glEdgeFlagv function

Flags edges as either boundary or nonboundary.

Syntax

void WINAPI glEdgeFlagv(
   const GLboolean *flag
);

Parameters

flag

Specifies a pointer to an array that contains a single Boolean element, which replaces the current edge flag value.

Return value

This function does not return a 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 glEdgeFlagv 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, glEdgeFlagv can be called between a call to glBegin and the corresponding call to glEnd.

The following functions retrieve information related to glEdgeFlagv:

glGet with argument GL_EDGE_FLAG

Requirements