conformance/extensions/oes-standard-derivatives.html - chromium/deps/webgl/sdk/tests - Git at Google

 <!--

 /*
 ** Copyright (c) 2012 The Khronos Group Inc.
 **
 ** Permission is hereby granted, free of charge, to any person obtaining a
 ** copy of this software and/or associated documentation files (the
 ** "Materials"), to deal in the Materials without restriction, including
 ** without limitation the rights to use, copy, modify, merge, publish,
 ** distribute, sublicense, and/or sell copies of the Materials, and to
 ** permit persons to whom the Materials are furnished to do so, subject to
 ** the following conditions:
 **
 ** The above copyright notice and this permission notice shall be included
 ** in all copies or substantial portions of the Materials.
 **
 ** THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 ** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 ** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 ** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 ** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 ** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 ** MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
 */

 -->

 <!DOCTYPE html>
 <html>
 <head>
 <meta charset="utf-8">
 <title>WebGL OES_standard_derivatives Conformance Tests</title>
 <link rel="stylesheet" href="../../resources/js-test-style.css"/>
 <script src="../../resources/desktop-gl-constants.js" type="text/javascript"></script>
 <script src="../../resources/js-test-pre.js"></script>
 <script src="../resources/webgl-test.js"></script>
 <script src="../resources/webgl-test-utils.js"></script>
 </head>
 <body>
 <div id="description"></div>
 <canvas id="canvas" style="width: 50px; height: 50px;"> </canvas>
 <div id="console"></div>
 <!-- Shaders for testing standard derivatives -->

 <!-- Shader omitting the required #extension pragma -->
 <script id="missingPragmaFragmentShader" type="x-shader/x-fragment">
 precision mediump float;
 varying vec2 texCoord;
 void main() {
     float dx = dFdx(texCoord.x);
     float dy = dFdy(texCoord.y);
     float w = fwidth(texCoord.x);
     gl_FragColor = vec4(dx, dy, w, 1.0);
 }
 </script>

 <!-- Shader to test macro definition -->
 <script id="macroFragmentShader" type="x-shader/x-fragment">
 precision mediump float;
 void main() {
 #ifdef GL_OES_standard_derivatives
     gl_FragColor = vec4(0.0, 0.0, 0.0, 0.0);
 #else
     // Error expected
     #error no GL_OES_standard_derivatives;
 #endif
 }
 </script>

 <!-- Shader with required #extension pragma -->
 <script id="testFragmentShader" type="x-shader/x-fragment">
 #extension GL_OES_standard_derivatives : enable
 precision mediump float;
 varying vec2 texCoord;
 void main() {
     float dx = dFdx(texCoord.x);
     float dy = dFdy(texCoord.y);
     float w = fwidth(texCoord.x);
     gl_FragColor = vec4(dx, dy, w, 1.0);
 }
 </script>
 <!-- Shaders to link with test fragment shaders -->
 <script id="goodVertexShader" type="x-shader/x-vertex">
 attribute vec4 vPosition;
 varying vec2 texCoord;
 void main() {
     texCoord = vPosition.xy;
     gl_Position = vPosition;
 }
 </script>
 <!-- Shaders to test output -->
 <script id="outputVertexShader" type="x-shader/x-vertex">
 attribute vec4 vPosition;
 varying vec4 position;
 void main() {
     position = vPosition;
     gl_Position = vPosition;
 }
 </script>
 <script id="outputFragmentShader" type="x-shader/x-fragment">
 #extension GL_OES_standard_derivatives : enable
 precision mediump float;
 varying vec4 position;
 void main() {
     float dzdx = dFdx(position.z);
     float dzdy = dFdy(position.z);
     float fw = fwidth(position.z);
     gl_FragColor = vec4(abs(dzdx) * 40.0, abs(dzdy) * 40.0, fw * 40.0, 1.0);
 }
 </script>

 <script>
 "use strict";
 description("This test verifies the functionality of the OES_standard_derivatives extension, if it is available.");

 debug("");

 var wtu = WebGLTestUtils;
 var canvas = document.getElementById("canvas");
 var gl = wtu.create3DContext(canvas);
 var ext = null;

 if (!gl) {
     testFailed("WebGL context does not exist");
 } else {
     testPassed("WebGL context exists");

