Check in webgl conformance tests r16844 from khronos.

third_party/webgl/sdk/tests/conformance/resources/glsl-generator.js

+GLSLGenerator = (function() {
+
+var vertexShaderTemplate = [
+  "attribute vec4 aPosition;",
+  "",
+  "varying vec4 vColor;",
+  "",
+  "$(extra)",
+  "$(emu)",
+  "",
+  "void main()",
+  "{",
+  "   gl_Position = aPosition;",
+  "   vec2 texcoord = vec2(aPosition.xy * 0.5 + vec2(0.5, 0.5));",
+  "   vec4 color = vec4(",
+  "       texcoord,",
+  "       texcoord.x * texcoord.y,",
+  "       (1.0 - texcoord.x) * texcoord.y * 0.5 + 0.5);",
+  "   $(test)",
+  "}"
+].join("\n");
+
+var fragmentShaderTemplate = [
+  "#if defined(GL_ES)",
+  "precision mediump float;",
+  "#endif",
+  "",
+  "varying vec4 vColor;",
+  "",
+  "$(extra)",
+  "$(emu)",
+  "",
+  "void main()",
+  "{",
+  "   $(test)",
+  "}"
+].join("\n");
+
+var baseVertexShader = [
+  "attribute vec4 aPosition;",
+  "",
+  "varying vec4 vColor;",
+  "",
+  "void main()",
+  "{",
+  "   gl_Position = aPosition;",
+  "   vec2 texcoord = vec2(aPosition.xy * 0.5 + vec2(0.5, 0.5));",
+  "   vColor = vec4(",
+  "       texcoord,",
+  "       texcoord.x * texcoord.y,",
+  "       (1.0 - texcoord.x) * texcoord.y * 0.5 + 0.5);",
+  "}"
+].join("\n");
+
+var baseFragmentShader = [
+  "#if defined(GL_ES)",
+  "precision mediump float;",
+  "#endif",
+  "varying vec4 vColor;",
+  "",
+  "void main()",
+  "{",
+  "   gl_FragColor = vColor;",
+  "}"
+].join("\n");
+
+var types = [
+  { type: "float",
+    code: [
+      "float $(func)_emu($(args)) {",
+      "  return $(func)_base($(baseArgs));",
+      "}"].join("\n")
+  },
+  { type: "vec2",
+    code: [
+      "vec2 $(func)_emu($(args)) {",
+      "  return vec2(",
+      "      $(func)_base($(baseArgsX)),",
+      "      $(func)_base($(baseArgsY)));",
+      "}"].join("\n")
+  },
+  { type: "vec3",
+    code: [
+      "vec3 $(func)_emu($(args)) {",
+      "  return vec3(",
+      "      $(func)_base($(baseArgsX)),",
+      "      $(func)_base($(baseArgsY)),",
+      "      $(func)_base($(baseArgsZ)));",
+      "}"].join("\n")
+  },
+  { type: "vec4",
+    code: [
+      "vec4 $(func)_emu($(args)) {",
+      "  return vec4(",
+      "      $(func)_base($(baseArgsX)),",
+      "      $(func)_base($(baseArgsY)),",
+      "      $(func)_base($(baseArgsZ)),",
+      "      $(func)_base($(baseArgsW)));",
+      "}"].join("\n")
+  }
+];
+
+var bvecTypes = [
+  { type: "bvec2",
+    code: [
+      "bvec2 $(func)_emu($(args)) {",
+      "  return bvec2(",
+      "      $(func)_base($(baseArgsX)),",
+      "      $(func)_base($(baseArgsY)));",
+      "}"].join("\n")
+  },
+  { type: "bvec3",
+    code: [
+      "bvec3 $(func)_emu($(args)) {",
+      "  return bvec3(",
+      "      $(func)_base($(baseArgsX)),",
+      "      $(func)_base($(baseArgsY)),",
+      "      $(func)_base($(baseArgsZ)));",
+      "}"].join("\n")
+  },
+  { type: "bvec4",
+    code: [
+      "vec4 $(func)_emu($(args)) {",
+      "  return bvec4(",
+      "      $(func)_base($(baseArgsX)),",
+      "      $(func)_base($(baseArgsY)),",
+      "      $(func)_base($(baseArgsZ)),",
+      "      $(func)_base($(baseArgsW)));",
+      "}"].join("\n")
+  }
+];
+
+var replaceRE = /\$\((\w+)\)/g;
+
+var replaceParams = function(str) {
+  var args = arguments;
+  return str.replace(replaceRE, function(str, p1, offset, s) {
+    for (var ii = 1; ii < args.length; ++ii) {
+      if (args[ii][p1] !== undefined) {
+        return args[ii][p1];
+      }
+    }
+    throw "unknown string param '" + p1 + "'";
