Overwriting text question

I’m a real newbie with OpenGL, so please excuse if this seems like a dumb question. I have an app that needs to update ASCII data in cells within a window. I can display text just fine using glRasterPos and glutBitmapCharacter, but when I try to update the character, the pixel bits get or’d with the currently displayed character. I need to replace characters at specific locations (as fast as possible). How can I do this?

Hi !

You can’t “modify” a rendered image in OpenGL because you just add stuff to it (that’s why you get the OR effect), you need to clear the color buffer and render evrything again.