Similar to SuperVidel's but requires an additional C2P pass.
Also, a few optimizations added like cursor is being assumed to be in
a persistent memory so we don't copy it over. And it's using a mask
instead of key.
This graphics mode is not perfect though and works reliably only with
source surfaces allocated via Surface::init() otherwise wrong memory
location is being read.
Still, can gain quite a few CPU cycles, especially on 640x480 screens.
- Atari TT support
- all video and audio is now handled via XBIOS
- reworked IKBD handling using Kbdvbase vectors, esp. Kbdvec()
- video uses proper triple buffer
- arbitrary game screen size support
- many fixes and optimizations
ScummVM engines are not built for synchronous screen locking (i.e.
updateScreen() can't be really used for any sort of blocking updates
otherwise performance suffers).
Single buffering now means deliberate tearing as a speed optimization
and triple buffering provides a tearingless picture with slight overhead.
Miro Kropacek