+// [HGM] mouse: next six used by mouse handler, which was moved to backend
+extern int fromX, fromY, toX, toY;
+typedef enum { Press, Release } ClickType;
+void PromotionPopUp P((void));
+void DragPieceBegin P((int x, int y));
+void DragPieceEnd P((int x, int y));
+void LeftClick P((ClickType c, int x, int y));