     // Run tests with extension disabled
     runHintTestDisabled();
     runShaderTests(false);

     // Query the extension and store globally so shouldBe can access it
     ext = gl.getExtension("OES_standard_derivatives");
     if (!ext) {
         testPassed("No OES_standard_derivatives support -- this is legal");

         runSupportedTest(false);
     } else {
         testPassed("Successfully enabled OES_standard_derivatives extension");

         runSupportedTest(true);

         runHintTestEnabled();
         runShaderTests(true);
         runOutputTests();
         runUniqueObjectTest();
     }
 }

 function runSupportedTest(extensionEnabled) {
     var supported = gl.getSupportedExtensions();
     if (supported.indexOf("OES_standard_derivatives") >= 0) {
         if (extensionEnabled) {
             testPassed("OES_standard_derivatives listed as supported and getExtension succeeded");
         } else {
             testFailed("OES_standard_derivatives listed as supported but getExtension failed");
         }
     } else {
         if (extensionEnabled) {
             testFailed("OES_standard_derivatives not listed as supported but getExtension succeeded");
         } else {
             testPassed("OES_standard_derivatives not listed as supported and getExtension failed -- this is legal");
         }
     }
 }

 function runHintTestDisabled() {
     debug("Testing FRAGMENT_SHADER_DERIVATIVE_HINT_OES with extension disabled");

     // Use the constant directly as we don't have the extension
     var FRAGMENT_SHADER_DERIVATIVE_HINT_OES = 0x8B8B;

     gl.getParameter(FRAGMENT_SHADER_DERIVATIVE_HINT_OES);
     glErrorShouldBe(gl, gl.INVALID_ENUM, "FRAGMENT_SHADER_DERIVATIVE_HINT_OES should not be queryable if extension is disabled");

     gl.hint(FRAGMENT_SHADER_DERIVATIVE_HINT_OES, gl.DONT_CARE);
     glErrorShouldBe(gl, gl.INVALID_ENUM, "hint should not accept FRAGMENT_SHADER_DERIVATIVE_HINT_OES if extension is disabled");
 }

 function runHintTestEnabled() {
     debug("Testing FRAGMENT_SHADER_DERIVATIVE_HINT_OES with extension enabled");

     shouldBe("ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES", "0x8B8B");

     gl.getParameter(ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES);
     glErrorShouldBe(gl, gl.NO_ERROR, "FRAGMENT_SHADER_DERIVATIVE_HINT_OES query should succeed if extension is enabled");

     // Default value is DONT_CARE
     if (gl.getParameter(ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES) == gl.DONT_CARE) {
         testPassed("Default value of FRAGMENT_SHADER_DERIVATIVE_HINT_OES is DONT_CARE");
     } else {
         testFailed("Default value of FRAGMENT_SHADER_DERIVATIVE_HINT_OES is not DONT_CARE");
     }

     // Ensure that we can set the target
     gl.hint(ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES, gl.DONT_CARE);
     glErrorShouldBe(gl, gl.NO_ERROR, "hint should accept FRAGMENT_SHADER_DERIVATIVE_HINT_OES");

     // Test all the hint modes
     var validModes = ["FASTEST", "NICEST", "DONT_CARE"];
     var anyFailed = false;
     for (var n = 0; n < validModes.length; n++) {
         var mode = validModes[n];
         gl.hint(ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES, gl[mode]);
         if (gl.getParameter(ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES) != gl[mode]) {
             testFailed("Round-trip of hint()/getParameter() failed on mode " + mode);
             anyFailed = true;
         }
     }
     if (!anyFailed) {
         testPassed("Round-trip of hint()/getParameter() with all supported modes");
     }
 }

 function runShaderTests(extensionEnabled) {
     debug("");
     debug("Testing various shader compiles with extension " + (extensionEnabled ? "enabled" : "disabled"));

