1991-2006
Silicon Graphics, Inc.
glFogCoordPointer
3G

# 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/.