LayoutTests/fast/canvas/webgl/oes-element-index-uint.html - WebKit - Git at Google

 <!DOCTYPE html>
 <html>
 <head>
 <meta charset="utf-8">
 <title>WebGL OES_element_index_uint Conformance Tests</title>
 <script src="resources/desktop-gl-constants.js" type="text/javascript"></script>
 <script src="../../../resources/js-test.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>
 <script id="vs" type="x-shader/x-vertex">
 attribute vec4 vPosition;
 attribute vec4 vColor;
 varying vec4 color;
 void main() {
     gl_Position = vPosition;
     color = vColor;
 }
 </script>
 <script id="fs" type="x-shader/x-fragment">
 #if defined(GL_ES)
 precision mediump float;
 #endif
 varying vec4 color;
 void main() {
   gl_FragColor = color;
 }
 </script>
 <script>
 description("This test verifies the functionality of the OES_element_index_uint extension, if it is available.");

 debug("");

 if (window.internals)
     window.internals.settings.setWebGLErrorsToConsoleEnabled(false);

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

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

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

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

         runSupportedTest(true);
         runDrawTests();

         // These tests are tweaked duplicates of the buffers/index-validation* tests
         // using unsigned int indices to ensure that behavior remains consistent
         runIndexValidationTests();
         runCopiesIndicesTests();
         runResizedBufferTests();
         runVerifiesTooManyIndicesTests();
         runCrashWithBufferSubDataTests();

         glErrorShouldBe(gl, gl.NO_ERROR, "there should be no errors");
     }
 }

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

 function runDrawTests() {
     debug("Test that draws with unsigned integer indices produce the expected results");

     canvas.width = 50; canvas.height = 50;
     gl.viewport(0, 0, canvas.width, canvas.height);

     var program = wtu.setupSimpleTextureProgram(gl);

     function setupDraw(s) {
         // Create a vertex buffer that cannot be fully indexed via shorts
         var quadArrayLen = 65537 * 3;
         var quadArray = new Float32Array(quadArrayLen);

         // Leave all but the last 4 values zero-ed out
         var idx = quadArrayLen - 12;

         // Initialized the last 4 values to a quad
         quadArray[idx++] = 1.0 * s;
         quadArray[idx++] = 1.0 * s;
         quadArray[idx++] = 0.0;

         quadArray[idx++] = -1.0 * s;
         quadArray[idx++] = 1.0 * s;
         quadArray[idx++] = 0.0;

         quadArray[idx++] = -1.0 * s;
         quadArray[idx++] = -1.0 * s;
         quadArray[idx++] = 0.0;

         quadArray[idx++] = 1.0 * s;
         quadArray[idx++] = -1.0 * s;
         quadArray[idx++] = 0.0;

         var vertexObject = gl.createBuffer();
         gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
         gl.bufferData(gl.ARRAY_BUFFER, quadArray, gl.STATIC_DRAW);

         // Create an unsigned int index buffer that indexes the last 4 vertices
         var baseIndex = (quadArrayLen / 3) - 4;

         var indexObject = gl.createBuffer();
         gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexObject);
         gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint32Array([
             baseIndex + 0,
             baseIndex + 1,
             baseIndex + 2,
             baseIndex + 2,
             baseIndex + 3,
             baseIndex + 0]), gl.STATIC_DRAW);

         var opt_positionLocation = 0;
         gl.enableVertexAttribArray(opt_positionLocation);
         gl.vertexAttribPointer(opt_positionLocation, 3, gl.FLOAT, false, 0, 0);
     };
     function readLocation(x, y) {
         var pixels = new Uint8Array(1 * 1 * 4);
         gl.readPixels(x, y, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, pixels);
         return pixels;
     };
     function testPixel(blackList, whiteList) {
         function testList(list, expected) {
             for (var n = 0; n < list.length; n++) {
                 var l = list[n];
                 var x = -Math.floor(l * canvas.width / 2) + canvas.width / 2;
                 var y = -Math.floor(l * canvas.height / 2) + canvas.height / 2;
                 var source = readLocation(x, y);
                 if (Math.abs(source[0] - expected) > 2) {
                     return false;
                 }
             }
             return true;
         }
         return testList(blackList, 0) && testList(whiteList, 255);
     };
     function verifyDraw(drawNumber, s) {
         gl.clearColor(1.0, 1.0, 1.0, 1.0);
         gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
         gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_INT, 0);

