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 Setting Canvas Pixel with lots of iterations - looking more at get/put (version: 1)

Comparing performance of: fillRect/concat vs fillRect/join vs 1×1 Image Data vs fillRect/template literal vs getImageData/putImageData vs getImageData/putImageData - set px.rgba vs getImageData/putImageData - set [px.r, px.g, px.b, px.a] vs getImageData/putImageData - set - no getImageData

Created: 4 years ago by: Registered User
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HTML Preparation code:
AخA
 
1
<canvas id="c" width="800" height="600"></canvas>
Script Preparation code:
 
$c = document.getElementById('c');
$ctx = $c.getContext('2d');
$ctx.clearRect(0, 0, 800, 300);
$px = $ctx.createImageData(1, 1);
$id = $ctx.getImageData(0, 0, 800, 600);
$pxls = [];
for (var i = 0; i < 1000000; ++i) {
    const pxl = {
        x: Math.random() * 800 << 0,
        y: Math.random() * 300 << 0,
        r: Math.random() * 255 << 0,
        g: Math.random() * 255 << 0,
        b: Math.random() * 255 << 0,
        a: Math.random() * 128 << 0 + 128
    };
    pxl.rgba = [pxl.r, pxl.g, pxl.b, pxl.a];
    $pxls.push(pxl);
};
$i = 0;
$iterations = 5000;
/*
At 1500+ $iterations the putimagedata/getimagedata starts to win and at 5000 it slaughters.  Below that the other methods win
So it depends on how many you plan on drawing each frame
*/
Tests:

  • fillRect/concat

     
    for (var i=$iterations;i--;){
    var px = $pxls[$i++ % 10000];
    $ctx.fillStyle = 'rgba(' + px.r + ',' + px.g + ',' + px.b + ',' + (px.a / 255) + ')';
    $ctx.fillRect(px.x, px.y, 1, 1);
    }

  • fillRect/join

     
    for (var i=$iterations;i--;){
    var px = $pxls[$i++ % 10000];
    $ctx.fillStyle = 'rgba(' + [px.r,px.g,px.b,px.a/255].join() + ')';
    $ctx.fillRect(px.x, px.y, 1, 1);
    }

  • 1×1 Image Data

     
    for (var i=$iterations;i--;){
    var px=$pxls[$i++ % 10000], d=$px.data;
    d[0] = px.r;
    d[1] = px.g;
    d[2] = px.b;
    d[3] = px.a;
    $ctx.putImageData($px, px.x, px.y);
    }

  • fillRect/template literal

     
    for (var i=$iterations;i--;){
    var px = $pxls[$i++ % 10000];
    $ctx.fillStyle = `rgba(${px.r},${px.g},${px.b},${px.a/255}})`;
    $ctx.fillRect(px.x, px.y, 1, 1);
    }

  • getImageData/putImageData

    ​x
     
    var canvasWidth = $c.width;
    var canvasHeight = $c.height;
    var id = $ctx.getImageData(0, 0, canvasWidth, canvasHeight);
    var pixels = id.data;
    ​
    for (var i=$iterations;i--;){
      var px = $pxls[$i++ % 10000];
      var off = (px.y * canvasWidth + px.x) * 4;
      pixels[off] = px.r;
      pixels[off + 1] = px.g;
      pixels[off + 2] = px.b;
      pixels[off + 3] = px.a;
    }
    $ctx.putImageData(id, 0, 0);

  • getImageData/putImageData - set px.rgba

     
    var canvasWidth = $c.width;
    var canvasHeight = $c.height;
    var id = $ctx.getImageData(0, 0, canvasWidth, canvasHeight);
    var pixels = id.data;
    ​
    for (var i=$iterations;i--;){
      var px = $pxls[$i++ % 10000];
      var off = (px.y * canvasWidth + px.x) * 4;
      pixels.set(px.rgba,off);
    }
    $ctx.putImageData(id, 0, 0);

  • getImageData/putImageData - set [px.r, px.g, px.b, px.a]

     
    var canvasWidth = $c.width;
    var canvasHeight = $c.height;
    var id = $ctx.getImageData(0, 0, canvasWidth, canvasHeight);
    var pixels = id.data;
    ​
    for (var i=$iterations;i--;){
      var px = $pxls[$i++ % 10000];
      var off = (px.y * canvasWidth + px.x) * 4;
      pixels.set([px.r,px.g,px.b,px.a],off);
    }
    $ctx.putImageData(id, 0, 0);

  • getImageData/putImageData - set - no getImageData

     
    var canvasWidth = $c.width;
    var canvasHeight = $c.height;
    //var id = $ctx.getImageData(0, 0, canvasWidth, canvasHeight);
    var pixels = $id.data;
    pixels.fill();
    ​
    for (var i=$iterations;i--;){
      var px = $pxls[$i++ % 10000];
      var off = (px.y * canvasWidth + px.x) * 4;
      pixels.set(px.rgba,off);
    }
    $ctx.putImageData($id, 0, 0);
Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Experimental features:

  • Test case name Result
    fillRect/concat
    fillRect/join
    1×1 Image Data
    fillRect/template literal
    getImageData/putImageData
    getImageData/putImageData - set px.rgba
    getImageData/putImageData - set [px.r, px.g, px.b, px.a]
    getImageData/putImageData - set - no getImageData

    Fastest: N/A

    Slowest: N/A

Latest run results:
Run details: (Test run date: 15 days ago)
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:134.0) Gecko/20100101 Firefox/134.0
Firefox 134 on Mac OS X 10.15
View result in a separate tab
Test name Executions per second
fillRect/concat 188.4 Ops/sec
fillRect/join 200.2 Ops/sec
1×1 Image Data 4.3 Ops/sec
fillRect/template literal 5.7 Ops/sec
getImageData/putImageData 302.4 Ops/sec
getImageData/putImageData - set px.rgba 281.4 Ops/sec
getImageData/putImageData - set [px.r, px.g, px.b, px.a] 276.8 Ops/sec
getImageData/putImageData - set - no getImageData 649.8 Ops/sec
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