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Next: 23.1.3 Perspective z-Coordinate Transformations Up: 23.1 Projection Matrices Previous: 23.1.1 Perspective Projection

23.1.2 Orthographic Projection

The call glOrtho, r, b, t, u, f(l, r, b, t, u, f) generates R, where:

\begin{displaymath}R = \pmatrix{{2 \over {r-l}}&0&0&-{{r+l} \over {r-l}}\cr
0&{...
...over 2}\cr
0&0&{{f-n} \over 2}&{{n+f} \over 2}\cr
0&0&0&1\cr}\end{displaymath}

R is defined as long as $l \neq r$, $t \neq b$, and $n \neq f$.



David Blythe
1999-08-06