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glGetConvolutionFilter - get current 1D or 2D convolution filter
kernel
void glGetConvolutionFilter( GLenum target,
GLenum format,
GLenum type,
GLvoid *image )
- 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.
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.
glGetConvolutionFilter 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 of the filter are returned
as zero. The assignments of internal color components to the components
of format are as follows.
Internal Component Resulting Component |
Red Red |
Green Green |
Blue Blue |
Alpha Alpha |
Luminance Red |
Intensity Red |
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.
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.
glGetConvolutionParameter
glGetSeparableFilter(3G)
, glConvolutionParameter(3G)
, glConvolutionFilter1D(3G)
,
glConvolutionFilter2D(3G)
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