Colors and alpha constant component

OpenGL OpenGL: Basic Coding
1

Is it possible to define a color with an alpha component glColor4f(R1,G1,B1, Ac) and after define a color glColor3f(R2,G2,B2) which conserves the Ac component ? In other word, could I fixed a constant alpha ?

I hope I’m not too blurred.

Thanks.

2

From the MSDN documentation:
"The glColor3 variants specify new red, green, and blue values explicitly, and set the current alpha value to 1.0 implicitly. "
So it is not possible.

If you do not have the opengl.chm file:
ftp://ftp.microsoft.com/developr/platformsdk/july2000/common/help/opengl.chm

3

I achieve my goal using register combiners.

Thanks a lot for the OpenGL doc !