(pc)) -1 (nil)
(nil))
*/
-static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
+static char *interpret_move(game_state *state, game_ui *ui, const game_drawstate *ds,
int x, int y, int button)
{
enum { NONE, FLIP_LIGHT, FLIP_IMPOSSIBLE } action = NONE;