1 files changed, 67 insertions, 0 deletions
diff --git a/doc/gl-docs/GLU/tessnormal.3gl b/doc/gl-docs/GLU/tessnormal.3gl
new file mode 100644
index 000000000..4d98298b4
--- /dev/null
+++ b/doc/gl-docs/GLU/tessnormal.3gl
@@ -0,0 +1,67 @@
+'\" e
+'\"! eqn | mmdoc
+'\"macro stdmacro
+.ds Vn Version 1.2
+.ds Dt 6 March 1997
+.ds Re Release 1.2.0
+.ds Dp May 02 11:53
+.ds Dm 37 tessnorma
+.ds Xs 47097 4 tessnormal.gl
+.TH GLUTESSNORMAL 3G
+.SH NAME
+.B "gluTessNormal
+\- specify a normal for a polygon
+
+.SH C SPECIFICATION
+void \f3gluTessNormal\fP(
+GLUtesselator* \fItess\fP,
+.nf
+.ta \w'\f3void \fPgluTessNormal( 'u
+	GLdouble \fIvalueX\fP,
+	GLdouble \fIvalueY\fP,
+	GLdouble \fIvalueZ\fP )
+.fi
+
+.EQ
+delim $$
+.EN
+.SH PARAMETERS
+.TP \w'\fIvalueX\fP\ \ 'u 
+\f2tess\fP
+Specifies the tessellation object (created with \%\f3gluNewTess\fP).
+.TP
+\f2valueX\fP
+Specifies the first component of the normal.
+.TP
+\f2valueY\fP
+Specifies the second component of the normal.
+.TP
+\f2valueZ\fP
+Specifies the third component of the normal.
+.SH DESCRIPTION
+\%\f3gluTessNormal\fP describes a normal for a polygon that the program is defining.
+All input data will be projected onto a plane perpendicular to one of 
+the three coordinate axes before tessellation and all output triangles
+will be oriented CCW with 
+respect to the normal (CW orientation can be obtained by reversing the
+sign of the supplied normal). For example, if you know that all polygons
+lie in the x-y plane, call \%\f3gluTessNormal\fP(tess, 0.0, 0.0, 1.0)
+before rendering any polygons.
+.P
+If the supplied normal is (0.0, 0.0, 0.0) (the initial value), the normal is
+determined as follows. The direction of the normal, up to its sign, is
+found by fitting a plane to the vertices, without regard to how the
+vertices are connected. It is expected that the input data lies approximately
+in the plane; otherwise, projection perpendicular to one of the three
+coordinate axes may substantially change the geometry. The sign of the
+normal is chosen so that the sum of the signed areas of all input
+contours is nonnegative (where a CCW contour has positive area).
+.P
+The supplied normal persists until it is changed by another call to 
+\%\f3gluTessNormal\fP.
+.SH SEE ALSO
+\%\f3gluTessBeginPolygon(3G)\fP, 
+\%\f3gluTessEndPolygon(3G)\fP
+
+
+