third_party/WebKit/LayoutTests/fast/canvas/webgl/index-validation-with-resized-buffer.html

   1 <html>
   2 <head>
   3 <script src="../../../resources/js-test.js"></script>
   4 <script src="resources/webgl-test.js"></script>
   5 </head>
   6 <body>
   7 <canvas id="example" width="1px" height="1px"></canvas>
   8 <div id="description"></div>
   9 <div id="console"></div>
  10
  11 <script id="vs" type="x-shader/x-vertex">
  12 attribute vec4 vPosition;
  13 attribute vec4 vColor;
  14 varying vec4 color;
  15 void main() {
  16     gl_Position = vPosition;
  17     color = vColor;
  18 }
  19 </script>
  20 <script id="fs" type="x-shader/x-fragment">
  21 #if defined(GL_ES)
  22 precision mediump float;
  23 #endif
  24 varying vec4 color;
  25 void main() {
  26   gl_FragColor = color;
  27 }
  28 </script>
  29 <script>
  30 description('Test that updating the size of a vertex buffer is properly noticed by the WebGL implementation.')
  31
  32 var gl = initWebGL("example", "vs", "fs", ["vPosition", "vColor"], [0, 0, 0, 1], 1);
  33 glErrorShouldBe(gl, gl.NO_ERROR, "after initialization");
  34
  35 gl.useProgram(gl.program);
  36 var vertexObject = gl.createBuffer();
  37 gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
  38 gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(
  39     [-1,1,0, 1,1,0, -1,-1,0,
  40      -1,-1,0, 1,1,0, 1,-1,0]), gl.STATIC_DRAW);
  41 gl.enableVertexAttribArray(0);
  42 gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);
  43 glErrorShouldBe(gl, gl.NO_ERROR, "after vertex setup");
  44
  45 var texCoordObject = gl.createBuffer();
  46 gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
  47 gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(
  48     [0,0, 1,0, 0,1,
  49      0,1, 1,0, 1,1]), gl.STATIC_DRAW);
  50 gl.enableVertexAttribArray(1);
  51 gl.vertexAttribPointer(1, 2, gl.FLOAT, false, 0, 0);
  52 glErrorShouldBe(gl, gl.NO_ERROR, "after texture coord setup");
  53
  54 // Now resize these buffers because we want to change what we're drawing.
  55 gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
  56 gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([
  57     -1,1,0, 1,1,0, -1,-1,0, 1,-1,0,
  58     -1,1,0, 1,1,0, -1,-1,0, 1,-1,0]), gl.STATIC_DRAW);
  59 glErrorShouldBe(gl, gl.NO_ERROR, "after vertex redefinition");
  60 gl.bindBuffer(gl.ARRAY_BUFFER, texCoordObject);
  61 gl.bufferData(gl.ARRAY_BUFFER, new Uint8Array([
  62     255, 0, 0, 255,
  63     255, 0, 0, 255,
  64     255, 0, 0, 255,
  65     255, 0, 0, 255,
  66     0, 255, 0, 255,
  67     0, 255, 0, 255,
  68     0, 255, 0, 255,
  69     0, 255, 0, 255]), gl.STATIC_DRAW);
  70 gl.vertexAttribPointer(1, 4, gl.UNSIGNED_BYTE, false, 0, 0);
  71 glErrorShouldBe(gl, gl.NO_ERROR, "after texture coordinate / color redefinition");
  72
  73 var numQuads = 2;
  74 var indices = new Uint8Array(numQuads * 6);
  75 for (var ii = 0; ii < numQuads; ++ii) {
  76     var offset = ii * 6;
  77     var quad = (ii == (numQuads - 1)) ? 4 : 0;
  78     indices[offset + 0] = quad + 0;
  79     indices[offset + 1] = quad + 1;
  80     indices[offset + 2] = quad + 2;
  81     indices[offset + 3] = quad + 2;
  82     indices[offset + 4] = quad + 1;
  83     indices[offset + 5] = quad + 3;
  84 }
  85 var indexObject = gl.createBuffer();
  86 gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexObject);
  87 gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, indices, gl.STATIC_DRAW);
  88 glErrorShouldBe(gl, gl.NO_ERROR, "after setting up indices");
  89 gl.drawElements(gl.TRIANGLES, numQuads * 6, gl.UNSIGNED_BYTE, 0);
  90 glErrorShouldBe(gl, gl.NO_ERROR, "after drawing");
  91
  92 debug("")
  93 </script>
  94
  95 </body>
  96 </html>