Class NVFogDistance
 java.lang.Object

 org.lwjgl.opengl.NVFogDistance

public final class NVFogDistance extends java.lang.Object
Native bindings to the NV_fog_distance extension.Ideally, the fog distance (used to compute the fog factor as described in Section 3.10) should be computed as the perfragment Euclidean distance to the fragment center from the eye. In practice, implementations "may choose to approximate the eyecoordinate distance from the eye to each fragment center by abs(ze). Further, [the fog factor] f need not be computed at each fragment, but may be computed at each vertex and interpolated as other data are."
This extension provides the application specific control over how OpenGL computes the distance used in computing the fog factor.
The extension supports three fog distance modes: "eye plane absolute", where the fog distance is the absolute planar distance from the eye plane (i.e., OpenGL's standard implementation allowance as cited above); "eye plane", where the fog distance is the signed planar distance from the eye plane; and "eye radial", where the fog distance is computed as a Euclidean distance. In the case of the eye radial fog distance mode, the distance may be computed pervertex and then interpolated perfragment.
The intent of this extension is to provide applications with better control over the tradeoff between performance and fog quality. The "eye planar" modes (signed or absolute) are straightforward to implement with good performance, but scenes are consistently underfogged at the edges of the field of view. The "eye radial" mode can provide for more accurate fog at the edges of the field of view, but this assumes that either the eye radial fog distance is computed perfragment, or if the fog distance is computed pervertex and then interpolated perfragment, then the scene must be sufficiently tessellated.


Field Summary
Fields Modifier and Type Field Description static int
GL_EYE_PLANE_ABSOLUTE_NV
GL_EYE_RADIAL_NVWhen thepname
parameter of Fogf, Fogi, Foggv, and Fogiv, is FOG_DISTANCE_MODE_NV, then the value ofparam
or the value pointed to byparams
may be.static int
GL_FOG_DISTANCE_MODE_NV
Accepted by thepname
parameters of Fogf, Fogi, Fogfv, Fogiv, GetBooleanv, GetIntegerv, GetFloatv, and GetDoublev.



Field Detail

GL_FOG_DISTANCE_MODE_NV
Accepted by thepname
parameters of Fogf, Fogi, Fogfv, Fogiv, GetBooleanv, GetIntegerv, GetFloatv, and GetDoublev.

GL_EYE_RADIAL_NV, GL_EYE_PLANE_ABSOLUTE_NV
When thepname
parameter of Fogf, Fogi, Foggv, and Fogiv, is FOG_DISTANCE_MODE_NV, then the value ofparam
or the value pointed to byparams
may be.

