUniformLocation location, GLfloat x); | |
| 1433 void uniform1fv(WebGLUniformLocation location, Float32Array v); | |
| 1434 void uniform1fv(WebGLUniformLocation location, float[] v); | |
| 1435 void uniform1i(WebGLUniformLocation location, GLint x); | |
| 1436 void uniform1iv(WebGLUniformLocation location, Int32Array v); | |
| 1437 void uniform1iv(WebGLUniformLocation location, long[] v); | |
| 1438 void uniform2f(WebGLUniformLocation location, GLfloat x, GLfloat y); | |
| 1439 void uniform2fv(WebGLUniformLocation location, Float32Array v); | |
| 1440 void uniform2fv(WebGLUniformLocation location, float[] v); | |
| 1441 void uniform2i(WebGLUniformLocation location, GLint x, GLint y); | |
| 1442 void uniform2iv(WebGLUniformLocation location, Int32Array v); | |
| 1443 void uniform2iv(WebGLUniformLocation location, long[] v); | |
| 1444 void uniform3f(WebGLUniformLocation location, GLfloat x, GLfloat y, GLfloat
z); | |
| 1445 void uniform3fv(WebGLUniformLocation location, Float32Array v); | |
| 1446 void uniform3fv(WebGLUniformLocation location, float[] v); | |
| 1447 void uniform3i(WebGLUniformLocation location, GLint x, GLint y, GLint z); | |
| 1448 void uniform3iv(WebGLUniformLocation location, Int32Array v); | |
| 1449 void uniform3iv(WebGLUniformLocation location, long[] v); | |
| 1450 void uniform4f(WebGLUniformLocation location, GLfloat x, GLfloat y, GLfloat
z, GLfloat w); | |
| 1451 void uniform4fv(WebGLUniformLocation location, Float32Array v); | |
| 1452 void uniform4fv(WebGLUniformLocation location, float[] v); | |
| 1453 void uniform4i(WebGLUniformLocation location, GLint x, GLint y, GLint z, GLi
nt w); | |
| 1454 void uniform4iv(WebGLUniformLocation location, Int32Array v); | |
| 1455 void uniform4iv(WebGLUniformLocation location, long[] v); | |
| 1456 | |
| 1457 void uniformMatrix2fv(WebGLUniformLocation location, GLboolean transpose, | |
| 1458 Float32Array value); | |
| 1459 void uniformMatrix2fv(WebGLUniformLocation location, GLboolean transpose, | |
| 1460 float[] value); | |
| 1461 void uniformMatrix3fv(WebGLUniformLocation location, GLboolean transpose, | |
| 1462 Float32Array value); | |
| 1463 void uniformMatrix3fv(WebGLUniformLocation location, GLboolean transpose, | |
| 1464 float[] value); | |
| 1465 void uniformMatrix4fv(WebGLUniformLocation location, GLboolean transpose, | |
| 1466 Float32Array value); | |
| 1467 void uniformMatrix4fv(WebGLUniformLocation location, GLboolean transpose, | |
| 1468 float[] value); | |
| 1469 | |
| 1470 void useProgram(WebGLProgram program); | |
| 1471 void validateProgram(WebGLProgram program); | |
| 1472 | |
| 1473 void vertexAttrib1f(GLuint indx, GLfloat x); | |
| 1474 void vertexAttrib1fv(GLuint indx, Float32Array values); | |
| 1475 void vertexAttrib1fv(GLuint indx, float[] values); | |
| 1476 void vertexAttrib2f(GLuint indx, GLfloat x, GLfloat y); | |
| 1477 void vertexAttrib2fv(GLuint indx, Float32Array values); | |
| 1478 void vertexAttrib2fv(GLuint indx, float[] values); | |
| 1479 void vertexAttrib3f(GLuint indx, GLfloat x, GLfloat y, GLfloat z); | |
| 1480 void vertexAttrib3fv(GLuint indx, Float32Array values); | |
| 1481 void vertexAttrib3fv(GLuint indx, float[] values); | |
| 1482 void vertexAttrib4f(GLuint indx, GLfloat x, GLfloat y, GLfloat z, GLfloat w)
; | |
| 1483 void vertexAttrib4fv(GLuint indx, Float32Array values); | |
| 1484 void vertexAttrib4fv(GLuint indx, float[] values); | |
| 1485 void vertexAttribPointer(GLuint indx, GLint size, GLenum type, | |
| 1486 GLboolean normalized, GLsizei stride, GLsizeiptr of
fset); | |
| 1487 | |
| 1488 void viewport(GLint x, GLint y, GLsizei width, GLsizei height); | |
| 1489 };</pre> | |
| 1490 | |
| 1491 <!-- ===========================================================================
============================ --> | |
| 1492 | |
| 1493 <h4>Attributes</h4> | |
| 1494 | |
| 1495 <p> | |
| 1496 The following attributes are available: | |
| 1497 </p> | |
| 1498 | |
| 1499 <dl class="methods"> | |
| 1500 <dt> | |
| 1501 <code class=attribute-name> | |
| 1502 <a id="DOM-WebGLRenderingContext-canvas"> | |
| 1503 canvas | |
| 1504 </a> | |
| 1505 </code> | |
| 1506 of type <code>HTMLCanvasElement</code> | |
| 1507 <dd> | |
| 1508 A reference to the canvas element which created this context. | |
| 1509 | |
| 1510 <dt> | |
| 1511 <code class=attribute-name> | |
| 1512 <a id="DOM-WebGLRenderingContext-drawingBufferWidth"> | |
| 1513 drawingBufferWidth | |
| 1514 </a> | |
| 1515 </code> | |
| 1516 of type <code>GLsizei</code> | |
| 1517 <dd> | |
| 1518 The actual width of the drawing buffer. May be different from the | |
| 1519 <code>width</code> attribute of the <code>HTMLCanvasElement</code> i
f | |
| 1520 the implementation is unable to satisfy the requested widthor height
. | |
| 1521 | |
| 1522 <dt> | |
| 1523 <code class=attribute-name> | |
| 1524 <a id="DOM-WebGLRenderingContext-drawingBufferHeight"> | |
| 1525 drawingBufferHeight | |
| 1526 </a> | |
| 1527 </code> | |
| 1528 of type <code>GLsizei</code> | |
| 1529 <dd> | |
| 1530 The actual height of the drawing buffer. May be different from the | |
| 1531 <code>height</code> attribute of the <code>HTMLCanvasElement</code>
if | |
| 1532 the implementation is unable to satisfy the requested width or heigh
t. | |
| 1533 </dl> | |
| 1534 | |
| 1535 <!-- ===========================================================================
============================ --> | |
| 1536 | |
| 1537 <h4>Getting information about the context</h4> | |
| 1538 | |
| 1539 <dl class="methods"> | |
| 1540 <dt class="idl-code">WebGLContextAttributes getContextAttributes() | |
| 1541 <dd> | |
| 1542 Returns the WebGLContextAttributes describing the current drawing bu
ffer. | |
| 1543 </dl> | |
| 1544 | |
| 1545 <!-- ===========================================================================
============================ --> | |
| 1546 | |
| 1547 <h4>Setting and getting state</h4> | |
| 1548 | |
| 1549 <p> | |
| 1550 OpenGL ES 2.0 maintains state values for use in rendering. All the calls
in this | |
| 1551 group behave identically to their OpenGL counterparts unless otherwise n
oted. | |
| 1552 </p> | |
| 1553 | |
| 1554 <dl class="methods"> | |
| 1555 <dt class="idl-code">void activeTexture(GLenum texture) | |
| 1556 <span class="gl-spec">(OpenGL ES 2.0 §3.7, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glActiveTexture.xml">man page</a>)</span> | |
| 1557 <dt class="idl-code"void blendColor(GLclampf red, GLclampf green, GLclam
pf blue, GLclampf alpha) | |
| 1558 <span class="gl-spec">(OpenGL ES 2.0 §4.1.6, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glBlendColor.xml">man page</a>)</span> | |
| 1559 <dt class="idl-code">void blendEquation(GLenum mode) | |
| 1560 <span class="gl-spec">(OpenGL ES 2.0 §4.1.6, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glBlendEquation.xml">man page</a>)</span
> | |
| 1561 <dt class="idl-code">void blendEquationSeparate(GLenum modeRGB, GLenum m
odeAlpha) | |
| 1562 <span class="gl-spec">(OpenGL ES 2.0 §4.1.6, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glBlendEquationSeparate.xml">man page</a
>)</span> | |
| 1563 <dt class="idl-code">void blendFunc(GLenum sfactor, GLenum dfactor) | |
| 1564 <span class="gl-spec">(OpenGL ES 2.0 §4.1.6, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glBlendFunc.xml">man page</a>)</span> | |
| 1565 <dd> | |
| 1566 See <a href="#CONSTANT_COLOR_BLEND">Blending With Constant Color
</a> for limitations imposed | |
| 1567 by WebGL. | |
| 1568 <dt class="idl-code">void blendFuncSeparate(GLenum srcRGB, GLenum dstRGB
, GLenum srcAlpha, GLenum dstAlpha) | |
| 1569 <span class="gl-spec">(OpenGL ES 2.0 §4.1.6, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glBlendFuncSeparate.xml">man page</a>)</
span> | |
| 1570 <dd> | |
| 1571 See <a href="#CONSTANT_COLOR_BLEND">Blending With Constant Color
</a> for limitations imposed | |
| 1572 by WebGL. | |
| 1573 <dt class="idl-code">void clearColor(GLclampf red, GLclampf green, GLcla
mpf blue, GLclampf alpha) | |
| 1574 <span class="gl-spec">(OpenGL ES 2.0 §4.2.3, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glClearColor.xml">man page</a>)</span> | |
| 1575 <dt class="idl-code">void clearDepth(GLclampf depth) | |
| 1576 <span class="gl-spec">(OpenGL ES 2.0 §4.2.3, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glClearDepthf.xml">man page</a>)</span> | |
| 1577 <dd> | |
| 1578 <code>depth</code> value is clamped to the range 0 to 1. | |
| 1579 <dt class="idl-code">void clearStencil(GLint s) | |
| 1580 <span class="gl-spec">(OpenGL ES 2.0 §4.2.3, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glClearStencil.xml">man page</a>)</span> | |
| 1581 <dt class="idl-code">void colorMask(GLboolean red, GLboolean green, GLbo
olean blue, GLboolean alpha) | |
| 1582 <span class="gl-spec">(OpenGL ES 2.0 §4.2.2, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glColorMask.xml">man page</a>)</span> | |
| 1583 <dt class="idl-code">void cullFace(GLenum mode) | |
| 1584 <span class="gl-spec">(OpenGL ES 2.0 §3.5.1, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glCullFace.xml">man page</a>)</span> | |
| 1585 <dt class="idl-code">void depthFunc(GLenum func) | |
| 1586 <span class="gl-spec">(OpenGL ES 2.0 §4.1.5, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glDepthFunc.xml">man page</a>)</span> | |
| 1587 <dt class="idl-code">void depthMask(GLboolean flag) | |
| 1588 <span class="gl-spec">(OpenGL ES 2.0 §4.2.2, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glDepthMask.xml">man page</a>)</span> | |
| 1589 <dt class="idl-code">void depthRange(GLclampf zNear, GLclampf zFar) | |
| 1590 <span class="gl-spec">(OpenGL ES 2.0 §2.12.1, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glDepthRangef.xml">man page</a>)</span> | |
| 1591 <dd> | |
| 1592 <code>zNear</code> and <code>zFar</code> values are clamped to t
he range 0 to 1 and | |
| 1593 <code>zNear</code> must be less than or equal to <code>zFar</cod
e>; see | |
| 1594 <a href="#VIEWPORT_DEPTH_RANGE">Viewport Depth Range</a>. | |
| 1595 <dt class="idl-code">void disable(GLenum cap) | |
| 1596 <span class="gl-spec">(<a href="http://www.khronos.org/opengles/sdk/
2.0/docs/man/glDisable.xml">man page</a>)</span> | |
| 1597 <dt class="idl-code">void enable(GLenum cap) | |
| 1598 <span class="gl-spec">(<a href="http://www.khronos.org/opengles/sdk/
2.0/docs/man/glEnable.xml">man page</a>)</span> | |
| 1599 <dt class="idl-code">void frontFace(GLenum mode) | |
| 1600 <span class="gl-spec">(OpenGL ES 2.0 §3.5.1, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glFrontFace.xml">man page</a>)</span> | |
| 1601 <dt class="idl-code">any getParameter(GLenum pname) | |
| 1602 <a class="gl-spec" href="http://www.khronos.org/opengles/sdk/2.0/doc
s/man/glGet.xml"> | |
| 1603 (glGet OpenGL ES 2.0 man page) | |
| 1604 </a> | |
| 1605 <a class="gl-spec" href="http://www.khronos.org/opengles/sdk/2.0/doc
s/man/glGetString.xml"> | |
| 1606 (glGetString OpenGL ES 2.0 man page) | |
| 1607 </a> | |
| 1608 <dd> | |
| 1609 Return the value for the passed pname. The type returned is the natu
ral type for the | |
| 1610 requested pname, as given in the following table: | |
| 1611 <table class="foo"> | |
| 1612 <tr><th>pname</th><th>returned type</th></tr> | |
| 1613 <tr><td>ACTIVE_TEXTURE</td><td>unsigned long</td></tr> | |
| 1614 <tr><td>ALIASED_LINE_WIDTH_RANGE</td><td>Float32Array (with 2 el
ements)</td></tr> | |
| 1615 <tr><td>ALIASED_POINT_SIZE_RANGE</td><td>Float32Array (with 2 el
ements)</td></tr> | |
| 1616 <tr><td>ALPHA_BITS</td><td>long</td></tr> | |
| 1617 <tr><td>ARRAY_BUFFER_BINDING</td><td>WebGLBuffer</td></tr> | |
| 1618 <tr><td>BLEND</td><td>boolean</td></tr> | |
| 1619 <tr><td>BLEND_COLOR</td><td>Float32Array (with 4 values)</td></t
r> | |
| 1620 <tr><td>BLEND_DST_ALPHA</td><td>unsigned long</td></tr> | |
| 1621 <tr><td>BLEND_DST_RGB</td><td>unsigned long</td></tr> | |
