fglGetConvolutionFilter(3G) OpenGL Reference fglGetConvolutionFilter(3G)NAMEfglGetConvolutionFilter - get current 1D or 2D convolution filter kernel
FORTRAN SPECIFICATION
SUBROUTINE fglGetConvolutionFilter( INTEGER*4 target,
INTEGER*4 format,
INTEGER*4 type,
CHARACTER*8 image )
PARAMETERS
target The filter to be retrieved. Must be one of GL_CONVOLUTION_1D or
GL_CONVOLUTION_2D.
format Format of the output image. Must be one of GL_RED, GL_GREEN,
GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_ABGR_EXT,
GL_LUMINANCE, or GL_LUMINANCE_ALPHA.
type Data type of components in the output image. Symbolic constants
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.
image Pointer to storage for the output image.
DESCRIPTIONfglGetConvolutionFilter returns the current 1D or 2D convolution filter
kernel as an image. The one- or two-dimensional image is placed in image
according to the specifications in format and type. No pixel transfer
operations are performed on this image, but the relevant pixel storage
modes are applied.
Color components that are present in format but not included in the
internal format of the filter are returned as zero. The assignments of
internal color components to the components of format are as follows.
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fglGetConvolutionFilter(3G) OpenGL Reference fglGetConvolutionFilter(3G)
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Internal Component Resulting Component
________________________________________
Red Red
Green Green
Blue Blue
Alpha Alpha
Luminance Red
Intensity Red
________________________________________
NOTESfglGetConvolutionFilter is present only if GL_ARB_imaging is returned
when fglGetString is called with an argument of GL_EXTENSIONS.
GL_ABGR_EXT is valid only if the EXT_abgr extension is supported.
The current separable 2D filter must be retrieved with
fglGetSeparableFilter rather than fglGetConvolutionFilter.
ERRORS
GL_INVALID_ENUM is generated if target is not one of the allowable
values.
GL_INVALID_ENUM is generated if format is not one of the allowable
values.
GL_INVALID_ENUM is generated if type is not one of the allowable values.
GL_INVALID_OPERATION is generated if fglGetConvolutionFilter is executed
between the execution of fglBegin and the corresponding execution of
fglEnd.
GL_INVALID_OPERATION is generated if type is one of
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 format is not
GL_RGB.
GL_INVALID_OPERATION is generated if type 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 format
is not GL_RGBA, GL_BGRA or GL_ABGR_EXT.
ASSOCIATED GETS
fglGetConvolutionParameter
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fglGetConvolutionFilter(3G) OpenGL Reference fglGetConvolutionFilter(3G)SEE ALSO
fglGetSeparableFilter, fglConvolutionParameter, fglConvolutionFilter1D,
fglConvolutionFilter2D
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