         var blackList = [];
         var whiteList = [];
         var points = [0.0, 0.2, 0.4, 0.6, 0.8, 1.0];
         for (var n = 0; n < points.length; n++) {
             if (points[n] <= s) {
                 blackList.push(points[n]);
             } else {
                 whiteList.push(points[n]);
             }
         }
         if (testPixel(blackList, whiteList)) {
             testPassed("Draw " + drawNumber + " passed pixel test");
         } else {
             testFailed("Draw " + drawNumber + " failed pixel test");
         }
     };

     setupDraw(0.5);
     verifyDraw(0, 0.5);
 }

 function runIndexValidationTests() {
     description("Tests that index validation verifies the correct number of indices");

     function sizeInBytes(type) {
       switch (type) {
       case gl.BYTE:
       case gl.UNSIGNED_BYTE:
         return 1;
       case gl.SHORT:
       case gl.UNSIGNED_SHORT:
         return 2;
       case gl.INT:
       case gl.UNSIGNED_INT:
       case gl.FLOAT:
         return 4;
       default:
         throw "unknown type";
       }
     }

     var program = loadStandardProgram(gl);

     // 3 vertices => 1 triangle, interleaved data
     var dataComplete = new Float32Array([0, 0, 0, 1,
                                          0, 0, 1,
                                          1, 0, 0, 1,
                                          0, 0, 1,
                                          1, 1, 1, 1,
                                          0, 0, 1]);
     var dataIncomplete = new Float32Array([0, 0, 0, 1,
                                            0, 0, 1,
                                            1, 0, 0, 1,
                                            0, 0, 1,
                                            1, 1, 1, 1]);
     var indices = new Uint32Array([0, 1, 2]);

     debug("Testing with valid indices");

     var bufferComplete = gl.createBuffer();
     gl.bindBuffer(gl.ARRAY_BUFFER, bufferComplete);
     gl.bufferData(gl.ARRAY_BUFFER, dataComplete, gl.STATIC_DRAW);
     var elements = gl.createBuffer();
     gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, elements);
     gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, indices, gl.STATIC_DRAW);
     gl.useProgram(program);
     var vertexLoc = gl.getAttribLocation(program, "a_vertex");
     var normalLoc = gl.getAttribLocation(program, "a_normal");
     gl.vertexAttribPointer(vertexLoc, 4, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), 0);
     gl.enableVertexAttribArray(vertexLoc);
     gl.vertexAttribPointer(normalLoc, 3, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), 4 * sizeInBytes(gl.FLOAT));
     gl.enableVertexAttribArray(normalLoc);
     shouldBe('gl.checkFramebufferStatus(gl.FRAMEBUFFER)', 'gl.FRAMEBUFFER_COMPLETE');
     glErrorShouldBe(gl, gl.NO_ERROR);
     shouldBeUndefined('gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_INT, 0)');
     glErrorShouldBe(gl, gl.NO_ERROR);

     debug("Testing with out-of-range indices");

     var bufferIncomplete = gl.createBuffer();
     gl.bindBuffer(gl.ARRAY_BUFFER, bufferIncomplete);
     gl.bufferData(gl.ARRAY_BUFFER, dataIncomplete, gl.STATIC_DRAW);
     gl.vertexAttribPointer(vertexLoc, 4, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), 0);
     gl.enableVertexAttribArray(vertexLoc);
     gl.disableVertexAttribArray(normalLoc);
     debug("Enable vertices, valid");
     glErrorShouldBe(gl, gl.NO_ERROR);
     shouldBeUndefined('gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_INT, 0)');
     glErrorShouldBe(gl, gl.NO_ERROR);
     debug("Enable normals, out-of-range");
     gl.vertexAttribPointer(normalLoc, 3, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), 4 * sizeInBytes(gl.FLOAT));
     gl.enableVertexAttribArray(normalLoc);
     glErrorShouldBe(gl, gl.NO_ERROR);
     shouldBeUndefined('gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_INT, 0)');
     glErrorShouldBe(gl, gl.INVALID_OPERATION);

     debug("Test with enabled attribute that does not belong to current program");

