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oliver67

OpenGL Matrox, 2D coordinate origin

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oliver67    122
Hi, I'm programming a 2d game for OpenGL (something like Thrust from the C64 or GForce from Atari to those who remember). With Windows 2000 and an NVidia graphic card, everything runs fine. But with Windows 2000 and a Matrox Marvel G400, the coordinate origin lies appox. 55 pixels above the wished one. After resizing the window with the mouse, the origin is set correctly. But fixing this bug with an additional call of the WindowResize function doesn't help. I need to improve this, as I'm using glReadPixels for the collision detection, where the absolute coordinates from the lower left of the window should be specified. At all, I think that the Matrox support of OpenGL is very bad, as other applications are also running slow and OpenGL benchmarks confirm this. Does anyone have made similar experiences with Matrox products or know hwo to help me? Thanks in advance Oliver

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vincoof    514
Which GL function retrieves 55 pixel difference ? selection buffer ? read pixels ? something else ?

I also had very bad surprises with Matrox series, and even if the support is going better every time, it's still pretty bad, especially considering the long time between driver releases.

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