     // Expect the macro shader to succeed ONLY if enabled
     var macroFragmentProgram = wtu.loadProgramFromScriptExpectError(gl, "goodVertexShader", "macroFragmentShader");
     if (extensionEnabled) {
         if (macroFragmentProgram) {
             // Expected result
             testPassed("GL_OES_standard_derivatives defined in shaders when extension is enabled");
         } else {
             testFailed("GL_OES_standard_derivatives not defined in shaders when extension is enabled");
         }
     } else {
         if (macroFragmentProgram) {
             testFailed("GL_OES_standard_derivatives defined in shaders when extension is disabled");
         } else {
             testPassed("GL_OES_standard_derivatives not defined in shaders when extension disabled");
         }
     }

     // Always expect the shader missing the #pragma to fail (whether enabled or not)
     var missingPragmaFragmentProgram = wtu.loadProgramFromScriptExpectError(gl, "goodVertexShader", "missingPragmaFragmentShader");
     if (missingPragmaFragmentProgram) {
         testFailed("Shader built-ins allowed without #extension pragma");
     } else {
         testPassed("Shader built-ins disallowed without #extension pragma");
     }

     // Try to compile a shader using the built-ins that should only succeed if enabled
     var testFragmentProgram = wtu.loadProgramFromScriptExpectError(gl, "goodVertexShader", "testFragmentShader");
     if (extensionEnabled) {
         if (testFragmentProgram) {
             testPassed("Shader built-ins compiled successfully when extension enabled");
         } else {
             testFailed("Shader built-ins failed to compile when extension enabled");
         }
     } else {
         if (testFragmentProgram) {
             testFailed("Shader built-ins compiled successfully when extension disabled");
         } else {
             testPassed("Shader built-ins failed to compile when extension disabled");
         }
     }
 }

 function runOutputTests() {
     // This tests does several draws with various values of z.
     // The output of the fragment shader is:
     // [dFdx(z), dFdy(z), fwidth(z), 1.0]
     // The expected math: (note the conversion to uint8)
     //    canvas.width = canvas.height = 50
     //    dFdx = totalChange.x / canvas.width  = 0.5 / 50.0 = 0.01
     //    dFdy = totalChange.y / canvas.height = 0.5 / 50.0 = 0.01
     //    fw = abs(dFdx + dFdy) = 0.01 + 0.01 = 0.02
     //    r = floor(dFdx * 40.0 * 255) = 102
     //    g = floor(dFdy * 40.0 * 255) = 102
     //    b = floor(fw * 40.0 * 255) = 204

     var e = 5; // Amount of variance to allow in result pixels - may need to be tweaked higher

     debug("Testing various draws for valid built-in function behavior");

     canvas.width = 50; canvas.height = 50;
     gl.viewport(0, 0, canvas.width, canvas.height);
     gl.hint(ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES, gl.NICEST);

     var positionLoc = 0;
     var texcoordLoc = 1;
     var program = wtu.setupProgram(gl, ["outputVertexShader", "outputFragmentShader"], ['vPosition', 'texCoord0'], [0, 1]);
     var quadParameters = wtu.setupUnitQuad(gl, positionLoc, texcoordLoc);

     function readLocation(x, y) {
         var pixels = new Uint8Array(1 * 1 * 4);
         var px = Math.floor(x * canvas.width);
         var py = Math.floor(y * canvas.height);
         gl.readPixels(px, py, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, pixels);
         return pixels;
     };
     function toString(arr) {
         var s = "[";
         for (var n = 0; n < arr.length; n++) {
             s += arr[n];
             if (n < arr.length - 1) {
                 s += ", ";
             }
         }
         return s + "]";
     };
     function expectResult(target, successMessage, failureMessage) {
         var locations = [
             readLocation(0.1, 0.1),
             readLocation(0.9, 0.1),
             readLocation(0.1, 0.9),
             readLocation(0.9, 0.9),
             readLocation(0.5, 0.5)
         ];
         var anyDiffer = false;
         for (var n = 0; n < locations.length; n++) {
             var source = locations[n];
             for (var m = 0; m < 4; m++) {
                 if (Math.abs(source[m] - target[m]) > e) {
                     anyDiffer = true;
                     testFailed(failureMessage + "; should be " + toString(target) + ", was " + toString(source));
                     break;
                 }
             }
         }
         if (!anyDiffer) {
             testPassed(successMessage);
         }
     };

     function setupBuffers(tl, tr, bl, br) {
         gl.bindBuffer(gl.ARRAY_BUFFER, quadParameters[0]);
         gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([
            1.0,  1.0, tr,
           -1.0,  1.0, tl,
           -1.0, -1.0, bl,
            1.0,  1.0, tr,
           -1.0, -1.0, bl,
            1.0, -1.0, br]), gl.STATIC_DRAW);
         gl.vertexAttribPointer(positionLoc, 3, gl.FLOAT, false, 0, 0);
     };

