Editing canvas drawImage vs. WebGL drawArrays

This edit will create a new revision.

Your details (optional)

Name

Email (won’t be displayed; might be used for Gravatar)

URL

Test case details

Title *

Published (uncheck if you want to fiddle around before making the page public)

Description (in case you feel further explanation is needed)(Markdown syntax is allowed)

Are you a spammer? (just answer the question)

Preparation code

Preparation code HTML (this will be inserted in the <body> of a valid HTML5 document in standards mode) (useful when testing DOM operations or including libraries)

Include JavaScript libraries as follows: <script src="//cdn.ext/library.js"></script>

Define setup for all tests (variables, functions, arrays or other objects that will be used in the tests) (runs before each clocked test loop, outside of the timed code region) (e.g. define local test variables, reset global variables, clear canvas, etc.) (see FAQ)

var img, tex, vloc, tloc,vertexBuff, texBuff;

var cvs2d = document.getElementById('cvs2d');
var cvs3d = document.getElementById('cvs3d');
var ctx2d = cvs2d.getContext('2d');
var ctx3d = cvs3d.getContext('experimental-webgl');
var uLoc;
var inc = 0;

// create shaders
var vertexShaderSrc = 
"attribute vec2 aVertex;" +
"attribute vec2 aUV;" + 
"varying vec2 vTex;" +
"uniform vec2 pos;" +
"void main(void) {" +
"  gl_Position = vec4(aVertex + pos, 0.0, 1.0);" +
"  vTex = aUV;" +
"}";

var fragmentShaderSrc =
"precision highp float;" +
"varying vec2 vTex;" +
"uniform sampler2D sampler0;" +
"void main(void){" +
"  gl_FragColor = texture2D(sampler0, vTex);"+
"}";

var vertShaderObj = ctx3d.createShader(ctx3d.VERTEX_SHADER);
var fragShaderObj = ctx3d.createShader(ctx3d.FRAGMENT_SHADER);
ctx3d.shaderSource(vertShaderObj, vertexShaderSrc);
ctx3d.shaderSource(fragShaderObj, fragmentShaderSrc);
ctx3d.compileShader(vertShaderObj);
ctx3d.compileShader(fragShaderObj);

var progObj = ctx3d.createProgram();
ctx3d.attachShader(progObj, vertShaderObj);
ctx3d.attachShader(progObj, fragShaderObj);

ctx3d.linkProgram(progObj);
ctx3d.useProgram(progObj);

ctx3d.viewport(0, 0, 1024, 768);

vertexBuff = ctx3d.createBuffer();
ctx3d.bindBuffer(ctx3d.ARRAY_BUFFER, vertexBuff);
ctx3d.bufferData(ctx3d.ARRAY_BUFFER, new Float32Array([-1/8, 1/6, -1/8, -1/6, 1/8, -1/6, 1/8, 1/6]), ctx3d.STATIC_DRAW);

texBuff = ctx3d.createBuffer();
ctx3d.bindBuffer(ctx3d.ARRAY_BUFFER, texBuff);
ctx3d.bufferData(ctx3d.ARRAY_BUFFER, new Float32Array([0, 1, 0, 0, 1, 0, 1, 1]), ctx3d.STATIC_DRAW);

vloc = ctx3d.getAttribLocation(progObj, "aVertex"); 
tloc = ctx3d.getAttribLocation(progObj, "aUV");
uLoc = ctx3d.getUniformLocation(progObj, "pos");

img = new Image();
img.src = 'data:image/png;base64,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%3D';

img.onload = function(){
  tex = ctx3d.createTexture();
  ctx3d.bindTexture(ctx3d.TEXTURE_2D, tex);
  ctx3d.texParameteri(ctx3d.TEXTURE_2D, ctx3d.TEXTURE_MIN_FILTER, ctx3d.NEAREST);
  ctx3d.texParameteri(ctx3d.TEXTURE_2D, ctx3d.TEXTURE_MAG_FILTER, ctx3d.NEAREST);
  ctx3d.generateMipmap(ctx3d.TEXTURE_2D);
  ctx3d.texImage2D(ctx3d.TEXTURE_2D, 0,  ctx3d.RGBA,  ctx3d.RGBA, ctx3d.UNSIGNED_BYTE, this);

ctx3d.enableVertexAttribArray(vloc);
ctx3d.bindBuffer(ctx3d.ARRAY_BUFFER, vertexBuff);
ctx3d.vertexAttribPointer(vloc, 2, ctx3d.FLOAT, false, 0, 0);

ctx3d.enableVertexAttribArray(tloc);
ctx3d.bindBuffer(ctx3d.ARRAY_BUFFER, texBuff);
ctx3d.bindTexture(ctx3d.TEXTURE_2D, tex);
ctx3d.vertexAttribPointer(tloc, 2, ctx3d.FLOAT, false, 0, 0);
};

Define teardown for all tests (runs after each clocked test loop, outside of the timed code region) (see FAQ)

Code snippets to compare

Test 1

Title

Async (check if this is an asynchronous test)

Code

ctx2d.drawImage(img, inc, inc);
inc += 0.1;

Test 2

Title

Async (check if this is an asynchronous test)

Code

ctx3d.uniform2fv(uLoc, [inc, inc]);
ctx3d.drawArrays(ctx3d.TRIANGLE_FAN, 0, 4);
inc += 0.1;