I am setting up two different rendering windows for a 2048x1556 textured image, using the same fragment shader for each. Same image processing, different sizes and locations.
The first window, which was current before all texture/drawing operations displays fine. When I call glMakeCurrent to switch to the other window, then call glBegin/glEnd to redraw the geometry, and swap buffers, I only get a white texture. OpenGL doesn’t seem to know about the current texture I have just set up.
Question: How much code do I have to re-write for the second window? Speed is critical as this is a realtime movie processing app.
I am grateful for your advice.