1GLGETMINMAX(3G) OpenGL Manual GLGETMINMAX(3G)
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6 glGetMinmax - get minimum and maximum pixel values
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9 void glGetMinmax(GLenum target, GLboolean reset, GLenum format,
10 GLenum types, GLvoid * values);
11
13 target
14 Must be GL_MINMAX.
15 reset
17 If GL_TRUE, all entries in the minmax table that are actually
18 returned are reset to their initial values. (Other entries are
19 unaltered.) If GL_FALSE, the minmax table is unaltered.
20 format
22 The format of the data to be returned in values. Must be one of
23 GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA,
24 GL_BGRA, GL_LUMINANCE, or GL_LUMINANCE_ALPHA.
25 types
27 The type of the data to be returned in values. Symbolic constants
28 GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT,
29 GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2,
30 GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5,
31 GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4,
32 GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1,
33 GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8,
34 GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and
35 GL_UNSIGNED_INT_2_10_10_10_REV are accepted.
36 values
38 A pointer to storage for the returned values.
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41 glGetMinmax returns the accumulated minimum and maximum pixel values
42 (computed on a per-component basis) in a one-dimensional image of width
43 2. The first set of return values are the minima, and the second set of
44 return values are the maxima. The format of the return values is
45 determined by format, and their type is determined by types.
46 If a non-zero named buffer object is bound to the GL_PIXEL_PACK_BUFFER
48 target (see glBindBuffer()) while minimum and maximum pixel values are
49 requested, values is treated as a byte offset into the buffer object's
50 data store.
51 No pixel transfer operations are performed on the return values, but
53 pixel storage modes that are applicable to one-dimensional images are
54 performed. Color components that are requested in the specified format,
55 but that are not included in the internal format of the minmax table,
56 are returned as zero. The assignment of internal color components to
57 the components requested by format are as follows:
58 ┌─────────────────────────────────┬───────────────────────────────────┐
60 │ │ │
61 │ Internal │ Resulting │
62 │Component │ Component │
63 │ │ │
64 ├─────────────────────────────────┼───────────────────────────────────┤
65 │Red │ Red │
66 ├─────────────────────────────────┼───────────────────────────────────┤
67 │Green │ Green │
68 ├─────────────────────────────────┼───────────────────────────────────┤
69 │Blue │ Blue │
70 ├─────────────────────────────────┼───────────────────────────────────┤
71 │Alpha │ Alpha │
72 ├─────────────────────────────────┼───────────────────────────────────┤
73 │Luminance │ Red │
74 └─────────────────────────────────┴───────────────────────────────────┘
75 If reset is GL_TRUE, the minmax table entries corresponding to the
77 return values are reset to their initial values. Minimum and maximum
78 values that are not returned are not modified, even if reset is
79 GL_TRUE.
80
82 glGetMinmax is present only if ARB_imaging is returned when
83 glGetString() is called with an argument of GL_EXTENSIONS.
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86 GL_INVALID_ENUM is generated if target is not GL_MINMAX.
87 GL_INVALID_ENUM is generated if format is not one of the allowable
89 values.
90 GL_INVALID_ENUM is generated if types is not one of the allowable
92 values.
93 GL_INVALID_OPERATION is generated if types is one of
95 GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
96 GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and format is
97 not GL_RGB.
98 GL_INVALID_OPERATION is generated if types is one of
100 GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV,
101 GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
102 GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,
103 GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV and
104 format is neither GL_RGBA nor GL_BGRA.
105 GL_INVALID_OPERATION is generated if a non-zero buffer object name is
107 bound to the GL_PIXEL_PACK_BUFFER target and the buffer object's data
108 store is currently mapped.
109 GL_INVALID_OPERATION is generated if a non-zero buffer object name is
111 bound to the GL_PIXEL_PACK_BUFFER target and the data would be packed
112 to the buffer object such that the memory writes required would exceed
113 the data store size.
114 GL_INVALID_OPERATION is generated if a non-zero buffer object name is
116 bound to the GL_PIXEL_PACK_BUFFER target and values is not evenly
117 divisible into the number of bytes needed to store in memory a datum
118 indicated by type.
119 GL_INVALID_OPERATION is generated if glGetMinmax is executed between
121 the execution of glBegin() and the corresponding execution of glEnd().
122
124 glGetMinmaxParameter()
125 glGet() with argument GL_PIXEL_PACK_BUFFER_BINDING
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129 glMinmax(), glResetMinmax(),
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132 Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
133 under the SGI Free Software B License. For details, see
134 http://oss.sgi.com/projects/FreeB/.
135
137 opengl.org
138opengl.org 06/10/2014 GLGETMINMAX(3G)