+  });
+};
+
+var generateReferenceShader = function(
+    shaderInfo, template, params, typeInfo, test) {
+  var input = shaderInfo.input;
+  var output = shaderInfo.output;
+  var feature = params.feature;
+  var testFunc = params.testFunc;
+  var emuFunc = params.emuFunc || "";
+  var extra = params.extra || '';
+  var args = params.args || "$(type) value";
+  var type = typeInfo.type;
+  var typeCode = typeInfo.code;
+
+  var baseArgs = params.baseArgs || "value$(field)";
+  var baseArgsX = replaceParams(baseArgs, {field: ".x"});
+  var baseArgsY = replaceParams(baseArgs, {field: ".y"});
+  var baseArgsZ = replaceParams(baseArgs, {field: ".z"});
+  var baseArgsW = replaceParams(baseArgs, {field: ".w"});
+  var baseArgs = replaceParams(baseArgs, {field: ""});
+
+  test = replaceParams(test, {
+    input: input,
+    output: output,
+    func: feature + "_emu"
+  });
+  emuFunc = replaceParams(emuFunc, {
+    func: feature
+  });
+  args = replaceParams(args, {
+    type: type
+  });
+  typeCode = replaceParams(typeCode, {
+    func: feature,
+    type: type,
+    args: args,
+    baseArgs: baseArgs,
+    baseArgsX: baseArgsX,
+    baseArgsY: baseArgsY,
+    baseArgsZ: baseArgsZ,
+    baseArgsW: baseArgsW
+  });
+  var shader = replaceParams(template, {
+    extra: extra,
+    emu: emuFunc + "\n\n" + typeCode,
+    test: test
+  });
+  return shader;
+};
+
+var generateTestShader = function(
+    shaderInfo, template, params, test) {
+  var input = shaderInfo.input;
+  var output = shaderInfo.output;
+  var feature = params.feature;
+  var testFunc = params.testFunc;
+  var extra = params.extra || '';
+
+  test = replaceParams(test, {
+    input: input,
+    output: output,
+    func: feature
+  });
+  var shader = replaceParams(template, {
+    extra: extra,
+    emu: '',
+    test: test
+  });
+  return shader;
+};
+
+var makeImage = function(canvas) {
+  var img = document.createElement('img');
+  img.src = canvas.toDataURL();
+  return img;
+};
+
+var runFeatureTest = function(params) {
+  if (window.initNonKhronosFramework) {
+    window.initNonKhronosFramework(false);
+  }
+
+  var wtu = WebGLTestUtils;
+  var gridRes = params.gridRes;
+  var vertexTolerance = params.tolerance || 0;
+  var fragmentTolerance = vertexTolerance;
+  if ('fragmentTolerance' in params)
+    fragmentTolerance = params.fragmentTolerance || 0;
+
+  description("Testing GLSL feature: " + params.feature);
+
+  var width = 32;
+  var height = 32;
+
+  var console = document.getElementById("console");
+  var canvas = document.createElement('canvas');
+  canvas.width = width;
+  canvas.height = height;
+  var gl = wtu.create3DContext(canvas);
+  if (!gl) {
+    testFailed("context does not exist");
+    finishTest();
+    return;
+  }
+
+  var canvas2d = document.createElement('canvas');
+  canvas2d.width = width;
+  canvas2d.height = height;
+  var ctx = canvas2d.getContext("2d");
+  var imgData = ctx.getImageData(0, 0, width, height);
+
+  var shaderInfos = [
+    { type: "vertex",
+      input: "color",
+      output: "vColor",
+      vertexShaderTemplate: vertexShaderTemplate,
+      fragmentShaderTemplate: baseFragmentShader,
+      tolerance: vertexTolerance
+    },
+    { type: "fragment",
+      input: "vColor",
+      output: "gl_FragColor",
+      vertexShaderTemplate: baseVertexShader,
+      fragmentShaderTemplate: fragmentShaderTemplate,
+      tolerance: fragmentTolerance
+    }
+  ];
+  for (var ss = 0; ss < shaderInfos.length; ++ss) {
+    var shaderInfo = shaderInfos[ss];
