GLGETTEXGEN() MachTen Programmer’s Manual GLGETTEXGEN()

NAME
glGetTexGendv, glGetTexGenfv, glGetTexGeniv - return tex-
ture 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 )

delim $$

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) tex-
ture 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. Inte-
ger values, when requested,
are mapped directly from the
internal floating-point repre-
sentation.

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 val-
ues 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 con-
tents of params.

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

GL_INVALID_OPERATION is generated if glGetTexGen is exe-
cuted between the execution of glBegin and the correspond-
ing execution of glEnd.