     // Draw 1: (no variation)
     setupBuffers(0.0, 0.0, 0.0, 0.0);
     wtu.clearAndDrawUnitQuad(gl);
     expectResult([0, 0, 0, 255],
                  "Draw 1 (no variation) returned the correct data",
                  "Draw 1 (no variation) returned incorrect data");

     // Draw 2: (variation in x)
     setupBuffers(1.0, 0.0, 1.0, 0.0);
     wtu.clearAndDrawUnitQuad(gl);
     expectResult([204, 0, 204, 255],
                  "Draw 2 (variation in x) returned the correct data",
                  "Draw 2 (variation in x) returned incorrect data");

     // Draw 3: (variation in y)
     setupBuffers(1.0, 1.0, 0.0, 0.0);
     wtu.clearAndDrawUnitQuad(gl);
     expectResult([0, 204, 204, 255],
                  "Draw 3 (variation in y) returned the correct data",
                  "Draw 3 (variation in y) returned incorrect data");

     // Draw 4: (variation in x & y)
     setupBuffers(1.0, 0.5, 0.5, 0.0);
     wtu.clearAndDrawUnitQuad(gl);
     expectResult([102, 102, 204, 255],
                  "Draw 4 (variation in x & y) returned the correct data",
                  "Draw 4 (variation in x & y) returned incorrect data");

 }

 function runUniqueObjectTest()
 {
     debug("Testing that getExtension() returns the same object each time");
     gl.getExtension("OES_standard_derivatives").myProperty = 2;
     gc();
     shouldBe('gl.getExtension("OES_standard_derivatives").myProperty', '2');
 }

 debug("");
 var successfullyParsed = true;
 </script>
 <script src="../../resources/js-test-post.js"></script>

 </body>
 </html>
	<!--

	/*
	** Copyright (c) 2012 The Khronos Group Inc.
	**
	** Permission is hereby granted, free of charge, to any person obtaining a
	** copy of this software and/or associated documentation files (the
	** "Materials"), to deal in the Materials without restriction, including
	** without limitation the rights to use, copy, modify, merge, publish,
	** distribute, sublicense, and/or sell copies of the Materials, and to
	** permit persons to whom the Materials are furnished to do so, subject to
	** the following conditions:
	**
	** The above copyright notice and this permission notice shall be included
	** in all copies or substantial portions of the Materials.
	**
	** THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
	** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
	** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
	** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
	** MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
	*/

	-->

	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<title>WebGL OES_standard_derivatives Conformance Tests</title>
	<link rel="stylesheet" href="../../resources/js-test-style.css"/>
	<script src="../../resources/desktop-gl-constants.js" type="text/javascript"></script>
	<script src="../../resources/js-test-pre.js"></script>
	<script src="../resources/webgl-test.js"></script>
	<script src="../resources/webgl-test-utils.js"></script>
	</head>
	<body>
	<div id="description"></div>
	<canvas id="canvas" style="width: 50px; height: 50px;"> </canvas>
	<div id="console"></div>
	<!-- Shaders for testing standard derivatives -->

	<!-- Shader omitting the required #extension pragma -->
	<script id="missingPragmaFragmentShader" type="x-shader/x-fragment">
	precision mediump float;
	varying vec2 texCoord;
	void main() {
	float dx = dFdx(texCoord.x);
	float dy = dFdy(texCoord.y);
	float w = fwidth(texCoord.x);
	gl_FragColor = vec4(dx, dy, w, 1.0);
	}
	</script>

	<!-- Shader to test macro definition -->
	<script id="macroFragmentShader" type="x-shader/x-fragment">
	precision mediump float;
	void main() {
	#ifdef GL_OES_standard_derivatives
	gl_FragColor = vec4(0.0, 0.0, 0.0, 0.0);
	#else
	// Error expected
	#error no GL_OES_standard_derivatives;
	#endif
	}
	</script>