+    var tests = params.tests;
+    var testTypes = params.emuFuncs || (params.bvecTest ? bvecTypes : types);
+    // Test vertex shaders
+    for (var ii = 0; ii < tests.length; ++ii) {
+      var type = testTypes[ii];
+      if (params.simpleEmu) {
+        type = {
+          type: type.type,
+          code: params.simpleEmu
+        };
+      }
+      debug("");
+      var str = replaceParams(params.testFunc, {
+        func: params.feature,
+        type: type.type,
+        arg0: type.type
+      });
+      debug("Testing: " + str + " in " + shaderInfo.type + " shader");
+
+      var referenceVertexShaderSource = generateReferenceShader(
+          shaderInfo,
+          shaderInfo.vertexShaderTemplate,
+          params,
+          type,
+          tests[ii]);
+      var referenceFragmentShaderSource = generateReferenceShader(
+          shaderInfo,
+          shaderInfo.fragmentShaderTemplate,
+          params,
+          type,
+          tests[ii]);
+      var testVertexShaderSource = generateTestShader(
+          shaderInfo,
+          shaderInfo.vertexShaderTemplate,
+          params,
+          tests[ii]);
+      var testFragmentShaderSource = generateTestShader(
+          shaderInfo,
+          shaderInfo.fragmentShaderTemplate,
+          params,
+          tests[ii]);
+
+      debug("");
+      addShaderSource(
+          "reference vertex shader", referenceVertexShaderSource);
+      addShaderSource(
+          "reference fragment shader", referenceFragmentShaderSource);
+      addShaderSource(
+          "test vertex shader", testVertexShaderSource);
+      addShaderSource(
+          "test fragment shader", testFragmentShaderSource);
+      debug("");
+
+      var refData = draw(
+          canvas, referenceVertexShaderSource, referenceFragmentShaderSource);
+      var refImg = makeImage(canvas);
+      if (ss == 0) {
+        var testData = draw(
+            canvas, testVertexShaderSource, referenceFragmentShaderSource);
+      } else {
+        var testData = draw(
+            canvas, referenceVertexShaderSource, testFragmentShaderSource);
+      }
+      var testImg = makeImage(canvas);
+
+      reportResults(refData, refImg, testData, testImg, shaderInfo.tolerance);
+    }
+  }
+
+  finishTest();
+
+  function addShaderSource(label, source) {
+    var div = document.createElement("div");
+    var s = document.createElement("pre");
+    s.className = "shader-source";
+    s.style.display = "none";
+    var ol = document.createElement("ol");
+    //s.appendChild(document.createTextNode(source));
+    var lines = source.split("\n");
+    for (var ii = 0; ii < lines.length; ++ii) {
+      var line = lines[ii];
+      var li = document.createElement("li");
+      li.appendChild(document.createTextNode(line));
+      ol.appendChild(li);
+    }
+    s.appendChild(ol);
+    var l = document.createElement("a");
+    l.href = "show-shader-source";
+    l.appendChild(document.createTextNode(label));
+    l.addEventListener('click', function(event) {
+        if (event.preventDefault) {
+          event.preventDefault();
+        }
+        s.style.display = (s.style.display == 'none') ? 'block' : 'none';
+        return false;
+      }, false);
+    div.appendChild(l);
+    div.appendChild(s);
+    console.appendChild(div);
+  }
+
+  function reportResults(refData, refImage, testData, testImage, tolerance) {
+    var same = true;
+    for (var yy = 0; yy < height; ++yy) {
+      for (var xx = 0; xx < width; ++xx) {
+        var offset = (yy * width + xx) * 4;
