gluBuild2DMipmapLevels(3g)

1GLUBUILD2DMIPMAPLEVE(3G)         OpenGL Manual        GLUBUILD2DMIPMAPLEVE(3G)
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NAME

6       gluBuild2DMipmapLevels - builds a subset of two-dimensional mipmap
7       levels
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C SPECIFICATION

10       GLint gluBuild2DMipmapLevels(GLenum target, GLint internalFormat,
11                                    GLsizei width, GLsizei height,
12                                    GLenum format, GLenum type, GLint level,
13                                    GLint base, GLint max, const void * data);
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PARAMETERS

16       target
17           Specifies the target texture. Must be GLU_TEXTURE_2D.
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19       internalFormat
20           Requests the internal storage format of the texture image. The most
21           current version of the SGI implementation of GLU does not check
22           this value for validity before passing it on to the underlying
23           OpenGL implementation. A value that is not accepted by the OpenGL
24           implementation will lead to an OpenGL error. The benefit of not
25           checking this value at the GLU level is that OpenGL extensions can
26           add new internal texture formats without requiring a revision of
27           the GLU implementation. Older implementations of GLU check this
28           value and raise a GLU error if it is not 1, 2, 3, or 4 or one of
29           the following symbolic constants: GLU_ALPHA, GLU_ALPHA4,
30           GLU_ALPHA8, GLU_ALPHA12, GLU_ALPHA16, GLU_LUMINANCE,
31           GLU_LUMINANCE4, GLU_LUMINANCE8, GLU_LUMINANCE12, GLU_LUMINANCE16,
32           GLU_LUMINANCE_ALPHA, GLU_LUMINANCE4_ALPHA4, GLU_LUMINANCE6_ALPHA2,
33           GLU_LUMINANCE8_ALPHA8, GLU_LUMINANCE12_ALPHA4,
34           GLU_LUMINANCE12_ALPHA12, GLU_LUMINANCE16_ALPHA16, GLU_INTENSITY,
35           GLU_INTENSITY4, GLU_INTENSITY8, GLU_INTENSITY12, GLU_INTENSITY16,
36           GLU_RGB, GLU_R3_G3_B2, GLU_RGB4, GLU_RGB5, GLU_RGB8, GLU_RGB10,
37           GLU_RGB12, GLU_RGB16, GLU_RGBA, GLU_RGBA2, GLU_RGBA4, GLU_RGB5_A1,
38           GLU_RGBA8, GLU_RGB10_A2, GLU_RGBA12, or GLU_RGBA16.
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40       width, height
41           Specifies the width and height, respectively, in pixels of the
42           texture image. These should be a power of 2.
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44       format
45           Specifies the format of the pixel data. Must be one of
46           GLU_COLOR_INDEX, GLU_DEPTH_COMPONENT, GLU_RED, GLU_GREEN, GLU_BLUE,
47           GLU_ALPHA, GLU_RGB, GLU_RGBA, GLU_BGR, GLU_BGRA, GLU_LUMINANCE, or
48           GLU_LUMINANCE_ALPHA.
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50       type
51           Specifies the data type for data. Must be one of GLU_UNSIGNED_BYTE,
52           GLU_BYTE, GLU_BITMAP, GLU_UNSIGNED_SHORT, GLU_SHORT,
53           GLU_UNSIGNED_INT, GLU_INT, GLU_FLOAT, GLU_UNSIGNED_BYTE_3_3_2,
54           GLU_UNSIGNED_BYTE_2_3_3_REV, GLU_UNSIGNED_SHORT_5_6_5,
55           GLU_UNSIGNED_SHORT_5_6_5_REV, GLU_UNSIGNED_SHORT_4_4_4_4,
56           GLU_UNSIGNED_SHORT_4_4_4_4_REV, GLU_UNSIGNED_SHORT_5_5_5_1,
57           GLU_UNSIGNED_SHORT_1_5_5_5_REV, GLU_UNSIGNED_INT_8_8_8_8,
58           GLU_UNSIGNED_INT_8_8_8_8_REV, GLU_UNSIGNED_INT_10_10_10_2, or
59           GLU_UNSIGNED_INT_2_10_10_10_REV.
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61       level
62           Specifies the mipmap level of the image data.
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64       base
65           Specifies the minimum mipmap level to pass to glTexImage2D().
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67       max
68           Specifies the maximum mipmap level to pass to glTexImage2D().
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70       data
71           Specifies a pointer to the image data in memory.
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DESCRIPTION

