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Diffstat (limited to 'doc/gl-docs/GLU/nextcontour.3gl')
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diff --git a/doc/gl-docs/GLU/nextcontour.3gl b/doc/gl-docs/GLU/nextcontour.3gl new file mode 100644 index 000000000..6640a6a72 --- /dev/null +++ b/doc/gl-docs/GLU/nextcontour.3gl @@ -0,0 +1,102 @@ +'\" 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 nextconto +.ds Xs 37451 5 nextcontour.gl +.TH GLUNEXTCONTOUR 3G +.SH NAME +.B "gluNextContour +\- mark the beginning of another contour + +.SH C SPECIFICATION +void \f3gluNextContour\fP( +GLUtesselator* \fItess\fP, +.nf +.ta \w'\f3void \fPgluNextContour( 'u + GLenum \fItype\fP ) +.fi + +.EQ +delim $$ +.EN +.SH PARAMETERS +.TP \w'\f2tess\fP\ \ 'u +\f2tess\fP +Specifies the tessellation object (created with \%\f3gluNewTess\fP). +.TP +\f2type\fP +Specifies the type of the contour being defined. Valid values are +\%\f3GLU_EXTERIOR\fP, +\%\f3GLU_INTERIOR\fP, +\%\f3GLU_UNKNOWN\fP, +\%\f3GLU_CCW\fP, and +\%\f3GLU_CW\fP. +.SH DESCRIPTION +\%\f3gluNextContour\fP is used in describing polygons with multiple contours. After the first +contour has been described through a series of \%\f3gluTessVertex\fP calls, +a \%\f3gluNextContour\fP call indicates that the previous contour is complete and that the +next contour is about to begin. +Another series of \%\f3gluTessVertex\fP calls is then used to describe the new +contour. This process can be repeated until all contours have been described. +.P +\f2type\fP defines what type of contour follows. +The legal contour types are as follows: +.TP 18 +\%\f3GLU_EXTERIOR\fP +An exterior contour defines an exterior boundary of the polygon. +.TP +\%\f3GLU_INTERIOR\fP +An interior contour defines an interior boundary of the polygon (such as +a hole). +.TP +\%\f3GLU_UNKNOWN\fP +An unknown contour is analyzed by the library to determine if it is interior +or exterior. +.TP +\%\f3GLU_CCW\fP, +.TP +\%\f3GLU_CW\fP +The first \%\f3GLU_CCW\fP or \%\f3GLU_CW\fP contour defined is considered to +be exterior. All other contours are considered to be exterior if they +are oriented in the same direction (clockwise or counterclockwise) as +the first contour, and interior if they are not. +.P +If one contour is of type \%\f3GLU_CCW\fP or \%\f3GLU_CW\fP, then all +contours must be of the same type (if they are not, then all \%\f3GLU_CCW\fP +and \%\f3GLU_CW\fP contours will be changed to \%\f3GLU_UNKNOWN\fP). +.P +Note that there is no real difference between the \%\f3GLU_CCW\fP and +\%\f3GLU_CW\fP contour types. +.P +Before the first contour is described, \%\f3gluNextContour\fP can be called to +define the type of the first contour. +If \%\f3gluNextContour\fP is not called before the first contour, then the first contour is +marked \%\f3GLU_EXTERIOR\fP. +.P +This command is obsolete and is provided for backward compatibility +only. Calls to \%\f3gluNextContour\fP are mapped to \%\f3gluTessEndContour\fP +followed by +\%\f3gluTessBeginContour\fP. +.SH EXAMPLE +A quadrilateral with a triangular hole in it can be described as follows: +.sp +.Ex +gluBeginPolygon(tobj); + gluTessVertex(tobj, v1, v1); + gluTessVertex(tobj, v2, v2); + gluTessVertex(tobj, v3, v3); + gluTessVertex(tobj, v4, v4); +gluNextContour(tobj, GLU_INTERIOR); + gluTessVertex(tobj, v5, v5); + gluTessVertex(tobj, v6, v6); + gluTessVertex(tobj, v7, v7); +gluEndPolygon(tobj); +.Ee +.SH SEE ALSO +\%\f3gluBeginPolygon(3G)\fP, \%\f3gluNewTess(3G)\fP, \%\f3gluTessCallback(3G)\fP, \%\f3gluTessVertex(3G)\fP, +\%\f3gluTessBeginContour(3G)\fP + |