67 function HomingWrap(var Gear: PGear): boolean;

  1813 (*

  1814 Applies wrap-around logic for the target of homing gears.

  1815 

  1816 In wrap-around world edge, the shortest way may to the target might

  1817 be across the border, so the X value of the target would lead the

  1818 gear to the wrong direction across the whole map. This procedure

  1819 changes the target X in this case.

  1820 This function must be called after the gear passed through

  1821 the wrap-around world edge (WorldWrap returned true).

  1822 

  1823 No-op for other world edges.

  1824 

  1825 Returns true if target has been changed.

  1826 *)

  1827 function HomingWrap(var Gear: PGear): boolean;

  1828 var dist_center, dist_right, dist_left: hwFloat;

  1829 begin

  1830     if WorldEdge = weWrap then

  1831         begin

  1832         HomingWrap:= false;

  1833         // We just check the same target 3 times:

  1834         // 1) in current section (no change)

  1835         // 2) clone in the right section

  1836         // 3) clone in the left section

  1837         // The gear will go for the target with the shortest distance to the gear.

  1838         // For simplicity, we only check distance on the X axis.

  1839         dist_center:= hwAbs(Gear^.X - int2hwFloat(Gear^.Target.X));

  1840         dist_right:= hwAbs(Gear^.X - int2hwFloat(Gear^.Target.X + (RightX-LeftX)));

  1841         dist_left:= hwAbs(Gear^.X - int2hwFloat(Gear^.Target.X - (RightX-LeftX)));

  1842         if (dist_left < dist_right) and (dist_left < dist_center) then

  1843             begin

  1844             dec(Gear^.Target.X, RightX-LeftX);

  1845             HomingWrap:= true;

  1846             end

  1847         else if (dist_right < dist_left) and (dist_right < dist_center) then

  1848             begin

  1849             inc(Gear^.Target.X, RightX-LeftX);

  1850             HomingWrap:= true;

  1851             end;

  1852         end;

  1853 end;