HP c8000 manual Decomposition of concave quadrilaterals, Vertices outside of a begin/end pair

overview of OpenGL

rendering details

decomposition of concave quadrilaterals

HP determines whether the concave quadrilateral will become front-facing or back-facing prior to dividing the quadrilateral into triangles. HP then divides the surface into two triangles between vertices zero and two or one and three depending on the vertex causing concavity.

vertices outside of a begin/end pair

HP’s implementation of this specification is indeterminate as defined by the OpenGL standard.

index mode dithering

If dithering is enabled in indexed visuals, 2D functions such as glDrawPixels() and glBitmap() will not be dithered.

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