| 1622 <tr><td>BLEND_EQUATION_ALPHA</td><td>unsigned long</td></tr> | |
| 1623 <tr><td>BLEND_EQUATION_RGB</td><td>unsigned long</td></tr> | |
| 1624 <tr><td>BLEND_SRC_ALPHA</td><td>unsigned long</td></tr> | |
| 1625 <tr><td>BLEND_SRC_RGB</td><td>unsigned long</td></tr> | |
| 1626 <tr><td>BLUE_BITS</td><td>long</td></tr> | |
| 1627 <tr><td>COLOR_CLEAR_VALUE</td><td>Float32Array (with 4 values)</
td></tr> | |
| 1628 <tr><td>COLOR_WRITEMASK</td><td>boolean[] (with 4 values)</td></
tr> | |
| 1629 <tr><td>COMPRESSED_TEXTURE_FORMATS</td><td>null</td></tr> | |
| 1630 <tr><td>CULL_FACE</td><td>boolean</td></tr> | |
| 1631 <tr><td>CULL_FACE_MODE</td><td>unsigned long</td></tr> | |
| 1632 <tr><td>CURRENT_PROGRAM</td><td>WebGLProgram</td></tr> | |
| 1633 <tr><td>DEPTH_BITS</td><td>long</td></tr> | |
| 1634 <tr><td>DEPTH_CLEAR_VALUE</td><td>float</td></tr> | |
| 1635 <tr><td>DEPTH_FUNC</td><td>unsigned long</td></tr> | |
| 1636 <tr><td>DEPTH_RANGE</td><td>Float32Array (with 2 elements)</td><
/tr> | |
| 1637 <tr><td>DEPTH_TEST</td><td>boolean</td></tr> | |
| 1638 <tr><td>DEPTH_WRITEMASK</td><td>boolean</td></tr> | |
| 1639 <tr><td>DITHER</td><td>boolean</td></tr> | |
| 1640 <tr><td>ELEMENT_ARRAY_BUFFER_BINDING</td><td>WebGLBuffer</td></t
r> | |
| 1641 <tr><td>FRAMEBUFFER_BINDING</td><td>WebGLFramebuffer</td></tr> | |
| 1642 <tr><td>FRONT_FACE</td><td>unsigned long</td></tr> | |
| 1643 <tr><td>GENERATE_MIPMAP_HINT</td><td>unsigned long</td></tr> | |
| 1644 <tr><td>GREEN_BITS</td><td>long</td></tr> | |
| 1645 <tr><td>LINE_WIDTH</td><td>float</td></tr> | |
| 1646 <tr><td>MAX_COMBINED_TEXTURE_IMAGE_UNITS</td><td>long</td></tr> | |
| 1647 <tr><td>MAX_CUBE_MAP_TEXTURE_SIZE</td><td>long</td></tr> | |
| 1648 <tr><td>MAX_FRAGMENT_UNIFORM_VECTORS</td><td>long</td></tr> | |
| 1649 <tr><td>MAX_RENDERBUFFER_SIZE</td><td>long</td></tr> | |
| 1650 <tr><td>MAX_TEXTURE_IMAGE_UNITS</td><td>long</td></tr> | |
| 1651 <tr><td>MAX_TEXTURE_SIZE</td><td>long</td></tr> | |
| 1652 <tr><td>MAX_VARYING_VECTORS</td><td>long</td></tr> | |
| 1653 <tr><td>MAX_VERTEX_ATTRIBS</td><td>long</td></tr> | |
| 1654 <tr><td>MAX_VERTEX_TEXTURE_IMAGE_UNITS</td><td>long</td></tr> | |
| 1655 <tr><td>MAX_VERTEX_UNIFORM_VECTORS</td><td>long</td></tr> | |
| 1656 <tr><td>MAX_VIEWPORT_DIMS</td><td>Int32Array (with 2 elements)</
td></tr> | |
| 1657 <tr><td>NUM_COMPRESSED_TEXTURE_FORMATS</td><td>long</td></tr> | |
| 1658 <tr><td>PACK_ALIGNMENT</td><td>long</td></tr> | |
| 1659 <tr><td>POLYGON_OFFSET_FACTOR</td><td>float</td></tr> | |
| 1660 <tr><td>POLYGON_OFFSET_FILL</td><td>boolean</td></tr> | |
| 1661 <tr><td>POLYGON_OFFSET_UNITS</td><td>float</td></tr> | |
| 1662 <tr><td>RED_BITS</td><td>long</td></tr> | |
| 1663 <tr><td>RENDERBUFFER_BINDING</td><td>WebGLRenderbuffer</td></tr> | |
| 1664 <tr><td>RENDERER</td><td>DOMString</td></tr> | |
| 1665 <tr><td>SAMPLE_BUFFERS</td><td>long</td></tr> | |
| 1666 <tr><td>SAMPLE_COVERAGE_INVERT</td><td>boolean</td></tr> | |
| 1667 <tr><td>SAMPLE_COVERAGE_VALUE</td><td>float</td></tr> | |
| 1668 <tr><td>SAMPLES</td><td>long</td></tr> | |
| 1669 <tr><td>SCISSOR_BOX</td><td>Int32Array (with 4 elements)</td></t
r> | |
| 1670 <tr><td>SCISSOR_TEST</td><td>boolean</td></tr> | |
| 1671 <tr><td>SHADING_LANGUAGE_VERSION</td><td>DOMString</td></tr> | |
| 1672 <tr><td>STENCIL_BACK_FAIL</td><td>unsigned long</td></tr> | |
| 1673 <tr><td>STENCIL_BACK_FUNC</td><td>unsigned long</td></tr> | |
| 1674 <tr><td>STENCIL_BACK_PASS_DEPTH_FAIL</td><td>unsigned long</td><
/tr> | |
| 1675 <tr><td>STENCIL_BACK_PASS_DEPTH_PASS</td><td>unsigned long</td><
/tr> | |
| 1676 <tr><td>STENCIL_BACK_REF</td><td>long</td></tr> | |
| 1677 <tr><td>STENCIL_BACK_VALUE_MASK</td><td>unsigned long</td></tr> | |
| 1678 <tr><td>STENCIL_BACK_WRITEMASK</td><td>unsigned long</td></tr> | |
| 1679 <tr><td>STENCIL_BITS</td><td>long</td></tr> | |
| 1680 <tr><td>STENCIL_CLEAR_VALUE</td><td>long</td></tr> | |
| 1681 <tr><td>STENCIL_FAIL</td><td>unsigned long</td></tr> | |
| 1682 <tr><td>STENCIL_FUNC</td><td>unsigned long</td></tr> | |
| 1683 <tr><td>STENCIL_PASS_DEPTH_FAIL</td><td>unsigned long</td></tr> | |
| 1684 <tr><td>STENCIL_PASS_DEPTH_PASS</td><td>unsigned long</td></tr> | |
| 1685 <tr><td>STENCIL_REF</td><td>long</td></tr> | |
| 1686 <tr><td>STENCIL_TEST</td><td>boolean</td></tr> | |
| 1687 <tr><td>STENCIL_VALUE_MASK</td><td>unsigned long</td></tr> | |
| 1688 <tr><td>STENCIL_WRITEMASK</td><td>unsigned long</td></tr> | |
| 1689 <tr><td>SUBPIXEL_BITS</td><td>long</td></tr> | |
| 1690 <tr><td>TEXTURE_BINDING_2D</td><td>WebGLTexture</td></tr> | |
| 1691 <tr><td>TEXTURE_BINDING_CUBE_MAP</td><td>WebGLTexture</td></tr> | |
| 1692 <tr><td>UNPACK_ALIGNMENT</td><td>int</td></tr> | |
| 1693 <tr><td>UNPACK_COLORSPACE_CONVERSION_WEBGL</td><td>unsigned long
</td></tr> | |
| 1694 <tr><td>UNPACK_FLIP_Y_WEBGL</td><td>boolean</td></tr> | |
| 1695 <tr><td>UNPACK_PREMULTIPLY_ALPHA_WEBGL</td><td>boolean</td></tr> | |
| 1696 <tr><td>VENDOR</td><td>DOMString</td></tr> | |
| 1697 <tr><td>VERSION</td><td>DOMString</td></tr> | |
| 1698 <tr><td>VIEWPORT</td><td>Int32Array (with 4 elements)</td></tr> | |
| 1699 </table><br> | |
| 1700 <p>The following <em>pname</em> arguments return a string describing
some aspect of the current WebGL implementation:</p> | |
| 1701 <table> | |
| 1702 <tr><td>VERSION</td> | |
| 1703 <td>Returns a version or release number of the form <code>WebG
L<space>1.0<space><vendor-specific information></code>.</td></
tr> | |
| 1704 <tr><td>SHADING_LANGUAGE_VERSION</td> | |
| 1705 <td>Returns a version or release number of the form <code>WebG
L<space>GLSL<space>ES<space>1.0<space><vendor-specifi
c information></code>.</td></tr> | |
| 1706 <tr><td>VENDOR</td> | |
| 1707 <td>Returns the company responsible for this WebGL implementat
ion. This name does not change from release to release.</td></tr> | |
| 1708 <tr><td>RENDERER</td> | |
| 1709 <td>Returns the name of the renderer. This name is typically s
pecific to a particular configuration of a hardware platform. It does not change
from release to release.</td></tr> | |
| 1710 </table><br> | |
| 1711 <p>See <a href="#EXTENSION_QUERIES">Extension Queries</a> for inform
ation on querying the | |
| 1712 available extensions in the current WebGL implementation.</p> | |
| 1713 <dt class="idl-code">GLenum getError() | |
| 1714 <span class="gl-spec">(OpenGL ES 2.0 §2.5, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glGetError.xml">man page</a>)</span> | |
| 1715 <dd> | |
| 1716 See <a href="#WEBGLCONTEXTEVENT">WebGLContextEvent</a> for documenta
tion of a | |
| 1717 WebGL-specific return value from getError. | |
| 1718 <dt class="idl-code">void hint(GLenum target, GLenum mode) | |
| 1719 <span class="gl-spec">(OpenGL ES 2.0 §5.2, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glHint.xml">man page</a>)</span> | |
| 1720 <dt class="idl-code">GLboolean isEnabled(GLenum cap) | |
| 1721 <span class="gl-spec">(OpenGL ES 2.0 §6.1.1, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glIsEnabled.xml">man page</a>)</span> | |
| 1722 <dt class="idl-code">void lineWidth(GLfloat width) | |
| 1723 <span class="gl-spec">(OpenGL ES 2.0 §3.4, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glLineWidth.xml">man page</a>)</span> | |
| 1724 <dt class="idl-code">void pixelStorei(GLenum pname, GLint param) | |
| 1725 <span class="gl-spec">(OpenGL ES 2.0 §3.6.1, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glPixelStorei.xml">man page</a>)</span> | |
| 1726 <dd> | |
| 1727 In addition to the parameters in the OpenGL ES 2.0 specification
, the WebGL | |
| 1728 specification accepts the parameters <code>UNPACK_FLIP_Y_WEBGL</
code>, | |
| 1729 <code>UNPACK_PREMULTIPLY_ALPHA_WEBGL</code> | |
| 1730 and <code>UNPACK_COLORSPACE_CONVERSION_WEBGL</code>. See <a href
="#PIXEL_STORAGE_PARAMETERS">Pixel | |
| 1731 Storage Parameters</a> for documentation of these parameters. | |
| 1732 <dt class="idl-code">void polygonOffset(GLfloat factor, GLfloat units) | |
| 1733 <span class="gl-spec">(OpenGL ES 2.0 §3.5.2, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glPolygonOffset.xml">man page</a>)</span
> | |
| 1734 <dt class="idl-code">void sampleCoverage(GLclampf value, GLboolean inver
t) | |
| 1735 <span class="gl-spec">(OpenGL ES 2.0 §4.1.3, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glSampleCoverage.xml">man page</a>)</spa
n> | |
| 1736 <dt class="idl-code">void stencilFunc(GLenum func, GLint ref, GLuint mas
k) | |
| 1737 <span class="gl-spec">(OpenGL ES 2.0 §4.1.4, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glStencilFunc.xml">man page</a>)</span> | |
| 1738 <dt class="idl-code">void stencilFuncSeparate(GLenum face, GLenum func,
GLint ref, GLuint mask) | |
| 1739 <span class="gl-spec">(OpenGL ES 2.0 §4.1.4, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glStencilFuncSeparate.xml">man page</a>)
</span> | |
| 1740 <dd> | |
| 1741 See <a href="#STENCIL_SEPARATE_LIMIT">Stencil Separate Mask and
Reference Value</a> for information | |
| 1742 on WebGL specific limitations to the allowable argument values. | |
| 1743 <dt class="idl-code">void stencilMask(GLuint mask) | |
| 1744 <span class="gl-spec">(OpenGL ES 2.0 §4.2.2, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glStencilMask.xml">man page</a>)</span> | |
| 1745 <dd> | |
| 1746 See <a href="#STENCIL_SEPARATE_LIMIT">Stencil Separate Mask and
Reference Value</a> for information | |
| 1747 on WebGL specific limitations to the allowable mask values. | |
| 1748 <dt class="idl-code">void stencilMaskSeparate(GLenum face, GLuint mask) | |
| 1749 <span class="gl-spec">(OpenGL ES 2.0 §4.2.2, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glStencilMaskSeparate.xml">man page</a>)
</span> | |
| 1750 <dt class="idl-code">void stencilOp(GLenum fail, GLenum zfail, GLenum zp
ass) | |
| 1751 <span class="gl-spec">(OpenGL ES 2.0 §4.1.4, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glStencilOp.xml">man page</a>)</span> | |
| 1752 <dt class="idl-code">void stencilOpSeparate(GLenum face, GLenum fail, GL
enum zfail, GLenum zpass) | |
| 1753 <span class="gl-spec">(OpenGL ES 2.0 §4.1.4, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glStencilOpSeparate.xml">man page</a>)</
span> | |
| 1754 </dl> | |
| 1755 | |
| 1756 <!-- ===========================================================================
============================ --> | |
| 1757 | |
| 1758 <h4>Viewing and clipping</h4> | |
| 1759 | |
| 1760 <p> | |
| 1761 The viewport specifies the affine transformation of x and y from normali
zed device | |
| 1762 coordinates to window coordinates. The size of the drawing buffer is det
ermined by | |
| 1763 the HTMLCanvasElement. The scissor box defines a rectangle which constra
ins drawing. | |
| 1764 When the scissor test is enabled only pixels that lie within the scisso
r box can | |
| 1765 be modified by drawing commands. When enabled drawing can only occur ins
ide the | |
| 1766 intersection of the viewport, canvas area and the scissor box. When the
scissor test | |
| 1767 is not enabled drawing can only occur inside the intersection of the vie
wport and | |
| 1768 canvas area. | |
| 1769 </p> | |
| 1770 | |
| 1771 <dl class="methods"> | |
| 1772 <dt class="idl-code">void scissor(GLint x, GLint y, GLsizei width, GLsiz
ei height) | |
| 1773 <span class="gl-spec">(OpenGL ES 2.0 §4.1.2, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glScissor.xml">man page</a>)</span> | |
| 1774 | |
| 1775 <dt class="idl-code">void viewport(GLint x, GLint y, GLsizei width, GLsi
zei height) | |
| 1776 <span class="gl-spec">(OpenGL ES 2.0 §2.12.1, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glViewport.xml">man page</a>)</span> | |
| 1777 </dl> | |
| 1778 | |
| 1779 <!-- ===========================================================================
============================ --> | |
| 1780 | |
| 1781 <h4>Buffer objects</h4> | |
| 1782 | |
| 1783 <p> | |
