1GLGETSEPARABLEFILTER(3G)         OpenGL Manual        GLGETSEPARABLEFILTER(3G)
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NAME

6       glGetSeparableFilter - get separable convolution filter kernel images
7

C SPECIFICATION

9       void glGetSeparableFilter(GLenum target, GLenum format, GLenum type,
10                                 GLvoid * row, GLvoid * column,
11                                 GLvoid * span);
12

PARAMETERS

14       target
15           The separable filter to be retrieved. Must be GL_SEPARABLE_2D.
16
17       format
18           Format of the output images. Must be one of GL_RED, GL_GREEN,
19           GL_BLUE, GL_ALPHA, GL_RGB, GL_BGRGL_RGBA, GL_BGRA, GL_LUMINANCE, or
20           GL_LUMINANCE_ALPHA.
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22       type
23           Data type of components in the output images. Symbolic constants
24           GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT,
25           GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2,
26           GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5,
27           GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4,
28           GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1,
29           GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8,
30           GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and
31           GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
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33       row
34           Pointer to storage for the row filter image.
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36       column
37           Pointer to storage for the column filter image.
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39       span
40           Pointer to storage for the span filter image (currently unused).
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DESCRIPTION

43       glGetSeparableFilter returns the two one-dimensional filter kernel
44       images for the current separable 2D convolution filter. The row image
45       is placed in row and the column image is placed in column according to
46       the specifications in format and type. (In the current implementation,
47       span is not affected in any way.) No pixel transfer operations are
48       performed on the images, but the relevant pixel storage modes are
49       applied.
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51       If a non-zero named buffer object is bound to the GL_PIXEL_PACK_BUFFER
52       target (see glBindBuffer()) while a separable convolution filter is
53       requested, row, column, and span are treated as a byte offset into the
54       buffer object's data store.
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56       Color components that are present in format but not included in the
57       internal format of the filters are returned as zero. The assignments of
58       internal color components to the components of format are as follows:
59
60       ┌─────────────────────────────────┬───────────────────────────────────┐
61       │                                 │                                   │
62Internal Resulting 
63Component                        Component                         
64       │                                 │                                   │
65       ├─────────────────────────────────┼───────────────────────────────────┤
66       │Red                              │ Red                               │
67       ├─────────────────────────────────┼───────────────────────────────────┤
68       │Green                            │ Green                             │
69       ├─────────────────────────────────┼───────────────────────────────────┤
70       │Blue                             │ Blue                              │
71       ├─────────────────────────────────┼───────────────────────────────────┤
72       │Alpha                            │ Alpha                             │
73       ├─────────────────────────────────┼───────────────────────────────────┤
74       │Luminance                        │ Red                               │
75       ├─────────────────────────────────┼───────────────────────────────────┤
76       │Intensity                        │ Red                               │
77       └─────────────────────────────────┴───────────────────────────────────┘
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NOTES

80       glGetSeparableFilter is present only if ARB_imaging is returned when
81       glGetString() is called with an argument of GL_EXTENSIONS.
82
83       Non-separable 2D filters must be retrieved with
84       glGetConvolutionFilter().
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ERRORS

87       GL_INVALID_ENUM is generated if target is not GL_SEPARABLE_2D.
88
89       GL_INVALID_ENUM is generated if format is not one of the allowable
90       values.
91
92       GL_INVALID_ENUM is generated if type is not one of the allowable
93       values.
94
95       GL_INVALID_OPERATION is generated if type is one of
96       GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
97       GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and format is
98       not GL_RGB.
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100       GL_INVALID_OPERATION is generated if type is one of
101       GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV,
102       GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
103       GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,
104       GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV and
105       format is neither GL_RGBA nor GL_BGRA.
106
107       GL_INVALID_OPERATION is generated if a non-zero buffer object name is
108       bound to the GL_PIXEL_PACK_BUFFER target and the buffer object's data
109       store is currently mapped.
110
111       GL_INVALID_OPERATION is generated if a non-zero buffer object name is
112       bound to the GL_PIXEL_PACK_BUFFER target and the data would be packed
113       to the buffer object such that the memory writes required would exceed
114       the data store size.
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116       GL_INVALID_OPERATION is generated if a non-zero buffer object name is
117       bound to the GL_PIXEL_PACK_BUFFER target and row or column is not
118       evenly divisible into the number of bytes needed to store in memory a
119       datum indicated by type.
120
121       GL_INVALID_OPERATION is generated if glGetSeparableFilter is executed
122       between the execution of glBegin() and the corresponding execution of
123       glEnd().
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ASSOCIATED GETS

126       glGetConvolutionParameter()
127
128       glGet() with argument GL_PIXEL_PACK_BUFFER_BINDING
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SEE ALSO

131       glGetConvolutionFilter(), glConvolutionParameter(),
132       glSeparableFilter2D()
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135       Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
136       under the SGI Free Software B License. For details, see
137       http://oss.sgi.com/projects/FreeB/.
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AUTHORS

140       opengl.org
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144opengl.org                        06/10/2014          GLGETSEPARABLEFILTER(3G)
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