.\" @(#)PEXOrthoProjMatrix.3 1.5 95/03/24 SMI;
.so man3/pex.macs
.TH PEXOrthoProjMatrix 3 "May 1995" "Solaris PEXlib Reference Manual" ""
.SH NAME
PEXOrthoProjMatrix - utility function
.SH SYNTAX
.HP
int PEXOrthoProjMatrix\^(\^double \fIheight\fP, double \fIaspect\fP, double \fInear\fP, double \fIfar\fP, PEXMatrix \fImatrix_return\fP\^)
.SH PARAMETERS
.IP \fIheight\fP 1i
The height of the orthographic viewing box.
.IP \fIaspect\fP 1i
The aspect ratio (width/height) of the orthographic viewing box.
.IP \fInear\fP 1i
The distance, in view reference coordinates, from the VRC origin to the
front clipping plane.
.IP \fIfar\fP 1i
The distance, in view reference coordinates, from the VRC origin to the
back clipping plane.
.IP \fImatrix_return\fP 1i
Matrix in which result is stored.
.SH RETURNS
.LP
Zero if successful; otherwise, one of the following:
.TP
.B PEXBadLimits
The viewing box depth, width, or height is zero.
.SH DESCRIPTION
.\" indexing
.IX PEXOrthoProjMatrix
.IX "Utility Functions" PEXOrthoProjMatrix
.LP
This routine formats a view mapping matrix.
.LP
A projection matrix defines a visible region of the coordinate space.
An orthographic projection defines the visible region as a box
specified by its height, width (the height multiplied by the aspect), and
its near and far boundaries.
.LP
The reference point for the projection is the origin of VRC; the near and
far clipping planes are defined with respect to it.  The height is
defined in view reference coordinates.  Clipping at the
planes is controlled by the clipping flags in the selected view table
entry.
.SH ERRORS
None
.SH SEE ALSO
.LP
.nf
.BR PEXLookAtViewMatrix (3)
.BR PEXViewOrientationMatrix (3)
.BR PEXViewMappingMatrix (3)
.BR PEXPerspProjMatrix (3)
.fi