org.lwjgl.opengles

Class EXTPolygonOffsetClamp

java.lang.Object

org.lwjgl.opengles.EXTPolygonOffsetClamp

public class EXTPolygonOffsetClamp
extends java.lang.Object

Native bindings to the EXT_polygon_offset_clamp extension.

This extension adds a new parameter to the polygon offset function that clamps the calculated offset to a minimum or maximum value. The clamping functionality is useful when polygons are nearly parallel to the view direction because their high slopes can result in arbitrarily large polygon offsets. In the particular case of shadow mapping, the lack of clamping can produce the appearance of unwanted holes when the shadow casting polygons are offset beyond the shadow receiving polygons, and this problem can be alleviated by enforcing a maximum offset value.

Field Summary

Fields

Modifier and Type	Field and Description
static int	GL_POLYGON_OFFSET_CLAMP_EXT Accepted by the pname parameters of GetBooleanv, GetIntegerv, GetInteger64v, GetFloatv, and GetDoublev.

Method Summary

Modifier and Type	Method and Description
static void	glPolygonOffsetClampEXT(float factor, float units, float clamp) The depth values of all fragments generated by the rasterization of a polygon may be offset by a single value that is computed for that polygon.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

GL_POLYGON_OFFSET_CLAMP_EXT

public static final int GL_POLYGON_OFFSET_CLAMP_EXT

Accepted by the pname parameters of GetBooleanv, GetIntegerv, GetInteger64v, GetFloatv, and GetDoublev.

See Also:

Constant Field Values

Method Detail

glPolygonOffsetClampEXT

public static void glPolygonOffsetClampEXT(float factor,
                                           float units,
                                           float clamp)

The depth values of all fragments generated by the rasterization of a polygon may be offset by a single value that is computed for that polygon. The function that determines this value is specified with this command.

factor scales the maximum depth slope of the polygon, and units scales an implementation-dependent constant that relates to the usable resolution of the depth buffer. The resulting values are summed to produce the polygon offset value, which may then be clamped to a minimum or maximum value specified by clamp. The values factor, units, and clamp may each be positive, negative, or zero. Calling the command PolygonOffset is equivalent to calling the command PolygonOffsetClampEXT with clamp equal to zero.

Parameters:

factor - scales the maximum depth slope of the polygon

units - scales an implementation-dependent constant that relates to the usable resolution of the depth buffer

clamp - the minimum or maximum clamp value