OpenGL Random White Dots

Question

I am trying to render a geometry in a white background. The problems is that random white dots appears inside the geometry. As I resize my window, the white points switch places... appearing and disappearing randomly inside the geometry (while I am resizing the window).

I have conducted extensive tests and have found that the dots only appears at the edges between two triangles. It seems like both triangles fail to render that pixels (as if that pixels isn't contained by any of the triangles), so the white background is rendered. I should note that only a few pixels at those borders are white (not all). And its not some kind of texture filtering issue since the problem happens even if I render the polygon with a solid color (that I set directly inside the shader).

Really, it seems some kind of hit test problem where the OpenGL implementation fails to detect some pixels on the boundaries of two adjacent triangles.

I am running this example in a 27'' iMac with a NVIDIA GeForce GTX 675MX. I'm going to test this same application on my MacBook with Intel Integrated Graphics Card.

Can someone shed some light on this topic?

Answer 1

Thanks @Damon. I solved the issue which wasn't that the vertices weren't exactly the same. The true problem is that (by design) some vertices needed to stay in the intersection between two triangles. This was causing problems with OpenGL. The solution was to move the vertex slightly down (inside the triangles) and adjust the texture coordinates accordingly.

Many thanks!