+        var imgOffset = ((height - yy - 1) * width + xx) * 4;
+        imgData.data[imgOffset + 0] = 0;
+        imgData.data[imgOffset + 1] = 0;
+        imgData.data[imgOffset + 2] = 0;
+        imgData.data[imgOffset + 3] = 255;
+        if (Math.abs(refData[offset + 0] - testData[offset + 0]) > tolerance ||
+            Math.abs(refData[offset + 1] - testData[offset + 1]) > tolerance ||
+            Math.abs(refData[offset + 2] - testData[offset + 2]) > tolerance ||
+            Math.abs(refData[offset + 3] - testData[offset + 3]) > tolerance) {
+          imgData.data[imgOffset] = 255;
+          same = false;
+        }
+      }
+    }
+
+    var diffImg = null;
+    if (!same) {
+      ctx.putImageData(imgData, 0, 0);
+      diffImg = makeImage(canvas2d);
+    }
+
+    var div = document.createElement("div");
+    div.className = "testimages";
+    insertImg(div, "ref", refImg);
+    insertImg(div, "test", testImg);
+    if (diffImg) {
+      insertImg(div, "diff", diffImg);
+    }
+    div.appendChild(document.createElement('br'));
+
+    function insertImg(element, caption, img) {
+      var div = document.createElement("div");
+      div.appendChild(img);
+      var label = document.createElement("div");
+      label.appendChild(document.createTextNode(caption));
+      div.appendChild(label);
+      element.appendChild(div);
+    }
+
+    console.appendChild(div);
+
+    if (!same) {
+      testFailed("images are different");
+    } else {
+      testPassed("images are the same");
+    }
+
+    console.appendChild(document.createElement('hr'));
+  }
+
+  function draw(canvas, vsSource, fsSource) {
+    var program = wtu.loadProgram(gl, vsSource, fsSource, testFailed);
+
+    var posLoc = gl.getAttribLocation(program, "aPosition");
+    WebGLTestUtils.setupQuad(gl, gridRes, posLoc);
+
+    gl.useProgram(program);
+    gl.clearColor(0, 0, 1, 1);
+    gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
+    gl.drawElements(gl.TRIANGLES, gridRes * gridRes * 6, gl.UNSIGNED_SHORT, 0);
+    wtu.glErrorShouldBe(gl, gl.NO_ERROR, "no errors from draw");
+
+    var img = new Uint8Array(width * height * 4);
+    gl.readPixels(0, 0, width, height, gl.RGBA, gl.UNSIGNED_BYTE, img);
+    return img;
+  }
+
+};
+
+var runBasicTest = function(params) {
+  if (window.initNonKhronosFramework) {
+    window.initNonKhronosFramework(false);
+  }
+
+  var wtu = WebGLTestUtils;
+  var gridRes = params.gridRes;
+  var vertexTolerance = params.tolerance || 0;
+  var fragmentTolerance = vertexTolerance;
+  if ('fragmentTolerance' in params)
+    fragmentTolerance = params.fragmentTolerance || 0;
+
+  description("Testing : " + document.getElementsByTagName("title")[0].innerText);
+
+  var width = 32;
+  var height = 32;
+
+  var console = document.getElementById("console");
+  var canvas = document.createElement('canvas');
+  canvas.width = width;
+  canvas.height = height;
+  var gl = wtu.create3DContext(canvas);
+  if (!gl) {
+    testFailed("context does not exist");
+    finishTest();
+    return;
+  }
+
+  var canvas2d = document.createElement('canvas');
+  canvas2d.width = width;
+  canvas2d.height = height;
+  var ctx = canvas2d.getContext("2d");
+  var imgData = ctx.getImageData(0, 0, width, height);
+
+  var shaderInfos = [
+    { type: "vertex",
+      input: "color",
+      output: "vColor",
+      vertexShaderTemplate: vertexShaderTemplate,
+      fragmentShaderTemplate: baseFragmentShader,
+      tolerance: vertexTolerance
+    },
+    { type: "fragment",