| 1784 Buffer objects (sometimes referred to as VBOs) hold vertex attribute dat
a for the GLSL | |
| 1785 shaders. | |
| 1786 </p> | |
| 1787 | |
| 1788 <dl class="methods"> | |
| 1789 <dt class="idl-code">void bindBuffer(GLenum target, WebGLBuffer buffer) | |
| 1790 <span class="gl-spec">(OpenGL ES 2.0 §2.9, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glBindBuffer.xml">man page</a>)</span> | |
| 1791 <dd> | |
| 1792 Binds the given WebGLBuffer object to the given binding point (targe
t), either | |
| 1793 ARRAY_BUFFER or ELEMENT_ARRAY_BUFFER. If the buffer is null then any
buffer currently | |
| 1794 bound to this target is unbound. A given WebGLBuffer object may only
be bound to one of | |
| 1795 the ARRAY_BUFFER or ELEMENT_ARRAY_BUFFER target in its lifetime. An
attempt to bind a | |
| 1796 buffer object to the other target will generate an <code>INVALID_OPE
RATION</code> error, and the | |
| 1797 current binding will remain untouched. | |
| 1798 | |
| 1799 <dt class="idl-code">void bufferData(GLenum target, GLsizei size, GLenum
usage) | |
| 1800 <span class="gl-spec">(OpenGL ES 2.0 §2.9, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glBufferData.xml">man page</a>)</span> | |
| 1801 <dd> | |
| 1802 Set the size of the currently bound WebGLBuffer object for the passe
d target. The | |
| 1803 buffer is initialized to 0. | |
| 1804 | |
| 1805 <dt><p class="idl-code">void bufferData(GLenum target, ArrayBufferView d
ata, GLenum usage)</p> | |
| 1806 <p class="idl-code">void bufferData(GLenum target, ArrayBuffer data,
GLenum usage) | |
| 1807 <span class="gl-spec">(OpenGL ES 2.0 §2.9, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glBufferData.xml">man page</a>)</span></p> | |
| 1808 <dd> | |
| 1809 Set the size of the currently bound WebGLBuffer object for the passe
d target to the | |
| 1810 size of the passed data, then write the contents of data to the buff
er object. | |
| 1811 <br><br> | |
| 1812 If the passed data is null then an <code>INVALID_VALUE</code> error
is generated. | |
| 1813 <dt><p class="idl-code">void bufferSubData(GLenum target, GLsizeiptr off
set, ArrayBufferView data)</p> | |
| 1814 <p class="idl-code">void bufferSubData(GLenum target, GLsizeiptr off
set, ArrayBuffer data) | |
| 1815 <span class="gl-spec">(OpenGL ES 2.0 §2.9, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glBufferSubData.xml">man page</a>)</span><
/p> | |
| 1816 <dd> | |
| 1817 For the WebGLBuffer object bound to the passed target write the pass
ed data starting | |
| 1818 at the passed offset. If the data would be written past the end of t
he buffer object | |
| 1819 an <code>INVALID_VALUE</code> error is generated. | |
| 1820 | |
| 1821 <dt class="idl-code">WebGLBuffer createBuffer() | |
| 1822 <span class="gl-spec">(OpenGL ES 2.0 §2.9, similar to <a href="
http://www.khronos.org/opengles/sdk/2.0/docs/man/glGenBuffers.xml">glGenBuffers<
/a>)</span> | |
| 1823 <dd> | |
| 1824 Create a WebGLBuffer object and initialize it with a buffer object n
ame as if by | |
| 1825 calling glGenBuffers. | |
| 1826 | |
| 1827 <dt class="idl-code">void deleteBuffer(WebGLBuffer buffer) | |
| 1828 <span class="gl-spec">(OpenGL ES 2.0 §2.9, similar to <a href="
http://www.khronos.org/opengles/sdk/2.0/docs/man/glDeleteBuffers.xml">glDeleteBu
ffers</a>)</span> | |
| 1829 <dd> | |
| 1830 Delete the buffer object contained in the passed WebGLBuffer as if b
y calling | |
| 1831 glDeleteBuffers. If the buffer has already been deleted the call has
no effect. | |
| 1832 Note that the buffer object will be deleted when the WebGLBuffer obj
ect is destroyed. | |
| 1833 This method merely gives the author greater control over when the bu
ffer object is | |
| 1834 destroyed. | |
| 1835 | |
| 1836 <dt class="idl-code">any getBufferParameter(GLenum target, GLenum pname) | |
| 1837 <span class="gl-spec">(OpenGL ES 2.0 §6.1.3, similar to <a href
="http://www.khronos.org/opengles/sdk/2.0/docs/man/glGetBufferParameteriv.xml">g
lGetBufferParameteriv</a>)</span> | |
| 1838 <dd> | |
| 1839 Return the value for the passed pname. The type returned is the natu
ral type for the | |
| 1840 requested pname, as given in the following table: | |
| 1841 <table class="foo"> | |
| 1842 <tr><th>pname</th><th>returned type</th></tr> | |
| 1843 <tr><td>BUFFER_SIZE</td><td>long</td></tr> | |
| 1844 <tr><td>BUFFER_USAGE</td><td>unsigned long</td></tr> | |
| 1845 </table> | |
| 1846 <dt class="idl-code">GLboolean isBuffer(WebGLBuffer buffer) | |
| 1847 <span class="gl-spec">(OpenGL ES 2.0 §6.1.6, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glIsBuffer.xml">man page</a>)</span> | |
| 1848 </dl> | |
| 1849 | |
| 1850 <!-- ===========================================================================
============================ --> | |
| 1851 | |
| 1852 <h4>Framebuffer objects</h4> | |
| 1853 | |
| 1854 <p> | |
| 1855 Framebuffer objects provide an alternative rendering target to the drawi
ng buffer. They | |
| 1856 are a collection of color, alpha, depth and stencil buffers and are ofte
n used to | |
| 1857 render an image that will later be used as a texture. | |
| 1858 </p> | |
| 1859 | |
| 1860 <dl class="methods"> | |
| 1861 <dt class="idl-code">void bindFramebuffer(GLenum target, WebGLFramebuffe
r framebuffer) | |
| 1862 <span class="gl-spec">(OpenGL ES 2.0 §4.4.1, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glBindFramebuffer.xml">man page</a>)</sp
an> | |
| 1863 <dd> | |
| 1864 Bind the given <code class="interface">WebGLFramebuffer</code> objec
t to the given binding point | |
| 1865 (<code class="param">target</code>), which must be <code class="enum
">FRAMEBUFFER</code>. | |
| 1866 If <code class="param">framebuffer</code> is null, the default frame
buffer provided by the context | |
| 1867 is bound and attempts to modify or query state on <code class="param
">target</code> <code class="enum">FRAMEBUFFER</code> | |
| 1868 will generate an <code class="error">INVALID_OPERATION</code> error. | |
| 1869 | |
| 1870 <dt class="idl-code">GLenum checkFramebufferStatus(GLenum target) | |
| 1871 <span class="gl-spec">(OpenGL ES 2.0 §4.4.5, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glCheckFramebufferStatus.xml">man page</
a>)</span> | |
| 1872 <dt class="idl-code">WebGLFramebuffer createFramebuffer() | |
| 1873 <span class="gl-spec">(OpenGL ES 2.0 §4.4.1, similar to <a href
="http://www.khronos.org/opengles/sdk/2.0/docs/man/glGenFramebuffers.xml">glGenF
ramebuffers</a>)</span> | |
| 1874 <dd> | |
| 1875 Create a WebGLFramebuffer object and initialize it with a framebuffe
r object name as if by | |
| 1876 calling glGenFramebuffers. | |
| 1877 | |
| 1878 <dt class="idl-code">void deleteFramebuffer(WebGLFramebuffer buffer) | |
| 1879 <span class="gl-spec">(OpenGL ES 2.0 §4.4.1, similar to <a href
="http://www.khronos.org/opengles/sdk/2.0/docs/man/glDeleteFramebuffers.xml">glD
eleteFramebuffers</a>)</span> | |
| 1880 <dd> | |
| 1881 Delete the framebuffer object contained in the passed WebGLFramebuff
er as if by calling | |
| 1882 glDeleteFramebuffers. If the framebuffer has already been deleted th
e call has no effect. | |
| 1883 Note that the framebuffer object will be deleted when the WebGLFrame
buffer object is destroyed. | |
| 1884 This method merely gives the author greater control over when the fr
amebuffer object is | |
| 1885 destroyed. | |
| 1886 | |
| 1887 <dt class="idl-code">void framebufferRenderbuffer(GLenum target, GLenum
attachment, | |
| 1888 GLenum renderbuffertarget, | |
| 1889 WebGLRenderbuffer renderbuffer) | |
| 1890 <span class="gl-spec">(OpenGL ES 2.0 §4.4.3, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glFramebufferRenderbuffer.xml">man page<
/a>)</span></dt> | |
| 1891 <dt class="idl-code">void framebufferTexture2D(GLenum target, GLenum att
achment, GLenum textarget, | |
| 1892 WebGLTexture texture, GLint level) | |
| 1893 <span class="gl-spec">(OpenGL ES 2.0 §4.4.3, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glFramebufferTexture2D.xml">man page</a>
)</span> | |
| 1894 <dt class="idl-code">any getFramebufferAttachmentParameter(GLenum target
, GLenum attachment, | |
| 1895 GLenum pname) | |
| 1896 <span class="gl-spec">(OpenGL ES 2.0 §6.1.3, similar to <a href
="http://www.khronos.org/opengles/sdk/2.0/docs/man/glGetFramebufferAttachmentPar
ameteriv.xml">glGetFramebufferAttachmentParameteriv</a>)</span> | |
| 1897 <dd> | |
| 1898 Return the value for the passed pname given the passed target and at
tachment. The type | |
| 1899 returned is the natural type for the requested pname, as given in th
e following table: | |
| 1900 <table class="foo"> | |
| 1901 <tr><th>pname</th><th>returned type</th></tr> | |
| 1902 <tr><td>FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE</td><td>unsigned long
</td></tr> | |
| 1903 <tr><td>FRAMEBUFFER_ATTACHMENT_OBJECT_NAME</td><td>WebGLRenderbu
ffer or WebGLTexture</td></tr> | |
| 1904 <tr><td>FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL</td><td>long</td></
tr> | |
| 1905 <tr><td>FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE</td><td>lon
g</td></tr> | |
| 1906 </table> | |
| 1907 <dt class="idl-code">GLboolean isFramebuffer(WebGLFramebuffer framebuffe
r) | |
| 1908 <span class="gl-spec">(OpenGL ES 2.0 §6.1.7, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glIsFramebuffer.xml">man page</a>)</span
> | |
| 1909 <dd> | |
| 1910 Return true if the passed WebGLFramebuffer is valid and false otherw
ise. | |
| 1911 </dl> | |
| 1912 | |
| 1913 <!-- ===========================================================================
============================ --> | |
| 1914 | |
| 1915 <h4>Renderbuffer objects</h4> | |
| 1916 | |
| 1917 <p> | |
| 1918 Renderbuffer objects are used to provide storage for the individual buff
ers used in a | |
| 1919 framebuffer object. | |
| 1920 </p> | |
| 1921 | |
| 1922 <dl class="methods"> | |
| 1923 <dt class="idl-code">void bindRenderbuffer(GLenum target, WebGLRenderbuf
fer renderbuffer) | |
| 1924 <span class="gl-spec">(OpenGL ES 2.0 §4.4.3, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glBindRenderbuffer.xml">man page</a>)</s
pan> | |
| 1925 <dd> | |
| 1926 Bind the given <code class="interface">WebGLRenderbuffer</code> obje
ct to the given binding point | |
| 1927 (<code class="param">target</code>), which must be <code class="enum
">RENDERBUFFER</code>. | |
| 1928 If <code class="param">renderbuffer</code> is null the renderbuffer
object currently bound to | |
| 1929 this <code class="param">target</code> is unbound. | |
| 1930 | |
| 1931 <dt class="idl-code">WebGLRenderbuffer createRenderbuffer() | |
| 1932 <span class="gl-spec">(OpenGL ES 2.0 §4.4.3, similar to <a href
="http://www.khronos.org/opengles/sdk/2.0/docs/man/glGenRenderbuffers.xml">glGen
Renderbuffers</a>)</span> | |
| 1933 <dd> | |
| 1934 Create a WebGLRenderbuffer object and initialize it with a renderbuf
fer object name as if by | |
| 1935 calling glGenRenderbuffers. | |
| 1936 | |
| 1937 <dt class="idl-code">void deleteRenderbuffer(WebGLRenderbuffer renderbuf
fer) | |
| 1938 <span class="gl-spec">(OpenGL ES 2.0 §4.4.3, similar to <a href
="http://www.khronos.org/opengles/sdk/2.0/docs/man/glDeleteRenderbuffers.xml">gl
DeleteRenderbuffers</a>)</span> | |
| 1939 <dd> | |
| 1940 Delete the renderbuffer object contained in the passed WebGLRenderbu
ffer as if by calling | |
| 1941 glDeleteRenderbuffers. If the renderbuffer has already been deleted
the call has no effect. | |
| 1942 Note that the renderbuffer object will be deleted when the WebGLRend
erbuffer object is destroyed. | |
| 1943 This method merely gives the author greater control over when the re
nderbuffer object is | |
| 1944 destroyed. | |
| 1945 <dt class="idl-code">any getRenderbufferParameter(GLenum target, GLenum
pname) | |
| 1946 <span class="gl-spec">(OpenGL ES 2.0 §6.1.3, similar to <a href
="http://www.khronos.org/opengles/sdk/2.0/docs/man/glGetRenderbufferParameteriv.