     gl.disableVertexAttribArray(normalLoc);
     var extraLoc = Math.max(vertexLoc, normalLoc) + 1;
     gl.enableVertexAttribArray(extraLoc);
     debug("Enable an extra attribute with null");
     glErrorShouldBe(gl, gl.NO_ERROR);
     shouldBeUndefined('gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_INT, 0)');
     glErrorShouldBe(gl, gl.INVALID_OPERATION);
     debug("Enable an extra attribute with insufficient data buffer");
     gl.vertexAttribPointer(extraLoc, 3, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), 4 * sizeInBytes(gl.FLOAT));
     glErrorShouldBe(gl, gl.NO_ERROR);
     shouldBeUndefined('gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_INT, 0)');
     debug("Pass large negative index to vertexAttribPointer");
     gl.vertexAttribPointer(normalLoc, 3, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), -2000000000 * sizeInBytes(gl.FLOAT));
     glErrorShouldBe(gl, gl.INVALID_VALUE);
     shouldBeUndefined('gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_INT, 0)');
     gl.disableVertexAttribArray(vertexLoc);
 }

 function runCopiesIndicesTests() {
     debug("Test that client data is always copied during bufferData and bufferSubData calls");

     var program = loadStandardProgram(gl);

     gl.useProgram(program);
     var vertexObject = gl.createBuffer();
     gl.enableVertexAttribArray(0);
     gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
     // 4 vertices -> 2 triangles
     gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([ 0,0,0, 0,1,0, 1,0,0, 1,1,0 ]), gl.STATIC_DRAW);
     gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);

     var indexObject = gl.createBuffer();

     gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexObject);
     var indices = new Uint32Array([ 10000, 0, 1, 2, 3, 10000 ]);
     gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, indices, gl.STATIC_DRAW);
     shouldGenerateGLError(gl, gl.NO_ERROR, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 4)");
     shouldGenerateGLError(gl, gl.INVALID_OPERATION, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 0)");
     shouldGenerateGLError(gl, gl.INVALID_OPERATION, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 8)");
     indices[0] = 2;
     indices[5] = 1;
     shouldGenerateGLError(gl, gl.NO_ERROR, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 4)");
     shouldGenerateGLError(gl, gl.INVALID_OPERATION, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 0)");
     shouldGenerateGLError(gl, gl.INVALID_OPERATION, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 8)");
 }

 function runResizedBufferTests() {
     debug("Test that updating the size of a vertex buffer is properly noticed by the WebGL implementation.");

     var program = wtu.setupProgram(gl, ["vs", "fs"], ["vPosition", "vColor"]);
     glErrorShouldBe(gl, gl.NO_ERROR, "after initialization");

     var vertexObject = gl.createBuffer();
     gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
     gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(
         [-1,1,0, 1,1,0, -1,-1,0,
          -1,-1,0, 1,1,0, 1,-1,0]), gl.STATIC_DRAW);
     gl.enableVertexAttribArray(0);
     gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);
     glErrorShouldBe(gl, gl.NO_ERROR, "after vertex setup");

     var texCoordObject = gl.createBuffer();
     gl.bindBuffer(gl.ARRAY_BUFFER, texCoordObject);
     gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(
         [0,0, 1,0, 0,1,
          0,1, 1,0, 1,1]), gl.STATIC_DRAW);
     gl.enableVertexAttribArray(1);
     gl.vertexAttribPointer(1, 2, gl.FLOAT, false, 0, 0);
     glErrorShouldBe(gl, gl.NO_ERROR, "after texture coord setup");

     // Now resize these buffers because we want to change what we're drawing.
     gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
     gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([
         -1,1,0, 1,1,0, -1,-1,0, 1,-1,0,
         -1,1,0, 1,1,0, -1,-1,0, 1,-1,0]), gl.STATIC_DRAW);
     glErrorShouldBe(gl, gl.NO_ERROR, "after vertex redefinition");
     gl.bindBuffer(gl.ARRAY_BUFFER, texCoordObject);
     gl.bufferData(gl.ARRAY_BUFFER, new Uint8Array([
         255, 0, 0, 255,
         255, 0, 0, 255,
         255, 0, 0, 255,
         255, 0, 0, 255,
         0, 255, 0, 255,
         0, 255, 0, 255,
         0, 255, 0, 255,
         0, 255, 0, 255]), gl.STATIC_DRAW);
     gl.vertexAttribPointer(1, 4, gl.UNSIGNED_BYTE, false, 0, 0);
     glErrorShouldBe(gl, gl.NO_ERROR, "after texture coordinate / color redefinition");