74       gluBuild2DMipmapLevels builds a subset of prefiltered two-dimensional
75       texture maps of decreasing resolutions called a mipmap. This is used
76       for the antialiasing of texture mapped primitives.
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78       A return value of zero indicates success, otherwise a GLU error code is
79       returned (see gluErrorString()).
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81       A series of mipmap levels from base to max is built by decimating data
82       in half along both dimensions until size 1 × 1 is reached. At each
83       level, each texel in the halved mipmap level is an average of the
84       corresponding four texels in the larger mipmap level. (In the case of
85       rectangular images, the decimation will ultimately reach an N × 1 or 1
86       × N configuration. Here, two texels are averaged instead.)
87       glTexImage2D() is called to load these mipmap levels from base to max.
88       If max is larger than the highest mipmap level for the texture of the
89       specified size, then a GLU error code is returned (see
90       gluErrorString()) and nothing is loaded.
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92       For example, if level is 2 and width is 16 and height is 8, the
93       following levels are possible: 16 × 8, 8 × 4, 4 × 2, 2 × 1, 1 × 1.
94       These correspond to levels 2 through 6 respectively. If base is 3 and
95       max is 5, then only mipmap levels 8 × 4, 4 × 2, and 2 × 1 are loaded.
96       However, if max is 7, then an error is returned and nothing is loaded
97       since max is larger than the highest mipmap level which is, in this
98       case, 6.
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100       The highest mipmap level can be derived from the formula log 2 ⁡ max ⁡
101       width height × 2 level.
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103       See the glTexImage1D() reference page for a description of the
104       acceptable values for format parameter. See the glDrawPixels()
105       reference page for a description of the acceptable values for type
106       parameter.
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NOTES

109       gluBuild2DMipmapLevels is only available if the GLU version is 1.3 or
110       greater.
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112       Formats GLU_BGR, and GLU_BGRA, and types GLU_UNSIGNED_BYTE_3_3_2,
113       GLU_UNSIGNED_BYTE_2_3_3_REV, GLU_UNSIGNED_SHORT_5_6_5,
114       GLU_UNSIGNED_SHORT_5_6_5_REV, GLU_UNSIGNED_SHORT_4_4_4_4,
115       GLU_UNSIGNED_SHORT_4_4_4_4_REV, GLU_UNSIGNED_SHORT_5_5_5_1,
116       GLU_UNSIGNED_SHORT_1_5_5_5_REV, GLU_UNSIGNED_INT_8_8_8_8,
117       GLU_UNSIGNED_INT_8_8_8_8_REV, GLU_UNSIGNED_INT_10_10_10_2, and
118       GLU_UNSIGNED_INT_2_10_10_10_REV are only available if the GL version is
119       1.2 or greater.
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ERRORS

122       GLU_INVALID_VALUE is returned if level > base, base < 0, max < base, or
123       max is > the highest mipmap level for data.
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125       GLU_INVALID_VALUE is returned if width or height is < 1.
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127       GLU_INVALID_ENUM is returned if internalFormat, format, or type is not
128       legal.
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130       GLU_INVALID_OPERATION is returned if type is GLU_UNSIGNED_BYTE_3_3_2 or
131       GLU_UNSIGNED_BYTE_2_3_3_REV and format is not GLU_RGB.
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133       GLU_INVALID_OPERATION is returned if type is GLU_UNSIGNED_SHORT_5_6_5
134       or GLU_UNSIGNED_SHORT_5_6_5_REV and format is not GLU_RGB.
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136       GLU_INVALID_OPERATION is returned if type is GLU_UNSIGNED_SHORT_4_4_4_4
137       or GLU_UNSIGNED_SHORT_4_4_4_4_REV and format is neither GLU_RGBA nor
138       GLU_BGRA.
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140       GLU_INVALID_OPERATION is returned if type is GLU_UNSIGNED_SHORT_5_5_5_1
141       or GLU_UNSIGNED_SHORT_1_5_5_5_REV and format is neither GLU_RGBA nor
142       GLU_BGRA.
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144       GLU_INVALID_OPERATION is returned if type is GLU_UNSIGNED_INT_8_8_8_8
145       or GLU_UNSIGNED_INT_8_8_8_8_REV and format is neither GLU_RGBA nor
146       GLU_BGRA.
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148       GLU_INVALID_OPERATION is returned if type is
149       GLU_UNSIGNED_INT_10_10_10_2 or GLU_UNSIGNED_INT_2_10_10_10_REV and
150       format is neither GLU_RGBA nor GLU_BGRA.
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COPYRIGHT

159       Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
160       under the SGI Free Software B License. For details, see
161       http://oss.sgi.com/projects/FreeB/.
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AUTHORS

164       opengl.org
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168opengl.org                        07/13/2018          GLUBUILD2DMIPMAPLEVE(3G)