xml">glGetRenderbufferParameteriv</a>)</span> | |
| 1947 <dd> | |
| 1948 Return the value for the passed pname given the passed target. The t
ype returned is the natural | |
| 1949 type for the requested pname, as given in the following table: | |
| 1950 <table class="foo"> | |
| 1951 <tr><th>pname</th><th>returned type</th></tr> | |
| 1952 <tr><td>RENDERBUFFER_WIDTH</td><td>long</td></tr> | |
| 1953 <tr><td>RENDERBUFFER_HEIGHT</td><td>long</td></tr> | |
| 1954 <tr><td>RENDERBUFFER_INTERNAL_FORMAT</td><td>unsigned long</td><
/tr> | |
| 1955 <tr><td>RENDERBUFFER_RED_SIZE</td><td>long</td></tr> | |
| 1956 <tr><td>RENDERBUFFER_GREEN_SIZE</td><td>long</td></tr> | |
| 1957 <tr><td>RENDERBUFFER_BLUE_SIZE</td><td>long</td></tr> | |
| 1958 <tr><td>RENDERBUFFER_ALPHA_SIZE</td><td>long</td></tr> | |
| 1959 <tr><td>RENDERBUFFER_DEPTH_SIZE</td><td>long</td></tr> | |
| 1960 <tr><td>RENDERBUFFER_STENCIL_SIZE</td><td>long</td></tr> | |
| 1961 </table> | |
| 1962 <dt class="idl-code">GLboolean isRenderbuffer(WebGLRenderbuffer renderbu
ffer) | |
| 1963 <span class="gl-spec">(OpenGL ES 2.0 §6.1.7, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glIsRenderbuffer.xml">man page</a>)</spa
n> | |
| 1964 <dd> | |
| 1965 Return true if the passed WebGLRenderbuffer is valid and false other
wise. | |
| 1966 <dt class="idl-code">void renderbufferStorage(GLenum target, GLenum inte
rnalformat, | |
| 1967 GLsizei width, GLsizei height) | |
| 1968 <span class="gl-spec">(OpenGL ES 2.0 §4.4.3, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glRenderbufferStorage.xml">man page</a>)
</span> | |
| 1969 </dl> | |
| 1970 | |
| 1971 <!-- ===========================================================================
============================ --> | |
| 1972 | |
| 1973 <h4>Texture objects</h4> | |
| 1974 | |
| 1975 <p> | |
| 1976 Texture objects provide storage and state for texturing operations. If n
o WebGLTexture is bound | |
| 1977 (e.g., passing null or 0 to bindTexture) then attempts to modify or quer
y the texture object shall | |
| 1978 generate an <code>INVALID_OPERATION</code> error. This is indicated in t
he functions below. | |
| 1979 </p> | |
| 1980 | |
| 1981 <dl class="methods"> | |
| 1982 <dt class="idl-code">void bindTexture(GLenum target, WebGLTexture textur
e) | |
| 1983 <span class="gl-spec">(OpenGL ES 2.0 §3.7.13, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glBindTexture.xml">man page</a>)</span> | |
| 1984 <dt class="idl-code">void copyTexImage2D(GLenum target, GLint level, GLe
num internalformat, | |
| 1985 GLint x, GLint y, GLsizei width, GLsizei height, | |
| 1986 GLint border) | |
| 1987 <span class="gl-spec">(OpenGL ES 2.0 §3.7.2, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glCopyTexImage2D.xml">man page</a>)</spa
n> | |
| 1988 <dd> | |
| 1989 If an attempt is made to call this function with no WebGLTexture bou
nd (see above), an | |
| 1990 <code>INVALID_OPERATION</code> error is generated. | |
| 1991 <dt class="idl-code">void copyTexSubImage2D(GLenum target, GLint level,
GLint xoffset, GLint yoffset, | |
| 1992 GLint x, GLint y, GLsizei width, GLsizei height) | |
| 1993 <span class="gl-spec">(OpenGL ES 2.0 §3.7.2, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glCopyTexSubImage2D.xml">man page</a>)</
span> | |
| 1994 <dd> | |
| 1995 If an attempt is made to call this function with no WebGLTexture bou
nd (see above), an | |
| 1996 <code>INVALID_OPERATION</code> error is generated. | |
| 1997 <dt class="idl-code">WebGLTexture createTexture() | |
| 1998 <span class="gl-spec">(OpenGL ES 2.0 §3.7.13, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glGenTextures.xml">man page</a>)</span> | |
| 1999 <dd> | |
| 2000 Create a WebGLTexture object and initialize it with a texture object
name as if by | |
| 2001 calling glGenTextures. | |
| 2002 | |
| 2003 <dt class="idl-code">void deleteTexture(WebGLTexture texture) | |
| 2004 <span class="gl-spec">(OpenGL ES 2.0 §3.7.13, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glDeleteTextures.xml">man page</a>)</sp
an> | |
| 2005 <dd> | |
| 2006 Delete the texture object contained in the passed WebGLTexture as if
by calling | |
| 2007 glDeleteTextures. If the texture has already been deleted the call h
as no effect. | |
| 2008 Note that the texture object will be deleted when the WebGLTexture o
bject is destroyed. | |
| 2009 This method merely gives the author greater control over when the te
xture object is | |
| 2010 destroyed. | |
| 2011 <dt class="idl-code">void generateMipmap(GLenum target) | |
| 2012 <span class="gl-spec">(OpenGL ES 2.0 §3.7.11, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glGenerateMipmap.xml">man page</a>)</sp
an> | |
| 2013 <dd> | |
| 2014 If an attempt is made to call this function with no WebGLTexture bou
nd (see above), an | |
| 2015 <code>INVALID_OPERATION</code> error is generated. | |
| 2016 <dt class="idl-code">any getTexParameter(GLenum target, GLenum pname) | |
| 2017 <span class="gl-spec">(OpenGL ES 2.0 §6.1.3, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glGetTexParameter.xml">man page</a>)</sp
an> | |
| 2018 <dd> | |
| 2019 Return the value for the passed pname given the passed target. The t
ype returned is the natural type for the | |
| 2020 requested pname, as given in the following table: | |
| 2021 <table class="foo"> | |
| 2022 <tr><th>pname</th><th>returned type</th></tr> | |
| 2023 <tr><td>TEXTURE_MAG_FILTER</td><td>unsigned long</td></tr> | |
| 2024 <tr><td>TEXTURE_MIN_FILTER</td><td>unsigned long</td></tr> | |
| 2025 <tr><td>TEXTURE_WRAP_S</td><td>unsigned long</td></tr> | |
| 2026 <tr><td>TEXTURE_WRAP_T</td><td>unsigned long</td></tr> | |
| 2027 </table> | |
| 2028 <dd> | |
| 2029 If an attempt is made to call this function with no WebGLTexture bou
nd (see above), an | |
| 2030 <code>INVALID_OPERATION</code> error is generated. | |
| 2031 <dt class="idl-code">GLboolean isTexture(WebGLTexture texture) | |
| 2032 <span class="gl-spec">(OpenGL ES 2.0 §6.1.4, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glIsTexture.xml">man page</a>)</span> | |
| 2033 <dd> | |
| 2034 Return true if the passed WebGLTexture is valid and false otherwise. | |
| 2035 <dt class="idl-code"><a name="TEXIMAGE2D">void texImage2D</a>(GLenum tar
get, GLint level, GLenum internalformat, | |
| 2036 GLsizei width, GLsizei height, GLint border, GLenum format, | |
| 2037 GLenum type, ArrayBufferView pixels) | |
| 2038 <span class="gl-spec">(OpenGL ES 2.0 §3.7.1, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glTexImage2D.xml">man page</a>)</span> | |
| 2039 <dd> | |
| 2040 If <code>pixels</code> is null, a buffer of sufficient size initiali
zed to 0 is | |
| 2041 passed. <br><br> | |
| 2042 | |
| 2043 If <code>pixels</code> is non-null, the type of <code>pixels</code>
must match the type | |
| 2044 of the data to be read. If it is UNSIGNED_BYTE, a Uint8Array must be
supplied; if it is | |
| 2045 UNSIGNED_SHORT_5_6_5, UNSIGNED_SHORT_4_4_4_4, or UNSIGNED_SHORT_5_5_
5_1, a Uint16Array | |
| 2046 must be supplied. If the types do not match, an INVALID_OPERATION er
ror is generated. | |
| 2047 <br><br> | |
| 2048 | |
| 2049 If an attempt is made to call this function with no WebGLTexture bou
nd (see above), an | |
| 2050 <code>INVALID_OPERATION</code> error is generated. <br><br> | |
| 2051 | |
| 2052 See <a href="#PIXEL_STORAGE_PARAMETERS">Pixel Storage Parameters</a>
for WebGL-specific | |
| 2053 pixel storage parameters that affect the behavior of this function. | |
| 2054 <dt><p class="idl-code"><a name="TEXIMAGE2D_HTML">void texImage2D</a>(GL
enum target, GLint level, GLenum internalformat, | |
| 2055 GLenum format, GLenum type, ImageData pixels)</p> | |
| 2056 <p class="idl-code">void texImage2D(GLenum target, GLint level, GLen
um internalformat, | |
| 2057 GLenum format, GLenum type, HTMLImageElement image)</p> | |
| 2058 <p class="idl-code">void texImage2D(GLenum target, GLint level, GLen
um internalformat, | |
| 2059 GLenum format, GLenum type, HTMLCanvasElement canvas)</p> | |
| 2060 <p class="idl-code">void texImage2D(GLenum target, GLint level, GLen
um internalformat, | |
| 2061 GLenum format, GLenum type, HTMLVideoElement video) | |
| 2062 <span class="gl-spec">(OpenGL ES 2.0 §3.7.1, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glTexImage2D.xml">man page</a>)</span></
p> | |
| 2063 <dd> | |
| 2064 Uploads the given element or image data to the currently bound WebGL
Texture. <br><br> | |
| 2065 | |
| 2066 The source image data is conceptually first converted to the data ty
pe and format | |
| 2067 specified by the <em>format</em> and <em>type</em> arguments, and th
en transferred to | |
| 2068 the OpenGL implementation. If a packed pixel format is specified whi
ch would imply loss | |
| 2069 of bits of precision from the image data, this loss of precision mus
t occur. <br><br> | |
| 2070 | |
| 2071 If the source image is an RGB or RGBA lossless image with 8 bits per
channel, the | |
| 2072 browser guarantees that the full precision of all channels is preser
ved. <br><br> | |
| 2073 | |
| 2074 If the original image contains an alpha channel and the | |
| 2075 <code>UNPACK_PREMULTIPLY_ALPHA_WEBGL</code> pixel storage parameter
is false, then the | |
| 2076 RGB values are guaranteed to never have been premultiplied by the al
pha channel, whether | |
| 2077 those values are derived directly from the original file format or c
onverted from some | |
| 2078 other color format. <br><br> | |
| 2079 | |
| 2080 If an attempt is made to call this function with no WebGLTexture bou
nd (see above), an | |
| 2081 <code>INVALID_OPERATION</code> error is generated. <br><br> | |
| 2082 | |
| 2083 See <a href="#PIXEL_STORAGE_PARAMETERS">Pixel Storage Parameters</a>
for WebGL-specific | |
| 2084 pixel storage parameters that affect the behavior of this function. | |
| 2085 <dt class="idl-code">void texParameterf(GLenum target, GLenum pname, GLf
loat param) | |
| 2086 <span class="gl-spec">(OpenGL ES 2.0 §3.7.4, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glTexParameter.xml">man page</a>)</span> | |
| 2087 <dd> | |
| 2088 If an attempt is made to call this function with no WebGLTexture bou
nd (see above), an | |
| 2089 <code>INVALID_OPERATION</code> error is generated. | |
| 2090 <dt class="idl-code">void texParameteri(GLenum target, GLenum pname, GLi
nt param) | |
| 2091 <span class="gl-spec">(OpenGL ES 2.0 §3.7.4, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glTexParameter.xml">man page</a>)</span> | |
| 2092 <dd> | |
| 2093 If an attempt is made to call this function with no WebGLTexture bou
nd (see above), an | |
| 2094 <code>INVALID_OPERATION</code> error is generated. | |
| 2095 <dt class="idl-code">void texSubImage2D(GLenum target, GLint level, GLin
t xoffset, GLint yoffset, | |
| 2096 GLsizei width, GLsizei height, | |
| 2097 GLenum format, GLenum type, ArrayBufferView pixels) | |
| 2098 <span class="gl-spec">(OpenGL ES 2.0 §3.7.2, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glTexSubImage2D.xml">man page</a>)</span
> | |
| 2099 <dd> | |
| 2100 See <a href="#TEXIMAGE2D">texImage2D</a> for restrictions on the <em
>format</em> | |
| 2101 and <em>pixels</em> arguments. <br><br> | |
| 2102 | |
| 2103 If an attempt is made to call this function with no WebGLTexture bou
nd (see above), an | |
| 2104 <code>INVALID_OPERATION</code> error is generated. <br><br> | |
| 2105 | |
| 2106 See <a href="#PIXEL_STORAGE_PARAMETERS">Pixel Storage Parameters</a>
for WebGL-specific | |
| 2107 pixel storage parameters that affect the behavior of this function. | |
| 2108 <dt><p class="idl-code">void texSubImage2D(GLenum target, GLint level, G
Lint xoffset, GLint yoffset, | |
| 2109 GLenum format, GLenum type, ImageData pixels)</p> | |
| 2110 <p class="idl-code">void texSubImage2D(GLenum target, GLint level, G
Lint xoffset, GLint yoffset, | |
| 2111 GLenum format, GLenum type, HTMLImageElement image)</p> | |
| 2112 <p class="idl-code">void texSubImage2D(GLenum target, GLint level, G
Lint xoffset, GLint yoffset, | |
| 2113 GLenum format, GLenum type, HTMLCanvasElement canvas)</p> | |