     var numQuads = 2;
     var indices = new Uint32Array(numQuads * 6);
     for (var ii = 0; ii < numQuads; ++ii) {
         var offset = ii * 6;
         var quad = (ii == (numQuads - 1)) ? 4 : 0;
         indices[offset + 0] = quad + 0;
         indices[offset + 1] = quad + 1;
         indices[offset + 2] = quad + 2;
         indices[offset + 3] = quad + 2;
         indices[offset + 4] = quad + 1;
         indices[offset + 5] = quad + 3;
     }
     var indexObject = gl.createBuffer();
     gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexObject);
     gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, indices, gl.STATIC_DRAW);
     glErrorShouldBe(gl, gl.NO_ERROR, "after setting up indices");
     gl.drawElements(gl.TRIANGLES, numQuads * 6, gl.UNSIGNED_INT, 0);
     glErrorShouldBe(gl, gl.NO_ERROR, "after drawing");
 }

 function runVerifiesTooManyIndicesTests() {
     description("Tests that index validation for drawElements does not examine too many indices");

     var program = loadStandardProgram(gl);

     gl.useProgram(program);
     var vertexObject = gl.createBuffer();
     gl.enableVertexAttribArray(0);
     gl.disableVertexAttribArray(1);
     gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
     // 4 vertices -> 2 triangles
     gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([ 0,0,0, 0,1,0, 1,0,0, 1,1,0 ]), gl.STATIC_DRAW);
     gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);

     var indexObject = gl.createBuffer();

     debug("Test out of range indices")
     gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexObject);
     gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint32Array([ 10000, 0, 1, 2, 3, 10000 ]), gl.STATIC_DRAW);
     shouldGenerateGLError(gl, gl.NO_ERROR, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 4)");
     shouldGenerateGLError(gl, gl.INVALID_OPERATION, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 0)");
     shouldGenerateGLError(gl, gl.INVALID_OPERATION, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 8)");
 }

 function runCrashWithBufferSubDataTests() {
     debug('Verifies that the index validation code which is within bufferSubData does not crash.')

     var elementBuffer = gl.createBuffer();
     gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, elementBuffer);
     gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, 256, gl.STATIC_DRAW);
     var data = new Uint32Array(127);
     gl.bufferSubData(gl.ELEMENT_ARRAY_BUFFER, 64, data);
     glErrorShouldBe(gl, gl.INVALID_VALUE, "after attempting to update a buffer outside of the allocated bounds");
     testPassed("bufferSubData, when buffer object was initialized with null, did not crash");
 }

 debug("");
 </script>
 </body>
 </html>
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<title>WebGL OES_element_index_uint Conformance Tests</title>
	<script src="resources/desktop-gl-constants.js" type="text/javascript"></script>
	<script src="../../../resources/js-test.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>
	<script id="vs" type="x-shader/x-vertex">
	attribute vec4 vPosition;
	attribute vec4 vColor;
	varying vec4 color;
	void main() {
	gl_Position = vPosition;
	color = vColor;
	}
	</script>
	<script id="fs" type="x-shader/x-fragment">
	#if defined(GL_ES)
	precision mediump float;
	#endif
	varying vec4 color;
	void main() {
	gl_FragColor = color;
	}
	</script>
	<script>
	description("This test verifies the functionality of the OES_element_index_uint extension, if it is available.");

	debug("");

	if (window.internals)
	window.internals.settings.setWebGLErrorsToConsoleEnabled(false);

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

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

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

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

	runSupportedTest(true);
	runDrawTests();

	// These tests are tweaked duplicates of the buffers/index-validation* tests
	// using unsigned int indices to ensure that behavior remains consistent
	runIndexValidationTests();
	runCopiesIndicesTests();
	runResizedBufferTests();
	runVerifiesTooManyIndicesTests();
	runCrashWithBufferSubDataTests();

	glErrorShouldBe(gl, gl.NO_ERROR, "there should be no errors");
	}
	}

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

	function runDrawTests() {
	debug("Test that draws with unsigned integer indices produce the expected results");

	canvas.width = 50; canvas.height = 50;
	gl.viewport(0, 0, canvas.width, canvas.height);

	var program = wtu.setupSimpleTextureProgram(gl);

	function setupDraw(s) {
	// Create a vertex buffer that cannot be fully indexed via shorts
	var quadArrayLen = 65537 * 3;
	var quadArray = new Float32Array(quadArrayLen);

	// Leave all but the last 4 values zero-ed out
	var idx = quadArrayLen - 12;

