Speed-optimize Denise::translate()

dirkwhoffmann / vAmiga

vAmiga is a user-friendly Amiga 500, 1000, 2000 emulator for macOS

https://dirkwhoffmann.github.io/vAmiga

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Open dirkwhoffmann opened 5 months ago

dirkwhoffmann commented 5 months ago

Findings after a brief code review:

At the end of Denise::translate(), the contents of iBuffer and mBuffer are identical (the mBuffer is modified later in drawSprites()).
The iBuffer is only needed in lines with HAM mode enabled.

Optimization:

At the end of Denise::translate(), check if this line is a HAM line. If yes, create the iBuffer by duplicating the mBuffer. Otherwise, go without the iBuffer.

dirkwhoffmann commented 5 months ago

Speed comparison (Kick 1.3, hand & disk boot screen):

Upper: Latest dev-branch (frame skipping, audio fast path, on-demand-iBuffer): Lower: vAmiga 2.5