You can do it with drawing lines (glBegin(GL_LINES)) . You should do it after drawing all other scene data. And also make sure that your scene transformations will not effect the axis drawing.
it will be like this
glPushMatrix()
DrawScene() // All scene drawing goes here.
glPopMatrix()
glPushMatrix()
glTranslatef( adjust the coordinates such that axis are at correct position)
DrawAxis() // draw axis will use lines.
glPopMatrix()
This will work. One more thing , don't mix up Opengl with GDI.
if you still want to modifu frame buffer use glDrawPixels
Hopes this helps
jkchan
cgmath.blogspot.com[
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