out-of-bounds-index-buffers-after-copying.html (8244B)
1 <!-- 2 Copyright (c) 2019 The Khronos Group Inc. 3 Use of this source code is governed by an MIT-style license that can be 4 found in the LICENSE.txt file. 5 --> 6 <!DOCTYPE html> 7 <html> 8 <head> 9 <meta charset="utf-8"> 10 <link rel="stylesheet" href="../../resources/js-test-style.css"/> 11 <script src="../../js/js-test-pre.js"></script> 12 <script src="../../js/webgl-test-utils.js"></script> 13 <title>WebGL Out-of-Bounds Index Buffer Caused by CopyBufferSubData Conformance Test</title> 14 </head> 15 <body> 16 <canvas id="canvas" width="8" height="8" style="width: 100px; height: 100px;"></canvas> 17 <div id="description"></div> 18 <div id="console"></div> 19 <script id="vsCheckOutOfBounds" type="x-shader/x-vertex"> 20 #define TEST_CASE_IN_BOUND 1 21 #define TEST_CASE_OUT_OF_BOUND 2 22 23 precision mediump float; 24 attribute vec2 position; 25 attribute vec4 vecRandom; 26 varying vec4 v_color; 27 uniform int u_testCase; 28 29 bool testFloatComponentAccurate(float component) { 30 return component == 0.2; 31 } 32 // Per the spec, each component can either contain existing contents 33 // of the buffer or 0. 34 bool testFloatComponent(float component) { 35 return (component == 0.2 || component == 0.0); 36 } 37 // The last component is additionally allowed to be 1.0. 38 bool testLastFloatComponent(float component) { 39 return testFloatComponent(component) || component == 1.0; 40 } 41 42 bool testData(vec4 data) { 43 if (u_testCase == TEST_CASE_IN_BOUND) { 44 return (testFloatComponentAccurate(data.x) && 45 testFloatComponentAccurate(data.y) && 46 testFloatComponentAccurate(data.z) && 47 testFloatComponentAccurate(data.w)); 48 } else if (u_testCase == TEST_CASE_OUT_OF_BOUND) { 49 return (testFloatComponent(data.x) && 50 testFloatComponent(data.y) && 51 testFloatComponent(data.z) && 52 testLastFloatComponent(data.w)); 53 } 54 return false; 55 } 56 57 void main() { 58 if (testData(vecRandom)) { 59 v_color = vec4(0.0, 1.0, 0.0, 1.0); // green -- We're good 60 } else { 61 v_color = vec4(1.0, 0.0, 0.0, 1.0); // red -- Unexpected value 62 } 63 gl_Position = vec4(position, 0.0, 1.0); 64 } 65 </script> 66 <script> 67 "use strict"; 68 description("This test verifies that out-of-bounds index buffers caused by CopyBufferSubData behave according to spec."); 69 70 // Ensure that drawElements flags either no error or INVALID_OPERATION. In the case of INVALID_OPERATION, 71 // no canvas pixels can be touched. In the case of NO_ERROR, all written values must either be the 72 // zero vertex or a value in the vertex buffer. See vsCheckOutOfBounds shader. 73 function verifyOutOfBoundsIndex(gl) { 74 var error = gl.getError(); 75 if (error === gl.INVALID_OPERATION) { 76 testPassed("drawElements flagged INVALID_OPERATION, which is valid so long as all canvas pixels were not touched."); 77 wtu.checkCanvas(gl, [0, 0, 255, 255]); 78 } else if (error === gl.NO_ERROR) { 79 testPassed("drawElements flagged NO_ERROR, which is valid so long as all canvas pixels are green."); 80 wtu.checkCanvas(gl, [0, 255, 0, 255]); 81 } else { 82 testFailed("Invalid error flagged by drawElements. Should be INVALID_OPERATION or NO_ERROR"); 83 } 84 } 85 86 // Create an element array buffer with a tri-strip that starts at startIndex and make 87 // it the active element array buffer. 88 function prepareElementArrayBuffer(gl, startIndex) { 89 var glElementArrayBuffer = gl.createBuffer(); 90 gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, glElementArrayBuffer); 91 var quadIndices = new Uint16Array(4); 92 for (var i = 0; i < quadIndices.length; i++) { 93 quadIndices[i] = startIndex + i; 94 } 95 gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, quadIndices, gl.STATIC_DRAW); 96 return glElementArrayBuffer; 97 } 98 99 100 var wtu = WebGLTestUtils; 101 var canvas = document.getElementById("canvas"); 102 var gl = wtu.create3DContext(canvas, {antialias: false}, 2); 103 104 var numberOfQuads = 200; 105 106 // Create a vertex buffer with 200 properly formed tri-strip quads. These quads will cover the canvas texture 107 // such that every single pixel is touched by the fragment shader. 