doubling color in back buffer?

Is there an easy way that I can double the color in the back buffer? ie, if the color stored in the back buffer was (.5, .5, .25) it would become (1, 1, .5) after a blending operation? The best that I can find is to do glBlendFunc (GL_DST_COLOR, GL_DST_COLOR) to try to add the dst color to itself, however this is not yielding the proper results.

Thanks for any help!

hum yes, that will be wrong…
that results in (src_colorDest_color)+(Dest_colorDest_color)

you want (1dst_color)+(1dst_color) that is
glBlendFunc (GL_DST_COLOR, GL_ONE); and glColor3f(1,1,1) and no light/texture or whatever can affect the source color

edit: forgot to mention, you should draw the white quad allover the area that you want to double

[This message has been edited by Mazy (edited 08-09-2002).]