NAME

glCopyConvolutionFilter1D - copy pixels into a one-dimensional convolution filter

C SPECIFICATION

void ggllCCooppyyCCoonnvvoolluuttiioonnFFiilltteerr11DD( 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 )

PARAMETERS

_t_a_r_g_e_t
Must be GGLL__CCOONNVVOOLLUUTTIIOONN__11DD.
_i_n_t_e_r_n_a_l_f_o_r_m_a_t
The internal of the convolution filter kernel. The allowable values are 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, or GGLL__RRGGBBAA1166.
_x, _y
The window space coordinates of the lower-left coordinate of the pixel array to copy.
_w_i_d_t_h
The width of the pixel array to copy.

DESCRIPTION

ggllCCooppyyCCoonnvvoolluuttiioonnFFiilltteerr11DD defines a one-dimensional convolution filter kernel with pixels from the current GGLL__RREEAADD__BBUUFFFFEERR (rather than from main memory, as is the case for ggllCCoonnvvoolluuttiioonnFFiilltteerr11DD).

The screen-aligned pixel rectangle with lower-left corner at (_x, _y), width _w_i_d_t_h and height 1 is used to define the convolution filter. 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 exactly as if ggllRReeaaddPPiixxeellss had been called with _f_o_r_m_a_t set to RGBA, but the process stops just before final conversion. The R, G, B, and A components of each pixel are next scaled by the four 1D GGLL__CCOONNVVOOLLUUTTIIOONN__FFIILLTTEERR__SSCCAALLEE parameters and biased by the four 1D GGLL__CCOONNVVOOLLUUTTIIOONN__FFIILLTTEERR__BBIIAASS parameters. (The scale and bias parameters are set by ggllCCoonnvvoolluuttiioonnPPaarraammeetteerr using the GGLL__CCOONNVVOOLLUUTTIIOONN__11DD target and the names GGLL__CCOONNVVOOLLUUTTIIOONN__FFIILLTTEERR__SSCCAALLEE and GGLL__CCOONNVVOOLLUUTTIIOONN__FFIILLTTEERR__BBIIAASS. The parameters themselves are vectors of four values that are applied to red, green, blue, and alpha, in that order.) The R, G, B, and A values are not clamped to [0,1] at any time during this process.

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
_


The red, green, blue, alpha, luminance, and/or intensity components of the resulting pixels are stored in floating-point rather than integer

Pixel ordering is such that lower x screen coordinates correspond to lower _i filter image coordinates.

Note that after a convolution is performed, the resulting color components are also scaled by their corresponding GGLL__PPOOSSTT__CCOONNVVOOLLUUTTIIOONN__cc__SSCCAALLEE parameters and biased by their corresponding GGLL__PPOOSSTT__CCOONNVVOOLLUUTTIIOONN__cc__BBIIAASS parameters (where _c takes on the values RREEDD, GGRREEEENN, BBLLUUEE, and AALLPPHHAA). These parameters are set by ggllPPiixxeellTTrraannssffeerr.

NOTES

ggllCCooppyyCCoonnvvoolluuttiioonnFFiilltteerr11DD is present only if GGLL__AARRBB__iimmaaggiinngg is returned when ggllGGeettSSttrriinngg is called with an argument of GGLL__EEXXTTEENNSSIIOONNSS.

ERRORS

GGLL__IINNVVAALLIIDD__EENNUUMM is generated if _t_a_r_g_e_t is not GGLL__CCOONNVVOOLLUUTTIIOONN__11DD.

GGLL__IINNVVAALLIIDD__EENNUUMM 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__IINNVVAALLIIDD__VVAALLUUEE is generated if _w_i_d_t_h is less than zero or greater than the maximum supported value. This value may be queried with ggllGGeettCCoonnvvoolluuttiioonnPPaarraammeetteerr using target GGLL__CCOONNVVOOLLUUTTIIOONN__11DD and name GGLL__MMAAXX__CCOONNVVOOLLUUTTIIOONN__WWIIDDTTHH.

GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllCCooppyyCCoonnvvoolluuttiioonnFFiilltteerr11DD is executed between the execution of ggllBBeeggiinn and the corresponding execution of ggllEEnndd.

ASSOCIATED GETS

ggllGGeettCCoonnvvoolluuttiioonnPPaarraammeetteerr, ggllGGeettCCoonnvvoolluuttiioonnFFiilltteerr

SEE ALSO

ggllCCoonnvvoolluuttiioonnFFiilltteerr11DD((33GG)), ggllCCoonnvvoolluuttiioonnPPaarraammeetteerr((33GG)), ggllPPiixxeellTTrraannssffeerr((33GG))