Save transform during transaction

include/sway/tree/view.h

@@ -59,6 +59,7 @@ struct sway_saved_buffer {
 	struct wlr_client_buffer *buffer;
 	int x, y;
 	int width, height;
+    enum wl_output_transform transform;
 	struct wl_list link; // sway_view::saved_buffers
 };
 

sway/desktop/render.c

@@ -312,7 +312,7 @@ static void render_saved_view(struct sway_view *view,
 		scale_box(&box, wlr_output->scale);
 
 		float matrix[9];
-		wlr_matrix_project_box(matrix, &box, WL_OUTPUT_TRANSFORM_NORMAL, 0,
+		wlr_matrix_project_box(matrix, &box, saved_buf->transform, 0,
 			wlr_output->transform_matrix);
 
 		render_texture(wlr_output, damage, saved_buf->buffer->texture,

sway/tree/view.c

@@ -1199,6 +1199,7 @@ static void view_save_buffer_iterator(struct wlr_surface *surface,
 		saved_buffer->height = surface->current.height;
 		saved_buffer->x = sx;
 		saved_buffer->y = sy;
+		saved_buffer->transform = wlr_output_transform_invert(surface->current.transform);
 		wl_list_insert(&view->saved_buffers, &saved_buffer->link);
 	}
 }