RE: [Algorithms] 256 colour palette

[Matthew D. <MD...@ac...>]

Doing a ray-casting engine for the Gameboy Advance in my spare time.  I'm
using its 256 colour bitmap mode.

Matt.


> -----Original Message-----
> From: Martin Fuller [mailto:mf...@ac...]
> Sent: Wednesday, August 30, 2000 11:50
> To: 'gda...@li...'
> Subject: RE: [Algorithms] 256 colour palette
> 
> 
> Doom used 16 shades of 16 colours if I remember correctly. 
> IMO this was a
> good balance. You could see each shade but it was a payoff 
> for the number of
> colours. I'd be tempted to do some sort of dynamic palette 
> changing. For
> example given a PVS:
> 
> ROOM A can see ROOM B <> ROOM B can see ROOM A
> ROOM B can see ROOM C <> ROOM C can see ROOM B
> 
> (Note ROOM A and C cannot see eachother and you cannot be 
> stood in ROOM B
> and see both ROOM A and ROOM C)
> 
> ROOM B referenced 208 pallete entries
> ROOM A has a different remaining 48 pallete entires to ROOM C.
> 
> So while the number of colours you need to reference never 
> exceeds 256 you
> can have more colours than that on the map. You have to have 
> low colour
> 'insulating' Rooms / corridors. It also means that agents / 
> fx can only
> reference the bottom 208 pallete entires. Makes building your 
> maps a little
> more tricky but might be worth it. 
> 
> What platform is this for?
> Cheers,
> Martin
> 
> 
> 
> -----Original Message-----
> From: Matthew Davies [mailto:MD...@ac...]
> Sent: 30 August 2000 03:12
> To: 'gda...@li...'
> Subject: RE: [Algorithms] 256 colour palette
> 
> 
> Hi,
> 
> Sorry, I may have not been clear.
> 
> I don't need to convert a 24-bit image to 256 colours using 
> quantisation.  I
> need to have a consistent single palette which doesn't 
> restrict me too much
> to the colours I can have in my textures.  For example, DOOM 
> used a 256
> colour palette to display all its graphics.
> 
> One idea is to have 32 different colours and 8 shades of 
> them.  I could
> design my textures in those 32 colours and 32 of a darker shade.
> 
> But I just wondered if anyone had a generic palette that they 
> knew worked
> well.
> 
> Best regards,
> Matt.
> 
> > -----Original Message-----
> > From: Tom Nettleship [mailto:to...@ar...]
> > Sent: Wednesday, August 30, 2000 10:47
> > To: 'gda...@li...'
> > Subject: RE: [Algorithms] 256 colour palette
> > 
> > 
> > The problem you're referring to is commonly called 
> quantization. Doing
> > a web search on that might glean some results.
> > 
> > The two main algorithms people often use are called 'Median Cut' and
> > 'Octree Quantization'. Both of these are efficient, and produce good
> > results.
> > 
> > Get hold of a copy of Graphics Gems 1... this has a paper describing
> > how to implement Octree Quantization, and also (i think) 
> source code,
> > though there may be some bugs in it.
> > 
> > Tom Nettleship
> > 
> > P.S. I turned this mail into plain text from the HTML you 
> > sent... please
> > don't
> > send HTML posts to mailing lists; people using some mail 
> readers can't
> > decipher
> > them.
> > 
> > > From: Matthew Davies [mailto:MD...@ac...]
> > > 
> > > Hi,
> > > 
> > > Can any of you guys give me some hints on choosing a decent 
> > 256 colour
> > > palette so that I can get a nice > spread of colours.  I 
> > need it for a
> > simple
> > > 3d game so basically I need to cover common colours and 
> > shades thereof.  
> > >  
> > > Do any of you have experience in this area.  I've had it so 
> > easy with
> > 24-bit graphics up until now!  :-)
> > _______________________________________________
> > GDAlgorithms-list mailing list
> > GDA...@li...
> > http://lists.sourceforge.net/mailman/listinfo/gdalgorithms-list
> > 
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