Support using OpenGL ES context on desktop

src/gpu/gl/GrGLAssembleGLESInterface.h

Index: src/gpu/gl/GrGLAssembleGLESInterface.h
diff --git a/src/gpu/gl/GrGLAssembleGLESInterface.h b/src/gpu/gl/GrGLAssembleGLESInterface.h
new file mode 100644
index 0000000000000000000000000000000000000000..30602c12d5e417a57b72d1ac4486ecbc99ecdef2
--- /dev/null
+++ b/src/gpu/gl/GrGLAssembleGLESInterface.h
@@ -0,0 +1,256 @@
+
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* This file is meant to be included "inline" the implementation that is using the function.
+ * The platform native GL implementation header file should be included before this file.
+ * Following macros should be defined before this file is included:
+ * GET_PROC and GET_PROC_SUFFIX
+ *   Call the get function and assign to the interface instance
+ * GET_PROC_LOCAL
+ *   Call the get function and assign to a local variable
+ * GET_LINKED and GET_LINKED_SUFFIX
+ *   Get the link-time address of the function and assign it to the interface instance. If
+ *   using the linked addresses is not intended, can be the same as GET_PROC.
+ */
+
+/**
+ * Generic function for creating a GrGLInterface for an OpenGL ES (but not Open GL) context. It
+ * calls get() to get each function address. ctx is a generic ptr passed to and interpreted by
+ * get().
+ */
+static const GrGLInterface* GrGLAssembleGLESInterface(void* ctx, GrGLGetProc get) {
+    const char* verStr = reinterpret_cast<const char*>(glGetString(GR_GL_VERSION));
+    GrGLVersion version = GrGLGetVersionFromString(verStr);
+
+    if (version < GR_GL_VER(2,0)) {
+        return NULL;
+    }
+
+    GET_PROC_LOCAL(GetIntegerv);
+    GET_PROC_LOCAL(GetStringi);
+    GrGLExtensions extensions;
+    if (!extensions.init(kGLES_GrGLStandard, glGetString, GetStringi, GetIntegerv)) {
+        return NULL;
+    }
+
+    GrGLInterface* interface = SkNEW(GrGLInterface);
+    GrGLInterface::Functions* functions = &interface->fFunctions;
+
+    GET_LINKED(ActiveTexture);
+    GET_LINKED(AttachShader);
+    GET_LINKED(BindAttribLocation);
+    GET_LINKED(BindBuffer);
+    GET_LINKED(BindTexture);
+    GET_LINKED_SUFFIX(BindVertexArray, OES);
+    GET_LINKED(BlendColor);
+    GET_LINKED(BlendFunc);
+    GET_LINKED(BufferData);
+    GET_LINKED(BufferSubData);
+    GET_LINKED(Clear);
+    GET_LINKED(ClearColor);
+    GET_LINKED(ClearStencil);
+    GET_LINKED(ColorMask);
+    GET_LINKED(CompileShader);
+    GET_LINKED(CompressedTexImage2D);
+    GET_LINKED(CompressedTexSubImage2D);
+    GET_LINKED(CopyTexSubImage2D);
+    GET_LINKED(CreateProgram);
+    GET_LINKED(CreateShader);
+    GET_LINKED(CullFace);
+    GET_LINKED(DeleteBuffers);
+    GET_LINKED(DeleteProgram);
+    GET_LINKED(DeleteShader);
+    GET_LINKED(DeleteTextures);
+    GET_LINKED_SUFFIX(DeleteVertexArrays, OES);
+    GET_LINKED(DepthMask);
+    GET_LINKED(Disable);
+    GET_LINKED(DisableVertexAttribArray);
+    GET_LINKED(DrawArrays);
+    GET_LINKED(DrawElements);
