1 <?xml version="1.0" encoding="UTF-8"?> 2 <protocol name="vsync_feedback_unstable_v1"> 3 4 <copyright> 5 Copyright 2016 The Chromium Authors. 6 7 Permission is hereby granted, free of charge, to any person obtaining a 8 copy of this software and associated documentation files (the "Software"), 9 to deal in the Software without restriction, including without limitation 10 the rights to use, copy, modify, merge, publish, distribute, sublicense, 11 and/or sell copies of the Software, and to permit persons to whom the 12 Software is furnished to do so, subject to the following conditions: 13 14 The above copyright notice and this permission notice (including the next 15 paragraph) shall be included in all copies or substantial portions of the 16 Software. 17 18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 21 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 22 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 23 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 24 DEALINGS IN THE SOFTWARE. 25 </copyright> 26 27 <description summary="Protocol for providing vertical synchronization timing"> 28 This protocol specifies a set of interfaces used to inform the client about 29 vertical synchronization timing in a precise way and without unnecessary 30 overhead. 31 32 Warning! The protocol described in this file is experimental and backward 33 incompatible changes may be made. Backward compatible changes may be added 34 together with the corresponding interface version bump. Backward 35 incompatible changes are done by bumping the version number in the protocol 36 and interface names and resetting the interface version. Once the protocol 37 is to be declared stable, the version number in the protocol is removed and 38 the interface version number is reset. 39 </description> 40 41 <interface name="zcr_vsync_feedback_v1" version="1"> 42 <description summary="Protocol for providing vertical synchronization timing"> 43 The global interface that allows clients to subscribe for vertical 44 synchronization timing data for given wl_output. 45 </description> 46 47 <request name="destroy" type="destructor"> 48 <description summary="destroy vsync feedback object"> 49 Destroy this vsync feedback object. Existing vsync timing objects shall 50 not be affected by this request. 51 </description> 52 </request> 53 54 <request name="get_vsync_timing"> 55 <description summary="get vsync timing object for given wl_output"> 56 Create a new vsync timing object that represents a subscription to 57 vertical synchronization timing updates of given wl_output object. 58 59 The newly created object will immediately signal an update to notify 60 the subscriber of initial timing parameters. 61 </description> 62 <arg name="id" type="new_id" interface="zcr_vsync_timing_v1" summary="the new vsync timing interface id"/> 63 <arg name="output" type="object" interface="wl_output" summary="the wl_output object to subscribe for timings of" allow-null="true"/> 64 </request> 65 </interface> 66 67 <interface name="zcr_vsync_timing_v1" version="1"> 68 <request name="destroy" type="destructor"> 69 <description summary="destroy vsync timing object"> 70 Destroy this vsync timing object. 71 </description> 72 </request> 73 74 <event name="update"> 75 <description summary="vsync timing updated"> 76 Notifies client that vertical synchronization timing of given wl_output 77 has changed. 78 79 Timing information consists of two data, timebase and interval. Timebase 80 is an absolute timestamp of the vsync event that caused the timing to 81 change. Interval is a period of time between subsequent vsync events. 82 83 The unit of all above mentioned time values shall be microseconds and 84 absolute timestamps should match the realm of the primary system 85 monotonic counter, i.e. the POSIX clock_gettime(CLOCK_MONOTONIC). Data 86 type of both values is defined to be a 64-bit unsigned integer, but 87 since the biggest unsigned integer datatype defined by the Wayland 88 protocol is the 32-bit uint, both timebase and interval are split into 89 most significant and least significant part, suffixed by "_h" and "_l" 90 respectively. 91 </description> 92 <arg name="timebase_l" type="uint" summary="new vsync timebase (lower 32 bits)"/> 93 <arg name="timebase_h" type="uint" summary="new vsync timebase (upper 32 bits)"/> 94 <arg name="interval_l" type="uint" summary="new vsync interval (lower 32 bits)"/> 95 <arg name="interval_h" type="uint" summary="new vsync interval (upper 32 bits)"/> 96 </event> 97 </interface> 98 99 </protocol> 100
