GLGETCONVOLUTIONFILTEUNIX)Programmer's GLGETCONVOLUTIONFILTER(3G)
NAME
glGetConvolutionFilter - get current 1D or 2D convolution
filter kernel
C SPECIFICATION
void glGetConvolutionFilter( GLenum target,
GLenum format,
GLenum type,
GLvoid *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_LUMINANCE, or
GL_LUMINANCE_ALPHA.
type Data type of components in the output image. Sym-
bolic 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.
DESCRIPTION
glGetConvolutionFilter returns the current 1D or 2D convolu-
tion 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 of the filter are returned as zero. The
assignments of internal color components to the components
of format are as follows.
MirBSD #10-current Printed 2021-12-07 1
GLGETCONVOLUTIONFILTEUNIX)Programmer's GLGETCONVOLUTIONFILTER(3G)
________________________________________
Internal Component Resulting Component
________________________________________
Red Red
Green Green
Blue Blue
Alpha Alpha
Luminance Red
Intensity Red
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NOTES
glGetConvolutionFilter is present only if GL_ARB_imaging is
returned when glGetString is called with an argument of
GL_EXTENSIONS.
The current separable 2D filter must be retrieved with
glGetSeparableFilter rather than glGetConvolutionFilter.
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 glGetConvolutionFilter
is executed between the execution of glBegin and the
corresponding execution of glEnd.
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 neither GL_RGBA
nor GL_BGRA.
ASSOCIATED GETS
glGetConvolutionParameter
SEE ALSO
glGetSeparableFilter(3G), glConvolutionParameter(3G),
glConvolutionFilter1D(3G), glConvolutionFilter2D(3G)
MirBSD #10-current Printed 2021-12-07 2