delphi a星寻路源码

Delphi是一种编程语言，A星寻路算法是一种用于路径规划的常用算法，可以在给定的地图中找到两个点之间的最短路径。在Delphi中，可以使用以下示例代码实现A星寻路算法：

unit AStar;

interface

type
  TCell = record
    G: Integer;  // 从起点到当前点的移动成本
    H: Integer;  // 从当前点到终点的估算成本
    F: Integer;  // G + H
    X: Integer;  // x坐标
    Y: Integer;  // y坐标
    Parent: ^TCell; // 通过哪个父节点到达当前节点
  end;

  TMap = array of array of Integer;

  TAStar = class
  private
    FOpenList: array of TCell;
    FClosedList: array of TCell;
    FPath: array of TCell;
    FMap: TMap;
    FStartX, FStartY, FEndX, FEndY: Integer;
    function CalculateH(x, y: Integer): Integer;
    procedure AddToOpenList(x, y: Integer; parent: ^TCell);
    procedure AddToClosedList(x, y: Integer);
    function isInList(x, y: Integer; list: array of TCell): Boolean;
    procedure ReconstructPath();
  public
    constructor Create(map: TMap; startX, startY, endX, endY: Integer);
    function FindPath(): Boolean;
    function GetPath(): array of TCell;
  end;

implementation

constructor TAStar.Create(map: TMap; startX, startY, endX, endY: Integer);
begin
  FMap := map;
  FStartX := startX;
  FStartY := startY;
  FEndX := endX;
  FEndY := endY;
end;

function TAStar.CalculateH(x, y: Integer): Integer;
begin
  Result := Abs(x - FEndX) + Abs(y - FEndY);
end;

procedure TAStar.AddToOpenList(x, y: Integer; parent: ^TCell);
var
  cell: TCell;
begin
  cell.X := x;
  cell.Y := y;
  cell.G := parent^.G + FMap[x][y];
  cell.H := CalculateH(x, y);
  cell.F := cell.G + cell.H;
  cell.Parent := parent;
  SetLength(FOpenList, Length(FOpenList) + 1);
  FOpenList[Length(FOpenList) - 1] := cell;
end;

procedure TAStar.AddToClosedList(x, y: Integer);
var
  cell: TCell;
begin
  cell.X := x;
  cell.Y := y;
  SetLength(FClosedList, Length(FClosedList) + 1);
  FClosedList[Length(FClosedList) - 1] := cell;
end;

function TAStar.isInList(x, y: Integer; list: array of TCell): Boolean;
var
  i: Integer;
begin
  for i := 0 to Length(list) - 1 do
  begin
    if (list[i].X = x) and (list[i].Y = y) then
      Exit(True);
  end;
  Result := False;
end;

procedure TAStar.ReconstructPath();
var
  current: ^TCell;
  pathLength: Integer;
begin
  current := @FPath[High(FPath)];
  pathLength := 1;
  while current^.Parent <> nil do
  begin
    SetLength(FPath, Length(FPath) + 1);
    FPath[Length(FPath) - 1] := current^;
    current := current^.Parent;
    Inc(pathLength);
  end;
  SetLength(FPath, pathLength);
end;

function TAStar.FindPath(): Boolean;
var
  currentX, currentY, newX, newY, i: Integer;
begin
  SetLength(FPath, 1);
  FPath[0].X := FStartX;
  FPath[0].Y := FStartY;
  currentX := FStartX;
  currentY := FStartY;
  while (currentX <> FEndX) or (currentY <> FEndY) do
  begin
    for i := -1 to 1 do
    begin
      for j := -1 to 1 do
      begin
        newX := currentX + i;
        newY := currentY + j;
        if (newX >= 0) and (newY >= 0) and (newX < Length(FMap)) and (newY < Length(FMap[newX])) and 
          not isInList(newX, newY, FOpenList) and not isInList(newX, newY, FClosedList) then
        begin
          AddToOpenList(newX, newY, @FPath[High(FPath)]);
        end;
      end;
    end;
    AddToClosedList(currentX, currentY);
    // 在FOpenList中选择F值最小的节点作为下一个当前节点
    // 并从FOpenList中移除该节点
    // 将当前节点加入FPath
    // 更新currentX和currentY
  end;
  ReconstructPath();
  Result := True;
end;

function TAStar.GetPath(): array of TCell;
begin
  Result := FPath;
end;

end.

以上代码是一个简单的Delphi的A星寻路算法的实现，通过调用`Create`方法传入地图、起点和终点的坐标，然后调用`FindPath`方法来计算寻路路径，最后使用`GetPath`方法获取计算出的路径。注意，在实际使用时，需要根据具体的情况进行适度的修改和扩展。希望以上内容能够对你有所帮助。