xwayland: add support for wp-tearing-control-v1

Signed-off-by: Xaver Hugl <xaver.hugl@gmail.com>
Acked-by: Michel Dänzer <mdaenzer@redhat.com>
Reviewed-by: Olivier Fourdan <ofourdan@redhat.com>

hw/xwayland/meson.build

@@ -48,6 +48,7 @@ xdg_shell_xml = join_paths(protodir, 'stable', 'xdg-shell', 'xdg-shell.xml')
 drm_lease_xml = join_paths(protodir, 'staging', 'drm-lease', 'drm-lease-v1.xml')
 shortcuts_inhibit_xml = join_paths(protodir, 'unstable', 'keyboard-shortcuts-inhibit', 'keyboard-shortcuts-inhibit-unstable-v1.xml')
 xwayland_shell_xml = join_paths(protodir, 'staging', 'xwayland-shell', 'xwayland-shell-v1.xml')
+tearing_xml = join_paths(protodir, 'staging', 'tearing-control', 'tearing-control-v1.xml')
 
 client_header = generator(scanner,
     output : '@BASENAME@-client-protocol.h',
@@ -76,6 +77,7 @@ srcs += client_header.process(xdg_shell_xml)
 srcs += client_header.process(drm_lease_xml)
 srcs += client_header.process(shortcuts_inhibit_xml)
 srcs += client_header.process(xwayland_shell_xml)
+srcs += client_header.process(tearing_xml)
 srcs += code.process(relative_xml)
 srcs += code.process(pointer_xml)
 srcs += code.process(gestures_xml)
@@ -88,6 +90,7 @@ srcs += code.process(xdg_shell_xml)
 srcs += code.process(drm_lease_xml)
 srcs += code.process(shortcuts_inhibit_xml)
 srcs += code.process(xwayland_shell_xml)
+srcs += code.process(tearing_xml)
 
 xwayland_glamor = []
 eglstream_srcs = []

hw/xwayland/xwayland-present.c

@@ -34,8 +34,9 @@
 #include "xwayland-pixmap.h"
 #include "glamor.h"
 
+#include "tearing-control-v1-client-protocol.h"
 
-#define XWL_PRESENT_CAPS PresentCapabilityAsync
+#define XWL_PRESENT_CAPS PresentCapabilityAsync | PresentCapabilityAsyncMayTear
 
 
 /*
@@ -794,6 +795,16 @@ xwl_present_flip(present_vblank_ptr vblank, RegionPtr damage)
                        damage_box->x2 - damage_box->x1,
                        damage_box->y2 - damage_box->y1);
 
+    if (xwl_window->tearing_control) {
+        uint32_t hint;
+        if (event->async_may_tear)
+            hint = WP_TEARING_CONTROL_V1_PRESENTATION_HINT_ASYNC;
+        else
+            hint = WP_TEARING_CONTROL_V1_PRESENTATION_HINT_VSYNC;
+
+        wp_tearing_control_v1_set_presentation_hint(xwl_window->tearing_control, hint);
+    }
+
     wl_surface_commit(xwl_window->surface);
 
     if (!vblank->sync_flip) {
@@ -997,11 +1008,15 @@ xwl_present_pixmap(WindowPtr window,
     }
 
     vblank->event_id = ++xwl_present_event_id;
+    event->async_may_tear = options & PresentOptionAsyncMayTear;
 
-    /* Xwayland presentations always complete (at least) one frame after they
+    /* Synchronous Xwayland presentations always complete (at least) one frame after they
      * are executed
      */
-    vblank->exec_msc = vblank->target_msc - 1;
+    if (event->async_may_tear)
+        vblank->exec_msc = vblank->target_msc;
+    else
+        vblank->exec_msc = vblank->target_msc - 1;
 
     vblank->queued = TRUE;
     if (crtc_msc < vblank->exec_msc) {

hw/xwayland/xwayland-present.h

@@ -59,6 +59,7 @@ struct xwl_present_event {
     present_vblank_rec vblank;
 
     PixmapPtr pixmap;
+    Bool async_may_tear;
 };
 
 Bool xwl_present_entered_for_each_frame_callback(void);

hw/xwayland/xwayland-screen.c

@@ -60,6 +60,7 @@
 #include "viewporter-client-protocol.h"
 #include "xdg-shell-client-protocol.h"
 #include "xwayland-shell-v1-client-protocol.h"
+#include "tearing-control-v1-client-protocol.h"
 
 static DevPrivateKeyRec xwl_screen_private_key;
 static DevPrivateKeyRec xwl_client_private_key;
@@ -458,6 +459,10 @@ registry_global(void *data, struct wl_registry *registry, uint32_t id,
         xwl_screen->xwayland_shell =
             wl_registry_bind(registry, id, &xwayland_shell_v1_interface, 1);
     }
+    else if (strcmp(interface, "wp_tearing_control_manager_v1") == 0) {
+        xwl_screen->tearing_control_manager =
+            wl_registry_bind(registry, id, &wp_tearing_control_manager_v1_interface, 1);
+    }
 #ifdef XWL_HAS_GLAMOR
     else if (xwl_screen->glamor) {
         xwl_glamor_init_wl_registry(xwl_screen, registry, id, interface,

hw/xwayland/xwayland-screen.h

@@ -107,6 +107,7 @@ struct xwl_screen {
     struct zxdg_output_manager_v1 *xdg_output_manager;
     struct wp_viewporter *viewporter;
     struct xwayland_shell_v1 *xwayland_shell;
+    struct wp_tearing_control_manager_v1 *tearing_control_manager;
     struct xorg_list drm_lease_devices;
     struct xorg_list queued_drm_lease_devices;
     struct xorg_list drm_leases;

hw/xwayland/xwayland-window.c

@@ -46,6 +46,7 @@
 #include "xwayland-shm.h"
 
 #include "linux-dmabuf-unstable-v1-client-protocol.h"
+#include "tearing-control-v1-client-protocol.h"
 #include "viewporter-client-protocol.h"
 #include "xdg-shell-client-protocol.h"
 #include "xwayland-shell-v1-client-protocol.h"
@@ -896,6 +897,11 @@ ensure_surface_for_window(WindowPtr window)
         xwl_window_check_resolution_change_emulation(xwl_window);
     }
 
+    if (xwl_screen->tearing_control_manager) {
+        xwl_window->tearing_control = wp_tearing_control_manager_v1_get_tearing_control(
+            xwl_screen->tearing_control_manager, xwl_window->surface);
+    }
+
     return TRUE;
 
 err:
@@ -1106,6 +1112,9 @@ xwl_unrealize_window(WindowPtr window)
         xwl_present_for_each_frame_callback(xwl_window, xwl_present_unrealize_window);
 #endif
 
+    if (xwl_window->tearing_control)
+        wp_tearing_control_v1_destroy(xwl_window->tearing_control);
+
     release_wl_surface_for_window(xwl_window);
     xorg_list_del(&xwl_window->link_damage);
     xorg_list_del(&xwl_window->link_window);

hw/xwayland/xwayland-window.h

@@ -121,6 +121,7 @@ struct xwl_window {
     struct xwl_dmabuf_feedback feedback;
     /* If TRUE, the window buffer format supports scanout with implicit modifier */
     Bool has_implicit_scanout_support;
+    struct wp_tearing_control_v1 *tearing_control;
 };
 
 struct xwl_window *xwl_window_get(WindowPtr window);