Canvas Pixel Manipulation (v144)

Revision 144 of this benchmark created by Carter on

Description

Tests two different methods of manipulating pixels using the canvas.

Preparation HTML

<canvas id="canvas" height="256" width="256"></canvas>

Setup

var canvas = document.getElementById('canvas');
    var canvasWidth = canvas.width;
    var canvasHeight = canvas.height;
    var ctx = canvas.getContext('2d');
    var imageData = ctx.getImageData(0, 0, canvasWidth, canvasHeight);
    
    var data = imageData.data;
    
    
    var buf = new ArrayBuffer(imageData.data.length);
    var d32=new Uint32Array(imageData.data.buffer);
    var buf8 = new Uint8ClampedArray(buf);
    var data32 = new Uint32Array(buf);
    var _x = 0;
    var _y = 0;
    var _v = 0;
    var _yd = 0;
    var totalDims = canvasWidth * canvasHeight;

Teardown


    ctx.putImageData(imageData, 0, 0);

Test runner

Ready to run.

Testing in
TestOps/sec
8-bit Pixel Manipulation
for (var y = 0; y < canvasHeight; ++y) {
  for (var x = 0; x < canvasWidth; ++x) {
    var value = x * y & 0xff;

    d32[y * canvasWidth + x] =
      (255 << 24) | // alpha
    (value << 16) | // blue
    (value << 8) | // green
    value; // red
  }
}
ready
32-bit Pixel Manipulation
for (var y = 0; y < canvasHeight; ++y) {
  for (var x = 0; x < canvasWidth; ++x) {
    var value = x * y & 0xff;

    data32[y * canvasWidth + x] =
      (255 << 24) | // alpha
    (value << 16) | // blue
    (value << 8) | // green
    value; // red
  }
}

imageData.data.set(buf8);
ready
Test3
for (var i = 0; i < 65536; i++) {
  _x = i % 256;
  _y = ~~ (i / 256);
  _v = _x * _y & 0xff;
  data32[i] =
    (255 << 24) | // alpha
  (_v << 16) | // blue
  (_v << 8) | // green
  _v; // red

}

imageData.data.set(buf8);
ready
Test4
for (_y = 0; _y < canvasHeight; _y++) {
  _yd = canvasWidth * _y;
  for (_x = 0; _x < canvasWidth; _x++) {
    _v = _x * _y & 0xff;

    data32[_yd + _x] =
      (255 << 24) | // alpha
    (_v << 16) | // blue
    (_v << 8) | // green
    _v; // red
  }
}

imageData.data.set(buf8);
ready

Revisions

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