Glfrustum - HP b2600 Reference Manual

glFrustum

glFrustum: multiply the current matrix by a perspective matrix.
C Specification
void glFrustum(
Parameters
left, right
bottom, top
zNear, zFar
Description
glFrustum describes a perspective matrix that produces a perspective projection. The
current matrix (see glMatrixMode) is multiplied by this matrix and the result replaces
the current matrix, as if glMultMatrix were called with the following matrix as its
argument:
E 0 A 0
0
0
0
where:
A = (right + left) / (right - left)
B = (top + bottom) / (top - bottom)
C = (far + near) / (far- near)
D = (2 far near) / (far- near)
E = (2 near) / (right - left)
F = (2 near) / (top - bottom)
Typically, the matrix mode is GL_PROJECTION, and (left, bottom, -zNear) and (right,
top, -zNear) specify the points on the near clipping plane that are mapped to the lower
left and upper right corners of the window, assuming that the eye is located at (0, 0, 0).
-zFar specifies the location of the far clipping plane. Both zNear and zFar must be
positive.
Chapter 6
GLdouble left,
GLdouble right,
GLdouble bottom,
GLdouble top,
GLdouble zNear,
GLdouble zFar)
Specify the coordinates for the left and right vertical clipping planes.
Specify the coordinates for the bottom and top horizontal clipping
planes.
Specify the distances to the near and far depth clipping planes. Both
distances must be positive.
F B 0
0 C D
0 -1 0
F
glFrustum
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