Documentation de Gambas - /comp/gb.opengl.glsl/gl/edgeflag

/comp/gb.opengl.glsl/gl/edgeflag

# Gl.EdgeFlag (gb.opengl)

Static Sub EdgeFlag ( Flag As Boolean )

Flag edges as either boundary or nonboundary.

### Parameters

flag

  Specifies the current edge flag value, either Gl.TRUE or Gl.FALSE. The initial value is Gl.TRUE.

### 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 Gl.Begin/Gl.End 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. Gl.EdgeFlag 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 Gl.PolygonMode.

### Notes

The current edge flag can be updated at any time. In particular, Gl.EdgeFlag can be called between a call to Gl.Begin and the corresponding call to Gl.End.

### Associated Gets

Gl.Get with argument Gl.EDGE_FLAG

### See also

- Gl.Begin,

Gl.EdgeFlagPointer,

- Gl.PolygonMode

See original documentation on OpenGL website