Run results for: Setting Canvas Pixe3

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4029.3 Safari/537.36

Browser: Chrome 81

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
fillRect/concat	780.2 Ops/sec
fillRect/optimized further	792.4 Ops/sec

HTML Preparation code:

<canvas id="c" width="800" height="300"></canvas>

Script Preparation code:

$c = document.getElementById('c');
$ctx = $c.getContext('2d');
$ctx.clearRect(0, 0, 800, 300);
$px = $ctx.createImageData(1, 1);
$pxls = [];
for (var i=0; i<10000; ++i) $pxls.push({
   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
});
$i = 0;

Tests:

fillRect/concat
for (var i=500;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/optimized further
var i=500, px=null, alphmult = 1 / 255 for (;i--;){ px = $pxls[$i++ % 10000]; $ctx.fillStyle = `rgba(${px.r},${px.g},${px.b},${px.a * alphmult})`; $ctx.fillRect(px.x, px.y, 1, 1); }

Run results for: Setting Canvas Pixe3

fillRect/concat

fillRect/optimized further