+      input: "vColor",
+      output: "gl_FragColor",
+      vertexShaderTemplate: baseVertexShader,
+      fragmentShaderTemplate: fragmentShaderTemplate,
+      tolerance: fragmentTolerance
+    }
+  ];
+  for (var ss = 0; ss < shaderInfos.length; ++ss) {
+    var shaderInfo = shaderInfos[ss];
+    var tests = params.tests;
+//    var testTypes = params.emuFuncs || (params.bvecTest ? bvecTypes : types);
+    // Test vertex shaders
+    for (var ii = 0; ii < tests.length; ++ii) {
+      var test = tests[ii];
+      debug("");
+      debug("Testing: " + test.name + " in " + shaderInfo.type + " shader");
+
+      function genShader(shaderInfo, template, shader, subs) {
+        shader = replaceParams(shader, subs, {
+            input: shaderInfo.input,
+            output: shaderInfo.output
+          });
+        shader = replaceParams(template, subs, {
+            test: shader,
+            emu: "",
+            extra: ""
+          });
+        return shader;
+      }
+
+      var referenceVertexShaderSource = genShader(
+          shaderInfo,
+          shaderInfo.vertexShaderTemplate,
+          test.reference.shader,
+          test.reference.subs);
+      var referenceFragmentShaderSource = genShader(
+          shaderInfo,
+          shaderInfo.fragmentShaderTemplate,
+          test.reference.shader,
+          test.reference.subs);
+      var testVertexShaderSource = genShader(
+          shaderInfo,
+          shaderInfo.vertexShaderTemplate,
+          test.test.shader,
+          test.test.subs);
+      var testFragmentShaderSource = genShader(
+          shaderInfo,
+          shaderInfo.fragmentShaderTemplate,
+          test.test.shader,
+          test.test.subs);
+
+      debug("");
+      addShaderSource(
+          "reference vertex shader", referenceVertexShaderSource);
+      addShaderSource(
+          "reference fragment shader", referenceFragmentShaderSource);
+      addShaderSource(
+          "test vertex shader", testVertexShaderSource);
+      addShaderSource(
+          "test fragment shader", testFragmentShaderSource);
+      debug("");
+
+      var refData = draw(
+          canvas, referenceVertexShaderSource, referenceFragmentShaderSource);
+      var refImg = makeImage(canvas);
+      if (ss == 0) {
+        var testData = draw(
+            canvas, testVertexShaderSource, referenceFragmentShaderSource);
+      } else {
+        var testData = draw(
+            canvas, referenceVertexShaderSource, testFragmentShaderSource);
+      }
+      var testImg = makeImage(canvas);
+
+      reportResults(refData, refImg, testData, testImg, shaderInfo.tolerance);
+    }
+  }
+
+  finishTest();
+
+  function addShaderSource(label, source) {
+    var div = document.createElement("div");
+    var s = document.createElement("pre");
+    s.className = "shader-source";
+    s.style.display = "none";
+    var ol = document.createElement("ol");
+    //s.appendChild(document.createTextNode(source));
+    var lines = source.split("\n");
+    for (var ii = 0; ii < lines.length; ++ii) {
+      var line = lines[ii];
+      var li = document.createElement("li");
+      li.appendChild(document.createTextNode(line));
+      ol.appendChild(li);
+    }
+    s.appendChild(ol);
+    var l = document.createElement("a");
+    l.href = "show-shader-source";
+    l.appendChild(document.createTextNode(label));
+    l.addEventListener('click', function(event) {
+        if (event.preventDefault) {
+          event.preventDefault();
+        }
