glGetTexGen — return texture coordinate generation parameters
void glGetTexGendv( | GLenum | coord, |
GLenum | pname, | |
GLdouble * | params) ; |
void glGetTexGenfv( | GLenum | coord, |
GLenum | pname, | |
GLfloat * | params) ; |
void glGetTexGeniv( | GLenum | coord, |
GLenum | pname, | |
GLint * | params) ; |
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.
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.
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.
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.
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