From 5a079a2d114f96d4847d1ee305d5b7c16eeec50e Mon Sep 17 00:00:00 2001
From: 3gg <3gg@shellblade.net>
Date: Sat, 27 Dec 2025 12:03:39 -0800
Subject: Initial commit

---
 contrib/SDL-3.2.8/src/video/x11/SDL_x11xsync.c | 148 +++++++++++++++++++++++++
 1 file changed, 148 insertions(+)
 create mode 100644 contrib/SDL-3.2.8/src/video/x11/SDL_x11xsync.c

(limited to 'contrib/SDL-3.2.8/src/video/x11/SDL_x11xsync.c')

diff --git a/contrib/SDL-3.2.8/src/video/x11/SDL_x11xsync.c b/contrib/SDL-3.2.8/src/video/x11/SDL_x11xsync.c
new file mode 100644
index 0000000..5310d67
--- /dev/null
+++ b/contrib/SDL-3.2.8/src/video/x11/SDL_x11xsync.c
@@ -0,0 +1,148 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+
+#include "SDL_internal.h"
+
+#if defined(SDL_VIDEO_DRIVER_X11) && defined(SDL_VIDEO_DRIVER_X11_XSYNC)
+
+#include "SDL_x11video.h"
+#include "SDL_x11xsync.h"
+
+static int xsync_initialized = 0;
+
+static int query_xsync_version(Display *display, int major, int minor)
+{
+    /* We don't care if this fails, so long as it sets major/minor on it's way out the door. */
+    X11_XSyncInitialize(display, &major, &minor);
+    return (major * 1000) + minor;
+}
+
+static bool xsync_version_atleast(const int version, const int wantmajor, const int wantminor)
+{
+    return version >= ((wantmajor * 1000) + wantminor);
+}
+
+void X11_InitXsync(SDL_VideoDevice *_this)
+{
+    SDL_VideoData *data =  _this->internal;
+
+    int version = 0;
+    int event, error;
+    int sync_opcode;
+
+    if (!SDL_X11_HAVE_XSYNC ||
+        !X11_XQueryExtension(data->display, "SYNC", &sync_opcode, &event, &error)) {
+        return;
+    }
+
+    /* We need at least 5.0 for barriers. */
+    version = query_xsync_version(data->display, 5, 0);
+    if (!xsync_version_atleast(version, 3, 0)) {
+        return; /* X server does not support the version we want at all. */
+    }
+
+    xsync_initialized = 1;
+}
+
+int X11_XsyncIsInitialized(void)
+{
+    return xsync_initialized;
+}
+
+int X11_InitResizeSync(SDL_Window *window)
+{
+    SDL_assert(window != NULL);
+    SDL_WindowData *data = window->internal;
+    Display *display = data->videodata->display;
+    Atom counter_prop = data->videodata->atoms._NET_WM_SYNC_REQUEST_COUNTER;
+    XSyncCounter counter;
+    CARD32 counter_id;
+
+    if (!X11_XsyncIsInitialized()){
+        return SDL_Unsupported();
+    }
+
+    counter = X11_XSyncCreateCounter(display, (XSyncValue){0, 0});
+    data->resize_counter = counter;
+    data->resize_id.lo = 0;
+    data->resize_id.hi = 0;
+    data->resize_in_progress = false;
+
+    if (counter == None){
+        return SDL_Unsupported();
+    }
+
+    counter_id = counter;
+    X11_XChangeProperty(display, data->xwindow, counter_prop, XA_CARDINAL, 32,
+                        PropModeReplace, (unsigned char *)&counter_id, 1);
+
+    return 0;
+}
+
+void X11_TermResizeSync(SDL_Window *window)
+{
+    SDL_WindowData *data = window->internal;
+    Display *display = data->videodata->display;
+    Atom counter_prop = data->videodata->atoms._NET_WM_SYNC_REQUEST_COUNTER;
+    XSyncCounter counter = data->resize_counter;
+
+    X11_XDeleteProperty(display, data->xwindow, counter_prop);
+    if (counter != None) {
+        X11_XSyncDestroyCounter(display, counter);
+    }
+}
+
+void X11_HandleSyncRequest(SDL_Window *window, XClientMessageEvent *event)
+{
+    SDL_WindowData *data = window->internal;
+
+    data->resize_id.lo = event->data.l[2];
+    data->resize_id.hi = event->data.l[3];
+    data->resize_in_progress = false;
+}
+
+void X11_HandleConfigure(SDL_Window *window, XConfigureEvent *event)
+{
+    SDL_WindowData *data = window->internal;
+
+    if (data->resize_id.lo || data->resize_id.hi) {
+        data->resize_in_progress = true;
+    }
+}
+
+void X11_HandlePresent(SDL_Window *window)
+{
+    SDL_WindowData *data = window->internal;
+    Display *display = data->videodata->display;
+    XSyncCounter counter = data->resize_counter;
+
+    if ((counter == None) || (!data->resize_in_progress)) {
+        return;
+    }
+
+    X11_XSyncSetCounter(display, counter, data->resize_id);
+
+    data->resize_id.lo = 0;
+    data->resize_id.hi = 0;
+    data->resize_in_progress = false;
+}
+
+#endif /* SDL_VIDEO_DRIVER_X11 && SDL_VIDEO_DRIVER_X11_XSYNC */
-- 
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