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FPS Boost Or Game Boost

Kamelito Loveless

Posts 206
28 May 2021 19:16


Xbox do have FPS boost, they speed existing games from 30 to 60 FPS or 60 to 120 FPS without modifying existing games. Sony have something similar that they call Game boost. Those options can be disabled per games.
  So Iím wondering if something similar could be done on the Amiga land.
  Some games already use the CPU if it is faster than the blitter but many more donít, Iíd say the majority of them.
  I think that the Vampire could do the same, the easiest way would be to double the blitter speed (more?). I guess some games also check the VBL and perform their blits every other frame maybe this should be tweaked too.
  I suppose that a Software blitter emulator using AMMX could replace a faster blitter but some logic using the MMU should be added to trap every blitter call and redirect them to the AMMX equivalent but I donít know if the overhead is light enough to improve the blits. Of course Iím talking about games below 50/60 FPS (PAL/NTSC)
  Your thoughts?


Gunnar von Boehn
(Apollo Team Member)
Posts 5483
01 Jul 2021 10:42


Kamelito Loveless wrote:

Your thoughts?

The way Amiga games are coded looks typically like this:

For a 50 FPS game:
--
1) WHAT FOR VBL EVENT

2) DRAW SCREEN

3) LOOP
--

Often for a 25 FPS GAME
--
1) WHAT FOR VBL EVENT

2) DRAW BACKGROUND , SOME SPRITES

3) WHAT FOR VBL EVENT

4) DRAW FOREGROUND/ MORE SPRITES

5) LOOP

--
Making the Blitter faster ... has typically no effect on game speed
as the games will do sync themselve to the Screen Display.




Kamelito Loveless

Posts 206
01 Jul 2021 10:51


This is why I put the sentence  «  I guess some games also check the VBL and perform their blits every other frame maybe this should be tweaked too.«  and « Of course Iím talking about games below 50/60 FPS (PAL/NTSC)« 

If the blitter is faster (or code trapped to use a software blitter using AMMX) by removing the 2nd wait then it should be doable. There is already a software blitter emulator with source code done by Xeron for OS 4. (Might be incomplete though)


Gunnar von Boehn
(Apollo Team Member)
Posts 5483
01 Jul 2021 11:03


Kamelito Loveless wrote:

If the blitter is faster

 
The Blitter is faster already on V4.
 
 
I think what you propose can be done.
But it you will need to "disasm/patch" each game individually one by one. You need to do this carefully to make sure the enemies not move twice as fast, and that the music not plays twice as fast.
I think this is certainly possible.. But its a lot of work.

But then we can ask where to start and where to stop?
If you want to double the FPS, maybe using the 16bit audio is a good idea too?
Or improve the game and sprites to show more colors?


posts 4