Original Post
Hello, i have voodoo4 video card and it supports extension GL_ARB_texture_compression.
The real problem is that when i want to upload RGBA 32-bit image
into OpenGL and compress it using internal format:
GL_COMPRESSED_RGBA_ARB
it introduces some terrible visual artifacts when rendering.
The texture is shown but it contains some strange pixels...
and GL_COMPRESSED_RGB_ARB
works perfectly
So the problem is alpha channel, is there something i should know more about to fix this
(I know i convert my textures right into 32-bit images..
because these 32-bit images works correctly when my internal format is GL_RGBA8 uncompressed)
Anyone experienced with voodoo4-5 + textures GL_COMPRESSED_RGBA_ARB used for example billboarding purpouses ?