	<!-- Shader with required #extension pragma -->
	<script id="testFragmentShader" type="x-shader/x-fragment">
	#extension GL_OES_standard_derivatives : enable
	precision mediump float;
	varying vec2 texCoord;
	void main() {
	float dx = dFdx(texCoord.x);
	float dy = dFdy(texCoord.y);
	float w = fwidth(texCoord.x);
	gl_FragColor = vec4(dx, dy, w, 1.0);
	}
	</script>
	<!-- Shaders to link with test fragment shaders -->
	<script id="goodVertexShader" type="x-shader/x-vertex">
	attribute vec4 vPosition;
	varying vec2 texCoord;
	void main() {
	texCoord = vPosition.xy;
	gl_Position = vPosition;
	}
	</script>
	<!-- Shaders to test output -->
	<script id="outputVertexShader" type="x-shader/x-vertex">
	attribute vec4 vPosition;
	varying vec4 position;
	void main() {
	position = vPosition;
	gl_Position = vPosition;
	}
	</script>
	<script id="outputFragmentShader" type="x-shader/x-fragment">
	#extension GL_OES_standard_derivatives : enable
	precision mediump float;
	varying vec4 position;
	void main() {
	float dzdx = dFdx(position.z);
	float dzdy = dFdy(position.z);
	float fw = fwidth(position.z);
	gl_FragColor = vec4(abs(dzdx) * 40.0, abs(dzdy) * 40.0, fw * 40.0, 1.0);
	}
	</script>

	<script>
	"use strict";
	description("This test verifies the functionality of the OES_standard_derivatives extension, if it is available.");

	debug("");

	var wtu = WebGLTestUtils;
	var canvas = document.getElementById("canvas");
	var gl = wtu.create3DContext(canvas);
	var ext = null;

	if (!gl) {
	testFailed("WebGL context does not exist");
	} else {
	testPassed("WebGL context exists");

	// Run tests with extension disabled
	runHintTestDisabled();
	runShaderTests(false);

	// Query the extension and store globally so shouldBe can access it
	ext = gl.getExtension("OES_standard_derivatives");
	if (!ext) {
	testPassed("No OES_standard_derivatives support -- this is legal");

	runSupportedTest(false);
	} else {
	testPassed("Successfully enabled OES_standard_derivatives extension");

	runSupportedTest(true);

	runHintTestEnabled();
	runShaderTests(true);
	runOutputTests();
	runUniqueObjectTest();
	}
	}

	function runSupportedTest(extensionEnabled) {
	var supported = gl.getSupportedExtensions();
	if (supported.indexOf("OES_standard_derivatives") >= 0) {
	if (extensionEnabled) {
	testPassed("OES_standard_derivatives listed as supported and getExtension succeeded");
	} else {
	testFailed("OES_standard_derivatives listed as supported but getExtension failed");
	}
	} else {
	if (extensionEnabled) {
	testFailed("OES_standard_derivatives not listed as supported but getExtension succeeded");
	} else {
	testPassed("OES_standard_derivatives not listed as supported and getExtension failed -- this is legal");
	}
	}
	}

	function runHintTestDisabled() {
	debug("Testing FRAGMENT_SHADER_DERIVATIVE_HINT_OES with extension disabled");

	// Use the constant directly as we don't have the extension
	var FRAGMENT_SHADER_DERIVATIVE_HINT_OES = 0x8B8B;

	gl.getParameter(FRAGMENT_SHADER_DERIVATIVE_HINT_OES);
	glErrorShouldBe(gl, gl.INVALID_ENUM, "FRAGMENT_SHADER_DERIVATIVE_HINT_OES should not be queryable if extension is disabled");

	gl.hint(FRAGMENT_SHADER_DERIVATIVE_HINT_OES, gl.DONT_CARE);
	glErrorShouldBe(gl, gl.INVALID_ENUM, "hint should not accept FRAGMENT_SHADER_DERIVATIVE_HINT_OES if extension is disabled");
	}

	function runHintTestEnabled() {
	debug("Testing FRAGMENT_SHADER_DERIVATIVE_HINT_OES with extension enabled");

	shouldBe("ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES", "0x8B8B");

	gl.getParameter(ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES);
	glErrorShouldBe(gl, gl.NO_ERROR, "FRAGMENT_SHADER_DERIVATIVE_HINT_OES query should succeed if extension is enabled");