| 2114 <p class="idl-code">void texSubImage2D(GLenum target, GLint level, G
Lint xoffset, GLint yoffset, | |
| 2115 GLenum format, GLenum type, HTMLVideoElement video) | |
| 2116 <span class="gl-spec">(OpenGL ES 2.0 §3.7.2, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glTexSubImage2D.xml">man page</a>)</span
></p> | |
| 2117 <dd> | |
| 2118 Updates a sub-rectangle of the currently bound WebGLTexture with the
contents of the | |
| 2119 given element or image data. <br><br> | |
| 2120 | |
| 2121 See <a href="#TEXIMAGE2D_HTML">texImage2D</a> for the interpretation
of | |
| 2122 the <em>format</em> and <em>type</em> arguments. <br><br> | |
| 2123 | |
| 2124 If an attempt is made to call this function with no WebGLTexture bou
nd (see above), an | |
| 2125 <code>INVALID_OPERATION</code> error is generated. <br><br> | |
| 2126 | |
| 2127 See <a href="#PIXEL_STORAGE_PARAMETERS">Pixel Storage Parameters</a>
for WebGL-specific | |
| 2128 pixel storage parameters that affect the behavior of this function. | |
| 2129 </dl> | |
| 2130 | |
| 2131 <!-- ===========================================================================
============================ --> | |
| 2132 | |
| 2133 <h4>Programs and Shaders</h4> | |
| 2134 | |
| 2135 <p> | |
| 2136 Rendering with OpenGL ES 2.0 requires the use of <i>shaders</i>, written
in OpenGL ES's shading language, GLSL ES. | |
| 2137 Shaders must be loaded with a source string (shaderSource), compiled | |
| 2138 (compileShader) and attached to a <i>program</i> (attachShader) which mu
st be linked | |
| 2139 (linkProgram) and then used (useProgram). | |
| 2140 </p> | |
| 2141 | |
| 2142 <dl class="methods"> | |
| 2143 <dt class="idl-code">void attachShader(WebGLProgram program, WebGLShader
shader) | |
| 2144 <span class="gl-spec">(OpenGL ES 2.0 §2.10.3, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glAttachShader.xml">man page</a>)</span
> | |
| 2145 <dt class="idl-code">void bindAttribLocation(WebGLProgram program, GLuin
t index, DOMString name) | |
| 2146 <span class="gl-spec">(OpenGL ES 2.0 §2.10.4, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glBindAttribLocation.xml">man page</a>)
</span> | |
| 2147 <dt class="idl-code">void compileShader(WebGLShader shader) | |
| 2148 <span class="gl-spec">(OpenGL ES 2.0 §2.10.1, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glCompileShader.xml">man page</a>)</spa
n> | |
| 2149 <dt class="idl-code">WebGLProgram createProgram() | |
| 2150 <span class="gl-spec">(OpenGL ES 2.0 §2.10.3, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glCreateProgram.xml">man page</a>)</spa
n> | |
| 2151 <dd> | |
| 2152 Create a WebGLProgram object and initialize it with a program object
name as if by | |
| 2153 calling glCreateProgram. | |
| 2154 | |
| 2155 <dt class="idl-code">WebGLShader createShader(type) | |
| 2156 <span class="gl-spec">(OpenGL ES 2.0 §2.10.1, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glCreateShader.xml">man page</a>)</span
> | |
| 2157 <dd> | |
| 2158 Create a WebGLShader object and initialize it with a shader object n
ame as if by | |
| 2159 calling glCreateShader. | |
| 2160 | |
| 2161 <dt class="idl-code">void deleteProgram(WebGLProgram program) | |
| 2162 <span class="gl-spec">(OpenGL ES 2.0 §2.10.3, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glDeleteProgram.xml">man page</a>)</spa
n> | |
| 2163 <dd> | |
| 2164 Delete the program object contained in the passed WebGLProgram as if
by calling | |
| 2165 glDeleteProgram. If the program has already been deleted the call ha
s no effect. | |
| 2166 Note that the program object will be deleted when the WebGLProgram o
bject is destroyed. | |
| 2167 This method merely gives the author greater control over when the pr
ogram object is | |
| 2168 destroyed. | |
| 2169 <dt class="idl-code">void deleteShader(WebGLShader shader) | |
| 2170 <span class="gl-spec">(OpenGL ES 2.0 §2.10.1, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glDeleteShader.xml">man page</a>)</span
> | |
| 2171 <dd> | |
| 2172 Delete the shader object contained in the passed WebGLShader as if b
y calling | |
| 2173 glDeleteShader. If the shader has already been deleted the call has
no effect. | |
| 2174 Note that the shader object will be deleted when the WebGLShader obj
ect is destroyed. | |
| 2175 This method merely gives the author greater control over when the sh
ader object is | |
| 2176 destroyed. | |
| 2177 <dt class="idl-code">void detachShader(WebGLProgram program, WebGLShader
shader) | |
| 2178 <span class="gl-spec">(OpenGL ES 2.0 §2.10.3, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glDetachShader.xml">man page</a>)</span
> | |
| 2179 <dt class="idl-code">WebGLShader[ ] getAttachedShaders(WebGLProgram prog
ram) | |
| 2180 <span class="gl-spec">(OpenGL ES 2.0 §6.1.8, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glGetAttachedShaders.xml">man page</a>)<
/span> | |
| 2181 <dd> | |
| 2182 Return the list of shaders attached to the passed program. | |
| 2183 <dt class="idl-code">any getProgramParameter(WebGLProgram program, GLenu
m pname) | |
| 2184 <span class="gl-spec">(OpenGL ES 2.0 §6.1.8, similar to <a href
="http://www.khronos.org/opengles/sdk/2.0/docs/man/glGetProgramiv.xml">man page<
/a>)</span> | |
| 2185 <dd> | |
| 2186 Return the value for the passed pname given the passed program. The
type returned is the natural | |
| 2187 type for the requested pname, as given in the following table: | |
| 2188 <table class="foo"> | |
| 2189 <tr><th>pname</th><th>returned type</th></tr> | |
| 2190 <tr><td>DELETE_STATUS</td><td>boolean</td></tr> | |
| 2191 <tr><td>LINK_STATUS</td><td>boolean</td></tr> | |
| 2192 <tr><td>VALIDATE_STATUS</td><td>boolean</td></tr> | |
| 2193 <tr><td>INFO_LOG_LENGTH</td><td>long</td></tr> | |
| 2194 <tr><td>ATTACHED_SHADERS</td><td>long</td></tr> | |
| 2195 <tr><td>ACTIVE_ATTRIBUTES</td><td>long</td></tr> | |
| 2196 <tr><td>ACTIVE_ATTRIBUTE_MAX_LENGTH</td><td>long</td></tr> | |
| 2197 <tr><td>ACTIVE_UNIFORMS</td><td>long</td></tr> | |
| 2198 <tr><td>ACTIVE_UNIFORM_MAX_LENGTH</td><td>long</td></tr> | |
| 2199 </table> | |
| 2200 <dt class="idl-code">DOMString getProgramInfoLog(WebGLProgram program) | |
| 2201 <span class="gl-spec">(OpenGL ES 2.0 §6.1.8, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glGetProgramInfoLog.xml">man page</a>)</
span> | |
| 2202 <dt class="idl-code">any getShaderParameter(WebGLShader shader, GLenum p
name) | |
| 2203 <span class="gl-spec">(OpenGL ES 2.0 §6.1.8, similar to <a href
="http://www.khronos.org/opengles/sdk/2.0/docs/man/glGetShaderiv.xml">man page</
a>)</span> | |
| 2204 <dd> | |
| 2205 Return the value for the passed pname given the passed shader. The t
ype returned is the natural | |
| 2206 type for the requested pname, as given in the following table: | |
| 2207 <table class="foo"> | |
| 2208 <tr><th>pname</th><th>returned type</th></tr> | |
| 2209 <tr><td>SHADER_TYPE</td><td>unsigned long</td></tr> | |
| 2210 <tr><td>DELETE_STATUS</td><td>boolean</td></tr> | |
| 2211 <tr><td>COMPILE_STATUS</td><td>boolean</td></tr> | |
| 2212 <tr><td>INFO_LOG_LENGTH</td><td>long</td></tr> | |
| 2213 <tr><td>SHADER_SOURCE_LENGTH</td><td>long</td></tr> | |
| 2214 </table> | |
| 2215 <dt class="idl-code">DOMString getShaderInfoLog(WebGLShader shader) | |
| 2216 <span class="gl-spec">(OpenGL ES 2.0 §6.1.8, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glGetShaderInfoLog.xml">man page</a>)</s
pan> | |
| 2217 <dt class="idl-code">DOMString getShaderSource(WebGLShader shader) | |
| 2218 <span class="gl-spec">(OpenGL ES 2.0 §6.1.8, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glGetShaderSource.xml">man page</a>)</sp
an> | |
| 2219 <dt class="idl-code">GLboolean isProgram(WebGLProgram program) | |
| 2220 <span class="gl-spec">(OpenGL ES 2.0 §6.1.8, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glIsProgram.xml">man page</a>)</span> | |
| 2221 <dd> | |
| 2222 Return true if the passed WebGLProgram is valid and false otherwise. | |
| 2223 <dt class="idl-code">GLboolean isShader(WebGLShader shader) | |
| 2224 <span class="gl-spec">(OpenGL ES 2.0 §6.1.8, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glIsShader.xml">man page</a>)</span> | |
| 2225 <dd> | |
| 2226 Return true if the passed WebGLShader is valid and false otherwise. | |
| 2227 <dt class="idl-code">void linkProgram(WebGLProgram program) | |
| 2228 <span class="gl-spec">(OpenGL ES 2.0 §2.10.3, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glLinkProgram.xml">man page</a>)</span> | |
| 2229 <dt class="idl-code">void shaderSource(WebGLShader shader, DOMString sou
rce) | |
| 2230 <span class="gl-spec">(OpenGL ES 2.0 §2.10.1, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glShaderSource.xml">man page</a>)</span
> | |
| 2231 <dt class="idl-code">void useProgram(WebGLProgram program) | |
| 2232 <span class="gl-spec">(OpenGL ES 2.0 §2.10.3, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glUseProgram.xml">man page</a>)</span> | |
| 2233 <dt class="idl-code">void validateProgram(WebGLProgram program) | |
| 2234 <span class="gl-spec">(OpenGL ES 2.0 §2.10.5, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glValidateProgram.xml">man page</a>)</s
pan> | |
| 2235 </dl> | |
| 2236 | |
| 2237 <!-- ===========================================================================
============================ --> | |
| 2238 | |
| 2239 <h4>Uniforms and attributes</h4> | |
| 2240 | |
| 2241 <p> | |
| 2242 Values used by the shaders are passed in as uniform of vertex attributes
. | |
| 2243 </p> | |
| 2244 | |
| 2245 <dl class="methods"> | |
| 2246 <dt class="idl-code">void disableVertexAttribArray(GLuint index) | |
| 2247 <span class="gl-spec">(OpenGL ES 2.0 §2.8, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glDisableVertexAttribArray.xml">man page</
a>)</span> | |
| 2248 <dt class="idl-code">void enableVertexAttribArray(GLuint index) | |
| 2249 <span class="gl-spec">(OpenGL ES 2.0 §2.8, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glEnableVertexAttribArray.xml">man page</a
>)</span> | |
| 2250 <dd> | |
| 2251 Enable the vertex attribute at <code>index</code> as an array. WebGL
imposes additional | |
| 2252 rules beyond OpenGL ES 2.0 regarding enabled vertex attributes; | |
| 2253 see <a href="#ATTRIBS_AND_RANGE_CHECKING">Enabled Vertex Attributes
and Range | |
| 2254 Checking</a>. | |
| 2255 <dt class="idl-code">WebGLActiveInfo getActiveAttrib(WebGLProgram progra
m, GLuint index) | |
| 2256 <span class="gl-spec">(OpenGL ES 2.0 §2.10.4, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glGetActiveAttrib.xml">man page</a>)</s
pan> | |
| 2257 <dd> | |
| 2258 Returns information about the size, type and name of the vertex attr
ibute at the | |
| 2259 passed index of the passed program object. | |
| 2260 <dt class="idl-code">WebGLActiveInfo getActiveUniform(WebGLProgram progr
am, GLuint index) | |
| 2261 <span class="gl-spec">(OpenGL ES 2.0 §2.10.4, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glGetActiveUniform.xml">man page</a>)</
span> | |
| 2262 <dd> | |
| 2263 Returns information about the size, type and name of the uniform at
the | |
| 2264 passed index of the passed program object. | |
| 2265 <dt class="idl-code">GLint getAttribLocation(WebGLProgram program, DOMSt
ring name) | |
| 2266 <span class="gl-spec">(OpenGL ES 2.0 §2.10.4, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glGetAttribLocation.xml">man page</a>)<
/span> | |
| 2267 <dt class="idl-code">any getUniform(WebGLProgram program, WebGLUniformLo
cation location) | |
| 2268 <span class="gl-spec">(OpenGL ES 2.0 §6.1.8, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glGetUniform.xml">man page</a>)</span> | |
| 2269 <dd> | |
| 2270 Return the uniform value at the passed location in the passed progra
m. The type returned is | |
| 2271 dependent on the uniform type, as shown in the following table: | |
| 2272 <table class="foo"> | |
| 2273 <tr><th>uniform type</th><th>returned type</th></tr> | |
| 2274 <tr><td>boolean</td><td>boolean</td></tr> | |
| 2275 <tr><td>int</td><td>long</td></tr> | |
| 2276 <tr><td>float</td><td>float</td></tr> | |
