NAME
glCopyColorTable
- copy pixels into a color table
C SPECIFICATION
void ggllCCooppyyCCoolloorrTTaabbllee(
GLenum _t_a_r_g_e_t,
GLenum _i_n_t_e_r_n_a_l_f_o_r_m_a_t,
GLint _x,
GLint _y,
GLsizei _w_i_d_t_h )
delim $$
PARAMETERS
-
_t_a_r_g_e_t
-
The color table target. Must be
GGLL__CCOOLLOORR__TTAABBLLEE,
GGLL__PPOOSSTT__CCOONNVVOOLLUUTTIIOONN__CCOOLLOORR__TTAABBLLEE,
or GGLL__PPOOSSTT__CCOOLLOORR__MMAATTRRIIXX__CCOOLLOORR__TTAABBLLEE.
-
_i_n_t_e_r_n_a_l_f_o_r_m_a_t
-
The internal storage of the texture image.
Must be one of the following symbolic constants:
GGLL__AALLPPHHAA,
GGLL__AALLPPHHAA44,
GGLL__AALLPPHHAA88,
GGLL__AALLPPHHAA1122,
GGLL__AALLPPHHAA1166,
GGLL__LLUUMMIINNAANNCCEE,
GGLL__LLUUMMIINNAANNCCEE44,
GGLL__LLUUMMIINNAANNCCEE88,
GGLL__LLUUMMIINNAANNCCEE1122,
GGLL__LLUUMMIINNAANNCCEE1166,
GGLL__LLUUMMIINNAANNCCEE__AALLPPHHAA,
GGLL__LLUUMMIINNAANNCCEE44__AALLPPHHAA44,
GGLL__LLUUMMIINNAANNCCEE66__AALLPPHHAA22,
GGLL__LLUUMMIINNAANNCCEE88__AALLPPHHAA88,
GGLL__LLUUMMIINNAANNCCEE1122__AALLPPHHAA44,
GGLL__LLUUMMIINNAANNCCEE1122__AALLPPHHAA1122,
GGLL__LLUUMMIINNAANNCCEE1166__AALLPPHHAA1166,
GGLL__IINNTTEENNSSIITTYY,
GGLL__IINNTTEENNSSIITTYY44,
GGLL__IINNTTEENNSSIITTYY88,
GGLL__IINNTTEENNSSIITTYY1122,
GGLL__IINNTTEENNSSIITTYY1166,
GGLL__RR33__GG33__BB22,
GGLL__RRGGBB,
GGLL__RRGGBB44,
GGLL__RRGGBB55,
GGLL__RRGGBB88,
GGLL__RRGGBB1100,
GGLL__RRGGBB1122,
GGLL__RRGGBB1166,
GGLL__RRGGBBAA,
GGLL__RRGGBBAA22,
GGLL__RRGGBBAA44,
GGLL__RRGGBB55__AA11,
GGLL__RRGGBBAA88,
GGLL__RRGGBB1100__AA22,
GGLL__RRGGBBAA1122,
GGLL__RRGGBBAA1166.
-
_x
-
The x coordinate of the lower-left corner of the pixel rectangle
to be transferred to the color table.
-
_y
-
The y coordinate of the lower-left corner of the pixel rectangle
to be transferred to the color table.
-
_w_i_d_t_h
-
The width of the pixel rectangle.
DESCRIPTION
ggllCCooppyyCCoolloorrTTaabbllee loads a color table with pixels from the current
GGLL__RREEAADD__BBUUFFFFEERR (rather than from main memory, as is the case for
ggllCCoolloorrTTaabbllee).
The screen-aligned pixel rectangle with lower-left corner at (_x, _y)
having width _w_i_d_t_h and height 1
is loaded into the color table. If any pixels within
this region are outside the window that is associated with the GL
context, the values obtained for those pixels are undefined.
The pixels in the rectangle are processed just as if
ggllRReeaaddPPiixxeellss were called, with _i_n_t_e_r_n_a_l_f_o_r_m_a_t set to RGBA,
but processing stops after the final conversion to RGBA.
The four scale parameters and the four bias parameters that are defined
for the table are then used to scale and bias the R, G, B, and A components
of each pixel. The scale and bias parameters are set by calling
ggllCCoolloorrTTaabblleePPaarraammeetteerr.
Next, the R, G, B, and A values are clamped to the range [0,1].
Each pixel is then converted to the internal specified by
_i_n_t_e_r_n_a_l_f_o_r_m_a_t. This conversion simply maps the component values of the pixel (R, G, B,
and A) to the values included in the internal (red, green, blue,
alpha, luminance, and intensity). The mapping is as follows:
center;
lb cb cb cb cb cb cb
l c c c c c c.
_
Internal Format RedGreenBlueAlphaLuminanceIntensity
_
GGLL__AALLPPHHAA A
GGLL__LLUUMMIINNAANNCCEE R
GGLL__LLUUMMIINNAANNCCEE__AALLPPHHAA AR
GGLL__IINNTTEENNSSIITTYY R
GGLL__RRGGBB RGB
GGLL__RRGGBBAA RGBA
_
Finally, the red, green, blue, alpha, luminance, and/or intensity components of
the resulting pixels are stored in the color table.
They form a one-dimensional table with indices in the range
[0, _w_i_d_t_h - 1].
NOTES
ggllCCooppyyCCoolloorrTTaabbllee is available only if GGLL__AARRBB__iimmaaggiinngg is returned from calling
ggllGGeettSSttrriinngg with an argument of GGLL__EEXXTTEENNSSIIOONNSS.
ERRORS
GGLL__IINNVVAALLIIDD__EENNUUMM is generated when _t_a_r_g_e_t is not one of the
allowable values.
GGLL__IINNVVAALLIIDD__VVAALLUUEE is generated if _w_i_d_t_h is less than zero.
GGLL__IINNVVAALLIIDD__VVAALLUUEE is generated if _i_n_t_e_r_n_a_l_f_o_r_m_a_t is not one of the
allowable values.
GGLL__TTAABBLLEE__TTOOOO__LLAARRGGEE is generated if the requested color table
is too large to be supported by the implementation.
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllCCooppyyCCoolloorrTTaabbllee is executed
between the execution of ggllBBeeggiinn and the corresponding
execution of ggllEEnndd.
ASSOCIATED GETS
ggllGGeettCCoolloorrTTaabbllee,
ggllGGeettCCoolloorrTTaabblleePPaarraammeetteerr
SEE ALSO
ggllCCoolloorrTTaabbllee((33GG)),
ggllCCoolloorrTTaabblleePPaarraammeetteerr((33GG)),
ggllRReeaaddPPiixxeellss((33GG))