1GLUBUILD1DMIPMAPS(3G)            OpenGL Manual           GLUBUILD1DMIPMAPS(3G)
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NAME

6       gluBuild1DMipmaps - builds a one-dimensional mipmap
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C SPECIFICATION

9       GLint gluBuild1DMipmaps(GLenum target, GLint internalFormat,
10                               GLsizei width, GLenum format, GLenum type,
11                               const void * data);
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PARAMETERS

14       target
15           Specifies the target texture. Must be GLU_TEXTURE_1D.
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17       internalFormat
18           Requests the internal storage format of the texture image. The most
19           current version of the SGI implementation of GLU does not check
20           this value for validity before passing it on to the underlying
21           OpenGL implementation. A value that is not accepted by the OpenGL
22           implementation will lead to an OpenGL error. The benefit of not
23           checking this value at the GLU level is that OpenGL extensions can
24           add new internal texture formats without requiring a revision of
25           the GLU implementation. Older implementations of GLU check this
26           value and raise a GLU error if it is not 1, 2, 3, or 4 or one of
27           the following symbolic constants: GLU_ALPHA, GLU_ALPHA4,
28           GLU_ALPHA8, GLU_ALPHA12, GLU_ALPHA16, GLU_LUMINANCE,
29           GLU_LUMINANCE4, GLU_LUMINANCE8, GLU_LUMINANCE12, GLU_LUMINANCE16,
30           GLU_LUMINANCE_ALPHA, GLU_LUMINANCE4_ALPHA4, GLU_LUMINANCE6_ALPHA2,
31           GLU_LUMINANCE8_ALPHA8, GLU_LUMINANCE12_ALPHA4,
32           GLU_LUMINANCE12_ALPHA12, GLU_LUMINANCE16_ALPHA16, GLU_INTENSITY,
33           GLU_INTENSITY4, GLU_INTENSITY8, GLU_INTENSITY12, GLU_INTENSITY16,
34           GLU_RGB, GLU_R3_G3_B2, GLU_RGB4, GLU_RGB5, GLU_RGB8, GLU_RGB10,
35           GLU_RGB12, GLU_RGB16, GLU_RGBA, GLU_RGBA2, GLU_RGBA4, GLU_RGB5_A1,
36           GLU_RGBA8, GLU_RGB10_A2, GLU_RGBA12, or GLU_RGBA16.
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38       width
39           Specifies the width, in pixels, of the texture image.
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41       format
42           Specifies the format of the pixel data. Must be one of
43           GLU_COLOR_INDEX, GLU_DEPTH_COMPONENT, GLU_RED, GLU_GREEN, GLU_BLUE,
44           GLU_ALPHA, GLU_RGB, GLU_RGBA, GLU_BGR, GLU_BGRA, GLU_LUMINANCE, or
45           GLU_LUMINANCE_ALPHA.
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47       type
48           Specifies the data type for data. Must be one of GLU_UNSIGNED_BYTE,
49           GLU_BYTE, GLU_BITMAP, GLU_UNSIGNED_SHORT, GLU_SHORT,
50           GLU_UNSIGNED_INT, GLU_INT, GLU_FLOAT, GLU_UNSIGNED_BYTE_3_3_2,
51           GLU_UNSIGNED_BYTE_2_3_3_REV, GLU_UNSIGNED_SHORT_5_6_5,
52           GLU_UNSIGNED_SHORT_5_6_5_REV, GLU_UNSIGNED_SHORT_4_4_4_4,
53           GLU_UNSIGNED_SHORT_4_4_4_4_REV, GLU_UNSIGNED_SHORT_5_5_5_1,
54           GLU_UNSIGNED_SHORT_1_5_5_5_REV, GLU_UNSIGNED_INT_8_8_8_8,
55           GLU_UNSIGNED_INT_8_8_8_8_REV, GLU_UNSIGNED_INT_10_10_10_2, or
56           GLU_UNSIGNED_INT_2_10_10_10_REV.
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58       data
59           Specifies a pointer to the image data in memory.
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DESCRIPTION