	// Initialized the last 4 values to a quad
	quadArray[idx++] = 1.0 * s;
	quadArray[idx++] = 1.0 * s;
	quadArray[idx++] = 0.0;

	quadArray[idx++] = -1.0 * s;
	quadArray[idx++] = 1.0 * s;
	quadArray[idx++] = 0.0;

	quadArray[idx++] = -1.0 * s;
	quadArray[idx++] = -1.0 * s;
	quadArray[idx++] = 0.0;

	quadArray[idx++] = 1.0 * s;
	quadArray[idx++] = -1.0 * s;
	quadArray[idx++] = 0.0;

	var vertexObject = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
	gl.bufferData(gl.ARRAY_BUFFER, quadArray, gl.STATIC_DRAW);

	// Create an unsigned int index buffer that indexes the last 4 vertices
	var baseIndex = (quadArrayLen / 3) - 4;

	var indexObject = gl.createBuffer();
	gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexObject);
	gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint32Array([
	baseIndex + 0,
	baseIndex + 1,
	baseIndex + 2,
	baseIndex + 2,
	baseIndex + 3,
	baseIndex + 0]), gl.STATIC_DRAW);

	var opt_positionLocation = 0;
	gl.enableVertexAttribArray(opt_positionLocation);
	gl.vertexAttribPointer(opt_positionLocation, 3, gl.FLOAT, false, 0, 0);
	};
	function readLocation(x, y) {
	var pixels = new Uint8Array(1 * 1 * 4);
	gl.readPixels(x, y, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, pixels);
	return pixels;
	};
	function testPixel(blackList, whiteList) {
	function testList(list, expected) {
	for (var n = 0; n < list.length; n++) {
	var l = list[n];
	var x = -Math.floor(l * canvas.width / 2) + canvas.width / 2;
	var y = -Math.floor(l * canvas.height / 2) + canvas.height / 2;
	var source = readLocation(x, y);
	if (Math.abs(source[0] - expected) > 2) {
	return false;
	}
	}
	return true;
	}
	return testList(blackList, 0) && testList(whiteList, 255);
	};
	function verifyDraw(drawNumber, s) {
	gl.clearColor(1.0, 1.0, 1.0, 1.0);
	gl.clear(gl.COLOR_BUFFER_BIT \| gl.DEPTH_BUFFER_BIT);
	gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_INT, 0);

	var blackList = [];
	var whiteList = [];
	var points = [0.0, 0.2, 0.4, 0.6, 0.8, 1.0];
	for (var n = 0; n < points.length; n++) {
	if (points[n] <= s) {
	blackList.push(points[n]);
	} else {
	whiteList.push(points[n]);
	}
	}
	if (testPixel(blackList, whiteList)) {
	testPassed("Draw " + drawNumber + " passed pixel test");
	} else {
	testFailed("Draw " + drawNumber + " failed pixel test");
	}
	};

	setupDraw(0.5);
	verifyDraw(0, 0.5);
	}

	function runIndexValidationTests() {
	description("Tests that index validation verifies the correct number of indices");

	function sizeInBytes(type) {
	switch (type) {
	case gl.BYTE:
	case gl.UNSIGNED_BYTE:
	return 1;
	case gl.SHORT:
	case gl.UNSIGNED_SHORT:
	return 2;
	case gl.INT:
	case gl.UNSIGNED_INT:
	case gl.FLOAT:
	return 4;
	default:
	throw "unknown type";
	}
	}

	var program = loadStandardProgram(gl);

	// 3 vertices => 1 triangle, interleaved data
	var dataComplete = new Float32Array([0, 0, 0, 1,
	0, 0, 1,
	1, 0, 0, 1,
	0, 0, 1,
	1, 1, 1, 1,
	0, 0, 1]);
	var dataIncomplete = new Float32Array([0, 0, 0, 1,
	0, 0, 1,
	1, 0, 0, 1,
	0, 0, 1,
	1, 1, 1, 1]);
	var indices = new Uint32Array([0, 1, 2]);

	debug("Testing with valid indices");

