I’m developping an application I replace GDI by OpenGL 2.0 functionality.
I draw images by splitting them into two textured triangles. The problem
is that in NVidia hardware the pixels at the triangles edge are not drawn
propertly.
Is that by any chance with enabled polygon antialiasing?
Do you have glEnable(GL_POLYGON_SMOOTH) in your code?
If yes, that doesn’t behave well with depth testing and requires specific blending behavior. It shouldn’t be required for blitting a texture.
Also be very careful with the coordinate placement when rendering different primitives in 2D.
For filled areas like rectangles use the pixel corner coordinates, for points and lines use pixel center coordinates.