glGetColorTableParameterSGI(3G) OpenGL Reference
NAME
glGetColorTableParameterfvSGI, glGetColorTableParameterivSGI - get color
lookup table parameters
C SPECIFICATION
void glGetColorTableParameterfvSGI( GLenum target,
GLenum pname,
GLfloat *params )
void glGetColorTableParameterivSGI( GLenum target,
GLenum pname,
GLint *params )
PARAMETERS
target The target color table. Must be GLTEXTURECOLORTABLESGI,
GLCOLORTABLESGI, GLPOSTCONVOLUTIONCOLORTABLESGI,
GLPOSTCOLORMATRIXCOLORTABLESGI,
GLPROXYTEXTURECOLORTABLESGI, GLPROXYCOLORTABLESGI,
GLPROXYPOSTCONVOLUTIONCOLORTABLESGI,
GLPROXYPOSTCOLORMATRIXCOLORTABLESGI.
pname The symbolic name of a color lookup table parameter. Must be one
of GLCOLORTABLEBIASSGI, GLCOLORTABLESCALESGI,
GLCOLORTABLEFORMATSGI, GLCOLORTABLEWIDTHSGI,
GLCOLORTABLEREDSIZESGI, GLCOLORTABLEGREENSIZESGI,
GLCOLORTABLEBLUESIZESGI, GLCOLORTABLEALPHASIZESGI,
GLCOLORTABLELUMINANCESIZESGI, or
GLCOLORTABLEINTENSITYSIZESGI.
params A pointer to an array where the values of the parameter will be
stored.
DESCRIPTION
glGetColorTableParameterSGI is part of the SGIcolortable extension,
which adds several color lookup tables to the pixel transfer path. It is
also used by SGItexturecolortable, which adds a color table lookup to
the texturing process.
When pname is set to GLCOLORTABLESCALESGI or GLCOLORTABLEBIASSGI,
glGetColorTableParameterSGI returns the color table scale or bias
parameters for the table specified by target. For these queries, target
must be set to GLTEXTURECOLORTABLESGI, GLCOLORTABLESGI,
GLPOSTCONVOLUTIONCOLORTABLESGI, or
GLPOSTCOLORMATRIXCOLORTABLESGI and _params points to an array of
four elements, which receive the scale or bias factors for red, green,
blue, and alpha, in that order.
The scale and bias parameters for the texture color table are set by
glTexParameter; the scale and bias parameters for the other tables are
set by glColorTableParameterSGI.
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glGetColorTableParameterSGI(3G) OpenGL Reference
glGetColorTableParameterSGI can also be used to retrieve the format and
size parameters for a color table. For these queries, set target to
either the color table target or the proxy color table target. (For
example, set target to either GLTEXTURECOLORTABLESGI or
GLPROXYTEXTURECOLORTABLESGI.) The format and size parameters are set
by glColorTableSGI.
The following table lists the format and size parameters that may be
queried. For each symbolic constant listed below for pname, params must
point to an array of the given length, and receive the values indicated.
pname N Meaning
______________________________________________________________________
GLCOLORTABLEFORMATSGI 1 Internal format (e.g. GLRGBA)
GLCOLORTABLEWIDTHSGI 1 Number of elements in table
GLCOLORTABLEREDSIZESGI 1 Size of red component, in bits
GLCOLORTABLEGREENSIZESGI 1 Size of green component
GLCOLORTABLEBLUESIZESGI 1 Size of blue component
GLCOLORTABLEALPHASIZESGI 1 Size of alpha component
GLCOLORTABLELUMINANCESIZESGI 1 Size of luminance component
GLCOLORTABLEINTENSITYSIZESGI 1 Size of intensity component
NOTES
If target is set to GLTEXTURECOLORTABLESGI and the
SGItexturecolortable extension is not supported then an
GLINVALIDENUM error is generated.
If target is set to GLCOLORTABLESGI,
GLPOSTCONVOLUTIONCOLORTABLESGI, or
GLPOSTCOLORMATRIXCOLORTABLESGI and the SGIcolortable extension is
not supported then an GLINVALIDENUM error is generated.
See glIntro for more information on using extensions.
ERRORS
GLINVALIDENUM is generated if target or pname is not an acceptable
value.
GLINVALIDOPERATION is generated if glGetColorTableParameterSGI is
executed between the execution of glBegin and the corresponding execution
of glEnd.
MACHINE DEPENDENCIES
The SGIcolortable extension is not supported on RealityEngine,
RealityEngine2, and VTX systems.
SEE ALSO
glColorTableSGI, glTexParameter, glColorTableParameterSGI.
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