| 2277 <tr><td>vec2</td><td>Float32Array (with 2 elements)</td></tr> | |
| 2278 <tr><td>ivec2</td><td>Int32Array (with 2 elements)</td></tr> | |
| 2279 <tr><td>bvec2</td><td>boolean[] (with 2 elements)</td></tr> | |
| 2280 <tr><td>vec3</td><td>Float32Array (with 3 elements)</td></tr> | |
| 2281 <tr><td>ivec3</td><td>Int32Array (with 3 elements)</td></tr> | |
| 2282 <tr><td>bvec3</td><td>boolean[] (with 3 elements)</td></tr> | |
| 2283 <tr><td>vec4</td><td>Float32Array (with 4 elements)</td></tr> | |
| 2284 <tr><td>ivec4</td><td>Int32Array (with 4 elements)</td></tr> | |
| 2285 <tr><td>bvec4</td><td>boolean[] (with 4 elements)</td></tr> | |
| 2286 <tr><td>mat2</td><td>Float32Array (with 4 elements)</td></tr> | |
| 2287 <tr><td>mat3</td><td>Float32Array (with 9 elements)</td></tr> | |
| 2288 <tr><td>mat4</td><td>Float32Array (with 16 elements)</td></tr> | |
| 2289 </table> | |
| 2290 <dt class="idl-code">WebGLUniformLocation getUniformLocation(WebGLProgra
m program, DOMString name) | |
| 2291 <span class="gl-spec">(OpenGL ES 2.0 §2.10.4, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glGetUniformLocation.xml">man page</a>)
</span> | |
| 2292 <dd> | |
| 2293 Return a WebGLUniformLocation object that represents the location of
a specific uniform variable | |
| 2294 within a program object. The return value is null if name does not c
orrespond to an active uniform | |
| 2295 variable in the passed program. | |
| 2296 | |
| 2297 <dt class="idl-code">any getVertexAttrib(GLuint index, GLenum pname) | |
| 2298 <span class="gl-spec">(OpenGL ES 2.0 §6.1.8, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glGetVertexAttrib.xml">man page</a>)</sp
an> | |
| 2299 <dd> | |
| 2300 Return the information requested in pname about the vertex attribute
at the passed index. The | |
| 2301 type returned is dependent on the information requested, as shown in
the following table: | |
| 2302 <table class="foo"> | |
| 2303 <tr><th>pname</th><th>returned type</th></tr> | |
| 2304 <tr><td>VERTEX_ATTRIB_ARRAY_BUFFER_BINDING</td><td>WebGLBuffer</
td></tr> | |
| 2305 <tr><td>VERTEX_ATTRIB_ARRAY_ENABLED</td><td>boolean</td></tr> | |
| 2306 <tr><td>VERTEX_ATTRIB_ARRAY_SIZE</td><td>long</td></tr> | |
| 2307 <tr><td>VERTEX_ATTRIB_ARRAY_STRIDE</td><td>long</td></tr> | |
| 2308 <tr><td>VERTEX_ATTRIB_ARRAY_TYPE</td><td>unsigned long</td></tr> | |
| 2309 <tr><td>VERTEX_ATTRIB_ARRAY_NORMALIZED</td><td>boolean</td></tr> | |
| 2310 <tr><td>CURRENT_VERTEX_ATTRIB</td><td>Float32Array (with 4 eleme
nts)</td></tr> | |
| 2311 </table> | |
| 2312 <dt class="idl-code">GLsizeiptr getVertexAttribOffset(GLuint index, GLen
um pname) | |
| 2313 <span class="gl-spec">(OpenGL ES 2.0 §6.1.8, similar to <a href
="http://www.khronos.org/opengles/sdk/2.0/docs/man/glGetVertexAttribPointerv.xml
">man page</a>)</span> | |
| 2314 <dt><p class="idl-code">void uniform[1234][fi](WebGLUniformLocation loca
tion, ...)</p> | |
| 2315 <p class="idl-code">void uniform[1234][fi]v(WebGLUniformLocation loc
ation, ...) | |
| 2316 <p class="idl-code">void uniformMatrix[234]fv(WebGLUniformLocation l
ocation, GLboolean transpose, ...) | |
| 2317 <span class="gl-spec">(OpenGL ES 2.0 §2.10.4, <a href="http://w
ww.khronos.org/opengles/sdk/2.0/docs/man/glUniform.xml">man page</a>)</span></p> | |
| 2318 <dd> | |
| 2319 Each of the uniform* functions above sets the specified uniform or u
niforms to the | |
| 2320 values provided. If the passed <code>location</code> is not null and
was not obtained | |
| 2321 from the currently used program via an earlier call to <code>getUnif
ormLocation</code>, | |
| 2322 an <code>INVALID_OPERATION</code> error will be generated. If the pa
ssed | |
| 2323 <code>location</code> is null, the data passed in will be silently i
gnored and | |
| 2324 no uniform variables will be changed. | |
| 2325 <dt><p class="idl-code">void vertexAttrib[1234]f(GLuint indx, ...)</p> | |
| 2326 <p class="idl-code">void vertexAttrib[1234]fv(GLuint indx, ...) | |
| 2327 <span class="gl-spec">(OpenGL ES 2.0 §2.7, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glVertexAttrib.xml">man page</a>)</span></
p> | |
| 2328 <dd> | |
| 2329 Sets the vertex attribute at the passed index to the given constant v
alue. Values set via the | |
| 2330 <code>vertexAttrib</code> are guaranteed to be returned from the <cod
e>getVertexAttrib</code> function | |
| 2331 with the <code>CURRENT_VERTEX_ATTRIB</code> param, even if there have
been intervening calls to | |
| 2332 <code>drawArrays</code> or <code>drawElements</code>. | |
| 2333 <dt class="idl-code">void vertexAttribPointer(GLuint indx, GLint size, GL
enum type, | |
| 2334 GLboolean normalized, GLsizei stride, GLsizeiptr off
set) | |
| 2335 <span class="gl-spec">(OpenGL ES 2.0 §2.8, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glVertexAttribPointer.xml">man page</a>)</
span> | |
| 2336 <dd> | |
| 2337 Assign the WebGLBuffer object currently bound to the ARRAY_BUFFER ta
rget to the vertex | |
| 2338 attribute at the passed index. Size is number of components per attr
ibute. Stride and | |
| 2339 offset are in units of bytes. Passed stride and offset must be appro
priate for the | |
| 2340 passed type and size or an <code>INVALID_VALUE</code> error will be | |
| 2341 generated; see <a href="#BUFFER_OFFSET_AND_STRIDE">Buffer Offset and
Stride | |
| 2342 Requirements</a>. If no WebGLBuffer is bound to the ARRAY_BUFFER tar
get, | |
| 2343 an <code>INVALID_OPERATION</code> error will be generated. In WebGL,
the maximum | |
| 2344 supported stride is 255; see <a href="#VERTEX_STRIDE"> Vertex Attrib
ute Data Stride</a>. | |
| 2345 </dl> | |
| 2346 | |
| 2347 <!-- ===========================================================================
============================ --> | |
| 2348 | |
| 2349 <h4>Writing to the drawing buffer</h4> | |
| 2350 | |
| 2351 <p> | |
| 2352 OpenGL ES 2.0 has 3 calls which can render to the drawing buffer: <code>
clear</code>, | |
| 2353 <code>drawArrays</code> and <code>drawElements</code>. Furthermore rende
ring can | |
| 2354 be directed to the drawing buffer or to a Framebuffer object. When rende
ring is | |
| 2355 directed to the drawing buffer, making any of the 3 rendering calls shal
l | |
| 2356 cause the drawing buffer to be presented to the HTML page compositor at
the start | |
| 2357 of the next compositing operation. | |
| 2358 </p> | |
| 2359 | |
| 2360 <dl class="methods"> | |
| 2361 <dt class="idl-code">void clear(GLbitfield mask) | |
| 2362 <span class="gl-spec">(OpenGL ES 2.0 §4.2.3, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glClear.xml">man page</a>)</span> | |
| 2363 <dt class="idl-code">void drawArrays(GLenum mode, GLint first, GLsizei c
ount) | |
| 2364 <span class="gl-spec">(OpenGL ES 2.0 §2.8, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glDrawArrays.xml">man page</a>)</span> | |
| 2365 <dd> | |
| 2366 If <em>first</em> is negative, an <code>INVALID_VALUE</code> error w
ill be generated. | |
| 2367 <dt class="idl-code">void drawElements(GLenum mode, GLsizei count, GLenu
m type, GLsizeiptr offset) | |
| 2368 <span class="gl-spec">(OpenGL ES 2.0 §2.8, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glDrawElements.xml">man page</a>)</span> | |
| 2369 <dd> | |
| 2370 Draw using the currently bound element array buffer. The given offs
et is in bytes, and | |
| 2371 must be a valid multiple of the size of the given type or an <code>I
NVALID_VALUE</code> | |
| 2372 error will be generated; see <a href="#BUFFER_OFFSET_AND_STRIDE">Buf
fer Offset and Stride | |
| 2373 Requirements</a>. If <code>count</code> is greater than zero, then a
non-null | |
| 2374 <code>WebGLBuffer</code> must be bound to the <code>ELEMENT_ARRAY_BU
FFER</code> binding | |
| 2375 point or an <code>INVALID_OPERATION</code> error will be generated.<
br><br> | |
| 2376 | |
| 2377 WebGL performs additional error checking beyond that specified in Op
enGL ES 2.0 during | |
| 2378 calls to <code>drawArrays</code> | |
| 2379 and <code>drawElements</code>. See <a href="#ATTRIBS_AND_RANGE_CHECK
ING">Enabled Vertex | |
| 2380 Attributes and Range Checking</a>. | |
| 2381 <dt class="idl-code">void finish() | |
| 2382 <span class="gl-spec">(OpenGL ES 2.0 §5.1, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glFinish.xml">man page</a>)</span> | |
| 2383 <dt class="idl-code">void flush() | |
| 2384 <span class="gl-spec">(OpenGL ES 2.0 §5.1, <a href="http://www.
khronos.org/opengles/sdk/2.0/docs/man/glFlush.xml">man page</a>)</span> | |
| 2385 </dl> | |
| 2386 | |
| 2387 <!-- ===========================================================================
============================ --> | |
| 2388 | |
| 2389 <h4><a name="readpixels">Reading back pixels</a></h4> | |
| 2390 | |
| 2391 <p> | |
| 2392 Pixels in the current framebuffer can be read back into an ArrayBufferVi
ew object. | |
| 2393 </p> | |
| 2394 | |
| 2395 <dl class="methods"> | |
| 2396 <dt class="idl-code">void readPixels(GLint x, GLint y, GLsizei width, GL
sizei height, | |
| 2397 GLenum format, GLenum type, ArrayBufferView pixels) | |
| 2398 <span class="gl-spec">(OpenGL ES 2.0 §4.3.1, <a href="http://ww
w.khronos.org/opengles/sdk/2.0/docs/man/glReadPixels.xml">man page</a>)</span> | |
| 2399 <dd> | |
| 2400 Fills <code>pixels</code> with the pixel data in the specified recta
ngle of the frame | |
| 2401 buffer. The data returned from readPixels must be up-to-date as of t
he most recently | |
| 2402 sent drawing command. | |
| 2403 <br><br> | |
| 2404 | |
| 2405 The type of <code>pixels</code> must match the type of the data to b
e read. For example, | |
| 2406 if it is UNSIGNED_BYTE, a Uint8Array must be supplied; if it is UNSI
GNED_SHORT_5_6_5, | |
| 2407 UNSIGNED_SHORT_4_4_4_4, or UNSIGNED_SHORT_5_5_5_1, a Uint16Array mus
t be supplied. If | |
| 2408 the types do not match, an INVALID_OPERATION error is generated. | |
| 2409 <br><br> | |
| 2410 | |
| 2411 The following are the allowed format and type combinations: | |
| 2412 | |
| 2413 <table class="foo"> | |
| 2414 <tr><th>format</th><th>type</th></tr> | |
| 2415 <tr><td>RGBA</td><td>UNSIGNED_BYTE</td></tr> | |
| 2416 </table> | |
| 2417 | |
| 2418 If <code>pixels</code> is null, an INVALID_VALUE error is generated.
If | |
| 2419 <code>pixels</code> is non-null, but is not large enough to retrieve
all of the pixels | |
| 2420 in the specified rectangle taking into account pixel store modes, an
INVALID_OPERATION | |
| 2421 value is generated. | |
| 2422 <br><br> | |
| 2423 | |
| 2424 For any pixel lying outside the frame buffer, the value read contain
s 0 in all channels. | |
| 2425 <br><br> | |
| 2426 | |
| 2427 </dl> | |
| 2428 | |
| 2429 <!-- ===========================================================================
============================ --> | |
| 2430 | |
| 2431 <h4>Detecting context lost events</h4> | |
| 2432 | |
| 2433 <p> | |
| 2434 Occurrences such as power events on mobile devices may cause the WebGL r
endering context to | |
| 2435 be lost at any time and require the application to rebuild it; | |
| 2436 see <a href="#WEBGLCONTEXTEVENT">WebGLContextEvent</a> for more details.
The | |
| 2437 following method assists in detecting context lost events. | |
| 2438 </p> | |
| 2439 | |
| 2440 <dl class="methods"> | |
| 2441 <dt class="idl-code">boolean isContextLost() | |
| 2442 <dd> | |
| 2443 Returns true if the context is in the lost state. | |
| 2444 </dl> | |
| 2445 | |
| 2446 <!-- ===========================================================================
============================ --> | |
| 2447 | |
| 2448 <h4>Detecting and enabling extensions</h4> | |
| 2449 | |
| 2450 <p> | |
| 2451 An implementation of WebGL must not support any additional parameters, c
onstants or functions | |
| 2452 without first enabling that functionality through the extension mechanis
m. The | |
| 2453 <code>getSupportedExtensions</code> function returns an array of the ext
ension strings supported | |
| 2454 by this implementation. Extension strings are case-insensitive. An exten
sion is enabled by | |
| 2455 passing one of those strings to the <code>getExtension</code> function.