	// Default value is DONT_CARE
	if (gl.getParameter(ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES) == gl.DONT_CARE) {
	testPassed("Default value of FRAGMENT_SHADER_DERIVATIVE_HINT_OES is DONT_CARE");
	} else {
	testFailed("Default value of FRAGMENT_SHADER_DERIVATIVE_HINT_OES is not DONT_CARE");
	}

	// Ensure that we can set the target
	gl.hint(ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES, gl.DONT_CARE);
	glErrorShouldBe(gl, gl.NO_ERROR, "hint should accept FRAGMENT_SHADER_DERIVATIVE_HINT_OES");

	// Test all the hint modes
	var validModes = ["FASTEST", "NICEST", "DONT_CARE"];
	var anyFailed = false;
	for (var n = 0; n < validModes.length; n++) {
	var mode = validModes[n];
	gl.hint(ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES, gl[mode]);
	if (gl.getParameter(ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES) != gl[mode]) {
	testFailed("Round-trip of hint()/getParameter() failed on mode " + mode);
	anyFailed = true;
	}
	}
	if (!anyFailed) {
	testPassed("Round-trip of hint()/getParameter() with all supported modes");
	}
	}

	function runShaderTests(extensionEnabled) {
	debug("");
	debug("Testing various shader compiles with extension " + (extensionEnabled ? "enabled" : "disabled"));

	// Expect the macro shader to succeed ONLY if enabled
	var macroFragmentProgram = wtu.loadProgramFromScriptExpectError(gl, "goodVertexShader", "macroFragmentShader");
	if (extensionEnabled) {
	if (macroFragmentProgram) {
	// Expected result
	testPassed("GL_OES_standard_derivatives defined in shaders when extension is enabled");
	} else {
	testFailed("GL_OES_standard_derivatives not defined in shaders when extension is enabled");
	}
	} else {
	if (macroFragmentProgram) {
	testFailed("GL_OES_standard_derivatives defined in shaders when extension is disabled");
	} else {
	testPassed("GL_OES_standard_derivatives not defined in shaders when extension disabled");
	}
	}

	// Always expect the shader missing the #pragma to fail (whether enabled or not)
	var missingPragmaFragmentProgram = wtu.loadProgramFromScriptExpectError(gl, "goodVertexShader", "missingPragmaFragmentShader");
	if (missingPragmaFragmentProgram) {
	testFailed("Shader built-ins allowed without #extension pragma");
	} else {
	testPassed("Shader built-ins disallowed without #extension pragma");
	}

	// Try to compile a shader using the built-ins that should only succeed if enabled
	var testFragmentProgram = wtu.loadProgramFromScriptExpectError(gl, "goodVertexShader", "testFragmentShader");
	if (extensionEnabled) {
	if (testFragmentProgram) {
	testPassed("Shader built-ins compiled successfully when extension enabled");
	} else {
	testFailed("Shader built-ins failed to compile when extension enabled");
	}
	} else {
	if (testFragmentProgram) {
	testFailed("Shader built-ins compiled successfully when extension disabled");
	} else {
	testPassed("Shader built-ins failed to compile when extension disabled");
	}
	}
	}

	function runOutputTests() {
	// This tests does several draws with various values of z.
	// The output of the fragment shader is:
	// [dFdx(z), dFdy(z), fwidth(z), 1.0]
	// The expected math: (note the conversion to uint8)
	// canvas.width = canvas.height = 50
	// dFdx = totalChange.x / canvas.width = 0.5 / 50.0 = 0.01
	// dFdy = totalChange.y / canvas.height = 0.5 / 50.0 = 0.01
	// fw = abs(dFdx + dFdy) = 0.01 + 0.01 = 0.02
	// r = floor(dFdx * 40.0 * 255) = 102
	// g = floor(dFdy * 40.0 * 255) = 102
	// b = floor(fw * 40.0 * 255) = 204

