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Diffstat (limited to 'protocol')
| -rw-r--r-- | protocol | 32 |
1 files changed, 27 insertions, 5 deletions
@@ -1,11 +1,15 @@ The DAMAGE Extension - Protocol Version 0.0 + Protocol Version 1.1 Document Revision 1 - 2003-11-03 + 2007-01-08 Keith Packard keithp@keithp.com + Eric Anholt + eric@anholt.net + Open Source Technology Center + Intel Corporation 1. Introduction Monitoring the regions affected by rendering has wide-spread use, from @@ -63,10 +67,23 @@ within the bounds of the window. In a system with a single frame buffer holding all windows, this means that damage will accumulate for all rendering operations that lie within the visible part of the window. -The precise reason for this architecture will be made clear in the XSPLITTREE -extension which will provide multiple pixel storage areas for the screen +The precise reason for this architecture is to enable the Composite +extension which provides multiple pixel storage areas for the screen contents. +3.1 Additions in the 1.1 version of the protocol + +Damage is automatically computed by the X Server for X rendering operations, +but direct rendering extensions have allowed clients to perform rendering +outside of the control of the X Server. The 1.1 version of the protocol +added a request to allow direct rendering clients to report damage to a +drawable. Some direct rendering clients, due to architectural limitations, +always perform rendering to the root window, even in when it should be +performed to the backing pixmap in the Composite case. To provide +less-incorrect rendering in this cases, the direct rendering client should +translate its damage region to screen coordinates and report the damage against +the root window rather than the drawable. + 4. Data types The "Damage" object holds any accumulated damage region and reflects the @@ -196,4 +213,9 @@ DamagePost Reports damage of the region within the given drawable. This may be used by direct rendering clients to report damage that the server would - otherwise be unaware of. + otherwise be unaware of. The damage region is relative to the origin + of the drawable. + + Damage posted in this way will appear in DamageNotify events as normal, + and also in server internal damage tracking (for shadow framebuffer + updates, pixmap damage, and other uses). |