One pass blend under and over depth-buf

I want to disscuss with you problem of multi-state checks which impact rendering modes.

Let’s have a SIMPLE example of state dependent rendering !!!EXPLOTION!!!

  1. If we’d have a new GLenum parameter in glBlendFunc() function telling OpenGL if this function should be used for under or over depth buffer rasterizing then we could render much more complex blending in one pass.

  2. Also we could add another enum which would specify current stencil relation with stencil buffer at which given blend function should be “executed”.

And at last possibility of specifying different blend functions for being resterized front or back face.

We could add here many many additional states on which blending would depend. But that was the beggining. Let’s imagine how HUGE would be that dependency expoltion in other functionalities than blending!

CAN YOU SEE INTERFACE WHICH WOULD HANDLE ALL THE MESS I DESCRIBED WITHOUT THE EXPLOTION OF ADDITIONAL PARAMETERS?

Thanx for all your replies.
Ciao, ZOM!

[This message has been edited by zom (edited 01-14-2002).]

The planed Pixel Shader Programms for OGL2 will enable you to do exactly this.