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.
When the GL_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.