This call returns an | |
| 2456 object which contains any constants or functions defined by that extensi
on. The definition of | |
| 2457 that object is specific to the extension and must be defined by the exte
nsion specification. | |
| 2458 </p> | |
| 2459 <p> | |
| 2460 Once an extension is enabled, no mechanism is provided to disable it. Mu
ltiple calls to | |
| 2461 <code>getExtension</code> with the same extension string shall return th
e same object. An | |
| 2462 attempt to use any features of an extension without first calling getExt
ension to enable it | |
| 2463 must generate an appropriate GL error and must not make use of the featu
re. | |
| 2464 </p> | |
| 2465 <p> | |
| 2466 This specification does not define any extensions. A separate <a href="#
refsREGISTRY">WebGL | |
| 2467 extension registry</a> defines extensions that may be supported by a par
ticular WebGL | |
| 2468 implementation. | |
| 2469 </p> | |
| 2470 | |
| 2471 <dl class="methods"> | |
| 2472 <dt class="idl-code">DOMString[ ] getSupportedExtensions() | |
| 2473 <dd> | |
| 2474 Returns an array of all the supported extension strings. Any string
in this list, when | |
| 2475 passed to <code>getExtension</code> must return a valid object. Any
other string passed to | |
| 2476 <code>getExtension</code> must return null. | |
| 2477 | |
| 2478 <dt class="idl-code">object getExtension(DOMString name) | |
| 2479 <dd> | |
| 2480 Returns an object if the passed extension is supported, or null if n
ot. The object | |
| 2481 returned from <code>getExtension</code> contains any constants or fu
nctions used by the | |
| 2482 extension, if any. A returned object may have no constants or functi
ons if the extension does | |
| 2483 not define any, but a unique object must still be returned. That obj
ect is used to indicate | |
| 2484 that the extension has been enabled. | |
| 2485 </dl> | |
| 2486 | |
| 2487 <!-- ===========================================================================
============================ --> | |
| 2488 | |
| 2489 <h3><a name="WEBGLCONTEXTEVENT">WebGLContextEvent</a></h3> | |
| 2490 | |
| 2491 <p> | |
| 2492 WebGL generates a WebGLContextEvent event in response to a status change
to the WebGL rendering context | |
| 2493 associated with the HTMLCanvasElement which has a listener for this even
t. Events are sent using | |
| 2494 the <a href="http://www.w3.org/TR/DOM-Level-2-Events/events.html">DOM Ev
ent System</a>. Event types can | |
| 2495 include the loss or restoration of state, or the inability to create a c
ontext. | |
| 2496 </p> | |
| 2497 <pre class="idl"> | |
| 2498 interface <dfn id="WebGLContextLostEvent">WebGLContextEvent</dfn> : Event { | |
| 2499 readonly attribute DOMString statusMessage; | |
| 2500 | |
| 2501 void initWebGLContextEvent(DOMString typeArg, | |
| 2502 boolean canBubbleArg, | |
| 2503 boolean cancelableArg, | |
| 2504 DOMString statusMessageArg); | |
| 2505 };</pre> | |
| 2506 | |
| 2507 <h4>Attributes</h4> | |
| 2508 | |
| 2509 <p> | |
| 2510 The following attributes are available: | |
| 2511 </p> | |
| 2512 | |
| 2513 <dl class="methods"> | |
| 2514 <dt><span class="prop-name"><code>statusMessage</code></span> of type <c
ode>DOMString</code> | |
| 2515 <dd> | |
| 2516 A string containing additional information, or the empty string if n
o additional information | |
| 2517 is available. | |
| 2518 </dl> | |
| 2519 | |
| 2520 <h4>Methods</h4> | |
| 2521 | |
| 2522 <p> | |
| 2523 The following methods are available: | |
| 2524 </p> | |
| 2525 | |
| 2526 <dl class="methods"> | |
| 2527 <dt class="idl-code">void initWebGLContextEvent(DOMString typeArg, boole
an canBubbleArg, boolean cancelableArg, | |
| 2528 DOMString statusMessageA
rg) | |
| 2529 <dd> | |
| 2530 Initialize the event created through the | |
| 2531 <a href="http://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-
Event">Event</a> | |
| 2532 interface. This method may only be called before the event has been
dispatched via | |
| 2533 the <code>dispatchEvent</code> method, though it may be called multi
ple times during | |
| 2534 that phase if necessary. If called multiple times, the final invocat
ion takes | |
| 2535 precedence. | |
| 2536 <P> | |
| 2537 <b>Parameters</b> | |
| 2538 <dl> | |
| 2539 <dt><code>typeArg</code> of type <code>DOMString</code> | |
| 2540 <dd>Specifies the event type (see below). | |
| 2541 <dt><code>canBubbleArg</code> of type <code>boolean</code> | |
| 2542 <dd>Specifies whether or not the event can bubble. | |
| 2543 <dt><code>cancelableArg</code> of type <code>boolean</code> | |
| 2544 <dd>Specifies whether or not the event can be canceled. | |
| 2545 <dt><code>statusMessageArg</code> of type <code>DOMString</code> | |
| 2546 <dd>A string containing additional information, or the empty str
ing if no additional information is available. | |
| 2547 </dl> | |
| 2548 <b>No Return Value</b><br> | |
| 2549 <b>No Exceptions</b><br> | |
| 2550 </dl> | |
| 2551 | |
| 2552 <h4>Event Types</h4> | |
| 2553 | |
| 2554 <dl class="methods"> | |
| 2555 <dt class="idl-code">webglcontextlost | |
| 2556 <dd> | |
| 2557 This event occurs when some system activity external to WebGL causes
the rendering context | |
| 2558 associated with the HTMLCanvasElement receiving the event to lose al
l of its state. When this | |
| 2559 event type is delivered, the associated context is in a "lost" state
. While the context is | |
| 2560 in the lost state: | |
| 2561 | |
| 2562 <ul> | |
| 2563 <li> The context's <code>isContextLost</code> method returns <code>true<
/code>.<br> | |
| 2564 <li> All methods returning <code>void</code> return immediately.<br> | |
| 2565 <li> All methods returning nullable values or <code>any</code> return <c
ode>null</code>.<br> | |
| 2566 <li> <code>checkFramebufferStatus</code> returns <code>FRAMEBUFFER_UNSUP
PORTED</code>.<br> | |
| 2567 <li> <code>getAttribLocation</code> returns <code>-1</code>.<br> | |
| 2568 <li> <code>getError</code> returns <code>CONTEXT_LOST_WEBGL</code> the f
irst time it is | |
| 2569 called while the context is lost. Afterward it will return <code>NO
_ERROR</code> until | |
| 2570 the context has been restored.<br> | |
| 2571 <li> <code>getVertexAttribOffset</code> returns <code>0</code>.<br> | |
| 2572 <li> All <code>is</code> queries return <code>false</code>.<br> | |
| 2573 </ul> | |
| 2574 <p> | |
| 2575 See the <code>webglcontextrestored</code> event type for information
on | |
| 2576 resuming rendering after the context has been lost. | |
| 2577 <p><p> | |
| 2578 The <code>statusMessage</code> attribute is always the empty string
for this event. | |
| 2579 </dl> | |
| 2580 | |
| 2581 <dl class="methods"> | |
| 2582 <dt class="idl-code">webglcontextrestored | |
| 2583 <dd> | |
| 2584 This event occurs when the WebGL implementation determines that a pr
eviously lost context can | |
| 2585 be restored. The system only restores the context if a handler for t
he | |
| 2586 <code>webglcontextrestored</code> event is installed on the HTMLCanv
asElement associated with | |
| 2587 the context. | |
| 2588 <p><p> | |
| 2589 Once the context is restored, WebGL resources such as textures and b
uffers that were created | |
| 2590 before the context was lost are no longer valid. The application mus
t reinitialize the | |
| 2591 context's state and recreate all such resources. | |
| 2592 <p><p> | |
| 2593 The <code>statusMessage</code> attribute is always the empty string
for this event. | |
| 2594 </dl> | |
| 2595 | |
| 2596 <dl class="methods"> | |
| 2597 <dt class="idl-code">webglcontextcreationerror | |
| 2598 <dd> | |
| 2599 This event occurs in response to a call to <code>getContext()</code>
on the HTMLCanvasElement | |
| 2600 receiving the event, when some error occurs during that call. When s
uch an error occurs | |
| 2601 the <code>getContext()</code> returns with a <code>null</code> value
. Later, at the normal | |
| 2602 event delivery time, this event is delivered with the details of the
failure. If the | |
| 2603 HTMLCanvasElement is listening for this event, it will be delivered
whenever | |
| 2604 <code>getContext()</code> returns <code>null</code>. | |
| 2605 <p> | |
| 2606 The <code>statusMessage</code> attribute may contain a platform depe
ndent string about the nature | |
| 2607 of the failure. | |
| 2608 </dl> | |
| 2609 | |
| 2610 <div class="example"> | |
| 2611 The following ECMAScript example shows how to register event listeners on a
Canvas called | |
| 2612 <code>canvas1</code> which will receive context lost and restored events and
restart the | |
| 2613 application. For completeness, it illustrates how an application performing
asynchronous image | |
| 2614 loading would handle a context lost event at an arbitrary point in time. | |
| 2615 <pre> | |
| 2616 window.onload = init; | |
| 2617 | |
| 2618 var g_gl; | |
| 2619 var g_canvas; | |
| 2620 var g_intervalId; | |
| 2621 var g_images = []; | |
| 2622 var g_imgURLs = [ | |
| 2623 "someimage.jpg", | |
| 2624 "someotherimage.jpg", | |
| 2625 "yetanotherimage.png" | |
| 2626 ]; | |
| 2627 | |
| 2628 function init() { | |
| 2629 g_canvas = document.getElementById("canvas1"); | |
| 2630 g_canvas.addEventListener("webglcontextlost", contextLostHandler, false); | |
| 2631 g_canvas.addEventListener("webglcontextrestored", contextRestoredHandler, fals
e); | |
| 2632 g_gl = canvas.getContext("webgl"); | |
| 2633 | |
| 2634 for (var ii = 0; ii < g_imgURLs.length; ++ii) { | |
| 2635 // Create an image tag. | |
| 2636 var image = document.createElement('img'); | |
| 2637 | |
| 2638 // Create a texture for this image. | |
| 2639 image.texture = g_gl.createTexture(); | |
| 2640 | |
| 2641 // Mark the image as not loaded. | |
| 2642 image.loaded = false; | |
| 2643 | |
| 2644 // Setup a load callback. | |
| 2645 image.onload = (function(image) { | |
| 2646 return function() { | |
| 2647 imageLoadedHandler(image); | |
| 2648 }; | |
| 2649 }(image)); | |
| 2650 | |
| 2651 // Start the image loading. | |
| 2652 image.src = g_imgURLs[ii]; | |
| 2653 | |
| 2654 // Remember the image. | |
| 2655 g_images.push(image); | |
| 2656 } | |
| 2657 | |
| 2658 g_intervalId = window.setInterval(renderHandler, 1000/60); | |
| 2659 } | |
| 2660 | |
| 2661 function renderHandler() { | |
| 2662 // draw with textures. | |
| 2663 // ... | |
| 2664 } | |
| 2665 | |
| 2666 function imageLoadedHandler(image) { | |
| 2667 // Mark the image as loaded. | |
| 2668 image.loaded = true; | |
| 2669 | |
| 2670 // Copy the image to the texture. | |
| 2671 updateTexture(image); | |
| 2672 } | |
| 2673 | |
| 2674 function updateTexture(image) { | |
| 2675 if (!g_gl.isContextLost() && image.loaded) { | |
| 2676 g_gl.bindTexture(g_gl.TEXTURE_2D, image.texture); | |
| 2677 g_gl.texImage2D(g_gl.TEXTURE_2D, 0, image); | |
| 2678 } | |
| 2679 } | |
| 2680 | |
| 2681 function contextLostHandler() { | |
| 2682 // stop rendering. | |
| 2683 window.clearInterval(g_internvalId); | |
| 2684 } | |
| 2685 | |
| 2686 function contextRestoredHandler() { | |
| 2687 // create new textures for all images and restore their contents. | |
| 2688 for (var ii = 0; ii < g_images.length; ++ii) { | |
| 2689 g_images[ii].texture = g_gl.createTexture(); | |
| 2690 updateTexture(g_images[ii]); | |
| 2691 } | |
| 2692 | |
| 2693 // Start rendering again. | |
| 2694 g_intervalId = window.setInterval(renderHandler, 1000/60); | |
| 2695 } | |
| 2696 </pre> | |
| 2697 </div> | |
| 2698 | |
| 2699 <!-- ===========================================================================
============================ --> | |
| 2700 | |
| 2701 <h2><a name="webgl_gl_differences">Differences Between WebGL and OpenGL ES 2
.0</a></h2> | |
| 2702 | |
| 2703 <p> | |
| 2704 | |
| 2705 This section describes changes made to the WebGL API relative to the OpenGL ES 2
.0 API to improve | |
| 2706 portability across various operating systems and devices. | |
| 2707 | |
| 2708 </p> | |
| 2709 | |
| 2710 <h3>Buffer Object Binding</h3> | |
| 2711 | |
| 2712 <p> | |
| 2713 | |
| 2714 In the WebGL API, a given buffer object may only be bound to one of the <code>AR
RAY_BUFFER</code> or | |
| 2715 <code>ELEMENT_ARRAY_BUFFER</code> binding points in its lifetime. This restricti
on implies that a | |
| 2716 given buffer object may contain either vertices or indices, but not both. | |
| 2717 | |
| 2718 </p> | |
| 2719 <p> | |
| 2720 | |
| 2721 The type of a WebGLBuffer is initialized the first time it is passed as an argum
ent | |
| 2722 to <code>bindBuffer</code>. A subsequent call to <code>bindBuffer</code> which a
ttempts to bind the | |
| 2723 same WebGLBuffer to the other binding point will generate an <code>INVALID_OPERA
TION</code> error, and | |
| 2724 the state of the binding point will remain untouched. | |
| 2725 | |
| 2726 </p> | |
| 2727 | |
| 2728 <h3>No Client Side Arrays</h3> | |
| 2729 | |
| 2730 <p> | |
| 2731 | |
| 2732 The WebGL API does not support client-side arrays. If <code>vertexAttribPointer<
/code> is called | |
| 2733 without a <code>WebGLBuffer</code> bound to the <code>ARRAY_BUFFER</code> bindin
g point, | |
| 2734 an <code>INVALID_OPERATION</code> error is generated. If <code>drawElements</cod
e> is called with | |
| 2735 a <code>count</code> greater than zero, and no <code>WebGLBuffer</code> is bound
to | |
| 2736 the <code>ELEMENT_ARRAY_BUFFER</code> binding point, an <code>INVALID_OPERATION<
/code> error is | |
| 2737 generated. | |
| 2738 | |
| 2739 </p> | |
| 2740 | |
| 2741 <h3><a name="BUFFER_OFFSET_AND_STRIDE">Buffer Offset and Stride Requirements
</a></h3> | |
| 2742 | |
| 2743 <p> | |
| 2744 | |
| 2745 The <code>offset</code> arguments to <code>drawElements</code> and <code>vertexA
ttribPointer</code>, | |
| 2746 and the <code>stride</code> argument to <code>vertexAttribPointer</code>, must b
e a multiple of the | |
| 2747 size of the data type passed to the call, or an <code>INVALID_OPERATION</code> e
rror is generated. | |
| 2748 | |
| 2749 </p> | |
| 2750 | |
| 2751 | |
| 2752 <h3><a name="ATTRIBS_AND_RANGE_CHECKING">Enabled Vertex Attributes and Range
Checking</a></h3> | |
| 2753 | |
| 2754 <p> | |
| 2755 | |
| 2756 If a vertex attribute is enabled as an array via <code>enableVertexAttribArray</
code> but no buffer | |
| 2757 is bound to that attribute via <code>bindBuffer</code> and <code>vertexAttribPoi
nter</code>, then | |
| 2758 calls to <code>drawArrays</code> or <code>drawElements</code> will generate an | |
| 2759 <code>INVALID_OPERATION</code> error. | |
| 2760 | |
| 2761 </p> | |
| 2762 <p> | |
| 2763 | |
| 2764 If a vertex attribute is enabled as an array, a buffer is bound to that attribut
e, and the attribute | |
| 2765 is consumed by the current program, then calls to <code>drawArrays</code> | |
| 2766 and <code>drawElements</code> will verify that each referenced vertex lies withi
n the storage of the | |
| 2767 bound buffer. If the range specified in <code>drawArrays</code> or any reference
d index | |
| 2768 in <code>drawElements</code> lies outside the storage of the bound buffer, an IN
VALID_OPERATION | |
| 2769 error is generated and no geometry is drawn. | |
| 2770 | |
| 2771 </p> | |
| 2772 <p> | |
| 2773 | |
| 2774 If a vertex attribute is enabled as an array, a buffer is bound to that attribut
e, but the attribute | |
| 2775 is not consumed by the current program, then regardless of the size of the bound
buffer, it will not | |
| 2776 cause any error to be generated during a call to <code>drawArrays</code> | |
| 2777 or <code>drawElements</code>. | |
| 2778 | |
| 2779 </p> | |
| 2780 | |
| 2781 <h3>Framebuffer Object Attachments</h3> | |
| 2782 | |
| 2783 <p> | |
| 2784 | |
| 2785 WebGL adds the <code>DEPTH_STENCIL_ATTACHMENT</code> framebuffer object attachme
nt point and | |
| 2786 the <code>DEPTH_STENCIL</code> renderbuffer internal format. To attach both dept
h and stencil | |
| 2787 buffers to a framebuffer object, call <code>renderbufferStorage</code> with | |
| 2788 the <code>DEPTH_STENCIL</code> internal format, and then call <code>framebufferR
enderbuffer</code> | |
| 2789 with the <code>DEPTH_STENCIL_ATTACHMENT</code> attachment point. | |
| 2790 | |
| 2791 </p> | |
| 2792 <p> | |
| 2793 | |
| 2794 A renderbuffer attached to the <code>DEPTH_ATTACHMENT</code> attachment point mu
st be allocated with | |
| 2795 the <code>DEPTH_COMPONENT16</code> internal format. A renderbuffer attached to | |
| 2796 the <code>STENCIL_ATTACHMENT</code> attachment point must be allocated with | |
| 2797 the <code>STENCIL_INDEX8</code> internal format. A renderbuffer attached to | |
| 2798 the <code>DEPTH_STENCIL_ATTACHMENT</code> attachment point must be allocated wit
h | |
| 2799 the <code>DEPTH_STENCIL</code> internal format. | |
| 2800 | |
| 2801 </p> | |
| 2802 <p> | |
| 2803 | |
| 2804 In the WebGL API, it is an error to concurrently attach renderbuffers to the fol
lowing combinations | |
| 2805 of attachment points: | |
| 2806 | |
| 2807 <ul> | |
| 2808 <li> <code>DEPTH_ATTACHMENT + DEPTH_STENCIL_ATTACHMENT</code> | |
| 2809 <li> <code>STENCIL_ATTACHMENT + DEPTH_STENCIL_ATTACHMENT</code> | |
| 2810 <li> <code>DEPTH_ATTACHMENT + STENCIL_ATTACHMENT</code> | |
| 2811 </ul> | |
| 2812 | |
| 2813 If any of the constraints above are violated, then: | |
| 2814 | |
| 2815 <ul> | |
| 2816 <li> <code>checkFramebufferStatus</code> must return <code>FRAMEBUFFER_UNSUPPORT
ED</code>. | |
| 2817 <li> The following calls, which either modify or read the framebuffer, must gene
rate | |
| 2818 an <code>INVALID_FRAMEBUFFER_OPERATION</code> error and return early, leavi
ng the contents of | |
| 2819 the framebuffer, destination texture or destination memory untouched. | |
| 2820 <ul> | |
| 2821 <li> clear | |
| 2822 <li> copyTexImage2D | |
| 2823 <li> copyTexSubImage2D | |
| 2824 <li> drawArrays | |
| 2825 <li> drawElements | |
| 2826 <li> readPixels | |
| 2827 </ul> | |
| 2828 </ul> | |
| 2829 | |
| 2830 <h3><a name="PIXEL_STORAGE_PARAMETERS">Pixel Storage Parameters</a></h3> | |
| 2831 | |
| 2832 <p> | |
| 2833 The WebGL API supports the following additional parameters to <code>pixelStorei<
/code>. | |
| 2834 | |
| 2835 <dl> | |
| 2836 <dt><code>UNPACK_FLIP_Y_WEBGL</code> of type <code>boolean</code> | |
| 2837 <dd>If set, then during any subsequent calls to <code>texImage2D</code> or | |
| 2838 <code>texSubImage2D</code>, the source data is flipped along the vertical axis,
so that conceptually | |
| 2839 the last row is the first one transferred. The default value is <code>false</cod
e>. Any non-zero | |
| 2840 value is interpreted as <code>true</code>. | |
| 2841 | |
| 2842 <dt><code>UNPACK_PREMULTIPLY_ALPHA_WEBGL</code> of type <code>boolean</code> | |
| 2843 <dd>If set, then during any subsequent calls to <code>texImage2D</code> | |
| 2844 or <code>texSubImage2D</code>, the alpha channel of the source data, if present,
is multiplied into | |
| 2845 the color channels during the data transfer. The default value is <code>false</c
ode>. Any non-zero | |
| 2846 value is interpreted as <code>true</code>. | |
| 2847 | |
| 2848 <dt><code>UNPACK_COLORSPACE_CONVERSION_WEBGL</code> of type <code>unsigned long<
/code> | |
| 2849 <dd>If set to <code>BROWSER_DEFAULT_WEBGL</code>, then the browser's default col
orspace conversion | |
| 2850 is applied during subsequent <code>texImage2D</code> and <code>texSubImage2D</co
de> calls | |
| 2851 taking <code>HTMLImageElement</code>. The precise conversions may be specific to
both the browser | |
| 2852 and file type. If set to <code>NONE</code>, no colorspace conversion is applied.