+        s.style.display = (s.style.display == 'none') ? 'block' : 'none';
+        return false;
+      }, false);
+    div.appendChild(l);
+    div.appendChild(s);
+    console.appendChild(div);
+  }
+
+  function reportResults(refData, refImage, testData, testImage, tolerance) {
+    var same = true;
+    for (var yy = 0; yy < height; ++yy) {
+      for (var xx = 0; xx < width; ++xx) {
+        var offset = (yy * width + xx) * 4;
+        var imgOffset = ((height - yy - 1) * width + xx) * 4;
+        imgData.data[imgOffset + 0] = 0;
+        imgData.data[imgOffset + 1] = 0;
+        imgData.data[imgOffset + 2] = 0;
+        imgData.data[imgOffset + 3] = 255;
+        if (Math.abs(refData[offset + 0] - testData[offset + 0]) > tolerance ||
+            Math.abs(refData[offset + 1] - testData[offset + 1]) > tolerance ||
+            Math.abs(refData[offset + 2] - testData[offset + 2]) > tolerance ||
+            Math.abs(refData[offset + 3] - testData[offset + 3]) > tolerance) {
+          imgData.data[imgOffset] = 255;
+          same = false;
+        }
+      }
+    }
+
+    var diffImg = null;
+    if (!same) {
+      ctx.putImageData(imgData, 0, 0);
+      diffImg = makeImage(canvas2d);
+    }
+
+    var div = document.createElement("div");
+    div.className = "testimages";
+    insertImg(div, "ref", refImg);
+    insertImg(div, "test", testImg);
+    if (diffImg) {
+      insertImg(div, "diff", diffImg);
+    }
+    div.appendChild(document.createElement('br'));
+
+    function insertImg(element, caption, img) {
+      var div = document.createElement("div");
+      div.appendChild(img);
+      var label = document.createElement("div");
+      label.appendChild(document.createTextNode(caption));
+      div.appendChild(label);
+      element.appendChild(div);
+    }
+
+    console.appendChild(div);
+
+    if (!same) {
+      testFailed("images are different");
+    } else {
+      testPassed("images are the same");
+    }
+
+    console.appendChild(document.createElement('hr'));
+  }
+
+  function draw(canvas, vsSource, fsSource) {
+    var program = wtu.loadProgram(gl, vsSource, fsSource, testFailed);
+
+    var posLoc = gl.getAttribLocation(program, "aPosition");
+    WebGLTestUtils.setupQuad(gl, gridRes, posLoc);
+
+    gl.useProgram(program);
+    gl.clearColor(0, 0, 1, 1);
+    gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
+    gl.drawElements(gl.TRIANGLES, gridRes * gridRes * 6, gl.UNSIGNED_SHORT, 0);
+    wtu.glErrorShouldBe(gl, gl.NO_ERROR, "no errors from draw");
+
+    var img = new Uint8Array(width * height * 4);
+    gl.readPixels(0, 0, width, height, gl.RGBA, gl.UNSIGNED_BYTE, img);
+    return img;
+  }
+
+};
+
+return {
+  /**
+   * runs a bunch of GLSL tests using the passed in parameters
+   * The parameters are:
+   *
+   * feature:
+   *    the name of the function being tested (eg, sin, dot,
+   *    normalize)
+   *
+   * testFunc:
+   *    The prototype of function to be tested not including the
+   *    return type.
+   *
+   * emuFunc:
+   *    A base function that can be used to generate emulation
+   *    functions. Example for 'ceil'
+   *
+   *      float $(func)_base(float value) {
+   *        float m = mod(value, 1.0);
+   *        return m != 0.0 ? (value + 1.0 - m) : value;
+   *      }
+   *
+   * args:
+   *    The arguments to the function
+   *
+   * baseArgs: (optional)
+   *    The arguments when a base function is used to create an
+   *    emulation function. For example 'float sign_base(float v)'
+   *    is used to implemenent vec2 sign_emu(vec2 v).
