1GLGETCONVOLUTIONFILT(3G) OpenGL Manual GLGETCONVOLUTIONFILT(3G)
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6 glGetConvolutionFilter - get current 1D or 2D convolution filter kernel
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9 void glGetConvolutionFilter(GLenum target, GLenum format, GLenum type,
10 GLvoid * image);
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13 target
14 The filter to be retrieved. Must be one of GL_CONVOLUTION_1D or
15 GL_CONVOLUTION_2D.
16 format
18 Format of the output image. Must be one of GL_RED, GL_GREEN,
19 GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE,
20 or GL_LUMINANCE_ALPHA.
21 type
23 Data type of components in the output image. 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.
32 image
34 Pointer to storage for the output image.
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37 glGetConvolutionFilter returns the current 1D or 2D convolution filter
38 kernel as an image. The one- or two-dimensional image is placed in
39 image according to the specifications in format and type. No pixel
40 transfer operations are performed on this image, but the relevant pixel
41 storage modes are applied.
42 If a non-zero named buffer object is bound to the GL_PIXEL_PACK_BUFFER
44 target (see glBindBuffer()) while a convolution filter is requested,
45 image is treated as a byte offset into the buffer object's data store.
46 Color components that are present in format but not included in the
48 internal format of the filter are returned as zero. The assignments of
49 internal color components to the components of format are as follows.
50 ┌─────────────────────────────────┬───────────────────────────────────┐
52 │ │ │
53 │ Internal │ Resulting │
54 │Component │ Component │
55 │ │ │
56 ├─────────────────────────────────┼───────────────────────────────────┤
57 │Red │ Red │
58 ├─────────────────────────────────┼───────────────────────────────────┤
59 │Green │ Green │
60 ├─────────────────────────────────┼───────────────────────────────────┤
61 │Blue │ Blue │
62 ├─────────────────────────────────┼───────────────────────────────────┤
63 │Alpha │ Alpha │
64 ├─────────────────────────────────┼───────────────────────────────────┤
65 │Luminance │ Red │
66 ├─────────────────────────────────┼───────────────────────────────────┤
67 │Intensity │ Red │
68 └─────────────────────────────────┴───────────────────────────────────┘
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71 glGetConvolutionFilter is present only if ARB_imaging is returned when
72 glGetString() is called with an argument of GL_EXTENSIONS.
73 The current separable 2D filter must be retrieved with
75 glGetSeparableFilter() rather than glGetConvolutionFilter.
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78 GL_INVALID_ENUM is generated if target is not one of the allowable
79 values.
80 GL_INVALID_ENUM is generated if format is not one of the allowable
82 values.
83 GL_INVALID_ENUM is generated if type is not one of the allowable
85 values.
86 GL_INVALID_OPERATION is generated if type is one of
88 GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
89 GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and format is
90 not GL_RGB.
91 GL_INVALID_OPERATION is generated if type is one of
93 GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV,
94 GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
95 GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,
96 GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV and
97 format is neither GL_RGBA nor GL_BGRA.
98 GL_INVALID_OPERATION is generated if a non-zero buffer object name is
100 bound to the GL_PIXEL_PACK_BUFFER target and the buffer object's data
101 store is currently mapped.
102 GL_INVALID_OPERATION is generated if a non-zero buffer object name is
104 bound to the GL_PIXEL_PACK_BUFFER target and the data would be packed
105 to the buffer object such that the memory writes required would exceed
106 the data store size.
107 GL_INVALID_OPERATION is generated if a non-zero buffer object name is
109 bound to the GL_PIXEL_PACK_BUFFER target and image is not evenly
110 divisible into the number of bytes needed to store in memory a datum
111 indicated by type.
112 GL_INVALID_OPERATION is generated if glGetConvolutionFilter is executed
114 between the execution of glBegin() and the corresponding execution of
115 glEnd().
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118 glGetConvolutionParameter()
119 glGet() with argument GL_PIXEL_PACK_BUFFER_BINDING
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123 glGetSeparableFilter(), glConvolutionParameter(),
124 glConvolutionFilter1D(), glConvolutionFilter2D()
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127 Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
128 under the SGI Free Software B License. For details, see
129 http://oss.sgi.com/projects/FreeB/.
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132 opengl.org
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