Sega Genesis Dev Kit (SGDK)

SGDK only sub forum

Moderator: Stef

themrcul
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Re: Sega Genesis Dev Kit (SGDK)

Post by themrcul » Wed May 15, 2019 11:49 pm

Thanks for your continued and great efforts Stef. I'm looking forward to getting my code base up to date with the new version you have released!

cero
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Re: Sega Genesis Dev Kit (SGDK)

Post by cero » Thu May 16, 2019 7:36 am

As posted in the thread before I sent zlib code in, aplib does not compress better:
viewtopic.php?f=19&t=2275

It may decompress faster, but as long as the compressor is closed source, it is unusable. I do have an unreleased project using zlib, but there's no need to keep it in just for me, since you already decided to remove it. I just want to say it's not a good idea to remove industry standard libs, on any platform having standard zlib/lz4/other libs means you get up to speed faster, without having to investigate something custom to that platform only.

You may know that I code on many platforms. I can say from experience it helps a lot that you can use standard solution X and don't have to use never-heard-of-custom-solution that requires several hours to investigate and setup.

LZ4W is probably ok, I haven't tested it since the compressor requires Java. Different goals for that anyway.

Stef
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Re: Sega Genesis Dev Kit (SGDK)

Post by Stef » Thu May 16, 2019 9:31 am

To be honest i completely forgot about the zlib discussion we had before (i couldn't really remember from where my zlib came :D)
If it was really useful for you, i would say that you should keep it aside (the unit is 100% independent) but definitely i don't want to confuse users with that zlib unit while rescomp doesn't even support ZIP compression.
I think i studied a possible replacement of APLIB with ZLIB but the problem is that ZLIB is definitely heavier than APLIB here despite your efforts to reduce that.

Sik
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Re: Sega Genesis Dev Kit (SGDK)

Post by Sik » Fri May 17, 2019 4:40 am

*insert shameless plug for SLZ* :​v
I mean, SLZ has a tool written in C, only uses up as much RAM as the decompressed data (and the function call :​P) and the SLZ format is documented. And on the Mega Drive side it's literally just a single function call, so it should be easy to learn. Though I should some day make a variant of the 68000-side asm code that's usable from C code in GCC (since the provided C routine is probably quite slower).

Serious question though: how much memory does zlib use? (excluding the decompressed data itself) Because I imagine that's the main factor, with there being only 64KB. If you start using up RAM for other stuff (especially anything that's a buffer) and can't reuse it, this is going to be a real problem. Speed isn't a big deal since you'd use it between two screens anyway (where display is presumably blank anyway). Just try to not waste seconds on it.
Sik is pronounced as "seek", not as "sick".

cero
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Re: Sega Genesis Dev Kit (SGDK)

Post by cero » Fri May 17, 2019 5:20 pm

SLZ looks very similar to LZ4 and Stef's LZ4W. The zlib code I had posted needed 4kb, but it's possible to go as low as 765 bytes, based on the 6502 asm implementation.

Chilly Willy
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Re: Sega Genesis Dev Kit (SGDK)

Post by Chilly Willy » Fri May 17, 2019 11:17 pm

4KB is pretty low. If I had had code like that, I might have been able to work it into the Neo Myth menu, regardless of the speed issue. At the time, the code needed 32KB (or was it 64KB?), and had to be accessible as bytes. It was too big for what work ram I had, and I couldn't put it in the Neo Myth ram because it could only be accessed as words. I spent some time trying to rewrite all the byte accesses to words, but gave it up as a lost cause.

Yukiko
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Re: Sega Genesis Dev Kit (SGDK)

Post by Yukiko » Wed May 22, 2019 3:03 pm

Code: Select all

 - added smart sprite cutting (detect empty space in sprite)
 - can now disable map optimization for IMAGE resources (see rescomp.txt for more information)
Yes, yes, yes! Now I get to be lazy!

Stef
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Re: Sega Genesis Dev Kit (SGDK)

Post by Stef » Thu May 23, 2019 11:44 am

That was 2 features really important to add :D

cloudstrifer
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Re: Sega Genesis Dev Kit (SGDK)

Post by cloudstrifer » Sat May 25, 2019 10:13 pm

Thank you for a new SGDK version.
Stef wrote:
Thu May 23, 2019 11:44 am
That was 2 features really important to add :D
Stef, is there an option to keep duplicated frames or other alternative to show 2 or 3 identical frames in a row?

frame 1 = 2 frames
frame 2 = 5 frames

Thank you!

Stef
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Re: Sega Genesis Dev Kit (SGDK)

Post by Stef » Mon May 27, 2019 2:12 pm

What you mean is have independent timing for each animation frame right ? Yeah i plan to add that too.
SPRITE resource still need a bit of work to be fully usable (per frame timing and per frame collision box to start with)

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