dom/canvas/test/webgl-conf/checkout/conformance/rendering/out-of-bounds-array-buffers.html

   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 Array Buffer 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     precision mediump float;
  21     attribute vec2 position;
  22     attribute vec4 vecRandom;
  23     varying vec4 v_color;
  24
  25     // Per the spec, each component can either contain existing contents
  26     // of the buffer or 0.
  27     bool testFloatComponent(float component) {
  28         return (component == 0.2 || component == 0.0);
  29     }
  30     // The last component is additionally allowed to be 1.0.
  31     bool testLastFloatComponent(float component) {
  32         return testFloatComponent(component) || component == 1.0;
  33     }
  34
  35     void main() {
  36         if (testFloatComponent(vecRandom.x) &&
  37             testFloatComponent(vecRandom.y) &&
  38             testFloatComponent(vecRandom.z) &&
  39             testLastFloatComponent(vecRandom.w)) {
  40             v_color = vec4(0.0, 1.0, 0.0, 1.0); // green -- We're good
  41         } else {
  42             v_color = vec4(1.0, 0.0, 0.0, 1.0); // red -- Unexpected value
  43         }
  44         gl_Position = vec4(position, 0.0, 1.0);
  45     }
  46 </script>
  47 <script>
  48 "use strict";
  49 description("This test verifies that out-of-bounds array buffers behave according to spec.");
  50
  51 var wtu = WebGLTestUtils;
  52 var canvas = document.getElementById("canvas");
  53 var gl = wtu.create3DContext(canvas, {antialias: false});
  54
  55 var numberOfQuads = 200;
  56
  57 // Draw out-of-bounds beginning with the start offset passed in.
  58 // Ensure that drawArrays flags either no error or INVALID_OPERATION. In the case of INVALID_OPERATION,
  59 // no canvas pixels can be touched.  In the case of NO_ERROR, all written values must either be the
  60 // zero vertex or a value in the vertex buffer.  See vsCheckOutOfBounds shader.
  61 function drawAndVerifyOutOfBoundsArrays(gl, first, count) {
  62     gl.clearColor(0.0, 0.0, 1.0, 1.0);  // Start with blue to indicate no pixels touched.
  63     gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
  64
  65     gl.drawArrays(gl.TRIANGLES, first, count);
  66     var error = gl.getError();
  67     if (error === gl.INVALID_OPERATION) {
  68         testPassed("drawArrays flagged INVALID_OPERATION, which is valid so long as all canvas pixels were not touched.");
  69         wtu.checkCanvas(gl, [0, 0, 255, 255]);
  70     } else if (error === gl.NO_ERROR) {
  71         testPassed("drawArrays flagged NO_ERROR, which is valid so long as all canvas pixels are green.");
  72         wtu.checkCanvas(gl, [0, 255, 0, 255]);
  73     } else {
  74         testFailed("Invalid error flagged by drawArrays. Should be INVALID_OPERATION or NO_ERROR");
  75     }
  76 }
  77
  78 // Create a vertex buffer with 200 properly formed triangle quads. These quads will cover the
  79 // canvas texture such that every single pixel is touched by the fragment shader.
  80 var glQuadBuffer = gl.createBuffer();
  81 gl.bindBuffer(gl.ARRAY_BUFFER, glQuadBuffer);
  82 var quadPositions = new Float32Array(numberOfQuads * /*ComponentsPerQuad*/2 * /*VerticesPerQuad*/6);
  83 for (var i = 0; i < quadPositions.length; i += /*ComponentsPerQuad*/2 * /*VerticesPerQuad*/6) {
  84     quadPositions[i+0] = -1.0;  // upper left
  85     quadPositions[i+1] =  1.0;
  86     quadPositions[i+2] =  1.0;  // upper right
  87     quadPositions[i+3] =  1.0;
  88     quadPositions[i+4] = -1.0;  // lower left
  89     quadPositions[i+5] = -1.0;
  90     quadPositions[i+6] =  1.0;  // upper right
  91     quadPositions[i+7] =  1.0;
  92     quadPositions[i+8] =  1.0;  // lower right
  93     quadPositions[i+9] = -1.0;
  94     quadPositions[i+10] = -1.0;  // lower left
  95     quadPositions[i+11] = -1.0;
  96 }
  97 gl.bufferData(gl.ARRAY_BUFFER, quadPositions, gl.STATIC_DRAW);
  98 gl.enableVertexAttribArray(0);
  99 gl.vertexAttribPointer(0, 2, gl.FLOAT, false, 0, 0);
 100
 101
 102 // Create a small vertex buffer with determined-ahead-of-time "random" values (0.2). This buffer will be
 103 // the one read past the end.
 104 var glVertexBuffer = gl.createBuffer();
 105 gl.bindBuffer(gl.ARRAY_BUFFER, glVertexBuffer);
 106 gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([0.2, 0.2, 0.2, 0.2, 0.2, 0.2]), gl.STATIC_DRAW);
 107 gl.enableVertexAttribArray(1);
 108 gl.vertexAttribPointer(1, 4, gl.FLOAT, false, 0, 0);
 109
 110 // Setup the verification program.
 111 var glProgram = wtu.setupProgram(gl, ["vsCheckOutOfBounds", wtu.simpleVertexColorFragmentShader], ["position", "vecRandom"]);
 112 wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Shader and buffer setup should not generate errors");
 113
 114 debug("Test -- Draw off the end of the vertex buffer near the beginning of the out of bounds area.");
 115 drawAndVerifyOutOfBoundsArrays(gl, /*first*/6, /*count*/6);
 116
 117 debug("");
 118
 119 debug("Test -- Draw off the end of the vertex buffer near the end of the out of bounds area.")
 120 drawAndVerifyOutOfBoundsArrays(gl, /*first*/(numberOfQuads - 1) * 6, /*count*/6);
 121
 122 var successfullyParsed = true;
 123 </script>
 124 <script src="../../js/js-test-post.js"></script>
 125 </body>
 126 </html>