glGetSeparableFilter(3gl)

1GLGETSEPARABLEFILTER(3G)                              GLGETSEPARABLEFILTER(3G)
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NAME

6       glGetSeparableFilter - get separable convolution filter kernel images
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C SPECIFICATION

10       void glGetSeparableFilter( GLenum target,
11                                  GLenum format,
12                                  GLenum type,
13                                  GLvoid *row,
14                                  GLvoid *column,
15                                  GLvoid *span )
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PARAMETERS

19       target  The separable filter to be retrieved.  Must be GL_SEPARABLE_2D.
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21       format  Format  of the output images.  Must be one of GL_RED, GL_GREEN,
22               GL_BLUE,   GL_ALPHA,   GL_RGB,   GL_BGR    GL_RGBA,    GL_BGRA,
23               GL_LUMINANCE, or GL_LUMINANCE_ALPHA.
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25       type    Data  type  of  components in the output images.  Symbolic con‐
26               stants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT,
27               GL_SHORT,        GL_UNSIGNED_INT,       GL_INT,       GL_FLOAT,
28               GL_UNSIGNED_BYTE_3_3_2,             GL_UNSIGNED_BYTE_2_3_3_REV,
29               GL_UNSIGNED_SHORT_5_6_5,           GL_UNSIGNED_SHORT_5_6_5_REV,
30               GL_UNSIGNED_SHORT_4_4_4_4,       GL_UNSIGNED_SHORT_4_4_4_4_REV,
31               GL_UNSIGNED_SHORT_5_5_5_1,       GL_UNSIGNED_SHORT_1_5_5_5_REV,
32               GL_UNSIGNED_INT_8_8_8_8,           GL_UNSIGNED_INT_8_8_8_8_REV,
33               GL_UNSIGNED_INT_10_10_10_2,  and GL_UNSIGNED_INT_2_10_10_10_REV
34               are accepted.
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36       row     Pointer to storage for the row filter image.
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38       column  Pointer to storage for the column filter image.
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40       span    Pointer  to  storage  for  the  span  filter  image  (currently
41               unused).
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DESCRIPTION

44       glGetSeparableFilter  returns  the  two  one-dimensional  filter kernel
45       images for the current separable 2D convolution filter.  The row  image
46       is  placed in row and the column image is placed in column according to
47       the specifications in format and type.  (In the current implementation,
48       span  is  not  affected  in any way.)  No pixel transfer operations are
49       performed on the images, but  the  relevant  pixel  storage  modes  are
50       applied.
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52       Color  components  that  are  present in format but not included in the
53       internal  of the filters are returned  as  zero.   The  assignments  of
54       internal color components to the components of format are as follows:
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58                      ─────────────────────────────────────────
59                      Internal Component   Resulting Component
60                      ─────────────────────────────────────────
61                      Red                  Red
62                      Green                Green
63                      Blue                 Blue
64                      Alpha                Alpha
65                      Luminance            Red
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67                      Intensity            Red
68                      ─────────────────────────────────────────
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NOTES

72       glGetSeparableFilter is present only if GL_ARB_imaging is returned when
73       glGetString is called with an argument of GL_EXTENSIONS.
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75       Non-separable 2D filters must be retrieved with glGetConvolutionFilter.
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ERRORS

78       GL_INVALID_ENUM is generated if target is not GL_SEPARABLE_2D.
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80       GL_INVALID_ENUM is generated if format is not one of the allowable val‐
81       ues.
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83       GL_INVALID_ENUM  is  generated if type is not one of the allowable val‐
84       ues.
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86       GL_INVALID_OPERATION is generated if glGetSeparableFilter  is  executed
87       between  the  execution  of  glBegin and the corresponding execution of
88       glEnd.
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90       GL_INVALID_OPERATION   is    generated    if    type    is    one    of
91       GL_UNSIGNED_BYTE_3_3_2,                     GL_UNSIGNED_BYTE_2_3_3_REV,
92       GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and  format  is
93       not GL_RGB.
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95       GL_INVALID_OPERATION    is    generated    if    type    is    one   of
96       GL_UNSIGNED_SHORT_4_4_4_4,               GL_UNSIGNED_SHORT_4_4_4_4_REV,
97       GL_UNSIGNED_SHORT_5_5_5_1,               GL_UNSIGNED_SHORT_1_5_5_5_REV,
98       GL_UNSIGNED_INT_8_8_8_8,                   GL_UNSIGNED_INT_8_8_8_8_REV,
99       GL_UNSIGNED_INT_10_10_10_2,  or GL_UNSIGNED_INT_2_10_10_10_REV and for‐
100       mat is neither GL_RGBA nor GL_BGRA.
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ASSOCIATED GETS

103       glGetConvolutionParameter
104