	var bufferComplete = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, bufferComplete);
	gl.bufferData(gl.ARRAY_BUFFER, dataComplete, gl.STATIC_DRAW);
	var elements = gl.createBuffer();
	gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, elements);
	gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, indices, gl.STATIC_DRAW);
	gl.useProgram(program);
	var vertexLoc = gl.getAttribLocation(program, "a_vertex");
	var normalLoc = gl.getAttribLocation(program, "a_normal");
	gl.vertexAttribPointer(vertexLoc, 4, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), 0);
	gl.enableVertexAttribArray(vertexLoc);
	gl.vertexAttribPointer(normalLoc, 3, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), 4 * sizeInBytes(gl.FLOAT));
	gl.enableVertexAttribArray(normalLoc);
	shouldBe('gl.checkFramebufferStatus(gl.FRAMEBUFFER)', 'gl.FRAMEBUFFER_COMPLETE');
	glErrorShouldBe(gl, gl.NO_ERROR);
	shouldBeUndefined('gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_INT, 0)');
	glErrorShouldBe(gl, gl.NO_ERROR);

	debug("Testing with out-of-range indices");

	var bufferIncomplete = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, bufferIncomplete);
	gl.bufferData(gl.ARRAY_BUFFER, dataIncomplete, gl.STATIC_DRAW);
	gl.vertexAttribPointer(vertexLoc, 4, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), 0);
	gl.enableVertexAttribArray(vertexLoc);
	gl.disableVertexAttribArray(normalLoc);
	debug("Enable vertices, valid");
	glErrorShouldBe(gl, gl.NO_ERROR);
	shouldBeUndefined('gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_INT, 0)');
	glErrorShouldBe(gl, gl.NO_ERROR);
	debug("Enable normals, out-of-range");
	gl.vertexAttribPointer(normalLoc, 3, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), 4 * sizeInBytes(gl.FLOAT));
	gl.enableVertexAttribArray(normalLoc);
	glErrorShouldBe(gl, gl.NO_ERROR);
	shouldBeUndefined('gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_INT, 0)');
	glErrorShouldBe(gl, gl.INVALID_OPERATION);

	debug("Test with enabled attribute that does not belong to current program");

	gl.disableVertexAttribArray(normalLoc);
	var extraLoc = Math.max(vertexLoc, normalLoc) + 1;
	gl.enableVertexAttribArray(extraLoc);
	debug("Enable an extra attribute with null");
	glErrorShouldBe(gl, gl.NO_ERROR);
	shouldBeUndefined('gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_INT, 0)');
	glErrorShouldBe(gl, gl.INVALID_OPERATION);
	debug("Enable an extra attribute with insufficient data buffer");
	gl.vertexAttribPointer(extraLoc, 3, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), 4 * sizeInBytes(gl.FLOAT));
	glErrorShouldBe(gl, gl.NO_ERROR);
	shouldBeUndefined('gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_INT, 0)');
	debug("Pass large negative index to vertexAttribPointer");
	gl.vertexAttribPointer(normalLoc, 3, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), -2000000000 * sizeInBytes(gl.FLOAT));
	glErrorShouldBe(gl, gl.INVALID_VALUE);
	shouldBeUndefined('gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_INT, 0)');
	gl.disableVertexAttribArray(vertexLoc);
	}

	function runCopiesIndicesTests() {
	debug("Test that client data is always copied during bufferData and bufferSubData calls");

	var program = loadStandardProgram(gl);

	gl.useProgram(program);
	var vertexObject = gl.createBuffer();
	gl.enableVertexAttribArray(0);
	gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
	// 4 vertices -> 2 triangles
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([ 0,0,0, 0,1,0, 1,0,0, 1,1,0 ]), gl.STATIC_DRAW);
	gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);

	var indexObject = gl.createBuffer();

	gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexObject);
	var indices = new Uint32Array([ 10000, 0, 1, 2, 3, 10000 ]);
	gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, indices, gl.STATIC_DRAW);
	shouldGenerateGLError(gl, gl.NO_ERROR, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 4)");
	shouldGenerateGLError(gl, gl.INVALID_OPERATION, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 0)");
	shouldGenerateGLError(gl, gl.INVALID_OPERATION, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 8)");
	indices[0] = 2;
	indices[5] = 1;
	shouldGenerateGLError(gl, gl.NO_ERROR, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 4)");
	shouldGenerateGLError(gl, gl.INVALID_OPERATION, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 0)");
	shouldGenerateGLError(gl, gl.INVALID_OPERATION, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 8)");
	}

	function runResizedBufferTests() {
	debug("Test that updating the size of a vertex buffer is properly noticed by the WebGL implementation.");

	var program = wtu.setupProgram(gl, ["vs", "fs"], ["vPosition", "vColor"]);
	glErrorShouldBe(gl, gl.NO_ERROR, "after initialization");

