fglEdgeFlag(3G) OpenGL Reference fglEdgeFlag(3G)NAME
fglEdgeFlag, fglEdgeFlagv - flag edges as either boundary or nonboundary
FORTRAN SPECIFICATION
SUBROUTINE fglEdgeFlag( LOGICAL*1 flag )
PARAMETERS
flag Specifies the current edge flag value, either GL_TRUE or GL_FALSE.
The initial value is GL_TRUE.
FORTRAN SPECIFICATION
SUBROUTINE fglEdgeFlagv( CHARACTER*8 flag )
PARAMETERS
flag Specifies a pointer to an array that contains a single boolean
element, which replaces the current edge flag value.
DESCRIPTION
Each vertex of a polygon, separate triangle, or separate quadrilateral
specified between a fglBegin/fglEnd pair is marked as the start of either
a boundary or nonboundary edge. If the current edge flag is true when
the vertex is specified, the vertex is marked as the start of a boundary
edge. Otherwise, the vertex is marked as the start of a nonboundary
edge. fglEdgeFlag sets the edge flag bit to GL_TRUE if flag is GL_TRUE,
and to GL_FALSE otherwise.
The vertices of connected triangles and connected quadrilaterals are
always marked as boundary, regardless of the value of the edge flag.
Boundary and nonboundary edge flags on vertices are significant only if
GL_POLYGON_MODE is set to GL_POINT or GL_LINE. See fglPolygonMode.
NOTES
The current edge flag can be updated at any time. In particular,
fglEdgeFlag can be called between a call to fglBegin and the
corresponding call to fglEnd.
ASSOCIATED GETS
fglGet with argument GL_EDGE_FLAG
SEE ALSO
fglBegin, fglEdgeFlagPointer, fglPolygonMode
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