The default value | |
| 2853 is <code>BROWSER_DEFAULT_WEBGL</code>. | |
| 2854 | |
| 2855 </dl> | |
| 2856 | |
| 2857 <h3><a name="STENCIL_SEPARATE_LIMIT">Stencil Separate Mask and Reference Value</
a></h3> | |
| 2858 | |
| 2859 <p> | |
| 2860 In the WebGL API it is illegal to specify a different mask or reference value fo
r front facing and | |
| 2861 back facing triangles in stencil operations. A call to <code>drawArrays</code> | |
| 2862 or <code>drawElements</code> will generate an <code>INVALID_OPERATION</code> err
or if: | |
| 2863 | |
| 2864 <ul> | |
| 2865 <li> <code>STENCIL_WRITEMASK</code> != <code>STENCIL_BACK_WRITEMASK</code> (as s
pecified by <code>stencilMaskSeparate</code> for the <code>mask</code> parameter
associated with the FRONT and BACK values of <code>face</code>, respectively) | |
| 2866 <li> <code>STENCIL_VALUE_MASK</code> != <code>STENCIL_BACK_VALUE_MASK</code> (as
specified by <code>stencilFuncSeparate</code> for the <code>mask</code> paramet
er associated with the FRONT and BACK values of <code>face</code>, respectively) | |
| 2867 <li> <code>STENCIL_REF</code> != <code>STENCIL_BACK_REF</code> (as specified by
<code>stencilFuncSeparate</code> for the <code>ref</code> parameter associated w
ith the FRONT and BACK values of <code>face</code>, respectively) | |
| 2868 </ul> | |
| 2869 | |
| 2870 </p> | |
| 2871 | |
| 2872 <h3><a name="VERTEX_STRIDE">Vertex Attribute Data Stride</a></h3> | |
| 2873 | |
| 2874 <p> | |
| 2875 The WebGL API supports vertex attribute data strides up to 255 bytes. A call to | |
| 2876 <code>vertexAttribPointer</code> will generate an <code>INVALID_VALUE</code> err
or if the value for | |
| 2877 the stride parameter exceeds 255. | |
| 2878 </p> | |
| 2879 | |
| 2880 <h3><a name="VIEWPORT_DEPTH_RANGE">Viewport Depth Range</a></h3> | |
| 2881 | |
| 2882 <p> | |
| 2883 The WebGL API does not support depth ranges with where the near plane is mapped
to a value greater | |
| 2884 than that of the far plane. A call to <code>depthRange</code> will generate an | |
| 2885 <code>INVALID_OPERATION</code> error if <code>zNear</code> is greater than <code
>zFar</code>. | |
| 2886 </p> | |
| 2887 | |
| 2888 <h3><a name="CONSTANT_COLOR_BLEND">Blending With Constant Color</a></h3> | |
| 2889 | |
| 2890 <p> | |
| 2891 In the WebGL API, constant color and constant alpha cannot be used together as s
ource and | |
| 2892 destination factors in the blend function. A call to <code>blendFunc</code> will
generate an | |
| 2893 <code>INVALID_OPERATION</code> error if one of the two factors is set to <code>C
ONSTANT_COLOR</code> | |
| 2894 or <code>ONE_MINUS_CONSTANT_COLOR</code> and the other to <code>CONSTANT_ALPHA</
code> or | |
| 2895 <code>ONE_MINUS_CONSTANT_ALPHA</code>. A call to <code>blendFuncSeparate</code>
will generate an | |
| 2896 <code>INVALID_OPERATION</code> error if <code>srcRGB</code> is set to <code>CONS
TANT_COLOR</code> | |
| 2897 or <code>ONE_MINUS_CONSTANT_COLOR</code> and <code>dstRGB</code> is set to <code
>CONSTANT_ALPHA</code> or | |
| 2898 <code>ONE_MINUS_CONSTANT_ALPHA</code> or vice versa. | |
| 2899 </p> | |
| 2900 | |
| 2901 <h3>Fixed point support</h3> | |
| 2902 | |
| 2903 The WebGL API does not support the <code>GL_FIXED</code> data type. | |
| 2904 | |
| 2905 <h3>GLSL Constructs</h3> | |
| 2906 | |
| 2907 <p> | |
| 2908 Per <a href="#SUPPORTED_GLSL_CONSTRUCTS">Supported GLSL Constructs</a>, identifi
ers starting with | |
| 2909 "webgl_" and "_webgl_" are reserved for use by WebGL. | |
| 2910 </p> | |
| 2911 | |
| 2912 <h3><a name="EXTENSION_QUERIES">Extension Queries</a></h3> | |
| 2913 | |
| 2914 <p> | |
| 2915 | |
| 2916 In the OpenGL ES 2.0 API, the available extensions are determined by calling | |
| 2917 <code>glGetString(GL_EXTENSIONS)</code>, which returns a space-separated list of
extension strings. | |
| 2918 In the WebGL API, the <code>EXTENSIONS</code> enumerant has been removed. | |
| 2919 Instead, <code>getSupportedExtensions</code> must be called to determine the set
of available | |
| 2920 extensions. | |
| 2921 | |
| 2922 </p> | |
| 2923 | |
| 2924 <h3><a name="IMPLEMENTATION_READ_FORMAT">Implementation Color Read Format an
d Type</a></h3> | |
| 2925 | |
| 2926 <p> | |
| 2927 | |
| 2928 In the OpenGL ES 2.0 API, the | |
| 2929 <code>IMPLEMENTATION_COLOR_READ_FORMAT</code> and | |
| 2930 <code>IMPLEMENTATION_COLOR_READ_TYPE</code> parameters are used to inform ap
plications of an | |
| 2931 additional format and type combination that may be passed to <code>ReadPixel
s</code>, in | |
| 2932 addition to the required <ncode>RGBA</code>/<code>UNSIGNED_BYTE</code> pair.
In WebGL 1.0, | |
| 2933 the supported format and type combinations to <code>ReadPixels</code> are do
cumented in the | |
| 2934 <a href="#readpixels">Reading back pixels</a> section. The <code>IMPLEMENTA
TION_COLOR_READ_FORMAT</code> | |
| 2935 and <code>IMPLEMENTATION_COLOR_READ_TYPE</code> enumerants have been removed
. | |
| 2936 </p> | |
| 2937 | |
| 2938 <h3><a name="COMPRESSED_TEXTURE_SUPPORT">Compressed Texture Support</a></h3> | |
| 2939 | |
| 2940 <p> | |
| 2941 WebGL does not support any compressed texture formats. Therefore the <code>C
ompressedTexImage2D</code> | |
| 2942 and <code>CompressedTexSubImage2D</code> functions are not included in this
specification. | |
| 2943 Likewise the <code>COMPRESSED_TEXTURE_FORMATS</code> and <code>NUM_COMPRESSE
D_TEXTURE_FORMATS</code> | |
| 2944 parameters to <code>getParameter</code> will return the value null or zero. | |
| 2945 </p> | |
| 2946 | |
| 2947 <h3><a name="MAX_GLSL_IDENTIFIER_NAME">Maximum GLSL Identifier Name Limit</a
></h3> | |
| 2948 | |
| 2949 <p> | |
| 2950 The GLSL ES spec <a href="#refsGLES20GLSL">[GLES20GLSL]</a> does not define
a limit to the length | |
| 2951 of identifier names. WebGL requires support of identifier names of at least
256 characters in length. | |
| 2952 </p> | |
| 2953 | |
| 2954 <!-- ===========================================================================
============================ --> | |
| 2955 | |
| 2956 <h2>References</h2> | |
| 2957 | |
| 2958 <h3>Normative references</h3> | |
| 2959 <dl> | |
| 2960 | |
| 2961 <dt id="refsTYPEDARRAYS">[TYPEDARRAYS]</dt> | |
| 2962 <dd><cite><a href="TypedArray-spec.html"> | |
| 2963 Typed Array Specification: Editor's Draft</a></cite>, | |
| 2964 V. Vukicevic, K. Russell, May 2010. | |
| 2965 </dd> | |
| 2966 <dt id="refsGLES20">[GLES20]</dt> | |
| 2967 <dd><cite><a href="http://www.khronos.org/registry/gles/specs/2.0/es_ful
l_spec_2.0.25.pdf"> | |
| 2968 OpenGL® ES Common Profile Specification Version 2.0.25</a></cite
>, | |
| 2969 A. Munshi, J. Leech, November 2010. | |
| 2970 </dd> | |
| 2971 <dt id="refsGLES20GLSL">[GLES20GLSL]</dt> | |
| 2972 <dd><cite><a href="http://www.khronos.org/registry/gles/specs/2.0/GLSL_E
S_Specification_1.0.17.pdf"> | |
| 2973 The OpenGL® ES Shading Language Version 1.00</a></cite>, | |
| 2974 R. Simpson, May 2009. | |
| 2975 </dd> | |
| 2976 <dt id="refsREGISTRY">[REGISTRY]</dt> | |
| 2977 <dd><cite><a href="http://www.khronos.org/registry/webgl/doc/spec/extens
ions/"> | |
| 2978 WebGL Extension Registry</a></cite> | |
| 2979 </dd> | |
| 2980 <dt id="refsRFC2119">[RFC2119]</dt> | |
| 2981 <dd><cite><a href="http://www.ietf.org/rfc/rfc2119.txt"> | |
| 2982 Key words for use in RFCs to Indicate Requirement Levels</a></cite>, | |
| 2983 S. Bradner. IETF, March 1997. | |
| 2984 </dd> | |
| 2985 <dt id="refsWEBIDL">[WEBIDL]</dt> | |
| 2986 <dd><cite><a href="http://dev.w3.org/2006/webapi/WebIDL/"> | |
| 2987 Web IDL: W3C Editor’s Draft</a></cite>, | |
| 2988 C. McCormack, September 2009. | |
| 2989 </dd> | |
| 2990 </dl> | |
| 2991 | |
| 2992 <h3>Other references</h3> | |
| 2993 | |
| 2994 <!-- ===========================================================================
============================ --> | |
| 2995 | |
| 2996 <h2>Acknowledgments</h2> | |
| 2997 <p>This specification is produced by the Khronos WebGL Working Group.</p> | |
| 2998 | |
| 2999 <p> | |
| 3000 Special thanks to: Arun Ranganathan (Mozilla), Jon Leech, Kenneth Russell
(Google), | |
| 3001 Kenneth Waters (Google), Mark Callow (HI), Mark Steele (Mozilla), Oliver
Hunt (Apple), | |
| 3002 Tim Johansson (Opera), Vangelis Kokkevis (Google), Vladimir Vukicevic (Mo
zilla), | |
| 3003 Gregg Tavares (Google) | |
| 3004 </p> | |
| 3005 <p> | |
| 3006 Additional thanks to: Alan Hudson (Yumetech), Bill Licea Kane (AMD), Ced
ric Vivier (Zegami), | |
| 3007 Dan Gessel (Apple), David Ligon (Qualcomm), Greg Ross (Nvidia), Jacob St
rom (Ericsson), Kari Pulli (Nokia), | |
| 3008 Leddie Stenvie (ST-Ericsson), Neil Trevett (Nvidia), Per Wennersten (Eri
csson), | |
| 3009 Per-Erik Brodin (Ericsson), Shiki Okasaka (Google), Tom Olson (ARM), Zhe
ngrong Yao (Ericsson), | |
| 3010 and the members of the Khronos WebGL Working Group. | |
| 3011 </p> | |
| 3012 | |
| 3013 </body> | |
| 3014 </html> | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 9360034:
Remove everthing except conformance tests in the deps/third_party/webgl (Closed)
Base URL: svn://chrome-svn/chrome/trunk/deps/