+    GET_LINKED(Enable);
+    GET_LINKED(EnableVertexAttribArray);
+    GET_LINKED(Finish);
+    GET_LINKED(Flush);
+    GET_LINKED(FrontFace);
+    GET_LINKED(GenBuffers);
+    GET_LINKED(GenerateMipmap);
+    GET_LINKED(GenTextures);
+    GET_LINKED_SUFFIX(GenVertexArrays, OES);
+    GET_LINKED(GetBufferParameteriv);
+    GET_LINKED(GetError);
+    GET_LINKED(GetIntegerv);
+    GET_LINKED(GetProgramInfoLog);
+    GET_LINKED(GetProgramiv);
+    GET_LINKED(GetShaderInfoLog);
+    GET_LINKED(GetShaderiv);
+    GET_LINKED(GetString);
+#if GL_ES_VERSION_3_0
+    GET_LINKED(GetStringi);
+#else
+    GET_PROC(GetStringi);
+#endif
+    GET_LINKED(GetUniformLocation);
+    GET_LINKED(LineWidth);
+    GET_LINKED(LinkProgram);
+    GET_LINKED(PixelStorei);
+    GET_LINKED(ReadPixels);
+    GET_LINKED(Scissor);
+#if GR_GL_USE_NEW_SHADER_SOURCE_SIGNATURE
+    functions->fShaderSource = (GrGLShaderSourceProc) glShaderSource;
+#else
+    GET_LINKED(ShaderSource);
+#endif
+    GET_LINKED(StencilFunc);
+    GET_LINKED(StencilFuncSeparate);
+    GET_LINKED(StencilMask);
+    GET_LINKED(StencilMaskSeparate);
+    GET_LINKED(StencilOp);
+    GET_LINKED(StencilOpSeparate);
+    GET_LINKED(TexImage2D);
+    GET_LINKED(TexParameteri);
+    GET_LINKED(TexParameteriv);
+    GET_LINKED(TexSubImage2D);
+
+    if (version >= GR_GL_VER(3,0)) {
+#if GL_ES_VERSION_3_0
+        GET_LINKED(TexStorage2D);
+#else
+        GET_PROC(TexStorage2D);
+#endif
+    } else {
+#if GL_EXT_texture_storage
+        GET_LINKED_SUFFIX(TexStorage2D, EXT);
+#else
+        GET_PROC_SUFFIX(TexStorage2D, EXT);
+#endif
+    }
+
+#if GL_EXT_discard_framebuffer
+    GET_LINKED_SUFFIX(DiscardFramebuffer, EXT);
+#endif
+    GET_LINKED(Uniform1f);
+    GET_LINKED(Uniform1i);
+    GET_LINKED(Uniform1fv);
+    GET_LINKED(Uniform1iv);
+    GET_LINKED(Uniform2f);
+    GET_LINKED(Uniform2i);
+    GET_LINKED(Uniform2fv);
+    GET_LINKED(Uniform2iv);
+    GET_LINKED(Uniform3f);
+    GET_LINKED(Uniform3i);
+    GET_LINKED(Uniform3fv);
+    GET_LINKED(Uniform3iv);
+    GET_LINKED(Uniform4f);
+    GET_LINKED(Uniform4i);
+    GET_LINKED(Uniform4fv);
+    GET_LINKED(Uniform4iv);
+    GET_LINKED(UniformMatrix2fv);
+    GET_LINKED(UniformMatrix3fv);
+    GET_LINKED(UniformMatrix4fv);
+    GET_LINKED(UseProgram);
+    GET_LINKED(VertexAttrib4fv);
+    GET_LINKED(VertexAttribPointer);
+    GET_LINKED(Viewport);
+    GET_LINKED(BindFramebuffer);
+    GET_LINKED(BindRenderbuffer);
+    GET_LINKED(CheckFramebufferStatus);
+    GET_LINKED(DeleteFramebuffers);
+    GET_LINKED(DeleteRenderbuffers);
+    GET_LINKED(FramebufferRenderbuffer);
+    GET_LINKED(FramebufferTexture2D);
+
+    if (version >= GR_GL_VER(3,0)) {
+#if GL_ES_VERSION_3_0
+        GET_LINKED(RenderbufferStorageMultisample);
+        GET_LINKED(BlitFramebuffer);
+#else
+        GET_PROC(RenderbufferStorageMultisample);
+        GET_PROC(BlitFramebuffer);
+#endif
+    }
+
+    if (extensions.has("GL_EXT_multisampled_render_to_texture")) {
