GLdouble righ )

PARAMETERS
       left, righ Specify the coordinates for the left and right vertical clip‐
                  ping planes.

       _param3, _param4
                  Specify the coordinates for the  bottom  and  top  horizontal
                  clipping planes.

       _param5, _param6
                  Specify  the  distances  to  the  near and far depth clipping
                  planes.  Both distances must be positive.

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:

                       ⎣___________           0           A  0⎦
                             0      _____________________ B  0
                             0                0           C  D
                             0                0           −1 0

                                     A=_________

                               B=_____________________

                               C=−_____________________

                               D=−_____________________

       Typically,  the  matrix  mode  is  GL_PROJECTION,  and  (left,  _param3,
       -_param5) and (righ, _param4,  -_param5) 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).   -_param6
       specifies  the  location  of  the  far clipping plane.  Both _param5 and
       _param6 must be positive.

       Use glPushMatrix and glPopMatrix to save and restore the current  matrix
       stack.

NOTES
       Depth  buffer  precision is affected by the values specified for _param5
       and _param6.  The greater the ratio of _param6 to _param5 is,  the  less
       effective  the  depth  buffer will be at distinguishing between surfaces
       that are near each other.  If

                                     r=__________

       roughly log2(r) bits of depth buffer precision are lost.  Because r  ap‐
       glGet with argument GL_TEXTURE_MATRIX
       glGet with argument GL_COLOR_MATRIX

SEE ALSO
       glOrtho, glMatrixMode, glMultMatrix, glPushMatrix, glViewport

                                                                  GLFRUSTUM(3G)