void GLAPIENTRY glSeparableFilter2D( GLenum targe )
PARAMETERS
targe Must be GL_SEPARABLE_2D.
_param2
The internal format of the convolution filter kernel. The allow‐
able values are GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12,
GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8,
GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA,
GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8,
GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12,
GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4,
GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2,
GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16,
GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2,
GL_RGBA12, or GL_RGBA16.
_param3
The number of elements in the pixel array referenced by _param7.
(This is the width of the separable filter kernel.)
_param4
The number of elements in the pixel array referenced by _param8.
(This is the height of the separable filter kernel.)
_param5
The format of the pixel data in _param7 and _param8. The allow‐
able values are GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB,
GL_BGR, GL_RGBA, GL_BGRA, GL_INTENSITY, GL_LUMINANCE, and
GL_LUMINANCE_ALPHA.
_param6
The type of the pixel data in _param7 and _param8. Symbolic con‐
stants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT,
GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT,
GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV,
GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,
GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV
are accepted.
_param7
Pointer to a one-dimensional array of pixel data that is pro‐
cessed to build the row filter kernel.
_param8
Pointer to a one-dimensional array of pixel data that is pro‐
cessed to build the column filter kernel.
GL_CONVOLUTION_FILTER_SCALE and GL_CONVOLUTION_FILTER_BIAS. The parame‐
ters 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 format specified by
_param2. This conversion simply maps the component values of the pixel
(R, G, B, and A) to the values included in the internal format (red,
green, blue, alpha, luminance, and intensity). The mapping is as fol‐
lows:
────────────────────────────────────────────────────────────────────────
Internal Format Red Green Blue Alpha Luminance Intensity
────────────────────────────────────────────────────────────────────────
GL_LUMINANCE R
GL_LUMINANCE_ALPHA A R
GL_INTENSITY R
GL_RGB R G B
GL_RGBA R G B A
────────────────────────────────────────────────────────────────────────
The red, green, blue, alpha, luminance, and/or intensity components of
the resulting pixels are stored in floating-point rather than integer
format. 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 _param7. The column image is indexed by coordinate j starting at
zero and increasing from bottom to top. Each location in the column im‐
age is derived from element j of _param8.
Note that after a convolution is performed, the resulting color compo‐
nents are also scaled by their corresponding GL_POST_CONVOLUTION_c_SCALE
parameters and biased by their corresponding GL_POST_CONVOLUTION_c_BIAS
parameters (where c takes on the values RED, GREEN, BLUE, and ALPHA).
These parameters are set by glPixelTransfer.
NOTES
glSeparableFilter2D is present only if GL_ARB_imaging is returned when
glGetString is called with an argument of GL_EXTENSIONS.
ERRORS
GL_INVALID_ENUM is generated if targe is not GL_SEPARABLE_2D.
GL_INVALID_ENUM is generated if _param2 is not one of the allowable val‐
ues.
GL_INVALID_VALUE is generated if _param3 is less than zero or greater
than the maximum supported value. This value may be queried with
glGetConvolutionParameter using target GL_SEPARABLE_2D and name
GL_MAX_CONVOLUTION_WIDTH.
GL_INVALID_VALUE is generated if _param4 is less than zero or greater
GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and _param5 is
not GL_RGB.
GL_INVALID_OPERATION is generated if _param4 is one of
GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,
GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV and
_param5 is neither GL_RGBA nor GL_BGRA.
ASSOCIATED GETS
glGetConvolutionParameter, glGetSeparableFilter
SEE ALSO
glConvolutionFilter1D, glConvolutionFilter2D, glConvolutionParameter,
glPixelTransfer
GLSEPARABLEFILTER2D(3G)
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