1GLUBUILD3DMIPMAPS(3G) GLUBUILD3DMIPMAPS(3G)
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6 gluBuild3DMipmaps - builds a three-dimensional mipmap
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10 GLint gluBuild3DMipmaps( GLenum target,
11 GLint internalFormat,
12 GLsizei width,
13 GLsizei height,
14 GLsizei depth,
15 GLenum format,
16 GLenum type,
17 const void *data )
18
21 target Specifies the target texture. Must be GL_TEXTURE_3D.
22 internalFormat Requests the internal storage of the texture image.
24 The most current version of the SGI implementation of
25 GLU does not check this value for validity before pass‐
26 ing it on to the underlying OpenGL implementation. A
27 value that is not accepted by the OpenGL implementation
28 will lead to an OpenGL error. The benefit of not
29 checking this value at the GLU level is that OpenGL
30 extensions can add new internal texture formats without
31 requiring a revision of the GLU implementation. Older
32 implementations of GLU check this value and raise a GLU
33 error if it is not 1, 2, 3, or 4 or one of the follow‐
34 ing symbolic constants: GL_ALPHA, GL_ALPHA4, GL_ALPHA8,
35 GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4,
36 GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16,
37 GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4,
38 GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8,
39 GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12,
40 GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4,
41 GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_RGB,
42 GL_R3_G3_B2, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10,
43 GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4,
44 GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or
45 GL_RGBA16.
46 width, height, depth
48 Specifies in pixels the width, height and depth respec‐
49 tively, in pixels of the texture image.
50 format Specifies the of the pixel data. Must be one of
52 GL_COLOR_INDEX, GL_DEPTH_COMPONENT, GL_RED, GL_GREEN,
53 GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA, GL_BGR, GL_BGRA,
54 GL_LUMINANCE, or GL_LUMINANCE_ALPHA.
55 type Specifies the data type for data. Must be one of:
57 GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP,
58 GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT,
59 GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2,
60 GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5,
61 GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4,
62 GL_UNSIGNED_SHORT_4_4_4_4_REV,
63 GL_UNSIGNED_SHORT_5_5_5_1,
64 GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8,
65 GL_UNSIGNED_INT_8_8_8_8_REV,
66 GL_UNSIGNED_INT_10_10_10_2, or
67 GL_UNSIGNED_INT_2_10_10_10_REV.
68 data Specifies a pointer to the image data in memory.
70
72 gluBuild3DMipmaps builds a series of prefiltered three-dimensional tex‐
73 ture maps of decreasing resolutions called a mipmap. This is used for
74 the antialiasing of texture-mapped primitives.
75 A return value of zero indicates success, otherwise a GLU error code is
77 returned (see gluErrorString).
78 Initially, the width, height and depth of data are checked to see if
80 they are a power of 2. If not, a copy of data (not data), is scaled up
81 or down to the nearest power of 2. (If width, height or depth is
82 exactly between powers of 2, then the copy of data will scale upwards.)
83 This copy will be used for subsequent mipmapping operations described
84 below. For example, if width is 57, height is 23 and depth is 24 then
85 a copy of data will scale up to 64 in width, down to 16 in height and
86 up to 32 in depth, before mipmapping takes place.
87 Then, proxy textures (see glTexImage3D) are used to determine if the
89 implementation can fit the requested texture. If not, all three dimen‐
90 sions are continually halved until it fits.
91 Next, a series of mipmap levels is built by decimating a copy of data
93 in half along all three dimensions until size 1×1×1 is reached. At each
94 level, each texel in the halved mipmap level is an average of the cor‐
95 responding eight texels in the larger mipmap level. (If exactly one of
96 the dimensions is 1, four texels are averaged. If exactly two of the
97 dimensions are 1, two texels are averaged.)
98 glTexImage3D is called to load each of these mipmap levels. Level 0 is
100 a copy of data. The highest level is log2(max(width,height,depth)).
101 For example, if width is 64, height is 16 and depth is 32, and the
102 implementation can store a texture of this size, the following mipmap
103 levels are built: 64×16×32, 32×8×16, 16×4×8, 8×2×4, 4×1×2, 2×1×1 and
104 1×1×1. These correspond to levels 0 through 6, respectively.
105 See the glTexImage1D reference page for a description of the acceptable
107 values for format parameter. See the glDrawPixels reference page for a
108 description of the acceptable values for type parameter.
109
111 Note that there is no direct way of querying the maximum level. This
112 can be derived indirectly via glGetTexLevelParameter. First, query for
113 the width, height and depth actually used at level 0. (The width,
114 height and depth may not be equal to width, height and depth respec‐
115 tively since proxy textures might have scaled them to fit the implemen‐
116 tation.) Then the maximum level can be derived from the formula
117 log2(max(width,height,depth)).
118 gluBuild3DMipmaps is only available if the GLU version is 1.3 or
120 greater.
121 Formats GL_BGR, and GL_BGRA, and types GL_UNSIGNED_BYTE_3_3_2,
123 GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5,
124 GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4,
125 GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1,
126 GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8,
127 GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and
128 GL_UNSIGNED_INT_2_10_10_10_REV are only available if the GL version is
129 1.2 or greater.
130
132 GLU_INVALID_VALUE is returned if width, height, or depth is < 1.
133 GLU_INVALID_ENUM is returned if internalFormat, format, or type is not
135 legal.
136 GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_BYTE_3_3_2 or
138 GL_UNSIGNED_BYTE_2_3_3_REV and format is not GL_RGB.
139 GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_SHORT_5_6_5 or
141 GL_UNSIGNED_SHORT_5_6_5_REV and format is not GL_RGB.
142 GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_SHORT_4_4_4_4
144 or GL_UNSIGNED_SHORT_4_4_4_4_REV and format is neither GL_RGBA nor
145 GL_BGRA.
146 GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_SHORT_5_5_5_1
148 or GL_UNSIGNED_SHORT_1_5_5_5_REV and format is neither GL_RGBA nor
149 GL_BGRA.
150 GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_INT_8_8_8_8 or
152 GL_UNSIGNED_INT_8_8_8_8_REV and format is neither GL_RGBA nor GL_BGRA.
153 GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_INT_10_10_10_2
155 or GL_UNSIGNED_INT_2_10_10_10_REV and format is neither GL_RGBA nor
156 GL_BGRA.
157
159 glDrawPixels(3G), glTexImage1D(3G), glTexImage2D(3G), glTexImage3D(3G),
160 gluBuild1DMipmaps(3G), gluBuild3DMipmaps(3G), gluErrorString(3G),
161 glGetTexImage(3G), glGetTexLevelParameter(3G),
162 gluBuild1DMipmapLevels(3G), gluBuild2DMipmapLevels(3G),
163 gluBuild3DMipmapLevels(3G)
164 GLUBUILD3DMIPMAPS(3G)