108 var quadBuffer = gl.createBuffer(); 109 gl.bindBuffer(gl.ARRAY_BUFFER, quadBuffer); 110 var quadPositions = new Float32Array(numberOfQuads * /*ComponentsPerQuad*/2 * /*VerticesPerQuad*/4); 111 for (var i = 0; i < quadPositions.length; i += /*ComponentsPerQuad*/2 * /*VerticesPerQuad*/4) { 112 quadPositions[i+0] = -1.0; // upper left 113 quadPositions[i+1] = 1.0; 114 quadPositions[i+2] = 1.0; // upper right 115 quadPositions[i+3] = 1.0; 116 quadPositions[i+4] = -1.0; // lower left 117 quadPositions[i+5] = -1.0; 118 quadPositions[i+6] = 1.0; // lower right 119 quadPositions[i+7] = -1.0; 120 } 121 gl.bufferData(gl.ARRAY_BUFFER, quadPositions, gl.STATIC_DRAW); 122 gl.enableVertexAttribArray(0); 123 gl.vertexAttribPointer(0, 2, gl.FLOAT, false, 0, 0); 124 125 // Create a small vertex buffer with determined-ahead-of-time "random" values (0.2). This buffer will be 126 // the one indexed off the end. 127 var vertexBuffer = gl.createBuffer(); 128 gl.bindBuffer(gl.ARRAY_BUFFER, vertexBuffer); 129 gl.bufferData(gl.ARRAY_BUFFER, 130 new Float32Array([0.2, 0.2, 0.2, 0.2, 131 0.2, 0.2, 0.2, 0.2, 132 0.2, 0.2, 0.2, 0.2, 133 0.2, 0.2, 0.2, 0.2]), 134 gl.STATIC_DRAW); 135 gl.enableVertexAttribArray(1); 136 gl.vertexAttribPointer(1, 4, gl.FLOAT, false, 0, 0); 137 138 // Setup the verification program. 139 var program = wtu.setupProgram(gl, ["vsCheckOutOfBounds", wtu.simpleVertexColorFragmentShader], ["position", "vecRandom"]); 140 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Shader and buffer setup should generate no errors"); 141 var loc = gl.getUniformLocation(program, "u_testCase"); 142 shouldBeNonNull(loc); 143 144 debug(""); 145 debug("Test -- Vertex indices are in bounds."); 146 gl.uniform1i(loc, 1); // TEST_CASE_IN_BOUND == 1 147 gl.clearColor(0.0, 0.0, 1.0, 1.0); // Start with blue to indicate no pixels touched. 148 gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); 149 var elementArrayBuffer = prepareElementArrayBuffer(gl, /*StartIndex*/0); 150 gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_SHORT, /*offset*/0); 151 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Draw call should generate no errors"); 152 wtu.checkCanvas(gl, [0, 255, 0, 255]); 153 154 debug(""); 155 debug("Test -- Index off the end of the vertex buffer near the beginning of the out of bounds area."); 156 gl.uniform1i(loc, 2); // TEST_CASE_OUT_OF_BOUND == 2 157 gl.clearColor(0.0, 0.0, 1.0, 1.0); // Start with blue to indicate no pixels touched. 158 gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); 159 var outOfBoundsElementArrayBuffer = prepareElementArrayBuffer(gl, /*StartIndex*/4); 160 gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, outOfBoundsElementArrayBuffer); 161 gl.bindBuffer(gl.COPY_WRITE_BUFFER, elementArrayBuffer); 162 gl.copyBufferSubData(gl.ELEMENT_ARRAY_BUFFER, gl.COPY_WRITE_BUFFER, 0, 0, 4 * Uint16Array.BYTES_PER_ELEMENT); 163 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "copyBufferSubData should generate no errors"); 164 gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, elementArrayBuffer); 165 gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_SHORT, /*offset*/0); 166 verifyOutOfBoundsIndex(gl); 167 168 debug(""); 169 debug("Test -- Index off the end of the vertex buffer near the end of the out of bounds area.") 170 gl.uniform1i(loc, 2); // TEST_CASE_OUT_OF_BOUND == 2 171 gl.clearColor(0.0, 0.0, 1.0, 1.0); // Start with blue to indicate no pixels touched. 172 gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); 173 outOfBoundsElementArrayBuffer = prepareElementArrayBuffer(gl, /*StartIndex*/numberOfQuads - 4); 174 gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, elementArrayBuffer); 175 gl.bindBuffer(gl.COPY_READ_BUFFER, outOfBoundsElementArrayBuffer); 176 gl.copyBufferSubData(gl.COPY_READ_BUFFER, gl.ELEMENT_ARRAY_BUFFER, 0, 0, 4 * Uint16Array.BYTES_PER_ELEMENT); 177 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "copyBufferSubData should generate no errors"); 178 gl.drawElements(gl.TRIANGLE_STRIP, 4, gl.UNSIGNED_SHORT, /*offset*/0); 179 verifyOutOfBoundsIndex(gl); 180 181 debug(""); 182 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Running tests should generate no errors"); 183 var successfullyParsed = true; 184 </script> 185 <script src="../../js/js-test-post.js"></script> 186 </body> 187 </html>