UI Performance Issues

[electronoora]

UI Performance Issues

[electronoora]

Sounds good. The scrolling pattern visualisation seems to be - at least on iOS Safari - the most CPU intensive part of the UI. Especially when switching over from one pattern to another, the change in visibility within the DOM seems to incur a serious performance hit.

I'm assuming a part of the problem is the fact that a single pattern consists of a huge number of span -elements. Using spans more sparingly and applying them only where colour other than the baseline gray is needed had a visible effect on performance. Still, busy multichannel modules are still quite heavy on the CPU. I don't know if there are better ways to emulate text mode character attributes without bloating up the DOM too much.

Using jQuery id selectors wherever applicable instead of class selectors seems to also improve performance significantly.

Regarding stuttering audio, the XM player code seems to be especially bad in some modules. I'm suspecting that this may not be UI-related, but instead an issue with bugs in the volume ramping and/or interpolation code - namely, some FP operations returning NaN or Inf. I'm assuming this is due to overhead from handling SIMD FP exceptions from the CPU.