	var vertexObject = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(
	[-1,1,0, 1,1,0, -1,-1,0,
	-1,-1,0, 1,1,0, 1,-1,0]), gl.STATIC_DRAW);
	gl.enableVertexAttribArray(0);
	gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);
	glErrorShouldBe(gl, gl.NO_ERROR, "after vertex setup");

	var texCoordObject = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, texCoordObject);
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(
	[0,0, 1,0, 0,1,
	0,1, 1,0, 1,1]), gl.STATIC_DRAW);
	gl.enableVertexAttribArray(1);
	gl.vertexAttribPointer(1, 2, gl.FLOAT, false, 0, 0);
	glErrorShouldBe(gl, gl.NO_ERROR, "after texture coord setup");

	// Now resize these buffers because we want to change what we're drawing.
	gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([
	-1,1,0, 1,1,0, -1,-1,0, 1,-1,0,
	-1,1,0, 1,1,0, -1,-1,0, 1,-1,0]), gl.STATIC_DRAW);
	glErrorShouldBe(gl, gl.NO_ERROR, "after vertex redefinition");
	gl.bindBuffer(gl.ARRAY_BUFFER, texCoordObject);
	gl.bufferData(gl.ARRAY_BUFFER, new Uint8Array([
	255, 0, 0, 255,
	255, 0, 0, 255,
	255, 0, 0, 255,
	255, 0, 0, 255,
	0, 255, 0, 255,
	0, 255, 0, 255,
	0, 255, 0, 255,
	0, 255, 0, 255]), gl.STATIC_DRAW);
	gl.vertexAttribPointer(1, 4, gl.UNSIGNED_BYTE, false, 0, 0);
	glErrorShouldBe(gl, gl.NO_ERROR, "after texture coordinate / color redefinition");

	var numQuads = 2;
	var indices = new Uint32Array(numQuads * 6);
	for (var ii = 0; ii < numQuads; ++ii) {
	var offset = ii * 6;
	var quad = (ii == (numQuads - 1)) ? 4 : 0;
	indices[offset + 0] = quad + 0;
	indices[offset + 1] = quad + 1;
	indices[offset + 2] = quad + 2;
	indices[offset + 3] = quad + 2;
	indices[offset + 4] = quad + 1;
	indices[offset + 5] = quad + 3;
	}
	var indexObject = gl.createBuffer();
	gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexObject);
	gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, indices, gl.STATIC_DRAW);
	glErrorShouldBe(gl, gl.NO_ERROR, "after setting up indices");
	gl.drawElements(gl.TRIANGLES, numQuads * 6, gl.UNSIGNED_INT, 0);
	glErrorShouldBe(gl, gl.NO_ERROR, "after drawing");
	}

	function runVerifiesTooManyIndicesTests() {
	description("Tests that index validation for drawElements does not examine too many indices");

	var program = loadStandardProgram(gl);

	gl.useProgram(program);
	var vertexObject = gl.createBuffer();
	gl.enableVertexAttribArray(0);
	gl.disableVertexAttribArray(1);
	gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
	// 4 vertices -> 2 triangles
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([ 0,0,0, 0,1,0, 1,0,0, 1,1,0 ]), gl.STATIC_DRAW);
	gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);

	var indexObject = gl.createBuffer();

	debug("Test out of range indices")
	gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexObject);
	gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint32Array([ 10000, 0, 1, 2, 3, 10000 ]), gl.STATIC_DRAW);
	shouldGenerateGLError(gl, gl.NO_ERROR, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 4)");
	shouldGenerateGLError(gl, gl.INVALID_OPERATION, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 0)");
	shouldGenerateGLError(gl, gl.INVALID_OPERATION, "gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_INT, 8)");
	}

	function runCrashWithBufferSubDataTests() {
	debug('Verifies that the index validation code which is within bufferSubData does not crash.')

	var elementBuffer = gl.createBuffer();
	gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, elementBuffer);
	gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, 256, gl.STATIC_DRAW);
	var data = new Uint32Array(127);
	gl.bufferSubData(gl.ELEMENT_ARRAY_BUFFER, 64, data);
	glErrorShouldBe(gl, gl.INVALID_VALUE, "after attempting to update a buffer outside of the allocated bounds");
	testPassed("bufferSubData, when buffer object was initialized with null, did not crash");
	}

	debug("");
	</script>
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