Commit 87643ca6 authored by Jan Möbius's avatar Jan Möbius

Fixed unwanted checkin

git-svn-id: 383ad7c9-94d9-4d36-a494-682f7c89f535
parent 933db392
......@@ -79,7 +79,7 @@ namespace ACG {
//== CLASS DEFINITION =========================================================
/** \class GLState <ACG/GL/GLState.hh>
/** \class GLState GLState.hh <ACG/Scenegraph/GLState.hh>
This class stores all relevant OpenGL states and can therefore
provide some nice and efficient functions like projecting,
......@@ -87,28 +87,28 @@ namespace ACG {
\note This class needs an OpenGL context. This is currently
given in a QGLContext.
\section pMatrix The projection matrix
The GLState class stores its own projection matrix which is of type
GLMatrixT. Creating a viewing frustum of a perspective projection
will result in the following projection matrix:
\image html pmatrix.png
Where n is the orthogonal distance from the viewing plane (near plane)
to the eye position, f is the orthogonal distance from the back clipping plane
(far plane) to the eye position, l, r, t, b are scalars indicating the left, right,
top and bottom coordinates of the viewing plane (so in fact we have a rectangle between
the points (b,l) and (t,r)) and phi is the opening angle (field of view), also
see figure 1.
\image html projection.png "Figure 1. A schematic illustration of a viewing frustum"
Some useful values that can directly be computed out of the projection matrix:
\image html pfovy.png "Computing the fovy out of the projection matrix"
\image html paspect.png "Computing the aspect out of the projection matrix"
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