#define COORD(x) ( (x+1) * TILE_SIZE + BORDER )
#define FROMCOORD(x) ( (x - BORDER) / TILE_SIZE - 1 )
-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)
{
int gx = FROMCOORD(x), gy = FROMCOORD(y), idx, curr;