Performance optimisations

[dirkwhoffmann]

I've reworked the VICII graphics pipeline and split both the canvas drawing routines and the sprite drawing routines into a "fast path" and a "slow path". This worked out quite well. After powering up and switching to warp mode, the current build (left side) runs more than 10% faster than v4.1 (right side):

For sprite-intensive stuff, the performance gain is even bigger. Here is the "Octopus in Redwine" demo which I frequently use for performance profiling. The demo draws the whole octopus with sprites and is a performance killer. The current build runs it with 5.31 MHz on my machine compared to 3.4 MHz in v4.1.

If I was Apple, I would drop the first experiment and advertise the new version as being up to 55% faster 😎.