Chromium Code Reviews| OLD | NEW |
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| 1 <!DOCTYPE HTML> | |
| 2 <html> | |
| 3 <head> | |
| 4 <title>GPU Memory Test: Use N MB of GPU Memory with WebGL</title> | |
| 5 | |
| 6 <script id="vertex-shader" type="x-shader/x-vertex"> | |
| 7 attribute vec2 a_position; | |
| 8 varying vec2 v_position; | |
| 9 void main() { | |
| 10 v_position = a_position; | |
| 11 gl_Position = vec4(a_position, 0, 1); | |
| 12 } | |
| 13 </script> | |
| 14 | |
| 15 <script id="fragment-shader" type="x-shader/x-fragment"> | |
| 16 precision mediump float; | |
| 17 uniform sampler2D u_image; | |
| 18 varying vec2 v_position; | |
| 19 void main() { | |
| 20 gl_FragColor = texture2D(u_image, v_position); | |
| 21 } | |
| 22 </script> | |
| 23 | |
| 24 <script> | |
| 25 var gl = null; | |
| 26 var shaderProgram = null; | |
| 27 var textures = []; | |
| 28 var fbos = []; | |
| 29 var t = 0.0; | |
| 30 var n = 1; | |
| 31 | |
| 32 // Create n textures of about 1MB each. | |
| 33 function useGpuMemory(mb_to_use) | |
| 34 { | |
| 35 n = mb_to_use; | |
| 36 | |
| 37 var canvas = document.getElementById("canvas_id"); | |
| 38 gl = canvas.getContext("experimental-webgl"); | |
| 39 if (!gl) { | |
| 40 throw "Unable to fetch WebGL rendering context for Canvas"; | |
| 41 } | |
| 42 | |
| 43 // Create n textures that are each about 1MB and FBOs to render to them. | |
| 44 for (var i = 0; i < n; ++i) { | |
| 45 var texture = gl.createTexture(); | |
| 46 var fbo = gl.createFramebuffer(); | |
| 47 textures.push(texture); | |
| 48 fbos.push(fbo); | |
| 49 | |
| 50 gl.bindTexture(gl.TEXTURE_2D, texture); | |
| 51 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE); | |
| 52 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE); | |
| 53 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST); | |
| 54 gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST); | |
| 55 gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 512, 512, 0, | |
| 56 gl.RGBA, gl.UNSIGNED_BYTE, null) | |
| 57 | |
| 58 gl.bindFramebuffer(gl.FRAMEBUFFER, fbo); | |
| 59 gl.framebufferTexture2D(gl.FRAMEBUFFER, | |
| 60 gl.COLOR_ATTACHMENT0, | |
| 61 gl.TEXTURE_2D, | |
| 62 texture, | |
| 63 0); | |
| 64 } | |
| 65 | |
| 66 // Create a shader that samples a 2D image. | |
| 67 var vertexShader = gl.createShader(gl.VERTEX_SHADER); | |
| 68 gl.shaderSource(vertexShader, | |
| 69 document.getElementById("vertex-shader").textContent); | |
| 70 gl.compileShader(vertexShader); | |
| 71 | |
| 72 var fragmentShader = gl.createShader(gl.FRAGMENT_SHADER); | |
| 73 gl.shaderSource(fragmentShader, | |
| 74 document.getElementById("fragment-shader").textContent); | |
| 75 gl.compileShader(fragmentShader); | |
| 76 | |
| 77 shaderProgram = gl.createProgram(); | |
| 78 gl.attachShader(shaderProgram, vertexShader); | |
| 79 gl.attachShader(shaderProgram, fragmentShader); | |
| 80 gl.linkProgram(shaderProgram); | |
| 81 gl.useProgram(shaderProgram); | |
| 82 | |
| 83 // Bind a vertex buffer with a single triangle | |
| 84 var buffer = gl.createBuffer(); | |
| 85 gl.bindBuffer(gl.ARRAY_BUFFER, buffer); | |
| 86 var bufferData = new Float32Array([-1.0, -1.0, 1.0, -1.0, -1.0, 1.0]); | |
| 87 gl.bufferData(gl.ARRAY_BUFFER, bufferData, gl.STATIC_DRAW); | |
| 88 gl.enableVertexAttribArray(shaderProgram.a_position); | |
| 89 gl.vertexAttribPointer(shaderProgram.a_position, 2, gl.FLOAT, false, 0, 0); | |
| 90 | |
| 91 // Signal back to the test runner that we're done allocating memory. | |
| 92 domAutomationController.send("DONE"); | |
| 93 | |
| 94 // Start the event loop. | |
| 95 tick(); | |
| 96 } | |
| 97 | |
| 98 function drawScene() | |
| 99 { | |
| 100 // Render a solid color to each texture. | |
| 101 for (var i = 0; i < n; ++i) { | |
| 102 gl.bindFramebuffer(gl.FRAMEBUFFER, fbos[i]); | |
| 103 gl.viewport(0, 0, 512, 512); | |
| 104 gl.clearColor(0.0, Math.sin(t/60.0)*0.25 + 0.75*(i+1.0)/n, 0.0, 1.0); | |
| 105 gl.clear(gl.COLOR_BUFFER_BIT); | |
| 106 } | |
| 107 | |
| 108 // Draw these textures to the screen, offset by 1 pixel increments | |
| 109 gl.bindFramebuffer(gl.FRAMEBUFFER, null); | |
| 110 gl.viewport(0, 0, 256, 256); | |
| 111 gl.clearColor(0.0, 0.0, 0.0, 1.0); | |
| 112 gl.clear(gl.COLOR_BUFFER_BIT); | |
| 113 for (var i = 0; i < n; ++i) { | |
| 114 gl.viewport(i, i, 256-i, 256-i); | |
| 115 gl.activeTexture(gl.TEXTURE0); | |
| 116 gl.bindTexture(gl.TEXTURE_2D, textures[i]); | |
| 117 gl.uniform1i(shaderProgram.u_image, 0); | |
| 118 gl.drawArrays(gl.TRIANGLES, 0, 3); | |
| 119 } | |
| 120 | |
| 121 t += 1; | |
| 122 } | |
| 123 | |
| 124 function tick() | |
| 125 { | |
| 126 window.webkitRequestAnimationFrame(tick); | |
| 127 drawScene(); | |
| 128 } | |
| 129 </script> | |
| 130 </head> | |
| 131 | |
| 132 <body> | |
| 133 <div class="test-div" style="width=100px; height=100px;"> | |
|
nduca
2013/01/05 05:14:42
is the outer test-div important here?
ccameron
2013/01/07 21:36:34
Nope, annihilated.
| |
| 134 <canvas id="canvas_id" width=256px height=256px style="width:256px; height:2 56px;"/> | |
| 135 </div> | |
| 136 </body> | |
| 137 </html> | |
| 138 | |
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