third_party/WebKit/LayoutTests/fast/canvas/webgl/gl-vertex-attrib-zero-issues.html

   1 <!DOCTYPE html>
   2 <html>
   3 <head>
   4 <title>WebGL Enable Vertex Attrib Zero Test</title>
   5 <script src="../../../resources/js-test.js"></script>
   6 <script src="resources/webgl-test.js"> </script>
   7 <script src="resources/webgl-test-utils.js"> </script>
   8 </head>
   9 <body>
  10 <canvas id="example" width="50" height="50">
  11 </canvas>
  12 <div id="description"></div>
  13 <div id="console"></div>
  14 <script id="vshader" type="x-shader/x-vertex">
  15     attribute vec4 vPosition;
  16     void main()
  17     {
  18         gl_Position = vPosition;
  19     }
  20 </script>
  21
  22 <script id="fshader" type="x-shader/x-fragment">
  23     void main()
  24     {
  25         gl_FragColor = vec4(0.0,0.0,0.0,0.0);
  26     }
  27 </script>
  28
  29 <script>
  30 description("Test some of the issues of the difference between attrib 0 on OpenGL vs WebGL");
  31 debug("");
  32 var wtu = WebGLTestUtils;
  33 var canvas = document.getElementById("example");
  34 var gl = wtu.create3DContext(canvas);
  35
  36 function setup(numVerts, attribIndex) {
  37   var program = wtu.setupProgram(
  38       gl,
  39       [wtu.loadShaderFromScript(gl, 'vshader', gl.VERTEX_SHADER),
  40        wtu.loadShaderFromScript(gl, 'fshader', gl.FRAGMENT_SHADER)],
  41       ['vPosition'], [attribIndex]);
  42   // draw with something on attrib zero with a small number of vertices
  43   var vertexObject = gl.createBuffer();
  44   g_program = program;
  45   g_attribLocation = attribIndex;
  46   shouldBe("g_attribLocation", "gl.getAttribLocation(g_program, 'vPosition')");
  47   gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
  48   gl.bufferData(
  49       gl.ARRAY_BUFFER, new Float32Array(numVerts * 3), gl.STATIC_DRAW);
  50   gl.vertexAttribPointer(attribIndex, 3, gl.FLOAT, false, 0, 0);
  51   var indices = new Uint16Array(numVerts);
  52   for (var ii = 0; ii < numVerts; ++ii) {
  53     indices[ii] = ii;
  54   }
  55   var indexBuffer = gl.createBuffer();
  56   gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexBuffer);
  57   gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, indices, gl.STATIC_DRAW);
  58   return program;
  59 }
  60
  61 var p1 = setup(3, 0);
  62 var p2 = setup(60000, 3);
  63
  64 for (var ii = 0; ii < 5; ++ii) {
  65   gl.useProgram(p1);
  66   gl.enableVertexAttribArray(0);
  67   gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_SHORT, 0);
  68   glErrorShouldBe(
  69       gl, gl.NO_ERROR,
  70       "drawing using attrib 0 with 3 verts");
  71
  72   gl.useProgram(p2);
  73   gl.enableVertexAttribArray(3);
  74   gl.drawArrays(gl.LINES, 0, 60000);
  75   glErrorShouldBe(
  76       gl, gl.NO_ERROR,
  77       "drawing using attrib 3 with 60000 verts");
  78 }
  79
  80 wtu.checkCanvas(gl, [0, 0, 0, 0], "canvas should be 0, 0, 0, 0");
  81 </script>
  82
  83 <script>
  84 </script>
  85
  86 </body>
  87 </html>
  88