From 89019ca647f03a0378d653e579e632c181045ddb Mon Sep 17 00:00:00 2001
From: Adam Jackson <ajax@redhat.com>
Date: Wed, 9 Sep 2020 15:44:19 -0400
Subject: [PATCH] Add EGL_MESA_swap_control_tear

---
 .../MESA/EGL_MESA_swap_control_tear.txt       | 89 +++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 extensions/MESA/EGL_MESA_swap_control_tear.txt

diff --git a/extensions/MESA/EGL_MESA_swap_control_tear.txt b/extensions/MESA/EGL_MESA_swap_control_tear.txt
new file mode 100644
index 00000000..48c32fc4
--- /dev/null
+++ b/extensions/MESA/EGL_MESA_swap_control_tear.txt
@@ -0,0 +1,89 @@
+Name
+
+    MESA_swap_control_tear
+
+Name Strings
+
+    EGL_MESA_swap_control_tear
+
+Contributors
+
+    Adam Jackson <ajax@redhat.com>
+
+    The contributors to GLX_EXT_swap_control_tear:
+    Brian Nguyen, NVIDIA, brnguyen at nvidia.com
+
+Contact
+
+    Adam Jackson <ajax@redhat.com>
+
+Status
+
+    DRAFT
+
+Version
+
+    Version 1 (9 September 2020)
+
+Number
+
+    XXX
+
+Dependencies
+
+    EGL 1.1 or greater is required for eglSwapInterval.
+
+    This specification is written against the EGL 1.5 specification.
+
+Overview
+
+    This extension extends EGL by allowing a negative <interval> parameter to
+    eglSwapInterval. The negative <interval> allows late swaps to occur without
+    synchronization to the video frame. This reduces the visual stutter on late
+    frames and reduces the stall on subsequent frames.
+
+IP Status
+
+    There are no known IP issues.
+
+Issues
+
+    1: Should there be queries?
+
+    UNRESOLVED. GLX has them (as of GLX_EXT_swap_control), but EGL does not
+    have any per-surface queries about swap intervals at all.
+
+New Procedures and Functions
+
+    None
+
+New Tokens
+
+    None
+
+Additions to the EGL 1.5 Specification
+
+    In Section 3.10.3 of the EGL specification (Posting Semantics),
+    to the paragraph beginning: 
+
+    "If <interval> is set to a value of 0, buffer swaps are not
+    synchronized to a video frame..."
+
+    Append:
+
+    "If <interval> is negative, the minimum number of video frames between
+    buffer swaps is the absolute value of <interval>. In this case, if
+    abs(<interval>) video frames have already passed from the previous swap
+    when the swap is ready to be performed, the swap will occur without
+    synchronization to a video frame. When an unsynchronized swap happens,
+    the missed frame will count towards the minimum number of video frames
+    for the next swap."
+
+Errors
+
+    None
+
+Version History
+
+    1. 09 September 2020 - ajax
+    Clone from GLX_EXT_swap_control_tear.