Hi,
I need to affect, change or clear the Alpha componant.
I know it works cause I can see the result on the screen with BLEND but why the glReadPixels always give me a value equal to 255 !?!?
Vinnie
Hi,
I need to affect, change or clear the Alpha componant.
I know it works cause I can see the result on the screen with BLEND but why the glReadPixels always give me a value equal to 255 !?!?
Vinnie
what format do you use in the glreadpixel function ???
I’m using the format GL_RGBA
Looks like similar problem :
glReadPixels on GeForce2 .
> I know it works cause I can see the result on the screen with BLEND
??? What do you mean?
Alpha blending works without alpha channel in the color buffer (if you don’t use _DST_ALPHA).
>> I know it works cause I can see the result >>on the screen with BLEND
>??? What do you mean?
I made an operation with glblendfunc using the alpha componant and it works.
I just can’t read something different than 255 with glReadPixels
I’m on a SGI o2
Vinnie
Does your pixel format include a destination alpha buffer? If not, then obviously, the alpha is not being read back because it doesn’t exist.