Message-ID: <3819114C.F6737540@snetch.cpg.com.au>
Date: Fri, 29 Oct 1999 13:15:24 +1000
From: Michael Abbott aka frEk <20014670 AT snetch DOT cpg DOT com DOT au>
Organization: Student of Computer Power Institute
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To: djgpp AT delorie DOT com
Subject: Re: Error blitting to bitmap
References: <F77915E7F086D31197F4009027CC81C903CA2A AT ASL-NT-EXCH2> <3817D3CE DOT 6A9FCBAB AT snetch DOT cpg DOT com DOT au> <1m4YOOVj79fEqhm+Jer3+PJKSioU AT 4ax DOT com>
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Reply-To: djgpp AT delorie DOT com

Heya

> On Thu, 28 Oct 1999 14:40:46 +1000,
> Michael Abbott aka frEk <20014670 AT snetch DOT cpg DOT com DOT au> wrote:
>
> > I write a lot of GameBoy stuff so recently I was trying to write a 4
> > colour quantizer to convert to the GameBoy's screen. I used
> > generate_optimized_palette with an array leaving 4 values and it left me
> > a protection fault. As soon as I changed the number of colours needed to
> > 256 colours it worked. Would there be any reason it's doing this?
>
> Your Game Boy(R) optimized palette would be
>
> {63, 63, 63}, {42, 42, 42}, {21, 21, 21}, {0, 0, 0}
> unless you're coding for Game Boy Color.

Actually, to get decent conversion (because of the brightness of the screen)
using brighter palette values helps :)

Yep, I'm doing GameBoy Color conversion....

To do GB and Pocket GB conversion the easiest method is a floyd-steinberg
dither with optimising tiles... The GameBoy Color is a different story...

The RGB of the GameBoy has just been proven to be not only with different
ratios to the PC's RGB, but also possibly subtractive :)

> Know of any good Web tutorials on Z80 and Game Boy coding?

Yeah, go for it at: http://hiwaay.net/~jfrohwei (I think)... The GameBoy
Mailing list is also a good idea (Send "subscribe" to
gameboy-request AT vip DOT co DOT za and then send messages to gameboy AT vip DOT co DOT za)...

If that URL's wrong a search under "Jeff AND frohwein" or just "gameboy
programming" will help :)

Otherwise, there is a bunch of URLs at my home page: http://frek.webjump.com/
under the "Emulation" section complete with my disassembler, RGB component
splitted mono conversion, old GB image conversion and a few more :)

Hope that helps,
Michael