getcolortable.3gl   [plain text]


'\" t
'\"! tbl | mmdoc
'\"macro stdmacro
.ds Vn Version 1.2
.ds Dt 24 September 1999
.ds Re Release 1.2.1
.ds Dp Jan 14 18:30
.ds Dm 01 getcolort
.ds Xs 62474 6 getcolortable.gl
.TH GLGETCOLORTABLE 3G
.SH NAME
.B "glGetColorTable
\- retrieve contents of a color lookup table

.SH C SPECIFICATION
void \f3glGetColorTable\fP(
GLenum \fItarget\fP,
.nf
.ta \w'\f3void \fPglGetColorTable( 'u
	GLenum \fIformat\fP,
	GLenum \fItype\fP,
	GLvoid \fI*table\fP )
.fi

.SH PARAMETERS
.TP \w'\f2target\fP\ \ 'u 
\f2target\fP
Must be \%\f3GL_COLOR_TABLE\fP,
\%\f3GL_POST_CONVOLUTION_COLOR_TABLE\fP,
or
\%\f3GL_POST_COLOR_MATRIX_COLOR_TABLE\fP.
.TP
\f2format\fP
The  of the pixel data in \f2table\fP.
The possible values are
\%\f3GL_RED\fP,
\%\f3GL_GREEN\fP,
\%\f3GL_BLUE\fP,
\%\f3GL_ALPHA\fP,
\%\f3GL_LUMINANCE\fP,
\%\f3GL_LUMINANCE_ALPHA\fP,
\%\f3GL_RGB\fP,
\%\f3GL_BGR\fP,
\%\f3GL_RGBA\fP, and
\%\f3GL_BGRA\fP.
.TP
\f2type\fP
The type of the pixel data in \f2table\fP.
Symbolic constants
\%\f3GL_UNSIGNED_BYTE\fP,
\%\f3GL_BYTE\fP,
\%\f3GL_BITMAP\fP,
\%\f3GL_UNSIGNED_SHORT\fP,
\%\f3GL_SHORT\fP,
\%\f3GL_UNSIGNED_INT\fP,
\%\f3GL_INT\fP,
\%\f3GL_FLOAT\fP,
\%\f3GL_UNSIGNED_BYTE_3_3_2\fP,
\%\f3GL_UNSIGNED_BYTE_2_3_3_REV\fP,
\%\f3GL_UNSIGNED_SHORT_5_6_5\fP,
\%\f3GL_UNSIGNED_SHORT_5_6_5_REV\fP,
\%\f3GL_UNSIGNED_SHORT_4_4_4_4\fP,
\%\f3GL_UNSIGNED_SHORT_4_4_4_4_REV\fP,
\%\f3GL_UNSIGNED_SHORT_5_5_5_1\fP,
\%\f3GL_UNSIGNED_SHORT_1_5_5_5_REV\fP,
\%\f3GL_UNSIGNED_INT_8_8_8_8\fP,
\%\f3GL_UNSIGNED_INT_8_8_8_8_REV\fP,
\%\f3GL_UNSIGNED_INT_10_10_10_2\fP, and
\%\f3GL_UNSIGNED_INT_2_10_10_10_REV\fP
are accepted.
.TP
\f2table\fP
Pointer to a one-dimensional array of pixel data containing the contents
of the color table.
.SH DESCRIPTION
\%\f3glGetColorTable\fP returns in \f2table\fP the contents of the color table specified 
by \f2target\fP. No pixel transfer operations are performed, but pixel 
storage modes that are applicable to
\%\f3glReadPixels\fP are performed. 
.P
Color components that are requested in
the specified \f2format\fP, but which are not included in the internal
 of the color lookup table, are returned as zero.  The
assignments of internal color components to the components
requested by \f2format\fP are
.P
.TS
center;
lb lb
l l.
_
Internal Component	Resulting Component
_
red	red
green	green
blue	blue
alpha	alpha
luminance	red
intensity	red
_
.TE

.P
.SH NOTES
\%\f3glGetColorTable\fP is present only if \%\f3GL_ARB_imaging\fP is returned when \%\f3glGetString\fP
is called with an argument of \%\f3GL_EXTENSIONS\fP.
.P
.SH ERRORS
\%\f3GL_INVALID_ENUM\fP is generated if \f2target\fP is not one of the allowable
values.
.P
\%\f3GL_INVALID_ENUM\fP is generated if \f2format\fP is not one of the allowable
values.
.P
\%\f3GL_INVALID_ENUM\fP is generated if \f2type\fP is not one of the allowable
values.
.P
\%\f3GL_INVALID_OPERATION\fP is generated if \f2type\fP is one of
\%\f3GL_UNSIGNED_BYTE_3_3_2\fP,
\%\f3GL_UNSIGNED_BYTE_2_3_3_REV\fP,
\%\f3GL_UNSIGNED_SHORT_5_6_5\fP, or
\%\f3GL_UNSIGNED_SHORT_5_6_5_REV\fP
and \f2format\fP is not \%\f3GL_RGB\fP.
.P
\%\f3GL_INVALID_OPERATION\fP is generated if \f2type\fP is one of
\%\f3GL_UNSIGNED_SHORT_4_4_4_4\fP,
\%\f3GL_UNSIGNED_SHORT_4_4_4_4_REV\fP,
\%\f3GL_UNSIGNED_SHORT_5_5_5_1\fP,
\%\f3GL_UNSIGNED_SHORT_1_5_5_5_REV\fP,
\%\f3GL_UNSIGNED_INT_8_8_8_8\fP,
\%\f3GL_UNSIGNED_INT_8_8_8_8_REV\fP,
\%\f3GL_UNSIGNED_INT_10_10_10_2\fP, or
\%\f3GL_UNSIGNED_INT_2_10_10_10_REV\fP
and \f2format\fP is neither \%\f3GL_RGBA\fP nor \%\f3GL_BGRA\fP.
.P
\%\f3GL_INVALID_OPERATION\fP is generated if \%\f3glGetColorTable\fP is executed
between the execution of \%\f3glBegin\fP and the corresponding
execution of \%\f3glEnd\fP.
.SH SEE ALSO
\%\f3glColorTable(3G)\fP,
\%\f3glColorTableParameter(3G)\fP,
\%\f3glGetColorTableParameter(3G)\fP