glEdgeFlag,
glEdgeFlagv
[New
- Windows 95, OEM Service Release 2]
The glEdgeFlag
and glEdgeFlagv functions flag edges as either boundary or nonboundary.
void glEdgeFlag(
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GLboolean flag |
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); |
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Parameters
flag
In glEdgeFlag,
specifies the current edge flag value, either TRUE or FALSE.
void glEdgeFlagv(
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const GLboolean * flag |
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); |
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Parameters
flag
In glEdgeFlagv,
specifies a pointer to an array that contains a single Boolean element, which
replaces the current edge flag value.
Remarks
Each vertex
of a polygon, separate triangle, or separate quadrilateral specified between a glBegin/glEnd 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.
If the current edge flag is FALSE, the vertex is marked as the start of a
nonboundary edge. The glEdgeFlag function sets the edge flag to TRUE if flag
is nonzero, 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 glPolygonMode.
Initially,
the edge flag bit is TRUE.
The current
edge flag can be updated at any time. In particular, glEdgeFlag can be
called between a call to glBegin and the corresponding call to glEnd.
The following
function retrieves information related to the glEdgeFlag function:
glGet with
argument GL_EDGE_FLAG
See Also