1From 2e1e3c857cdf365c5a13bcd5d09685cf12f8047c Mon Sep 17 00:00:00 2001
2From: Jeff Wannamaker <jeff_wannamaker@cable.comcast.com>
3Date: Thu, 19 Jan 2017 18:56:07 +0000
4Subject: [PATCH] Implement triple buffering for wayland
5
6Change from double to triple buffering for wayland.
7This enables higher frame rates without tearing artifacts
8by allowing both the glFinish and the buffer release
9interlock to operate without pushing the frame period
10to two vertical intervals
11
12Signed-off-by: Jeff Wannamaker <jeff_wannamaker@cable.comcast.com>
13Signed-off-by: Khem Raj <raj.khem@gmail.com>
14---
15 interface/khronos/egl/egl_client.c         |  3 ++-
16 interface/khronos/egl/egl_client_surface.c |  8 ++++++++
17 interface/khronos/egl/egl_client_surface.h | 11 +++++++++++
18 3 files changed, 21 insertions(+), 1 deletion(-)
19
20diff --git a/interface/khronos/egl/egl_client.c b/interface/khronos/egl/egl_client.c
21index 13a110c..0380274 100644
22--- a/interface/khronos/egl/egl_client.c
23+++ b/interface/khronos/egl/egl_client.c
24@@ -2323,7 +2323,8 @@ EGLAPI EGLBoolean EGLAPIENTRY eglSwapBuffers(EGLDisplay dpy, EGLSurface surf)
25
26                   buffer_temp = surface->front_wl_buffer;
27                   surface->front_wl_buffer = surface->back_wl_buffer;
28-                  surface->back_wl_buffer = buffer_temp;
29+                  surface->back_wl_buffer = surface->middle_wl_buffer;
30+                  surface->middle_wl_buffer = buffer_temp;
31
32                   configid = egl_config_to_id(surface->config);
33                   color = egl_config_get_color_format(configid);
34diff --git a/interface/khronos/egl/egl_client_surface.c b/interface/khronos/egl/egl_client_surface.c
35index 9a9582c..10b3b04 100644
36--- a/interface/khronos/egl/egl_client_surface.c
37+++ b/interface/khronos/egl/egl_client_surface.c
38@@ -402,12 +402,14 @@ EGL_SURFACE_T *egl_surface_create(
39    if (type == WINDOW && wl_display) {
40       surface->wl_egl_window = (struct wl_egl_window*)win;
41       surface->front_wl_buffer = NULL;
42+      surface->middle_wl_buffer = NULL;
43       surface->back_wl_buffer = allocate_wl_buffer(
44             surface->wl_egl_window, color);
45       resource = surface->back_wl_buffer->resource;
46    } else {
47       surface->wl_egl_window = NULL;
48       surface->front_wl_buffer = NULL;
49+      surface->middle_wl_buffer = NULL;
50       surface->back_wl_buffer = NULL;
51       resource = DISPMANX_NO_HANDLE;
52    }
53@@ -696,6 +698,12 @@ void egl_surface_free(EGL_SURFACE_T *surface)
54          surface->back_wl_buffer = 0;
55       }
56
57+      if (surface->middle_wl_buffer) {
58+         wl_buffer_destroy(surface->middle_wl_buffer->wl_buffer);
59+         free(surface->middle_wl_buffer);
60+         surface->middle_wl_buffer = 0;
61+      }
62+
63       if (surface->front_wl_buffer) {
64          wl_buffer_destroy(surface->front_wl_buffer->wl_buffer);
65          free(surface->front_wl_buffer);
66diff --git a/interface/khronos/egl/egl_client_surface.h b/interface/khronos/egl/egl_client_surface.h
67index e328b77..58a3184 100644
68--- a/interface/khronos/egl/egl_client_surface.h
69+++ b/interface/khronos/egl/egl_client_surface.h
70@@ -312,6 +312,17 @@ typedef struct {
71    */
72    struct wl_dispmanx_client_buffer *front_wl_buffer;
73
74+   /*
75+      middle_wl_buffer
76+
77+      Validity:
78+      type == WINDOW
79+
80+      Invariant:
81+      client-side information about the wl_buffer in the middle
82+   */
83+   struct wl_dispmanx_client_buffer *middle_wl_buffer;
84+
85    /*
86       back_wl_buffer
87
88