Hi, I’v searched and couldn’t find a post spot on about this so I figured I’d ask.
Im just trying to do a simple monocrome shader that preserves the incoming textures alpha channel.
glSampleMapATI(GL_REG_0_ATI, GL_TEXTURE0_ARB, GL_SWIZZLE_STR_ATI);
GL_REG_0_ATI, GL_NONE, GL_SATURATE_BIT_ATI,
GL_REG_0_ATI, GL_NONE, GL_NONE,
GL_CON_0_ATI, GL_NONE, GL_BIAS_BIT_ATI | GL_2X_BIT_ATI);
Results in an alpha of 0. (CON_0 is (.3,.6,.1,0))
But if I add this statement before the DOT4 statement everything works fine (yes, its a garbage statement):
GL_REG_1_ATI, GL_NONE, GL_NONE,
GL_REG_0_ATI, GL_ALPHA, GL_NONE);
I do need to use DOT4 and not DOT3 because this shader is used for other reasons also.
Any ideas, can anyone test this and see if they get the same behavior?
[This message has been edited by MalcolmB (edited 08-01-2003).]