NAME
glSeparableFilter2D
- define a separable two-dimensional convolution filter
C SPECIFICATION
void ggllSSeeppaarraabblleeFFiilltteerr22DD(
GLenum _t_a_r_g_e_t,
GLenum _i_n_t_e_r_n_a_l_f_o_r_m_a_t,
GLsizei _w_i_d_t_h,
GLsizei _h_e_i_g_h_t,
GLenum _f_o_r_m_a_t,
GLenum _t_y_p_e,
const GLvoid _*_r_o_w,
const GLvoid _*_c_o_l_u_m_n )
PARAMETERS
-
_t_a_r_g_e_t
-
Must be GGLL__SSEEPPAARRAABBLLEE__22DD.
-
_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.
-
_w_i_d_t_h
-
The number of elements in the pixel array referenced by _r_o_w.
(This is the width of the separable filter kernel.)
-
_h_e_i_g_h_t
-
The number of elements in the pixel array referenced by _c_o_l_u_m_n.
(This is the height of the separable filter kernel.)
-
_f_o_r_m_a_t
-
The of the pixel data in _r_o_w and _c_o_l_u_m_n.
The allowable values are
GGLL__RREEDD,
GGLL__GGRREEEENN,
GGLL__BBLLUUEE,
GGLL__AALLPPHHAA,
GGLL__RRGGBB,
GGLL__BBGGRR,
GGLL__RRGGBBAA,
GGLL__BBGGRRAA,
GGLL__IINNTTEENNSSIITTYY,
GGLL__LLUUMMIINNAANNCCEE, and
GGLL__LLUUMMIINNAANNCCEE__AALLPPHHAA.
-
_t_y_p_e
-
The type of the pixel data in _r_o_w and _c_o_l_u_m_n.
Symbolic constants
GGLL__UUNNSSIIGGNNEEDD__BBYYTTEE,
GGLL__BBYYTTEE,
GGLL__BBIITTMMAAPP,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT,
GGLL__SSHHOORRTT,
GGLL__UUNNSSIIGGNNEEDD__IINNTT,
GGLL__IINNTT,
GGLL__FFLLOOAATT,
GGLL__UUNNSSIIGGNNEEDD__BBYYTTEE__33__33__22,
GGLL__UUNNSSIIGGNNEEDD__BBYYTTEE__22__33__33__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__55__66__55,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__55__66__55__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__44__44__44__44,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__44__44__44__44__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__55__55__55__11,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__11__55__55__55__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__IINNTT__88__88__88__88,
GGLL__UUNNSSIIGGNNEEDD__IINNTT__88__88__88__88__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__IINNTT__1100__1100__1100__22, and
GGLL__UUNNSSIIGGNNEEDD__IINNTT__22__1100__1100__1100__RREEVV
are accepted.
-
_r_o_w
-
Pointer to a one-dimensional array of pixel data that is processed to
build the row filter kernel.
-
_c_o_l_u_m_n
-
Pointer to a one-dimensional array of pixel data that is processed to
build the column filter kernel.
DESCRIPTION
ggllSSeeppaarraabblleeFFiilltteerr22DD builds a two-dimensional separable convolution filter kernel from
two arrays of pixels.
The pixel arrays specified by (_w_i_d_t_h, _f_o_r_m_a_t, _t_y_p_e, _r_o_w)
and (_h_e_i_g_h_t, _f_o_r_m_a_t, _t_y_p_e, _c_o_l_u_m_n) are processed just as if
they had been passed to ggllDDrraawwPPiixxeellss,
but processing stops after the final expansion to RGBA is completed.
Next, the R, G, B, and A components of all pixels in both arrays are scaled
by the four separable 2D GGLL__CCOONNVVOOLLUUTTIIOONN__FFIILLTTEERR__SSCCAALLEE parameters and
biased by the four separable 2D GGLL__CCOONNVVOOLLUUTTIIOONN__FFIILLTTEERR__BBIIAASS parameters.
(The scale and bias parameters are set by ggllCCoonnvvoolluuttiioonnPPaarraammeetteerr
using the GGLL__SSEEPPAARRAABBLLEE__22DD 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;
l c c c c c c.
_
Internal Format RedGreenBlueAlphaLuminanceIntensity
_
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
They form two one-dimensional filter kernel images.
The row image is indexed by coordinate _i starting at zero and
increasing from left to right.
Each location in the row image is derived from element _i of _r_o_w.
The column image is indexed by coordinate _j starting at zero
and increasing from bottom to top.
Each location in the column image is derived from element _j of _c_o_l_u_m_n.
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
ggllSSeeppaarraabblleeFFiilltteerr22DD 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__SSEEPPAARRAABBLLEE__22DD.
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__SSEEPPAARRAABBLLEE__22DD and name
GGLL__MMAAXX__CCOONNVVOOLLUUTTIIOONN__WWIIDDTTHH.
GGLL__IINNVVAALLIIDD__VVAALLUUEE is generated if _h_e_i_g_h_t is less than zero or greater
than the maximum supported value.
This value may be queried with ggllGGeettCCoonnvvoolluuttiioonnPPaarraammeetteerr
using target GGLL__SSEEPPAARRAABBLLEE__22DD and name
GGLL__MMAAXX__CCOONNVVOOLLUUTTIIOONN__HHEEIIGGHHTT.
GGLL__IINNVVAALLIIDD__EENNUUMM is generated if _f_o_r_m_a_t is not one of the allowable
values.
GGLL__IINNVVAALLIIDD__EENNUUMM is generated if _t_y_p_e is not one of the allowable
values.
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllSSeeppaarraabblleeFFiilltteerr22DD is executed
between the execution of ggllBBeeggiinn and the corresponding
execution of ggllEEnndd.
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if _h_e_i_g_h_t is one of
GGLL__UUNNSSIIGGNNEEDD__BBYYTTEE__33__33__22,
GGLL__UUNNSSIIGGNNEEDD__BBYYTTEE__22__33__33__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__55__66__55, or
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__55__66__55__RREEVV
and _f_o_r_m_a_t is not GGLL__RRGGBB.
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if _h_e_i_g_h_t is one of
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__44__44__44__44,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__44__44__44__44__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__55__55__55__11,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__11__55__55__55__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__IINNTT__88__88__88__88,
GGLL__UUNNSSIIGGNNEEDD__IINNTT__88__88__88__88__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__IINNTT__1100__1100__1100__22, or
GGLL__UUNNSSIIGGNNEEDD__IINNTT__22__1100__1100__1100__RREEVV
and _f_o_r_m_a_t is neither GGLL__RRGGBBAA nor GGLL__BBGGRRAA.
ASSOCIATED GETS
ggllGGeettCCoonnvvoolluuttiioonnPPaarraammeetteerr, ggllGGeettSSeeppaarraabblleeFFiilltteerr
SEE ALSO
ggllCCoonnvvoolluuttiioonnFFiilltteerr11DD((33GG)),
ggllCCoonnvvoolluuttiioonnFFiilltteerr22DD((33GG)),
ggllCCoonnvvoolluuttiioonnPPaarraammeetteerr((33GG)),
ggllPPiixxeellTTrraannssffeerr((33GG))