GLGETCONVOLUTIONFILTER(3G)GLGETCONVOLUTIONFILTER(3G)NAMEglGetConvolutionFilter - 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. 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.
DESCRIPTIONglGetConvolutionFilter 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
-----------------------------------------
NOTESglGetConvolutionFilter 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 ALSOglGetSeparableFilter(3G), glConvolutionParameter(3G),
glConvolutionFilter1D(3G), glConvolutionFilter2D(3G)
March 1, 2011
