[Plib-devel] Texture loading problems (bmp/rgb)

[Jan R. <slo...@gm...>]

Hello,

I'm currently having two problems with texture loading, and I want
your opinion if these are real bugs, missing features or whatever.

First: bmp loading

As already stated in bug tracker item 1275291, bmp textures are
displayed flipped (upside down). Is this a generall problem?
Or does bmp support different modes (like "first pixel bottom left" /
"first pixel top left") which aren't properly evaluated?
The loader seems to always flip the loaded data. If someone can
give me a heads-up on the bmp format details I'd like to prepare
a bugfix.


Second: rgb loading

When loading an rgb texture, there's a check if the number of
bit planes is two or four. If this is the case, the texture
is deemed to be translucent (translucent greyscale or RGBA).
But this makes a textured object translucent no matter if the
texture really uses the alpha channel or not. Wouldn't it make
more sense to check if any pixels in the alpha channel are
really set to values less than 1.0? None of the tools I'm currently
working with (mainly the GIMP) seems to be capable of producing
a pure RGB .rgb image, only RGBA, so the textured objects will
randomly be hidden behind other translucent objects. My only
choice right now is to fall back to .bmp textures which I don't
like for several reasons, one being the bug mentioned above.
Would it hurt to extend the rgb loader like this?

Kind regards,
Jan R.

-- 
Jan Reucker
email: jan dot reucker at web dot de
web:   http://www.reucker-online.de