| <!DOCTYPE HTML> |
| <html> |
| <head> |
| <title>GPU Memory Test: Use N MB of GPU Memory with WebGL</title> |
| |
| <script id="vertex-shader" type="x-shader/x-vertex"> |
| attribute vec2 a_position; |
| varying vec2 v_position; |
| void main() { |
| v_position = a_position; |
| gl_Position = vec4(a_position, 0, 1); |
| } |
| </script> |
| |
| <script id="fragment-shader" type="x-shader/x-fragment"> |
| precision mediump float; |
| uniform sampler2D u_image; |
| varying vec2 v_position; |
| void main() { |
| gl_FragColor = texture2D(u_image, v_position); |
| } |
| </script> |
| |
| <script> |
| var gl = null; |
| var shaderProgram = null; |
| var textures = []; |
| var fbos = []; |
| var t = 0.0; |
| var n = 1; |
| |
| // Create n textures of about 1MB each. |
| function useGpuMemory(mb_to_use) |
| { |
| n = mb_to_use; |
| |
| var canvas = document.getElementById("canvas_id"); |
| gl = canvas.getContext("experimental-webgl"); |
| if (!gl) { |
| throw "Unable to fetch WebGL rendering context for Canvas"; |
| } |
| |
| // Create n textures that are each about 1MB and FBOs to render to them. |
| for (var i = 0; i < n; ++i) { |
| var texture = gl.createTexture(); |
| var fbo = gl.createFramebuffer(); |
| textures.push(texture); |
| fbos.push(fbo); |
| |
| gl.bindTexture(gl.TEXTURE_2D, texture); |
| gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE); |
| gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE); |
| gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST); |
| gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST); |
| gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 512, 512, 0, |
| gl.RGBA, gl.UNSIGNED_BYTE, null) |
| |
| gl.bindFramebuffer(gl.FRAMEBUFFER, fbo); |
| gl.framebufferTexture2D(gl.FRAMEBUFFER, |
| gl.COLOR_ATTACHMENT0, |
| gl.TEXTURE_2D, |
| texture, |
| 0); |
| } |
| |
| // Create a shader that samples a 2D image. |
| var vertexShader = gl.createShader(gl.VERTEX_SHADER); |
| gl.shaderSource(vertexShader, |
| document.getElementById("vertex-shader").textContent); |
| gl.compileShader(vertexShader); |
| |
| var fragmentShader = gl.createShader(gl.FRAGMENT_SHADER); |
| gl.shaderSource(fragmentShader, |
| document.getElementById("fragment-shader").textContent); |
| gl.compileShader(fragmentShader); |
| |
| shaderProgram = gl.createProgram(); |
| gl.attachShader(shaderProgram, vertexShader); |
| gl.attachShader(shaderProgram, fragmentShader); |
| gl.linkProgram(shaderProgram); |
| gl.useProgram(shaderProgram); |
| |
| // Bind a vertex buffer with a single triangle |
| var buffer = gl.createBuffer(); |
| gl.bindBuffer(gl.ARRAY_BUFFER, buffer); |
| var bufferData = new Float32Array([-1.0, -1.0, 1.0, -1.0, -1.0, 1.0]); |
| gl.bufferData(gl.ARRAY_BUFFER, bufferData, gl.STATIC_DRAW); |
| gl.enableVertexAttribArray(shaderProgram.a_position); |
| gl.vertexAttribPointer(shaderProgram.a_position, 2, gl.FLOAT, false, 0, 0); |
| |
| // Signal back to the test runner that we're done allocating memory. |
| domAutomationController.send("DONE_USE_GPU_MEMORY"); |
| |
| // Start the event loop. |
| tick(); |
| } |
| |
| function drawScene() |
| { |
| // Render a solid color to each texture. |
| for (var i = 0; i < n; ++i) { |
| gl.bindFramebuffer(gl.FRAMEBUFFER, fbos[i]); |
| gl.viewport(0, 0, 512, 512); |
| gl.clearColor(0.0, Math.sin(t/60.0)*0.25 + 0.75*(i+1.0)/n, 0.0, 1.0); |
| gl.clear(gl.COLOR_BUFFER_BIT); |
| } |
| |
| // Draw these textures to the screen, offset by 1 pixel increments |
| gl.bindFramebuffer(gl.FRAMEBUFFER, null); |
| gl.viewport(0, 0, 256, 256); |
| gl.clearColor(0.0, 0.0, 0.0, 1.0); |
| gl.clear(gl.COLOR_BUFFER_BIT); |
| for (var i = 0; i < n; ++i) { |
| gl.viewport(i, i, 256-i, 256-i); |
| gl.activeTexture(gl.TEXTURE0); |
| gl.bindTexture(gl.TEXTURE_2D, textures[i]); |
| gl.uniform1i(shaderProgram.u_image, 0); |
| gl.drawArrays(gl.TRIANGLES, 0, 3); |
| } |
| |
| t += 1; |
| } |
| |
| function tick() |
| { |
| window.webkitRequestAnimationFrame(tick); |
| drawScene(); |
| } |
| </script> |
| </head> |
| |
| <body> |
| <canvas id="canvas_id" width=256px height=256px style="width:256px; height:256px;"/> |
| </body> |
| </html> |
| |
