SDL Image Alpha channel and OpenGL textures

SDL Development
1

I get stucked when i want to use the alpha channel info from png
images for opengl textures.

Any tips on how to code this fast && portable?–
cu
Joern mailto:@Joern_Woerdehoff

2

Joern Woerdehoff schrieb am 07 Jun 2000:

I get stucked when i want to use the alpha channel info from png
images for opengl textures.

SDL has the alpha channels inverted (don’t ask me why).

Any tips on how to code this fast && portable?

For converting a SDL_Surface (e.g. a png file loaded with SDL_image)
to an OpenGL texture, see http://www.ards.net/Andreas/sdl_textures.html

  • Andreas–
    Check out my 3D lightcycle game: http://www.gltron.org
    More than 60’000 Downloads of the latest version (0.53)
3

Hello A.,

Wednesday, June 07, 2000, 1:32:30 PM, you wrote:

AU> Joern Woerdehoff <@Joern_Woerdehoff> schrieb am 07 Jun 2000:

I get stucked when i want to use the alpha channel info from png
images for opengl textures.

AU> SDL has the alpha channels inverted (don’t ask me why).

Any tips on how to code this fast && portable?

AU> For converting a SDL_Surface (e.g. a png file loaded with SDL_image)
AU> to an OpenGL texture, see http://www.ards.net/Andreas/sdl_textures.html

AU> - Andreas

Have you wrote this example just for me? .)
Gltron is on the latest CT Rom, i think you know that. Thanks for the
help.–
Best regards,
Joern mailto:@Joern_Woerdehoff

4

“Andreas Umbach” wrote:

For converting a SDL_Surface (e.g. a png file loaded with SDL_image)
to an OpenGL texture, see http://www.ards.net/Andreas/sdl_textures.html

On your Web page you say :

Texture size and width must be powers of two for most implementations

IIRC, this is in the OpenGL specs : texture sizes must be power of 2.

             Franck.