Gl.PolygonMode (gb.opengl)

Static Sub PolygonMode ( Face As Integer, Mode As Integer )

Select a polygon rasterization mode.

Parameters

face: Specifies the polygons that mode applies to. Must be Gl.FRONT_AND_BACK for front- and back-facing polygons.
mode: Specifies how polygons will be rasterized. Accepted values are Gl.POINT, Gl.LINE, and Gl.FILL. The initial value is Gl.FILL for both front- and back-facing polygons.

Description

Gl.PolygonMode controls the interpretation of polygons for rasterization. face describes which polygons mode applies to: both front and back-facing polygons (Gl.FRONT_AND_BACK). The polygon mode affects only the final rasterization of polygons. In particular, a polygon's vertices are lit and the polygon is clipped and possibly culled before these modes are applied.

Three modes are defined and can be specified in mode:

Gl.POINT: Polygon vertices that are marked as the start of a boundary edge are drawn as points. Point attributes such as Gl.POINT_SIZE and Gl.POINT_SMOOTH control the rasterization of the points. Polygon rasterization attributes other than Gl.POLYGON_MODE have no effect.
Gl.LINE: Boundary edges of the polygon are drawn as line segments. Line attributes such as Gl.LINE_WIDTH and Gl.LINE_SMOOTH control the rasterization of the lines. Polygon rasterization attributes other than Gl.POLYGON_MODE have no effect.
Gl.FILL: The interior of the polygon is filled. Polygon attributes such as Gl.POLYGON_SMOOTH control the rasterization of the polygon.

Examples

To draw a surface with outlined polygons, call

glPolygonMode(Gl.FRONT_AND_BACK, Gl.LINE);

Notes

Vertices are marked as boundary or nonboundary with an edge flag. Edge flags are generated internally by the GL when it decomposes triangle stips and fans.

Errors

Gl.INVALID_ENUM is generated if either face or mode is not an accepted value.

Associated Gets

Gl.Get with argument Gl.POLYGON_MODE