For my game engine.

[mckenytech]

Would you suggest using this instead of QuickJS for my C++ game engine? I have a game engine in React Native that uses C++. The update loop is slow in JS (where users write their logic), so I embedded QuickJS, which now allows me to update 15k game objects.

[vExcess]

MicroQuickJS is meant for use where resources, especially memory, are very constrained (for example in microcontrollers). I assume a game engine is not running on any devices that only have 10 kB of RAM. For your use case, QuickJS is more suitable. It is a more mature project and will provide better performance.

My benchmarking (https://github.com/vExcess/js-engine-bench/blob/main/results.md) shows that microquickjs is 42% slower than quickjs.

[bellard]

My benchmarking (https://github.com/vExcess/js-engine-bench/blob/main/results.md) shows that microquickjs is 42% slower than quickjs. In addition microquickjs crashes during one of the benchmarks demonstrating that it is not a stable engine yet.

It seems that your mandelbrot.js test has a bug: the allocated pixels array is not large enough:
var pixels = new Uint8ClampedArray(600 * 600); -> var pixels = new Uint8ClampedArray(600 * 600 * 4);

MicroQuickJS raises an error in this case while the other engines silently accept it. I was not able to reproduce the crash you mentioned.

[vExcess]

I had assumed because microquickjs failed and every other engine passed, that it was a bug in microquickjs. You are correct; it was because of that bug in my code and your engine being stricter (as JavaScript should be). Not sure how I messed up the allocated size in the javascript since I did it correctly in all the other languages. I've retracted the bug statement and updated my benchmark.

[mhart]

var pixels = new Uint8ClampedArray(600 * 600 * 4);

Why * 4 and not * 3? There are just 3 values assigned per x/y coordinate.

var p = (x + y * 600) << 2;
pixels[p + 0] = 255 - bright;
pixels[p + 1] = 255 - bright;
pixels[p + 2] = 255 - bright;

EDIT: ah, I see, the << 2 is actually quadrupling the x/y space. So ((599 + 599 * 600) << 2) + 2 === 1439998