+   *
+   * simpleEmu:
+   *    if supplied, the code that can be used to generate all
+   *    functions for all types.
+   *
+   *    Example for 'normalize':
+   *
+   *        $(type) $(func)_emu($(args)) {
+   *           return value / length(value);
+   *        }
+   *
+   * gridRes: (optional)
+   *    The resolution of the mesh to generate. The default is a
+   *    1x1 grid but many vertex shaders need a higher resolution
+   *    otherwise the only values passed in are the 4 corners
+   *    which often have the same value.
+   *
+   * tests:
+   *    The code for each test. It is assumed the tests are for
+   *    float, vec2, vec3, vec4 in that order.
+   *
+   * tolerance: (optional)
+   *    Allow some tolerance in the comparisons. The tolerance is applied to 
+   *    both vertex and fragment shaders. The default tolerance is 0, meaning 
+   *    the values have to be identical.
+   *
+   * fragmentTolerance: (optional)
+   *    Specify a tolerance which only applies to fragment shaders. The 
+   *    fragment-only tolerance will override the shared tolerance for 
+   *    fragment shaders if both are specified. Fragment shaders usually
+   *    use mediump float precision so they sometimes require higher tolerance
+   *    than vertex shaders which use highp.
+   */
+  runFeatureTest: runFeatureTest,
+
+  /*
+   * Runs a bunch of GLSL tests using the passed in parameters
+   *
+   * The parameters are:
+   *
+   * tests:
+   *    Array of tests. For each test the following parameters are expected
+   *
+   *    name:
+   *       some description of the test
+   *    reference:
+   *       parameters for the reference shader (see below)
+   *    test:
+   *       parameters for the test shader (see below)
+   *
+   *    The parameter for the reference and test shaders are
+   *
+   *    shader: the GLSL for the shader
+   *    subs: any substitutions you wish to define for the shader.
+   *
+   *    Each shader is created from a basic template that
+   *    defines an input and an output. You can see the
+   *    templates at the top of this file. The input and output
+   *    change depending on whether or not we are generating
+   *    a vertex or fragment shader.
+   *
+   *    All this code function does is a bunch of string substitutions.
+   *    A substitution is defined by $(name). If name is found in
+   *    the 'subs' parameter it is replaced. 4 special names exist.
+   *
+   *    'input' the input to your GLSL. Always a vec4. All change
+   *    from 0 to 1 over the quad to be drawn.
+   *
+   *    'output' the output color. Also a vec4
+   *
+   *    'emu' a place to insert extra stuff
+   *    'extra' a place to insert extra stuff.
+   *
+   *    You can think of the templates like this
+   *
+   *       $(extra)
+   *       $(emu)
+   *
+   *       void main() {
+   *          // do math to calculate input
+   *          ...
+   *
+   *          $(shader)
+   *       }
+   *
+   *    Your shader first has any subs you provided applied as well
+   *    as 'input' and 'output'
+   *
+   *    It is then inserted into the template which is also provided
+   *    with your subs.
+   *
+   * gridRes: (optional)
+   *    The resolution of the mesh to generate. The default is a
+   *    1x1 grid but many vertex shaders need a higher resolution
+   *    otherwise the only values passed in are the 4 corners
+   *    which often have the same value.
+   *
+   * tolerance: (optional)
+   *    Allow some tolerance in the comparisons. The tolerance is applied to
+   *    both vertex and fragment shaders. The default tolerance is 0, meaning
+   *    the values have to be identical.
+   *
+   * fragmentTolerance: (optional)
+   *    Specify a tolerance which only applies to fragment shaders. The
+   *    fragment-only tolerance will override the shared tolerance for
+   *    fragment shaders if both are specified. Fragment shaders usually
+   *    use mediump float precision so they sometimes require higher tolerance
+   *    than vertex shaders which use highp.
+   */
+  runBasicTest: runBasicTest,
+
+  none: false
+};
+
+}());
+