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gotmilk065 · Joined: 28 Nov 2009 Posts: 25

Is it even possible to swizzle a 24-bit image?

I think I'm misunderstanding the concept entirely.. In all the examples I see, it's only being done to paletted images.

If you can, does it yield a performance increase?

a_noob · Posted: Sun Nov 29, 2009 4:04 am Post subject:

The psp's gpu does not support 24 bit images. You will need to upsample it to to 32bit or down sample it to 16 or palletted. And yes you can swizzle 32 and 16bit unpalletted.
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gotmilk065 · Joined: 28 Nov 2009 Posts: 25

gotmilk065 · Joined: 28 Nov 2009 Posts: 25

Sorry for any bump, but I'd really like to understand why swizzling works and how to do it with a 32-bit image being rendered with GU_PSM_8888..

jojojoris · Joined: 30 Mar 2008 Posts: 261

http://wiki.ps2dev.org/psp:ge_faq
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gotmilk065 · Joined: 28 Nov 2009 Posts: 25

From what I gather, I should swizzle it with the width parameter multiplied by four, since it's a 32-bit image..?

Please correct me if I'm wrong; I'm trying to understand this to my fullest.

a_noob · Posted: Wed Dec 02, 2009 2:37 pm Post subject:

That should do the trick, also don't forget to tell the GPU that the texture is swizzled when binding it.
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Raphael · Joined: 17 Jan 2006 Posts: 646 Location: Germany

To add up on a_noobs reply (hi there btw :):
the swizzle function doesn't know, nor care about pixelformats. It only works on raw bytes and "swizzles" them around, hence it needs a byte-width as parameter, rather than pixel-width... everything else is cared for by the GU when unswizzling for rendering.
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Alexander Berl

gotmilk065 · Joined: 28 Nov 2009 Posts: 25

anmabagima · Joined: 01 Oct 2009 Posts: 96

Hi there,

I would like to have swizzled textures as well. How do I do this ? Is there code part of the SDK i was unable to locate or do someone have the code this thread is referring to ?

Thanks for the help.
AnMaBaGiMa

Raphael · Joined: 17 Jan 2006 Posts: 646 Location: Germany

Basically every available graphics engine (OSL, triEngine, JGE, ...) and even a lot of graphics sample codes have a swizzling function included. Doing a search on the forum would have helped too.
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<Don't push the river, it flows.>
http://wordpress.fx-world.org - my devblog
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Alexander Berl

anmabagima · Joined: 01 Oct 2009 Posts: 96

Hi,

thanks. I've found what I need ;o)