2 files changed, 57 insertions, 10 deletions

diff --git a/rootston/cursor.c b/rootston/cursor.c
index 2742e7cd..8839e9d7 100644
--- a/rootston/cursor.c
+++ b/rootston/cursor.c
@@ -32,15 +32,14 @@ void view_begin_move(struct roots_input *input, struct wlr_cursor *cursor,
 void cursor_update_position(struct roots_input *input, uint32_t time) {
 	struct roots_desktop *desktop = input->server->desktop;
 	struct roots_view *view;
+	struct wlr_surface *surface;
+	double sx, sy;
 	switch (input->mode) {
 	case ROOTS_CURSOR_PASSTHROUGH:
-		view = view_at(desktop, input->cursor->x, input->cursor->y);
+		view = view_at(desktop, input->cursor->x, input->cursor->y, &surface,
+			&sx, &sy);
 		if (view) {
-			struct wlr_box box;
-			view_get_input_bounds(view, &box);
-			double sx = input->cursor->x - view->x;
-			double sy = input->cursor->y - view->y;
-			wlr_seat_pointer_enter(input->wl_seat, view->wlr_surface, sx, sy);
+			wlr_seat_pointer_enter(input->wl_seat, surface, sx, sy);
 			wlr_seat_pointer_send_motion(input->wl_seat, time, sx, sy);
 		} else {
 			wlr_seat_pointer_clear_focus(input->wl_seat);
@@ -109,8 +108,10 @@ static void do_cursor_button_press(struct roots_input *input,
 		struct wlr_cursor *cursor, struct wlr_input_device *device,
 		uint32_t time, uint32_t button, uint32_t state) {
 	struct roots_desktop *desktop = input->server->desktop;
+	struct wlr_surface *surface;
+	double sx, sy;
 	struct roots_view *view = view_at(desktop,
-			input->cursor->x, input->cursor->y);
+			input->cursor->x, input->cursor->y, &surface, &sx, &sy);
 	uint32_t serial = wlr_seat_pointer_send_button(
 			input->wl_seat, time, button, state);
 	int i;
@@ -128,7 +129,7 @@ static void do_cursor_button_press(struct roots_input *input,
 			% (sizeof(input->input_events) / sizeof(input->input_events[0]));
 		set_view_focus(input, desktop, view);
 		if (view) {
-			wlr_seat_keyboard_enter(input->wl_seat, view->wlr_surface);
+			wlr_seat_keyboard_enter(input->wl_seat, surface);
 		}
 		break;
 	}
diff --git a/rootston/desktop.c b/rootston/desktop.c
index 4d1cb199..3233f25a 100644
--- a/rootston/desktop.c
+++ b/rootston/desktop.c
@@ -41,14 +41,60 @@ void view_activate(struct roots_view *view, bool activate) {
 	}
 }
 
-struct roots_view *view_at(struct roots_desktop *desktop, int x, int y) {
+static struct wlr_subsurface *subsurface_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 =
+			subsurface_at(subsurface->surface, _sub_x + sx, _sub_y + sy,
+				sub_x, sub_y);
+		if (sub) {
+			// TODO: convert sub_x and sub_y to the parent coordinate system
+			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 && sub_y < sub_y + sub_height)) {
+			*sub_x = _sub_x;
+			*sub_y = _sub_y;
+			return subsurface;
+		}
+	}
+
+	return NULL;
+}
+
+struct roots_view *view_at(struct roots_desktop *desktop, double lx, double ly,
+		struct wlr_surface **surface, double *sx, double *sy) {
 	for (size_t i = 0; i < desktop->views->length; ++i) {
 		struct roots_view *view = desktop->views->items[i];
+
+		double view_sx = lx - view->x;
+		double view_sy = ly - view->y;
+
+		double sub_x, sub_y;
+		struct wlr_subsurface *subsurface =
+			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;
+			return view;
+		}
+
 		struct wlr_box box;
 		view_get_input_bounds(view, &box);
 		box.x += view->x;
 		box.y += view->y;
-		if (wlr_box_contains_point(&box, x, y)) {
+		if (wlr_box_contains_point(&box, lx, ly)) {
+			*sx = view_sx;
+			*sy = view_sy;
+			*surface = view->wlr_surface;
 			return view;
 		}
 	}