Color update problem

Hi,
I am new with OpenGL, and trying to build a Windows application that displays, modifies, and re-displays (as the image gets modified) a grayscale image (in PGM format). Upto now, I could load/display an image, and also could modify it, eg, say, drawing a circle in it (I checked where I saved the modified image to verify that the modification actually worked). After the modification, the circle should appear in ‘white’ as I drew it in the maximum grayscale intensity. But the problem is, it is appearing in ‘black’, instead of white. Any suggestion how to resolve this?
Thanks!

There is many reasons for which you see black instead of white… please try to be more precise.

For example, you should tell us how you have implemented this stuff.

This topic was automatically closed 183 days after the last reply. New replies are no longer allowed.