README revision 7ba80e0c509c0bf1b14c2a20db579055b999f066 
1/**********************************************************
2 * Copyright 2009-2011 VMware, Inc. All rights reserved.
3 *
4 * Permission is hereby granted, free of charge, to any person
5 * obtaining a copy of this software and associated documentation
6 * files (the "Software"), to deal in the Software without
7 * restriction, including without limitation the rights to use, copy,
8 * modify, merge, publish, distribute, sublicense, and/or sell copies
9 * of the Software, and to permit persons to whom the Software is
10 * furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22 * SOFTWARE.
23 *
24 *********************************************************
25 * Authors:
26 * Zack Rusin <zackr-at-vmware-dot-com>
27 * Thomas Hellstrom <thellstrom-at-vmware-dot-com>
28 */
29
30The XA state tracker is intended as a versioned interface to gallium for
31xorg driver writers. Initially it's mostly based on Zack Rusin's
32composite / video work for the Xorg state tracker.
33
34The motivation behind this state tracker is that the Xorg state tracker has
35a number of interfaces to work with:
36
371) The Xorg sdk (versioned)
382) Gallium3D (not versioned)
393) KMS modesetting (versioned)
404) Driver-private (hopefully versioned)
41
42Since Gallium3D is not versioned, the Xorg state tracker needs to be compiled
43with Gallium, but it's really beneficial to be able to compile xorg drivers
44standalone.
45
46Therefore the xa state tracker is intended to supply the following
47functionality:
48
491) Versioning.
502) Surface functionality (creation and copying for a basic dri2 implementation)
513) YUV blits for textured Xv.
52
53and coming up:
544) Solid fills with ROP functionality.
555) Copies with ROP functionality, format conversion and - reinterpretation.
566) Xrender- type compositing for general acceleration.
57
584-6 is not implemented yet since they are not directly used by the
59vmwgfx driver.
60
61The first user will be the vmwgfx xorg driver. When there are more users,
62we need to be able to load the appropriate gallium pipe driver, and we
63should investigate sharing the loadig mechanism with the EGL state tracker.
64
65