4 files changed, 39 insertions, 52 deletions

diff --git a/include/wlr/types/wlr_surface.h b/include/wlr/types/wlr_surface.h
index 4d03df73..6ece247a 100644
--- a/include/wlr/types/wlr_surface.h
+++ b/include/wlr/types/wlr_surface.h
@@ -122,20 +122,24 @@ void wlr_surface_make_subsurface(struct wlr_surface *surface,
 		struct wlr_surface *parent, uint32_t id);
 
 /**
- * Get the top of the subsurface tree for this surface.
+ * Get the root of the subsurface tree for this surface.
  */
-struct wlr_surface *wlr_surface_get_main_surface(struct wlr_surface *surface);
+struct wlr_surface *wlr_surface_get_root_surface(struct wlr_surface *surface);
 
 /**
- * Find a subsurface within this surface at the surface-local coordinates.
- * Returns the surface and coordinates in the topmost surface coordinate system
- * or NULL if no subsurface is found at that location.
+ * Check if the surface accepts input events at the given surface-local
+ * coordinates.
  */
-struct wlr_subsurface *wlr_surface_subsurface_at(struct wlr_surface *surface,
-		double sx, double sy, double *sub_x, double *sub_y);
+bool wlr_surface_point_accepts_input(struct wlr_surface *surface,
+		double sx, double sy);
 
-bool wlr_surface_point_accepts_input(
-		struct wlr_surface *surface, double sx, double sy);
+/**
+ * Find a surface in this surface's tree that accepts input events at the given
+ * surface-local coordinates. Returns the surface and coordinates in the leaf
+ * surface coordinate system or NULL if no surface is found at that location.
+ */
+struct wlr_surface *wlr_surface_surface_at(struct wlr_surface *surface,
+		double sx, double sy, double *sub_x, double *sub_y);
 
 void wlr_surface_send_enter(struct wlr_surface *surface,
 		struct wlr_output *output);
diff --git a/rootston/desktop.c b/rootston/desktop.c
index f6801332..60426474 100644
--- a/rootston/desktop.c
+++ b/rootston/desktop.c
@@ -605,14 +605,13 @@ static bool view_at(struct roots_view *view, double lx, double ly,
 		}
 	}
 
-	double sub_x, sub_y;
-	struct wlr_subsurface *subsurface =
-		wlr_surface_subsurface_at(view->wlr_surface,
-			view_sx, view_sy, &sub_x, &sub_y);
-	if (subsurface) {
-		*sx = view_sx - sub_x;
-		*sy = view_sy - sub_y;
-		*surface = subsurface->surface;
+	double _sx, _sy;
+	struct wlr_surface *_surface = wlr_surface_surface_at(view->wlr_surface,
+		view_sx, view_sy, &_sx, &_sy);
+	if (surface != NULL) {
+		*sx = _sx;
+		*sy = _sy;
+		*surface = _surface;
 		return true;
 	}
 
@@ -623,13 +622,6 @@ static bool view_at(struct roots_view *view, double lx, double ly,
 		return true;
 	}
 
-	if (wlr_surface_point_accepts_input(view->wlr_surface, view_sx, view_sy)) {
-		*sx = view_sx;
-		*sy = view_sy;
-		*surface = view->wlr_surface;
-		return true;
-	}
-
 	return false;
 }
 
diff --git a/types/wlr_compositor.c b/types/wlr_compositor.c
index f27655c0..181d0323 100644
--- a/types/wlr_compositor.c
+++ b/types/wlr_compositor.c
@@ -126,7 +126,7 @@ static void subcompositor_get_subsurface(struct wl_client *client,
 		return;
 	}
 
-	if (wlr_surface_get_main_surface(parent) == surface) {
+	if (wlr_surface_get_root_surface(parent) == surface) {
 		wl_resource_post_error(resource,
 			WL_SUBCOMPOSITOR_ERROR_BAD_SURFACE,
 			"%s%d: wl_surface@%d is an ancestor of parent",
diff --git a/types/wlr_surface.c b/types/wlr_surface.c
index e9bd6a66..ddcf86f8 100644
--- a/types/wlr_surface.c
+++ b/types/wlr_surface.c
@@ -868,43 +868,34 @@ void wlr_surface_make_subsurface(struct wlr_surface *surface,
 }
 
 
-struct wlr_surface *wlr_surface_get_main_surface(struct wlr_surface *surface) {
-	struct wlr_subsurface *sub;
-
-	while (surface && (sub = surface->subsurface)) {
+struct wlr_surface *wlr_surface_get_root_surface(struct wlr_surface *surface) {
+	while (surface != NULL) {
+		struct wlr_subsurface *sub = surface->subsurface;
+		if (sub == NULL) {
+			return surface;
+		}
 		surface = sub->parent;
 	}
-
-	return surface;
+	return NULL;
 }
 
-struct wlr_subsurface *wlr_surface_subsurface_at(struct wlr_surface *surface,
+struct wlr_surface *wlr_surface_surface_at(struct wlr_surface *surface,
 		double sx, double sy, double *sub_x, double *sub_y) {
 	struct wlr_subsurface *subsurface;
 	wl_list_for_each(subsurface, &surface->subsurface_list, parent_link) {
 		double _sub_x = subsurface->surface->current->subsurface_position.x;
 		double _sub_y = subsurface->surface->current->subsurface_position.y;
-		struct wlr_subsurface *sub =
-			wlr_surface_subsurface_at(subsurface->surface, _sub_x + sx,
-				_sub_y + sy, sub_x, sub_y);
-		if (sub) {
-			// TODO: This won't work for nested subsurfaces. Convert sub_x and
-			// sub_y to the parent coordinate system
+		struct wlr_surface *sub = wlr_surface_surface_at(subsurface->surface,
+			sx - _sub_x, sy - _sub_y, sub_x, sub_y);
+		if (sub != NULL) {
 			return sub;
 		}
+	}
 
-		int sub_width = subsurface->surface->current->buffer_width;
-		int sub_height = subsurface->surface->current->buffer_height;
-		if ((sx > _sub_x && sx < _sub_x + sub_width) &&
-				(sy > _sub_y && sy < _sub_y + sub_height)) {
-			if (pixman_region32_contains_point(
-						&subsurface->surface->current->input,
-						sx - _sub_x, sy - _sub_y, NULL)) {
-				*sub_x = _sub_x;
-				*sub_y = _sub_y;
-				return subsurface;
-			}
-		}
+	if (wlr_surface_point_accepts_input(surface, sx, sy)) {
+		*sub_x = sx;
+		*sub_y = sy;
+		return surface;
 	}
 
 	return NULL;
@@ -953,8 +944,8 @@ void wlr_surface_set_role_committed(struct wlr_surface *surface,
 	surface->role_data = role_data;
 }
 
-bool wlr_surface_point_accepts_input(
-		struct wlr_surface *surface, double sx, double sy) {
+bool wlr_surface_point_accepts_input(struct wlr_surface *surface,
+		double sx, double sy) {
 	return sx >= 0 && sx <= surface->current->width &&
 		sy >= 0 && sy <= surface->current->height &&
 		pixman_region32_contains_point(&surface->current->input, sx, sy, NULL);