1GLCONVOLUTIONFILTER1D(3G) GLCONVOLUTIONFILTER1D(3G)
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6 glConvolutionFilter1D - define a one-dimensional convolution filter
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10 void glConvolutionFilter1D( GLenum target,
11 GLenum internalformat,
12 GLsizei width,
13 GLenum format,
14 GLenum type,
15 const GLvoid *image )
16
19 target Must be GL_CONVOLUTION_1D.
20 internalformat The internal of the convolution filter kernel. The
22 allowable values are GL_ALPHA, GL_LUMINANCE,
23 GL_LUMINANCE_ALPHA, GL_INTENSITY, GL_RGB, and GL_RGBA.
24 width The width of the pixel array referenced by image.
26 format The of the pixel data in image. The allowable values
28 are GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12,
29 GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8,
30 GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA,
31 GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2,
32 GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4,
33 GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16,
34 GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8,
35 GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2, GL_RGB,
36 GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12,
37 GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4, GL_RGB5_A1,
38 GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.
39 type The type of the pixel data in image. Symbolic con‐
41 stants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP,
42 GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT,
43 GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2,
44 GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5,
45 GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4,
46 GL_UNSIGNED_SHORT_4_4_4_4_REV,
47 GL_UNSIGNED_SHORT_5_5_5_1,
48 GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8,
49 GL_UNSIGNED_INT_8_8_8_8_REV,
50 GL_UNSIGNED_INT_10_10_10_2, and
51 GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
52 image Pointer to a one-dimensional array of pixel data that
54 is processed to build the convolution filter kernel.
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57 glConvolutionFilter1D builds a one-dimensional convolution filter ker‐
58 nel from an array of pixels.
59 The pixel array specified by width, format, type, and image is
61 extracted from memory and processed just as if glDrawPixels were
62 called, but processing stops after the final expansion to RGBA is com‐
63 pleted.
64 The R, G, B, and A components of each pixel are next scaled by the four
66 1D GL_CONVOLUTION_FILTER_SCALE parameters and biased by the four 1D
67 GL_CONVOLUTION_FILTER_BIAS parameters. (The scale and bias parameters
68 are set by glConvolutionParameter using the GL_CONVOLUTION_1D target
69 and the names GL_CONVOLUTION_FILTER_SCALE and
70 GL_CONVOLUTION_FILTER_BIAS. The parameters themselves are vectors of
71 four values that are applied to red, green, blue, and alpha, in that
72 order.) The R, G, B, and A values are not clamped to [0,1] at any time
73 during this process.
74 Each pixel is then converted to the internal specified by internalfor‐
76 mat. This conversion simply maps the component values of the pixel (R,
77 G, B, and A) to the values included in the internal (red, green, blue,
78 alpha, luminance, and intensity). The mapping is as follows:
79 ────────────────────────────────────────────────────────────────────────
82 Internal Format Red Green Blue Alpha Luminance Intensity
83 ────────────────────────────────────────────────────────────────────────
84 GL_ALPHA A
85 GL_LUMINANCE R
86 GL_LUMINANCE_ALPHA A R
87 GL_INTENSITY R
88 GL_RGB R G B
89 GL_RGBA R G B A
90 ────────────────────────────────────────────────────────────────────────
91 The red, green, blue, alpha, luminance, and/or intensity components of
93 the resulting pixels are stored in floating-point rather than integer
94 They form a one-dimensional filter kernel image indexed with coordinate
95 i such that i starts at 0 and increases from left to right. Kernel
96 location i is derived from the ith pixel, counting from 0.
97 Note that after a convolution is performed, the resulting color compo‐
99 nents are also scaled by their corresponding
100 GL_POST_CONVOLUTION_c_SCALE parameters and biased by their correspond‐
101 ing GL_POST_CONVOLUTION_c_BIAS parameters (where c takes on the values
102 RED, GREEN, BLUE, and ALPHA). These parameters are set by
103 glPixelTransfer.
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106 glConvolutionFilter1D is present only if GL_ARB_imaging is returned
107 when glGetString is called with an argument of GL_EXTENSIONS.
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110 GL_INVALID_ENUM is generated if target is not GL_CONVOLUTION_1D.
111 GL_INVALID_ENUM is generated if internalformat is not one of the allow‐
113 able values.
114 GL_INVALID_VALUE is generated if width is less than zero or greater
116 than the maximum supported value. This value may be queried with
117 glGetConvolutionParameter using target GL_CONVOLUTION_1D and name
118 GL_MAX_CONVOLUTION_WIDTH.
119 GL_INVALID_ENUM is generated if format is not one of the allowable val‐
121 ues.
122 GL_INVALID_ENUM is generated if type is not one of the allowable val‐
124 ues.
125 GL_INVALID_OPERATION is generated if glConvolutionFilter1D is executed
127 between the execution of glBegin and the corresponding execution of
128 glEnd.
129 GL_INVALID_OPERATION is generated if format is one of
131 GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
132 GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and type is not
133 GL_RGB.
134 GL_INVALID_OPERATION is generated if format is one of
136 GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV,
137 GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
138 GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,
139 GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV and type
140 is neither GL_RGBA nor GL_BGRA.
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143 glGetConvolutionParameter, glGetConvolutionFilter
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146 glConvolutionFilter2D(3G), glSeparableFilter2D(3G),
147 glConvolutionParameter(3G), glPixelTransfer(3G)
148 GLCONVOLUTIONFILTER1D(3G)