Changeset 20 for trunk/UGame.pas

Timestamp:

Oct 5, 2019, 2:00:50 PM (5 years ago)

Author:

chronos

Message:

• Added: Player can undo last move.
• Modified: Optimized code of TGame.CanMove method.

File:

• trunk/UGame.pas (modified) (12 diffs)

trunk/UGame.pas

@@ -55 +55 @@
     FRunning: Boolean;
     FScore: Integer;
+    FCanUndo: Boolean;
+    FBoardUndo: TBoard;
+    function CanMoveDirection(Direction: TDirection): Boolean;
     function GetTileColor(Value: Integer): TColor;
     procedure SetScore(AValue: Integer);
     procedure DoChange;
     procedure RenderTile(Canvas: TCanvas; Tile: TTile; TileRect: TRect);
+    procedure GameOver;
+    procedure Win;
+    function FillRandomTile: Integer;
   public
     Board: TBoard;
     TopScore: Integer;
     AnimationDuration: Integer;
-    Won: Boolean;
-    procedure GameOver;
-    procedure Win;
-    function FillRandomTile: Integer;
+    WinScore: Integer;
+    function CanUndo: Boolean;
+    procedure Undo;
     function CanMove: Boolean;
     procedure Assign(Source: TGame);
@@ -146 +151 @@
     CurrentContext := RegContext;
 
+    WriteInteger('SizeX', Size.X);
+    WriteInteger('SizeY', Size.Y);
     Value := '';
     for Y := 0 to Size.Y - 1 do begin
@@ -171 +178 @@
     CurrentContext := RegContext;
 
+    Size := Point(ReadIntegerWithDefault('SizeX', 4), ReadIntegerWithDefault('SizeY', 4));
     Items := TStringList.Create;
     Items.Delimiter := ',';
@@ -257 +265 @@
 procedure TGame.Win;
 begin
-  if not Won then begin
-    Won := True;
-    if MessageDlg(SWinCaption, SWinMessage, mtConfirmation,
-    mbYesNo, 0) = mrNo then begin
-      Running := False;
-    end;
+  if MessageDlg(SWinCaption, SWinMessage, mtConfirmation,
+  mbYesNo, 0) = mrNo then begin
+    Running := False;
   end;
 end;
@@ -281 +286 @@
 
 function TGame.CanMove: Boolean;
-var
-  TempGame: TGame;
-begin
-  Result := False;
-  TempGame := TGame.Create;
-  try
-    TempGame.Assign(Self);
-    TempGame.AnimationDuration := 0;
-    Result := TempGame.MoveAll(drDown) > 0;
-    if Result then Exit;
-    Result := TempGame.MoveAll(drUp) > 0;
-    if Result then Exit;
-    Result := TempGame.MoveAll(drRight) > 0;
-    if Result then Exit;
-    Result := TempGame.MoveAll(drLeft) > 0;
-  finally
-    TempGame.Free;
-  end;
+begin
+  Result := CanMoveDirection(drLeft) or CanMoveDirection(drRight) or
+    CanMoveDirection(drUp) or CanMoveDirection(drDown);
 end;
 
 procedure TGame.Assign(Source: TGame);
-var
-  X, Y: Integer;
 begin
   FScore := Source.FScore;
   TopScore := Source.TopScore;
   AnimationDuration := Source.AnimationDuration;
-  Won := Source.Won;
   Board.Assign(Source.Board);
 end;
@@ -316 +303 @@
   I: Integer;
 begin
+  FCanUndo := False;
   Board.Clear;
   Score := 0;
-  Won := False;
   Running := True;
   for I := 0 to 1 do FillRandomTile;
@@ -413 +400 @@
 end;
 
