glGetSeparableFilter
GLGETSEPARABLEFILTER(3G) GLGETSEPARABLEFILTER(3G)
NAME
glGetSeparableFilter - get separable convolution filter kernel images
C SPECIFICATION
void glGetSeparableFilter( GLenum target,
GLenum format,
GLenum type,
GLvoid *row,
GLvoid *column,
GLvoid *span )
PARAMETERS
target The separable filter to be retrieved. Must be
GL_SEPARABLE_2D.
format Format of the output images. 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 images. 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.
row Pointer to storage for the row filter image.
column Pointer to storage for the column filter image.
span Pointer to storage for the span filter image (currently
unused).
DESCRIPTION
glGetSeparableFilter returns the two one-dimensional filter kernel
images for the current separable 2D convolution filter. The row image
is placed in row and the column image is placed in column according to
the specifications in format and type. (In the current implementa-
tion, span is not affected in any way.) No pixel transfer operations
are performed on the images, but the relevant pixel storage modes are
applied.
Color components that are present in format but not included in the
internal of the filters 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
-----------------------------------------
NOTES
glGetSeparableFilter is present only if GL_ARB_imaging is returned
when glGetString is called with an argument of GL_EXTENSIONS.
Non-separable 2D filters must be retrieved with
glGetConvolutionFilter.
ERRORS
GL_INVALID_ENUM is generated if target is not GL_SEPARABLE_2D.
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 val-
ues.
GL_INVALID_OPERATION is generated if glGetSeparableFilter 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 for-
mat is neither GL_RGBA nor GL_BGRA.
ASSOCIATED GETS
glGetConvolutionParameter
SEE ALSO
glGetConvolutionFilter(3G), glConvolutionParameter(3G),
glSeparableFilter2D(3G)
GLGETSEPARABLEFILTER(3G)