62       gluBuild1DMipmaps builds a series of prefiltered one-dimensional
63       texture maps of decreasing resolutions called a mipmap. This is used
64       for the antialiasing of texture mapped primitives.
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66       A return value of zero indicates success, otherwise a GLU error code is
67       returned (see gluErrorString()).
68
69       Initially, the width of data is checked to see if it is a power of 2.
70       If not, a copy of data is scaled up or down to the nearest power of 2.
71       (If width is exactly between powers of 2, then the copy of data will
72       scale upwards.) This copy will be used for subsequent mipmapping
73       operations described below. For example, if width is 57, then a copy of
74       data will scale up to 64 before mipmapping takes place.
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76       Then, proxy textures (see glTexImage1D()) are used to determine if the
77       implementation can fit the requested texture. If not, width is
78       continually halved until it fits.
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80       Next, a series of mipmap levels is built by decimating a copy of data
81       in half until size 1 × 1 is reached. At each level, each texel in the
82       halved mipmap level is an average of the corresponding two texels in
83       the larger mipmap level.
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85       glTexImage1D() is called to load each of these mipmap levels. Level 0
86       is a copy of data. The highest level is log 2 ⁡ width. For example, if
87       width is 64 and the implementation can store a texture of this size,
88       the following mipmap levels are built: 64 × 1, 32 × 1, 16 × 1, 8 × 1, 4
89       × 1, 2 × 1, and 1 × 1. These correspond to levels 0 through 6,
90       respectively.
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92       See the glTexImage1D() reference page for a description of the
93       acceptable values for the type parameter. See the glDrawPixels()
94       reference page for a description of the acceptable values for the data
95       parameter.
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NOTES

98       Note that there is no direct way of querying the maximum level. This
99       can be derived indirectly via glGetTexLevelParameter(). First, query
100       for the width actually used at level 0. (The width may not be equal to
101       width since proxy textures might have scaled it to fit the
102       implementation.) Then the maximum level can be derived from the formula
103       log 2 ⁡ width.
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105       Formats GLU_BGR, and GLU_BGRA, and types GLU_UNSIGNED_BYTE_3_3_2,
106       GLU_UNSIGNED_BYTE_2_3_3_REV, GLU_UNSIGNED_SHORT_5_6_5,
107       GLU_UNSIGNED_SHORT_5_6_5_REV, GLU_UNSIGNED_SHORT_4_4_4_4,
108       GLU_UNSIGNED_SHORT_4_4_4_4_REV, GLU_UNSIGNED_SHORT_5_5_5_1,
109       GLU_UNSIGNED_SHORT_1_5_5_5_REV, GLU_UNSIGNED_INT_8_8_8_8,
110       GLU_UNSIGNED_INT_8_8_8_8_REV, GLU_UNSIGNED_INT_10_10_10_2, and
111       GLU_UNSIGNED_INT_2_10_10_10_REV are only available if the GL version is
112       1.2 or greater, and if the GLU version is 1.3 or greater.
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ERRORS

115       GLU_INVALID_VALUE is returned if width is < 1.
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117       GLU_INVALID_ENUM is returned if format or type are not legal.
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119       GLU_INVALID_OPERATION is returned if type is GLU_UNSIGNED_BYTE_3_3_2 or
120       GLU_UNSIGNED_BYTE_2_3_3_REV and format is not GLU_RGB.
121
122       GLU_INVALID_OPERATION is returned if type is GLU_UNSIGNED_SHORT_5_6_5
123       or GLU_UNSIGNED_SHORT_5_6_5_REV and format is not GLU_RGB.
124
125       GLU_INVALID_OPERATION is returned if type is GLU_UNSIGNED_SHORT_4_4_4_4
126       or GLU_UNSIGNED_SHORT_4_4_4_4_REV and format is neither GLU_RGBA nor
127       GLU_BGRA.
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129       GLU_INVALID_OPERATION is returned if type is GLU_UNSIGNED_SHORT_5_5_5_1
130       or GLU_UNSIGNED_SHORT_1_5_5_5_REV and format is neither GLU_RGBA nor
131       GLU_BGRA.
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133       GLU_INVALID_OPERATION is returned if type is GLU_UNSIGNED_INT_8_8_8_8
134       or GLU_UNSIGNED_INT_8_8_8_8_REV and format is neither GLU_RGBA nor
135       GLU_BGRA.
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137       GLU_INVALID_OPERATION is returned if type is
138       GLU_UNSIGNED_INT_10_10_10_2 or GLU_UNSIGNED_INT_2_10_10_10_REV and
139       format is neither GLU_RGBA nor GLU_BGRA.
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SEE ALSO

142       gluBuild1DMipmapLevels(), gluBuild2DMipmapLevels(),
143       gluBuild2DMipmaps(), gluBuild3DMipmapLevels(), gluBuild3DMipmaps(),
144       gluErrorString(), glDrawPixels(), glGetTexImage(),
145       glGetTexLevelParameter(), glTexImage1D(), glTexImage2D(),
146       glTexImage3D()
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149       Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
150       under the SGI Free Software B License. For details, see
151       http://oss.sgi.com/projects/FreeB/.
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AUTHORS

154       opengl.org
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158opengl.org                        07/13/2018             GLUBUILD1DMIPMAPS(3G)
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