More ST-V emulation progress
- Thread starter mal
- Start date
Runik
Staff member
The priorities are involved also in this interaction : you can have a display pattern like this one :
VDP2 plane -> some sprites -> VDP2 plane -> rest of sprites
or even
some sprites -> VDP2 planes -> rest of sprites.
Right now in Saturnin I display the VDP2 planes first with their correct priority, and then I draw the sprites. So the priority isn't correct, and the resulting MSB calculations aren't correct also.
I'm thinking of a way to display the sprites at the correct moment in the framebuffer, but the performance may decrease ... (and I don't need that right now 😉 )
VDP2 plane -> some sprites -> VDP2 plane -> rest of sprites
or even
some sprites -> VDP2 planes -> rest of sprites.
Right now in Saturnin I display the VDP2 planes first with their correct priority, and then I draw the sprites. So the priority isn't correct, and the resulting MSB calculations aren't correct also.
I'm thinking of a way to display the sprites at the correct moment in the framebuffer, but the performance may decrease ... (and I don't need that right now 😉 )
The main reason MAME is so slow is that a major goal of the project is to be not only accurate, but also portable, readable, consistent, and maintainable, i.e. a "reference implementation" of sorts. The kinds of speed hacks that made emulators like NeoRAGE X and Callus kicky fast are somewhat incompatible with this goal. There are still some protection and oddball patches around, but for instance I'm told that the entire system16/18 drivers are being rewritten because they were too full of ugly hacks.
It's also worth noting that MAME runs Psikyo's SH-2 games well by using pretty straightforward (but game-specific) idle loop detection, which offers a huge speed boost. I remember dropping Strikers 1945 III into the driver and being floored by how slow it was compared to Sol Divide. I have no doubt that Saturn emulator authors are pursuing this sort of optimization in a more generic way.
It's also worth noting that MAME runs Psikyo's SH-2 games well by using pretty straightforward (but game-specific) idle loop detection, which offers a huge speed boost. I remember dropping Strikers 1945 III into the driver and being floored by how slow it was compared to Sol Divide. I have no doubt that Saturn emulator authors are pursuing this sort of optimization in a more generic way.
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