xwayland: Do not plumb damage region through function parameters

Each function can get the damage region from the xwl_window instead.
Add xwl_window_get_damage_region helper for this.

v2:
* Use xwl_window_get_damage_region in xwl_window_attach_buffer as well
  (Olivier Fourdan)

Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1314>

hw/xwayland/xwayland-glamor.c

@@ -874,9 +874,10 @@ xwl_glamor_pixmap_get_wl_buffer(PixmapPtr pixmap)
 
 Bool
 xwl_glamor_post_damage(struct xwl_window *xwl_window,
-                       PixmapPtr pixmap, RegionPtr region)
+                       PixmapPtr pixmap)
 {
     struct xwl_screen *xwl_screen = xwl_window->xwl_screen;
+    RegionPtr region = xwl_window_get_damage_region(xwl_window);
 
     if (xwl_screen->egl_backend->post_damage)
         return xwl_screen->egl_backend->post_damage(xwl_window, pixmap, region);

hw/xwayland/xwayland-glamor.h

@@ -137,7 +137,7 @@ void xwl_glamor_init_wl_registry(struct xwl_screen *xwl_screen,
 Bool xwl_glamor_has_wl_interfaces(struct xwl_screen *xwl_screen,
                                  struct xwl_egl_backend *xwl_egl_backend);
 Bool xwl_glamor_post_damage(struct xwl_window *xwl_window,
-                            PixmapPtr pixmap, RegionPtr region);
+                            PixmapPtr pixmap);
 Bool xwl_glamor_allow_commits(struct xwl_window *xwl_window);
 void xwl_glamor_egl_make_current(struct xwl_screen *xwl_screen);
 Bool xwl_glamor_needs_buffer_flush(struct xwl_screen *xwl_screen);

hw/xwayland/xwayland-window-buffers.c

@@ -114,9 +114,9 @@ xwl_window_buffer_maybe_dispose(struct xwl_window_buffer *xwl_window_buffer)
 }
 
 static void
-xwl_window_buffer_add_damage_region(struct xwl_window *xwl_window,
+xwl_window_buffer_add_damage_region(struct xwl_window *xwl_window)
-                                    RegionPtr damage_region)
 {
+    RegionPtr region = xwl_window_get_damage_region(xwl_window);
     struct xwl_window_buffer *xwl_window_buffer;
 
     /* Add damage region to all buffers */
@@ -125,14 +125,14 @@ xwl_window_buffer_add_damage_region(struct xwl_window *xwl_window,
                              link_buffer) {
         RegionUnion(xwl_window_buffer->damage_region,
                     xwl_window_buffer->damage_region,
-                    damage_region);
+                    region);
     }
     xorg_list_for_each_entry(xwl_window_buffer,
                              &xwl_window->window_buffers_unavailable,
                              link_buffer) {
         RegionUnion(xwl_window_buffer->damage_region,
                     xwl_window_buffer->damage_region,
-                    damage_region);
+                    region);
     }
 }
 
@@ -332,8 +332,7 @@ xwl_window_recycle_pixmap(struct xwl_window *xwl_window)
 }
 
 PixmapPtr
-xwl_window_buffers_get_pixmap(struct xwl_window *xwl_window,
+xwl_window_buffers_get_pixmap(struct xwl_window *xwl_window)
-                              RegionPtr damage_region)
 {
     struct xwl_screen *xwl_screen = xwl_window->xwl_screen;
     struct xwl_window_buffer *xwl_window_buffer;
@@ -346,7 +345,7 @@ xwl_window_buffers_get_pixmap(struct xwl_window *xwl_window,
         return window_pixmap;
 #endif /* XWL_HAS_GLAMOR */
 
-    xwl_window_buffer_add_damage_region(xwl_window, damage_region);
+    xwl_window_buffer_add_damage_region(xwl_window);
 
     xwl_window_buffer = xwl_window_buffer_get_available(xwl_window);
     if (xwl_window_buffer) {

hw/xwayland/xwayland-window-buffers.h

@@ -30,12 +30,10 @@
 #include <xwayland-config.h>
 
 #include "xwayland-types.h"
-#include "regionstr.h"
 
 void xwl_window_buffers_init(struct xwl_window *xwl_window);
 void xwl_window_buffers_dispose(struct xwl_window *xwl_window);
 void xwl_window_recycle_pixmap(struct xwl_window *xwl_window);
-PixmapPtr xwl_window_buffers_get_pixmap(struct xwl_window *xwl_window,
+PixmapPtr xwl_window_buffers_get_pixmap(struct xwl_window *xwl_window);
-                                        RegionPtr damage_region);
 
 #endif /* XWAYLAND_WINDOW_BUFFERS_H */

hw/xwayland/xwayland-window.c

@@ -77,6 +77,12 @@ window_get_damage(WindowPtr window)
     return dixLookupPrivate(&window->devPrivates, &xwl_damage_private_key);
 }
 
+RegionPtr
+xwl_window_get_damage_region(struct xwl_window *xwl_window)
+{
+    return DamageRegion(window_get_damage(xwl_window->window));
+}
+
 struct xwl_window *
 xwl_window_from_window(WindowPtr window)
 {
@@ -1380,8 +1386,7 @@ xwl_window_attach_buffer(struct xwl_window *xwl_window)
     PixmapPtr pixmap;
     int i;
 
-    region = DamageRegion(window_get_damage(xwl_window->window));
+    pixmap = xwl_window_buffers_get_pixmap(xwl_window);
-    pixmap = xwl_window_buffers_get_pixmap(xwl_window, region);
     buffer = xwl_pixmap_get_wl_buffer(pixmap);
 
     if (!buffer) {
@@ -1391,7 +1396,7 @@ xwl_window_attach_buffer(struct xwl_window *xwl_window)
 
 #ifdef XWL_HAS_GLAMOR
     if (xwl_screen->glamor) {
-        if (!xwl_glamor_post_damage(xwl_window, pixmap, region)) {
+        if (!xwl_glamor_post_damage(xwl_window, pixmap)) {
             ErrorF("glamor: Failed to post damage\n");
             return FALSE;
         }
@@ -1404,6 +1409,7 @@ xwl_window_attach_buffer(struct xwl_window *xwl_window)
      * connection. If we flood it too much anyway, this could
      * abort in libwayland-client.
      */
+    region = xwl_window_get_damage_region(xwl_window);
     if (RegionNumRects(region) > 256) {
         box = RegionExtents(region);
         xwl_surface_damage(xwl_screen, xwl_window->surface,

hw/xwayland/xwayland-window.h

@@ -123,6 +123,7 @@ struct xwl_window {
 };
 
 struct xwl_window *xwl_window_get(WindowPtr window);
+RegionPtr xwl_window_get_damage_region(struct xwl_window *xwl_window);
 struct xwl_window *xwl_window_from_window(WindowPtr window);
 
 Bool is_surface_from_xwl_window(struct wl_surface *surface);