glGetTexGen Subroutine

OpenGL 1.1 for AIX: Reference Manual

glGetTexGen Subroutine

Purpose

Returns texture coordinate generation parameters.

Library

OpenGL C bindings library: libGL.a

C Syntax

void glGetTexGendv(GLenum Coordinate,
      GLenum ParameterName, 
      GLdouble *ParameterValues)

void glGetTexGenfv(GLenum Coordinate,
      GLenum ParameterName, 
      GLfloat *ParameterValues)

void glGetTexGeniv(GLenum Coordinate,
      GLenum ParameterName,
      GLint *ParameterValues)

Parameters

Coordinate	Specifies a texture coordinate. Must be GL_S, GL_T, GL_R, or GL_Q.
ParameterName	Specifies the symbolic name of the values to be returned. Must be either GL_TEXTURE_GEN_MODE or the name of one of the texture generation plane equations, either GL_OBJECT_PLANE or GL_EYE_PLANE.
ParameterValues	Returns the requested data.

Description

The glGetTexGen subroutine returns in ParameterValues selected parameters of a texture coordinate generation function specified with glTexGen. Coordinate names one of the (s, t, r, q) texture coordinates, using the symbolic constant GL_S, GL_T, GL_R, or GL_Q.

ParameterName specifies one of three symbolic names:

GL_TEXTURE_GEN_MODE	ParameterValues returns the single-valued texture generation function, a symbolic constant.
GL_OBJECT_PLANE	ParameterValues 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	ParameterValues 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 identified at the time glTexGen was called.

Notes

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

Errors

GL_INVALID_ENUM	Either Coordinate or ParameterName is not an accepted value.
GL_INVALID_OPERATION	The glGetTexGen subroutine is called between a call to glBegin and the corresponding call to glEnd.

Files

/usr/include/GL/gl.h

Contains C language constants, variable type definitions, and ANSI function prototypes for OpenGL.

Related Information

The glBegin or glEnd subroutine, glTexGen subroutine.

OpenGL Overview.