+function TGame.CanUndo: Boolean;
+begin
+  Result := FCanUndo;
+end;
+
+procedure TGame.Undo;
+begin
+  if CanUndo then begin
+    Board.Assign(FBoardUndo);
+    FCanUndo := False;
+    FRunning := CanMove;
+    DoChange;
+  end;
+end;
+
+function TGame.CanMoveDirection(Direction: TDirection): Boolean;
+var
+  StartPoint: TPoint;
+  AreaSize: TPoint;
+  Increment: TPoint;
+  P: TPoint;
+  PNew: TPoint;
+  PI: TPoint;
+begin
+  Result := False;
+  case Direction of
+    drLeft: begin
+      StartPoint := Point(1, 0);
+      AreaSize := Point(Board.Size.X - 2, Board.Size.Y - 1);
+      Increment := Point(1, 1);
+    end;
+    drUp: begin
+      StartPoint := Point(0, 1);
+      AreaSize := Point(Board.Size.X - 1, Board.Size.Y - 2);
+      Increment := Point(1, 1);
+    end;
+    drRight: begin
+      StartPoint := Point(Board.Size.X - 2, 0);
+      AreaSize := Point(Board.Size.X - 2, Board.Size.Y - 1);
+      Increment := Point(-1, 1);
+    end;
+    drDown: begin
+      StartPoint := Point(0, Board.Size.Y - 2);
+      AreaSize := Point(Board.Size.X - 1, Board.Size.Y - 2);
+      Increment := Point(1, -1);
+    end;
+  end;
+
+  PI.Y := 0;
+  while PI.Y <= AreaSize.Y do begin
+    PI.X := 0;
+    while PI.X <= AreaSize.X do begin
+      P := Point(StartPoint.X + PI.X * Increment.X, StartPoint.Y + PI.Y * Increment.Y);
+      PNew.X := P.X + DirectionDiff[Direction].X;
+      PNew.Y := P.Y + DirectionDiff[Direction].Y;
+      if IsValidPos(PNew) then begin
+        if (Board.Tiles[P.Y, P.X].Value <> 0) then begin
+          if (Board.Tiles[PNew.Y, PNew.X].Value = 0) or
+          (Board.Tiles[PNew.Y, PNew.X].Value = Board.Tiles[P.Y, P.X].Value) then begin
+            Result := True;
+            Break;
+          end;
+        end;
+        P.X := PNew.X;
+        P.Y := PNew.Y;
+        PNew.X := P.X + DirectionDiff[Direction].X;
+        PNew.Y := P.Y + DirectionDiff[Direction].Y;
+      end;
+      Inc(PI.X);
+    end;
+    if Result then Break;
+    Inc(PI.Y);
+  end;
+end;
 
 function TGame.MoveAll(Direction: TDirection): Integer;
@@ -430 +491 @@
   Time: TDateTime;
   Part: Double;
+  HighestValue: Integer;
 begin
   FMoving := True;
+  HighestValue := Board.GetHighestTileValue;
+  FBoardUndo.Assign(Board);
+  FCanUndo := True;
   //Diff := DirectionDiff[Direction];
   case Direction of
@@ -535 +600 @@
   end;
   Result := MovedCount;
+
+  // Update state after move
+  if MovedCount > 0 then FillRandomTile;
+  if not CanMove and (Board.GetEmptyTilesCount = 0) then
+    GameOver;
+  if (HighestValue < WinScore) and
+  (Board.GetHighestTileValue >= WinScore) then Win;
+
   FMoving := False;
 end;
@@ -560 +633 @@
     WriteInteger('TopScore', TopScore);
     WriteInteger('AnimationDuration', AnimationDuration);
-    WriteInteger('SizeX', Board.Size.X);
-    WriteInteger('SizeY', Board.Size.Y);
     WriteInteger('Score', Score);
     WriteBool('GameRunning', FRunning);
-    WriteBool('Won', Won);
+    WriteBool('CanUndo', FCanUndo);
   finally
     Free;
   end;
-  Board.SaveToRegistry(RegContext);
+  FBoardUndo.SaveToRegistry(TRegistryContext.Create(RegContext.RootKey, RegContext.Key + '\BoardUndo'));
+  Board.SaveToRegistry(TRegistryContext.Create(RegContext.RootKey, RegContext.Key + '\Board'));
 end;
 
@@ -576 +648 @@
   try
     CurrentContext := RegContext;
-    Board.Size := Point(ReadIntegerWithDefault('SizeX', 4), ReadIntegerWithDefault('SizeY', 4));
     AnimationDuration := ReadIntegerWithDefault('AnimationDuration', 30);
     TopScore := ReadIntegerWithDefault('TopScore', 0);
     Score := ReadIntegerWithDefault('Score', 0);
     FRunning := ReadBoolWithDefault('GameRunning', False);
-    Won := ReadBoolWithDefault('Won', False);
+    FCanUndo := ReadBoolWithDefault('CanUndo', False);
   finally
     Free;
   end;
-  Board.LoadFromRegistry(RegContext);
+  FBoardUndo.LoadFromRegistry(TRegistryContext.Create(RegContext.RootKey, RegContext.Key + '\BoardUndo'));
+  Board.LoadFromRegistry(TRegistryContext.Create(RegContext.RootKey, RegContext.Key + '\Board'));
 end;
 
@@ -591 +663 @@
 begin
   AnimationDuration := 30;
+  WinScore := 2048;
   Board := TBoard.Create;
+  FBoardUndo := TBoard.Create;
 end;
 
 destructor TGame.Destroy;
 begin
+  FreeAndNil(FBoardUndo);
   FreeAndNil(Board);
   inherited;