Wich VDP operations do you perform during vblank? Can't you split road rendering in several parts and use a flag to regulate vdp accessess inside and outside the vblank instead of di/ei?
I did this way on Freedom Fighter to update scrolling (during normal program flow) and sprites (hooked in the ISR)
Good graphics but awful playability: if you crash with another car or with the road decor your car explodes. It would be better to lose speed instead of ending with a complete stop.
There has been no recent news, because, as it's often the case, life happened ...
From time to time, I go back on the code of that project and write/modify stuff. A few months ago, I optimized the rendering engine to make it quicker. I also wanted to modify the V9990 version, in order to maximize the use of the 2 planes of the P1 mode. But that did not work out, as my rendering engine uses a lot of di/ei sequences, which messed up the 2 screen splits needed.
The project's main problem is still the same: a full frame rendering takes about 250.000 t-states, which makes currently about 13 fps @50Hz. And I still have to fully implement the traffic, the sideroad items, collision and time/score. Which means that the fps will drop even further. At some point, I'm starting to think that the MSX is not powerful enough to do it.
Plus the fact that, in the V9938 version, I need to use the 32x32 sprites, which makes the graphic design very complex, if I want to avoid a ugly blocky look. That alone, with the sheer amount of sprites needed, makes me think that the V9990 version is better suited to the task. But even the V9990 version has some problems, as the rendering engine is a little bit slower than the V9938, due to the fact that every VRAM writing needs a third byte to be outputted.
So, you could say I kinda lost faith in the project.
Still, I cannot resist to give you a little treat. It's a new video showing the WIP as it was in January of last year, with FM soundtrack, and some early place-holder for traffic and sideroad.
Well, this demo looks quite impressive. It's too bad the framerate would drop further on a normal MSX2. As it looks right now, it would have been great. Outrun was one of my favourite arace games. I've spent quite some money on that machine.
