1Name
2
3    NV_post_convert_rounding
4
5Name Strings
6
7    EGL_NV_post_convert_rounding
8
9Contributors
10
11    Bryan Eyler, NVIDIA
12    Daniel Kartch, NVIDIA
13    Greg Roth, NVIDIA
14    Mark Vojkovich, NVIDIA
15    Nicolai de Haan Brogger, NVIDIA
16    Peter Pipkorn, NVIDIA
17    
18Contacts
19
20    Nicolai de Haan Brogger, NVIDIA Corporation (nicolaid 'at' nvidia.com)
21
22Status
23
24    Complete
25
26Version
27
28    Last Modified 17 Oct 2012
29    Version 2
30
31Number
32
33    EGL Extension #44
34
35Dependencies
36
37    Requires EGL 1.0.
38
39    This extension is written against the wording of the EGL 1.4
40    Specification.
41
42Overview
43
44    This extension defines the conversions for posting operations
45    when the destination's number of components or component sizes do
46    not match the color buffer. This extension supports posting a 24 bit
47    (888) color buffer to a 16 bit (565) destination buffer, posting a
48    16 bit (565) color buffer to a 24 bit (888) destination buffer, and
49    posting a component that is present in the source buffer, but not
50    present in the destination buffer.    
51
52New Procedures and Functions
53
54    None
55
56Changes to Chapter 3 of the EGL 1.4 Specification (EGL Functions and
57Errors)
58
59    In Chapter 3.9.3, replace paragraph 3 with:
60        "    For each color component, if the bit depth of the color
61         buffer being posted is 24 (888) and the destination buffer is
62         16 (565), the lower order bits of the color buffer are
63         truncated.
64
65         If the bit depth of the destination buffer is 24 (888) and the
66         color buffer being posted is 16 bit (565), a RGB gain and
67         rounding operation is applied to the color buffer values prior
68         to posting. The destination buffer will contain the rounded
69         (nearest) and clamped result of the vector product of [1.03125,
70         1.015625, 1.03125] with the RGB values of the color buffer.
71
72         For cases where a component is present in the color buffer but
73         the matching component is not present in the destination
74         buffer, that component will be dropped."
75
76    In Chapter 3.9.3, remove paragraph 5.
77
78Issues
79
80Revision History
81#2 (Greg Roth, Oct 17, 2012)
82   - Clarify limitations and reformat a bit.
83
84#1 (Nicolai de Haan Brogger, July 07, 2010)
85   - First Draft
86