+#if GL_EXT_multisampled_render_to_texture
+        GET_LINKED_SUFFIX(FramebufferTexture2DMultisample, EXT);
+        functions->fRenderbufferStorageMultisampleES2EXT = glRenderbufferStorageMultisampleEXT;
+#else
+        GET_PROC_SUFFIX(FramebufferTexture2DMultisample, EXT);
+        functions->fRenderbufferStorageMultisampleES2EXT = (GrGLRenderbufferStorageMultisampleProc) get(ctx, "glRenderbufferStorageMultisampleEXT");
+#endif
+    } else if (extensions.has("GL_IMG_multisampled_render_to_texture")) {
+#if GL_IMG_multisampled_render_to_texture
+        GET_LINKED_SUFFIX(FramebufferTexture2DMultisample, IMG);
+        functions->fRenderbufferStorageMultisampleES2EXT = glRenderbufferStorageMultisampleIMG;
+#else
+        GET_PROC_SUFFIX(FramebufferTexture2DMultisample, IMG);
+        functions->fRenderbufferStorageMultisampleES2EXT = (GrGLRenderbufferStorageMultisampleProc) get(ctx, "glRenderbufferStorageMultisampleIMG");
+#endif
+    }
+
+    GET_LINKED(GenFramebuffers);
+    GET_LINKED(GenRenderbuffers);
+    GET_LINKED(GetFramebufferAttachmentParameteriv);
+    GET_LINKED(GetRenderbufferParameteriv);
+    GET_LINKED(RenderbufferStorage);
+
+#if GL_OES_mapbuffer
+    GET_LINKED_SUFFIX(MapBuffer, OES);
+    GET_LINKED_SUFFIX(UnmapBuffer, OES);
+#else
+    GET_PROC_SUFFIX(MapBuffer, OES);
+    GET_PROC_SUFFIX(UnmapBuffer, OES);
+#endif
+
+    if (version >= GR_GL_VER(3,0)) {
+#if GL_ES_VERSION_3_0
+        GET_LINKED(MapBufferRange);
+        GET_LINKED(FlushMappedBufferRange);
+#else
+        GET_PROC(MapBufferRange);
+        GET_PROC(FlushMappedBufferRange);
+#endif
+    } else if (extensions.has("GL_EXT_map_buffer_range")) {
+#if GL_EXT_map_buffer_range
+        GET_LINKED_SUFFIX(MapBufferRange, EXT);
+        GET_LINKED_SUFFIX(FlushMappedBufferRange, EXT);
+#else
+        GET_PROC_SUFFIX(MapBufferRange, EXT);
+        GET_PROC_SUFFIX(FlushMappedBufferRange, EXT);
+#endif
+    }
+
+    if (extensions.has("GL_EXT_debug_marker")) {
+        GET_PROC(InsertEventMarker);
+        GET_PROC(PushGroupMarker);
+        GET_PROC(PopGroupMarker);
+        // The below check is here because a device has been found that has the extension string but
+        // returns NULL from the eglGetProcAddress for the functions
+        if (NULL == functions->fInsertEventMarker ||
+            NULL == functions->fPushGroupMarker ||
+            NULL == functions->fPopGroupMarker) {
+            extensions.remove("GL_EXT_debug_marker");
+        }
+    }
+
+#if GL_ES_VERSION_3_0
+    GET_LINKED(InvalidateFramebuffer);
+    GET_LINKED(InvalidateSubFramebuffer);
+#else
+    GET_PROC(InvalidateFramebuffer);
+    GET_PROC(InvalidateSubFramebuffer);
+#endif
+    GET_PROC(InvalidateBufferData);
+    GET_PROC(InvalidateBufferSubData);
+    GET_PROC(InvalidateTexImage);
+    GET_PROC(InvalidateTexSubImage);
+
+    interface->fStandard = kGLES_GrGLStandard;
+    interface->fExtensions.swap(&extensions);
+
+    return interface;
+}