jsPerf.app is an online JavaScript performance benchmark test runner & jsperf.com mirror. It is a complete rewrite in homage to the once excellent jsperf.com now with hopefully a more modern & maintainable codebase.
jsperf.com URLs are mirrored at the same path, e.g:
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 = newArrayBuffer(imageData.data.length);
var buf8 = newUint8ClampedArray(buf);
var data32 = newUint32Array(buf);
// Determine whether Uint32 is little- or big-endian.
data32[1] = 0x0a0b0c0d;
var isLittleEndian = true;
if (buf[4] === 0x0a && buf[5] === 0x0b && buf[6] === 0x0c &&
buf[7] === 0x0d) {
isLittleEndian = false;
}
Teardown
ctx.putImageData(imageData, 0, 0);
Test runner
Ready to run.
Testing in
Test
Ops/sec
8-bit Pixel Manipulation
for (var y = 0; y < canvasHeight; ++y) {
for (var x = 0; x < canvasWidth; ++x) {
var index = (y * canvasWidth + x) * 4;
var value = x * y & 0xff;
data[index] = value; // red
data[++index] = value; // green
data[++index] = value; // blue
data[++index] = 255; // alpha
}
}
ready
32-bit Pixel Manipulation
if (isLittleEndian) {
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
}
}
} else {
for (y = 0; y < canvasHeight; ++y) {
for (x = 0; x < canvasWidth; ++x) {
value = x * y & 0xff;
data32[y * canvasWidth + x] =
(value << 24) | // red
(value << 16) | // green
(value << 8) | // blue255; // alpha
}
}
}
imageData.data.set(buf8);