plib-devel

[Plib-devel] ssgImageLoader

[Dave M. <dp...@ef...>]

I would like to have textures with alpha so I can do
non-rectangular buttons mapped to panels.

Do either of the current formats BMP or SGI (bw) support that?

If not, the only way I can think of doing this cleanly is to
derive from ssgImageLoader and install my "new"
image loader into SSG.  That way I can allow my
new image loader to load PNG files and link with libpng.

Any alternatives?

//current image loader
ssgImageLoader defaultImageLoader;
ssgImageLoader* _ssgImageLoader = defaultImageLoader;
//and make some of ssgImageLoader functions virtual

--Dave

Re: [Plib-devel] ssgImageLoader

[Steve B. <sjb...@ai...>]

Dave McClurg wrote:
> 
> I would like to have textures with alpha so I can do
> non-rectangular buttons mapped to panels.
> 
> Do either of the current formats BMP or SGI (bw) support that?

Yes - SGI format images support alpha, you can choose between
intensity/alpha and r/g/b/alpha formats.

BMP does not seem to.

> If not, the only way I can think of doing this cleanly is to
> derive from ssgImageLoader and install my "new"
> image loader into SSG.  That way I can allow my
> new image loader to load PNG files and link with libpng.

Adding PNG support would be great - but it's a complex format
and I'd have to link libpng and zlib - which would increase the
number of dependancies that PLIB would have - which is not a
popular thing to do.

What's really needed is some dynamic loading of image loaders...
but anyway....
 
> Any alternatives?

Use SGI format - it does alpha just fine.
 

-- 
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