	var e = 5; // Amount of variance to allow in result pixels - may need to be tweaked higher

	debug("Testing various draws for valid built-in function behavior");

	canvas.width = 50; canvas.height = 50;
	gl.viewport(0, 0, canvas.width, canvas.height);
	gl.hint(ext.FRAGMENT_SHADER_DERIVATIVE_HINT_OES, gl.NICEST);

	var positionLoc = 0;
	var texcoordLoc = 1;
	var program = wtu.setupProgram(gl, ["outputVertexShader", "outputFragmentShader"], ['vPosition', 'texCoord0'], [0, 1]);
	var quadParameters = wtu.setupUnitQuad(gl, positionLoc, texcoordLoc);

	function readLocation(x, y) {
	var pixels = new Uint8Array(1 * 1 * 4);
	var px = Math.floor(x * canvas.width);
	var py = Math.floor(y * canvas.height);
	gl.readPixels(px, py, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, pixels);
	return pixels;
	};
	function toString(arr) {
	var s = "[";
	for (var n = 0; n < arr.length; n++) {
	s += arr[n];
	if (n < arr.length - 1) {
	s += ", ";
	}
	}
	return s + "]";
	};
	function expectResult(target, successMessage, failureMessage) {
	var locations = [
	readLocation(0.1, 0.1),
	readLocation(0.9, 0.1),
	readLocation(0.1, 0.9),
	readLocation(0.9, 0.9),
	readLocation(0.5, 0.5)
	];
	var anyDiffer = false;
	for (var n = 0; n < locations.length; n++) {
	var source = locations[n];
	for (var m = 0; m < 4; m++) {
	if (Math.abs(source[m] - target[m]) > e) {
	anyDiffer = true;
	testFailed(failureMessage + "; should be " + toString(target) + ", was " + toString(source));
	break;
	}
	}
	}
	if (!anyDiffer) {
	testPassed(successMessage);
	}
	};

	function setupBuffers(tl, tr, bl, br) {
	gl.bindBuffer(gl.ARRAY_BUFFER, quadParameters[0]);
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([
	1.0, 1.0, tr,
	-1.0, 1.0, tl,
	-1.0, -1.0, bl,
	1.0, 1.0, tr,
	-1.0, -1.0, bl,
	1.0, -1.0, br]), gl.STATIC_DRAW);
	gl.vertexAttribPointer(positionLoc, 3, gl.FLOAT, false, 0, 0);
	};

	// Draw 1: (no variation)
	setupBuffers(0.0, 0.0, 0.0, 0.0);
	wtu.clearAndDrawUnitQuad(gl);
	expectResult([0, 0, 0, 255],
	"Draw 1 (no variation) returned the correct data",
	"Draw 1 (no variation) returned incorrect data");

	// Draw 2: (variation in x)
	setupBuffers(1.0, 0.0, 1.0, 0.0);
	wtu.clearAndDrawUnitQuad(gl);
	expectResult([204, 0, 204, 255],
	"Draw 2 (variation in x) returned the correct data",
	"Draw 2 (variation in x) returned incorrect data");

	// Draw 3: (variation in y)
	setupBuffers(1.0, 1.0, 0.0, 0.0);
	wtu.clearAndDrawUnitQuad(gl);
	expectResult([0, 204, 204, 255],
	"Draw 3 (variation in y) returned the correct data",
	"Draw 3 (variation in y) returned incorrect data");

	// Draw 4: (variation in x & y)
	setupBuffers(1.0, 0.5, 0.5, 0.0);
	wtu.clearAndDrawUnitQuad(gl);
	expectResult([102, 102, 204, 255],
	"Draw 4 (variation in x & y) returned the correct data",
	"Draw 4 (variation in x & y) returned incorrect data");

	}

	function runUniqueObjectTest()
	{
	debug("Testing that getExtension() returns the same object each time");
	gl.getExtension("OES_standard_derivatives").myProperty = 2;
	gc();
	shouldBe('gl.getExtension("OES_standard_derivatives").myProperty', '2');
	}

	debug("");
	var successfullyParsed = true;
	</script>
	<script src="../../resources/js-test-post.js"></script>

	</body>
	</html>