Re: [PyOpenGL-Users] per pixel alpha transparency on textures

[<pos...@sl...>]

Definately possible. One thing that took me a while was to get the image
imported in the right (RGBA) format. I have these snippets:

glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA )

textureSurface = pygame.Surface(destination_dim, pygame.SRCALPHA, 32)

textureSurface.fill((0,0,0,0))

textureSurface.blit( sourceSurface, (x_offset,y_offset), (frame_min_x,
frame_min_y, sprite_width, sprite_height) )

textureData = pygame.image.tostring(textureSurface, "RGBA", 1)

glBindTexture(GL_TEXTURE_2D, textures[i])
glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, textureSurface.get_width(),
textureSurface.get_height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, textureData );

glEnable( GL_BLEND )

glEnable( GL_ALPHA_TEST )
glAlphaFunc( GL_GREATER, 0.1 )

glEnable(GL_TEXTURE_2D)
glBindTexture( GL_TEXTURE_2D, texture )

Hope that helps. glAlphaFunc is key.

-austin

> Is per pixel alpha transparency on textures possible?
>
> I've investigated glBlend and glTexEnvfv, but neither come up with the
> results i expected.
>
> What do other people do to achieve this?
>
> Sw.
>
>
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