[hatari-devel] Improving color alignment with pixels
jb.berlioz at freemind-tobe.com
Mon Dec 22 23:47:00 CET 2008
> I just committed a patch to do this. As we only have to differentiate
> between cpu and blitter at the bus level, I added a variable named
> 'BusMode' which is by default BUS_MODE_CPU.
> When the blitter starts working, it sets BusMode to BUS_MODE_BLITTER.
> When done, it sets it back to BUS_MODE_CPU.
> This way, the overhead is minimal and I don't think we should see any
> performance impact (no modification to IoMem functions required and no
> parameter to add).
> Tobé, you can now adjust blitter specific timings in cycles.c and
> spec512.c (I might put the special case of spec512.c in cycles.c too,
> so only cycles.c will be relevant).
> By knowing how many words were already processed by the blitter, you
> should be able to determine how many cycles should be added to have a
> precise value of the write cycle and obtain correct color alignment
> and border removal with the blitter.
I've checked out the Mercurial repository and my new FreeBSD
installation will hopefully be finished tomorrow so I'll be able to code :)
Mercurial is interesting, i like the idea of having multiple branches
Just before i trashed my Ubuntu installation, i did dome tests with
mixed YM and DMA sounds, i don't know if theses problems are know:
- Playing DMA samples make YM sounds very noisy
- DMA sounds starts too late
- DMA volume is too high (or YM too low)
It was tested against an MegaSTE.
Have a nice christmas :)
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