[openMSX-devel] VRAM/timing progress

[Maarten t. H. <mt...@st...>]

Hi,

Most sprite problems are fixed now. Space Manbow, Vampire Killer and Psycho 
World all display correctly now.

I fixed a lot of issues with the VDP subcomponent timings, so I'm not sure 
exactly which changes made the difference. My guess is these were the two 
most important problems:
- VDP::frameStart first updated the internal VDP per-frame state (PAL/NTSC, 
vertical adjust) before calling frameStart on Renderer and SpriteChecker. 
This is wrong: Renderer and SpriteChecker have to update to the end-of-frame 
time and should do so with the state of the old frame, not the new one.
- SpriteChecker::sync would read from VRAM, which would update the command 
engine, which would write VRAM, which would call SpriteChecker::sync. This 
could also occur through a longer chain involving the Renderer as well. But 
the sync method is not re-entrant. Solved by creating checkUntil 
(SpriteChecker) and renderUntil (Renderer), which update using the current 
VRAM state and only synchronise with VRAM in sync().

Remaining problems:
- SCREEN7/8 sprites are broken at the moment, because reorder is not applied.
- I saw some remaining glitches in the starfield of UR.
- "Rendered into next frame's time" messages still appear.
- SDLGL is not up-to-date.
- It's a bit slow.
Did I forget something?

I left some asserts in the code, if you manage to trigger any of them, please 
inform me.

Bye,
		Maarten