1991-2006 Silicon Graphics, Inc.

glGetTexGen

3G

glGetTexGen

return texture coordinate generation parameters

# C Specification

                    void glGetTexGendv
                    GLenum coord
                    GLenum pname
                    GLdouble * params

                    void glGetTexGenfv
                    GLenum coord
                    GLenum pname
                    GLfloat * params

                    void glGetTexGeniv
                    GLenum coord
                    GLenum pname
                    GLint * params

## Parameters

`coord`

- Specifies a texture coordinate. Must be `GL_S`, `GL_T`, `GL_R`, or `GL_Q`.

`pname`

- Specifies the symbolic name of the value(s) to be returned. Must be either `GL_TEXTURE_GEN_MODE` or the name of one of the texture generation plane equations: `GL_OBJECT_PLANE` or `GL_EYE_PLANE`.

`params`

- Returns the requested data.

## Description

`glGetTexGen` returns in `params` selected parameters of a texture coordinate generation function that was specified using

glTexGen

. `coord` names one of the (s, t, r, q) texture coordinates, using the symbolic constant `GL_S`, `GL_T`, `GL_R`, or `GL_Q`.

`pname` specifies one of three symbolic names:

`GL_TEXTURE_GEN_MODE`

- `params` returns the single-valued texture generation function, a symbolic constant. The initial value is `GL_EYE_LINEAR`.

`GL_OBJECT_PLANE`

- `params` returns the four plane equation coefficients that specify object linear-coordinate generation. Integer values, when requested, are mapped directly from the internal floating-point representation.

`GL_EYE_PLANE`

- `params` returns the four plane equation coefficients that specify eye linear-coordinate generation. Integer values, when requested, are mapped directly from the internal floating-point representation. The returned values are those maintained in eye coordinates. They are not equal to the values specified using

  glTexGen

  , unless the modelview matrix was identity when

  glTexGen

  was called.

## Notes

If an error is generated, no change is made to the contents of `params`.

For OpenGL versions 1.3 and greater, or when the `ARB_multitexture` extension is supported, `glGetTexGen` returns the texture coordinate generation parameters for the active texture unit.

## Errors

`GL_INVALID_ENUM` is generated if `coord` or `pname` is not an accepted value.

`GL_INVALID_OPERATION` is generated if `glGetTexGen` is executed between the execution of

glBegin

and the corresponding execution of

glEnd

.

## See Also

glActiveTexture

,

glTexGen

## 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/.