From f9aa6acb7a9456b9ce6dbe5a9e8b819929e96672 Mon Sep 17 00:00:00 2001
From: Carlos Aragones <c.aragones@gmail.com>
Date: Wed, 28 Apr 2021 11:07:25 +0200
Subject: [PATCH] try to accurate software vsync

---
 src/macosx/MacMiniFB.m      | 24 +++++++++++++-----------
 src/wayland/WaylandMiniFB.c | 22 ++++++++++++----------
 src/windows/WinMiniFB.c     | 24 ++++++++++++------------
 src/x11/X11MiniFB.c         | 22 +++++++++++-----------
 4 files changed, 48 insertions(+), 44 deletions(-)

diff --git a/src/macosx/MacMiniFB.m b/src/macosx/MacMiniFB.m
index c6dc272..7e40040 100644
--- a/src/macosx/MacMiniFB.m
+++ b/src/macosx/MacMiniFB.m
@@ -321,18 +321,8 @@ mfb_wait_sync(struct mfb_window *window) {
         double      current;
         uint32_t    millis = 1;
         while(1) {
-            event = [NSApp nextEventMatchingMask:NSEventMaskAny untilDate:[NSDate distantPast] inMode:NSDefaultRunLoopMode dequeue:YES];
-            if (event) {
-                [NSApp sendEvent:event];
-            }
-
-            if(window_data->close) {
-                destroy_window_data(window_data);
-                return false;
-            }
-
             current = mfb_timer_now(window_data_osx->timer);
-            if (current >= g_time_for_frame) {
+            if (current >= g_time_for_frame * 0.96) {
                 mfb_timer_reset(window_data_osx->timer);
                 return true;
             }
@@ -342,6 +332,18 @@ mfb_wait_sync(struct mfb_window *window) {
 
             usleep(millis * 1000);
             //sched_yield();
+
+            if(millis == 1) {
+                event = [NSApp nextEventMatchingMask:NSEventMaskAny untilDate:[NSDate distantPast] inMode:NSDefaultRunLoopMode dequeue:YES];
+                if (event) {
+                    [NSApp sendEvent:event];
+
+                    if(window_data->close) {
+                        destroy_window_data(window_data);
+                        return false;
+                    }
+                }
+            }
         }
     }
 
diff --git a/src/wayland/WaylandMiniFB.c b/src/wayland/WaylandMiniFB.c
index eb0a3a6..120eee8 100644
--- a/src/wayland/WaylandMiniFB.c
+++ b/src/wayland/WaylandMiniFB.c
@@ -817,17 +817,8 @@ mfb_wait_sync(struct mfb_window *window) {
     double      current;
     uint32_t    millis = 1;
     while(1) {
-        if (wl_display_dispatch_pending(window_data_way->display) == -1) {
-            return false;
-        }
-
-        if(window_data->close) {
-            destroy_window_data(window_data);
-            return false;
-        }
-
         current = mfb_timer_now(window_data_way->timer);
-        if (current >= g_time_for_frame) {
+        if (current >= g_time_for_frame * 0.96) {
             mfb_timer_reset(window_data_way->timer);
             return true;
         }
@@ -837,6 +828,17 @@ mfb_wait_sync(struct mfb_window *window) {
 
         usleep(millis * 1000);
         //sched_yield();
+
+        if(millis == 1) {
+            if (wl_display_dispatch_pending(window_data_way->display) == -1) {
+                return false;
+            }
+
+            if(window_data->close) {
+                destroy_window_data(window_data);
+                return false;
+            }
+        }
     }
 
     return true;
diff --git a/src/windows/WinMiniFB.c b/src/windows/WinMiniFB.c
index 8f2d002..6be9dc2 100644
--- a/src/windows/WinMiniFB.c
+++ b/src/windows/WinMiniFB.c
@@ -666,18 +666,8 @@ mfb_wait_sync(struct mfb_window *window) {
     double      current;
     uint32_t    millis = 1;
     while (1) {
-        if(PeekMessage(&msg, window_data_win->window, 0, 0, PM_REMOVE)) {
-            TranslateMessage(&msg);
-            DispatchMessage(&msg);
-        }
-
-        if (window_data->close) {
-            destroy_window_data(window_data);
-            return false;
-        }
-
-        current = mfb_timer_now(window_data_win->timer);;
-        if (current >= g_time_for_frame) {
+        current = mfb_timer_now(window_data_win->timer);
+        if (current >= g_time_for_frame * 0.96) {
             mfb_timer_reset(window_data_win->timer);
             return true;
         }
@@ -686,6 +676,16 @@ mfb_wait_sync(struct mfb_window *window) {
         }
 
         Sleep(millis);
+
+        if(millis == 1 && PeekMessage(&msg, window_data_win->window, 0, 0, PM_REMOVE)) {
+            TranslateMessage(&msg);
+            DispatchMessage(&msg);
+
+            if (window_data->close) {
+                destroy_window_data(window_data);
+                return false;
+            }
+        }
     }
 
     return true;
diff --git a/src/x11/X11MiniFB.c b/src/x11/X11MiniFB.c
index 4593c9b..5bae00a 100644
--- a/src/x11/X11MiniFB.c
+++ b/src/x11/X11MiniFB.c
@@ -452,18 +452,8 @@ mfb_wait_sync(struct mfb_window *window) {
     double      current;
     uint32_t    millis = 1;
     while(1) {
-        if(XEventsQueued(window_data_x11->display, QueuedAlready) > 0) {
-            XNextEvent(window_data_x11->display, &event);
-            processEvent(window_data, &event);
-        }
-
-        if(window_data->close) {
-            destroy_window_data(window_data);
-            return false;
-        }
-
         current = mfb_timer_now(window_data_x11->timer);
-        if (current >= g_time_for_frame) {
+        if (current >= g_time_for_frame * 0.96) {
             mfb_timer_reset(window_data_x11->timer);
             return true;
         }
@@ -473,6 +463,16 @@ mfb_wait_sync(struct mfb_window *window) {
 
         usleep(millis * 1000);
         //sched_yield();
+
+        if(millis == 1 && XEventsQueued(window_data_x11->display, QueuedAlready) > 0) {
+            XNextEvent(window_data_x11->display, &event);
+            processEvent(window_data, &event);
+
+            if(window_data->close) {
+                destroy_window_data(window_data);
+                return false;
+            }
+        }
     }
 
     return true;