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1Name
2
3    EXT_bgra
4
5Name Strings
6
7    GL_EXT_bgra
8
9Version
10
11    Microsoft revision 1.0, May 19, 1997 (drewb)
12    $Date: 1999/04/03 08:40:34 $ $Revision: 1.4 $
13
14Number
15
16    129
17
18Dependencies
19
20    None
21
22Overview
23
24    EXT_bgra extends the list of host-memory color formats.
25    Specifically, it provides formats which match the memory layout of
26    Windows DIBs so that applications can use the same data in both
27    Windows API calls and OpenGL pixel API calls.
28
29New Procedures and Functions
30
31    None
32
33New Tokens
34
35    Accepted by the <format> parameter of DrawPixels, GetTexImage,
36    ReadPixels, TexImage1D, and TexImage2D:
37
38        BGR_EXT                 0x80E0
39        BGRA_EXT                0x80E1
40
41Additions to Chapter 2 of the 1.1 Specification (OpenGL Operation)
42
43    None
44
45Additions to Chapter 3 of the 1.1 Specification (Rasterization)
46
47    One entry is added to table 3.5 (DrawPixels and ReadPixels formats).
48    The new table is:
49
50        Name                    Type            Elements                Target Buffer
51        ----                    ----            --------                ------
52        COLOR_INDEX             Index           Color Index             Color
53        STENCIL_INDEX           Index           Stencil value           Stencil
54        DEPTH_COMPONENT         Component       Depth value             Depth
55        RED                     Component       R                       Color
56        GREEN                   Component       G                       Color
57        BLUE                    Component       B                       Color
58        ALPHA                   Component       A                       Color
59        RGB                     Component       R, G, B                 Color
60        RGBA                    Component       R, G, B, A              Color
61        LUMINANCE               Component       Luminance value         Color
62        LUMINANCE_ALPHA         Component       Luminance value, A      Color
63        BGR_EXT                 Component       B, G, R                 Color
64        BGRA_EXT                Component       B, G, R, A              Color
65
66        Table 3.5: DrawPixels and ReadPixels formats.  The third column
67        gives a description of and the number and order of elements in a
68        group.
69
70Additions to Chapter 4 of the 1.1 Specification (Per-Fragment Operations
71and the Framebuffer)
72
73    The new format is added to the discussion of Obtaining Pixels from
74    the Framebuffer. It should read " If the <format> is one of RED,
75    GREEN, BLUE, ALPHA, RGB, RGBA, BGR_EXT, BGRA_EXT, LUMINANCE, or
76    LUMINANCE_ALPHA, and the GL is in color index mode, then the color
77    index is obtained."
78
79    The new format is added to the discussion of Index Lookup. It should
80    read "If <format> is one of RED, GREEN, BLUE, ALPHA, RGB, RGBA,
81    BGR_EXT, BGRA_EXT, LUMINANCE, or LUMINANCE_ALPHA, then the index is
82    used to reference 4 tables of color components: PIXEL_MAP_I_TO_R,
83    PIXEL_MAP_I_TO_G, PIXEL_MAP_I_TO_B, and PIXEL_MAP_I_TO_A."
84
85Additions to Chapter 5 of the GL Specification (Special Functions)
86
87    None
88
89Additions to Chapter 6 of the GL Specification (State and State
90Requests)
91
92    None
93
94Revision History
95
96    Original draft, revision 0.9, October 13, 1995 (drewb)
97        Created
98    Minor revision, revision 1.0, May 19, 1997 (drewb)
99        Removed Microsoft Confidential.
100