third_party/WebKit/LayoutTests/fast/canvas/webgl/point-size.html

   1 <html>
   2 <head>
   3 <script src="../../../resources/js-test.js"></script>
   4 <script src="resources/webgl-test.js"></script>
   5 <script id="vshader" type="x-shader/x-vertex">
   6 attribute vec3 pos;
   7 attribute vec4 colorIn;
   8 uniform float pointSize;
   9 varying vec4 color;
  10
  11 void main()
  12 {
  13     gl_PointSize = pointSize;
  14     color = colorIn;
  15     gl_Position = vec4(pos.xyz, 3.0);
  16 }
  17 </script>
  18
  19 <script id="fshader" type="x-shader/x-fragment">
  20 #ifdef GL_ES
  21 precision mediump float;
  22 #endif
  23 varying vec4 color;
  24
  25 void main()
  26 {
  27     gl_FragColor = color;
  28 }
  29 </script>
  30
  31 <script>
  32 function runTest()
  33 {
  34     var gl = initWebGL('testbed', 'vshader', 'fshader', ['pos', 'colorIn'], [0, 0, 0, 1], 1, { antialias: false });
  35     if (!gl) {
  36         testFailed('initWebGL(..) failed');
  37         return false;
  38     }
  39     gl.disable(gl.BLEND);
  40     gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
  41
  42     // The choice of (0.4, 0.4) ensures that the centers of the surrounding
  43     // pixels are not contained within the point when it is of size 1, but
  44     // that they definitely are when it is of size 2.
  45     var vertices = new Float32Array([
  46         0.4, 0.4, 0.0]);
  47     var colors = new Uint8Array([
  48         255, 0, 0, 255]);
  49
  50     var colorOffset = vertices.byteLength;
  51
  52     var vbo = gl.createBuffer();
  53     gl.bindBuffer(gl.ARRAY_BUFFER, vbo);
  54     gl.bufferData(gl.ARRAY_BUFFER, colorOffset + colors.byteLength, gl.STATIC_DRAW);
  55     gl.bufferSubData(gl.ARRAY_BUFFER, 0, vertices);
  56     gl.bufferSubData(gl.ARRAY_BUFFER, colorOffset, colors);
  57
  58     gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);
  59     gl.enableVertexAttribArray(0);
  60     gl.vertexAttribPointer(1, 4, gl.UNSIGNED_BYTE, true, 0, colorOffset);
  61     gl.enableVertexAttribArray(1);
  62
  63     var locPointSize = gl.getUniformLocation(gl.program, 'pointSize');
  64
  65     debug('Draw a point of size 1 and verify it does not touch any other pixels.');
  66
  67     gl.uniform1f(locPointSize, 1.0);
  68     gl.drawArrays(gl.POINTS, 0, vertices.length / 3);
  69     var buf = new Uint8Array(2 * 2 * 4);
  70     gl.readPixels(0, 0, 2, 2, gl.RGBA, gl.UNSIGNED_BYTE, buf);
  71     var index = 0;
  72     for (var y = 0; y < 2; ++y) {
  73         for (var x = 0; x < 2; ++x) {
  74             var correctColor = [0, 0, 0];
  75             if (x == 1 && y == 1)
  76                 correctColor[0] = 255;
  77             if (buf[index] != correctColor[0] || buf[index + 1] != correctColor[1] || buf[index + 2] != correctColor[2]) {
  78                 testFailed('Drawing a point of size 1 touched pixels that should not be touched');
  79                 return false;
  80             }
  81             index += 4;
  82         }
  83     }
  84     gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
  85
  86     debug('Draw a point of size 2 and verify it fills the appropriate region.');
  87
  88     var pointSizeRange = gl.getParameter(gl.ALIASED_POINT_SIZE_RANGE);
  89     if (pointSizeRange < 2.0)
  90         return true;
  91
  92     gl.uniform1f(locPointSize, 2.0);
  93     gl.drawArrays(gl.POINTS, 0, vertices.length / 3);
  94     gl.readPixels(0, 0, 2, 2, gl.RGBA, gl.UNSIGNED_BYTE, buf);
  95     index = 0;
  96     for (var y = 0; y < 2; ++y) {
  97         for (var x = 0; x < 2; ++x) {
  98             var correctColor = [255, 0, 0];
  99             if (buf[index] != correctColor[0] || buf[index + 1] != correctColor[1] || buf[index + 2] != correctColor[2]) {
 100                 testFailed('Drawing a point of size 2 failed to fill the appropriate region');
 101                 return false;
 102             }
 103             index += 4;
 104         }
 105     }
 106
 107     return true;
 108 }
 109 </script>
 110 </head>
 111 <body>
 112 <canvas id="testbed" width="2px" height="2px"></canvas>
 113 <div id="description"></div>
 114 <div id="console"></div>
 115 <script>
 116 description('Verify GL_VERTEX_PROGRAM_POINT_SIZE is enabled in WebGL');
 117
 118 if (runTest())
 119     testPassed("");
 120 </script>
 121
 122
 123 </body>
 124 </html>