Unit toolsProc;

Interface

Uses dataUnit;

Procedure doMagnet(Var g:GameState);

Implementation

Function inBounds(g:GameState; row, col:integer): Boolean;
Begin
  If (row <= g.mapHeight) And
     (col  <= g.mapWidth) And
     (row  >= 1) And
     (col  >= 1) Then
    Exit(true)
  Else
    Exit(false);
End;

Procedure doMagnet(Var g:GameState);

Var 
  row, col, i, s: integer;
  rstep: integer = 0;
  cstep: integer = 0;
Begin
  For row := 1 To g.mapHeight Do
    For col := 1 To g.mapWidth Do
      Begin
        Case g.map[row,col] Of 
          magnetx: cstep := 1;
          magnety: rstep := 1;
          Else continue;
        End;
        For i := 0 To 1 Do
          Begin
            s := 2*i-1;
            (* Follow man *)
            If inBounds(g,row - 2*s*rstep, col - 2*s*cstep) And
               (g.map[row - 2*s*rstep, col - 2*s*cstep] = man) And
               (g.map[row - s*rstep, col - s*cstep] = empty) Then
              Begin
                g.map[row - s*rstep, col - s*cstep] := g.map[row,col];
                g.map[row,col] := empty;
                (* Drag pushables *)
                If inBounds(g, row + s*rstep, col + s*cstep) And
                   (g.map[row + s*rstep, col + s*cstep] In pushable) Then
                  Begin
                    g.map[row,col] := g.map[row + s*rstep, col + s*cstep];
                    g.map[row + s*rstep, col + s*cstep] := empty;
                  End;
              End;
            (* Pull pushables *)
            If inBounds(g, row + 2*s*rstep, col + 2*s*cstep) And
               (g.map[row + 2*s*rstep, col + 2*s*cstep] In pushable) And
               (g.map[row + s*rstep, col + s*cstep] = empty) Then
              Begin
                g.map[row + s*rstep, col + s*cstep] :=  g.map[row + 2*s*rstep, col + 2*s*cstep];
                g.map[row + 2*s*rstep, col + 2*s*cstep] := empty;
              End;
          End;
      End;
End;

End.