How can I write faster JavaScript?
- by a paid nerd
I'm writing an HTML5 canvas visualization. According to the Chrome Developer Tools profiler, 90% of the work is being done in (program), which I assume is the V8 interpreter at work calling functions and switching contexts and whatnot.
Other than logic optimizations (e.g., only redrawing parts of the visualization that have changed), what can I do to optimize the CPU usage of my JavaScript? I'm willing to sacrifice some amount of readability and extensibility for performance. Is there a big list I'm missing because my Google skills suck? I have some ideas but I'm not sure if they're worth it:
Limit function calls
When possible, use arrays instead of objects and properties
Use variables for math operation results as much as possible
Cache common math operations such as Math.PI / 180
Use sin and cos approximation functions instead of Math.sin() and Math.cos()
Reuse objects when passing around data instead of creating new ones
Replace Math.abs() with ~~
Study jsperf.com until my eyes bleed
Use a preprocessor on my JavaScript to do some of the above operations
