Decomposition Of Concave Quadrilaterals; Vertices Outside Of A Begin/End Pair; Index Mode Dithering - HP b2600 Supplementary Manual

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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