How can I get more alpha bits? glGetIntegerv(GL_ALPHA_BITS) gives 8… need more. (Using Linux and GLUT)
I’m working a particle system. Given the nature of the project, I’m cheating by not making actual particles, but rather layering a bunch of textured quads on top of each other, where each quad is textured with an RGBA texture.
I have to use 128 layers of these images to achieve a dense enough particle field, and I need each particle to be barely transparent. In this way, solid white is only seen where there are a lot of particles.
The problem that arises is that I need to add up really really small alpha values. With 8 bits, I must use an alpha value that is larger than 0.00196078431 (=1/(2^8 -1 -1)), but I need to use smaller values than this, or I get rough edges in my particle field. A simple gradient ramp is really chunky right now. The following images should be fading from transparent to opaque.
…so, how do I set the alpha bits? And how is that related to BPP? And how are these related to OpenGL/Glut and possibly adding platform dependency?