GLFOGCOORDPOINTER(3G)

NAME
glFogCoordPointer - define an array of fog coordinates

C SPECIFICATION

void glFogCoordPointer(GLenum type, GLsizei stride, GLvoid * pointer);

PARAMETERS

type
    Specifies the data type of each fog coordinate. Symbolic constants GL_FLOAT, or GL_DOUBLE are accepted. The initial value is GL_FLOAT.

stride
    Specifies the byte offset between consecutive fog coordinates. If stride is 0, the array elements are understood to be tightly packed. The initial value is 0.

pointer
    Specifies a pointer to the first coordinate of the first fog coordinate in the array. The initial value is 0.

DESCRIPTION

glFogCoordPointer specifies the location and data format of an array of fog coordinates to use when rendering. type specifies the data type of each fog coordinate, and stride specifies the byte stride from one fog coordinate to the next, allowing vertices and attributes to be packed into a single array or stored in separate arrays.

If a non-zero named buffer object is bound to the GL_ARRAY_BUFFER target (see glBindBuffer()) while a fog coordinate array is specified, pointer is treated as a byte offset into the buffer object's data store. Also, the buffer object binding (GL_ARRAY_BUFFER_BINDING) is saved as fog coordinate vertex array client-side state (GL_FOG_COORD_ARRAY_BUFFER_BINDING).

When a fog coordinate array is specified, type, stride, and pointer are saved as client-side state, in addition to the current vertex array buffer object binding.

To enable and disable the fog coordinate array, call glEnableClientState() and glDisableClientState() with the argument GL_FOG_COORD_ARRAY. If enabled, the fog coordinate array is used when glDrawArrays(), glMultiDrawArrays(), glDrawElements(), glMultiDrawElements(), glDrawRangeElements(), or glArrayElement() is called.

NOTES

glFogCoordPointer is available only if the GL version is 1.4 or greater.

Fog coordinates are not supported for interleaved vertex array formats (see glInterleavedArrays()).

The fog coordinate array is initially disabled and isn't accessed when glArrayElement(), glDrawElements(), glDrawRangeElements(), glDrawArrays(), glMultiDrawArrays(), or glMultiDrawElements() is called.

Execution of glFogCoordPointer is not allowed between the execution of glBegin() and the corresponding execution of glEnd(), but an error may or may not be generated. If no error is generated, the operation is undefined.

glFogCoordPointer is typically implemented on the client side with no protocol.

Fog coordinate array parameters are client-side state and are therefore not saved or restored by glPushAttrib() and glPopAttrib(). Use glPushClientAttrib() and glPopClientAttrib() instead.

ERRORS

GL_INVALID_ENUM is generated if type is not either GL_FLOAT or GL_DOUBLE.

GL_INVALID_VALUE is generated if stride is negative.

ASSOCIATED GETS

glIsEnabled() with argument GL_FOG_COORD_ARRAY

glGet() with argument GL_FOG_COORD_ARRAY_STRIDE

glGet() with argument GL_FOG_COORD_ARRAY_TYPE

glGet() with argument GL_FOG_COORD_ARRAY_BUFFER_BINDING

glGet() with argument GL_ARRAY_BUFFER_BINDING

glGetPointerv() with argument GL_FOG_COORD_ARRAY_POINTER

SEE ALSO

glArrayElement(), glBindBuffer(), glColorPointer(), glDisableClientState(), glDrawArrays(), glDrawElements(), glDrawRangeElements(), glEdgeFlagPointer(), glEnableClientState(), glFogCoord(), glIndexPointer(), glInterleavedArrays(), glMultiDrawArrays(), glMultiDrawElements(), glNormalPointer(), glPopClientAttrib(), glPushClientAttrib(), glSecondaryColorPointer(), glTexCoordPointer(), glVertexAttribPointer(), glVertexPointer()

COPYRIGHT

Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.