Isometric Worlds

[Proph3t]

Hi guys.

So I have finished my platformer with great performance thanks to those of you who helped me! Once I finished the Super Mario lookalike, I got bored at drawing simple flat objects on the screen, so I decided to tackle Isometric worlds next. I found it to be much easier to program than my previous 2D game and I already have set up the map. Now I have two questions.

1. How do you implement zoom in an Isometric world? Like in Age Of Empires, you can zoom in and out. I have searched the NET, but found nothing.

2. I also created a map editor, but I need a little help with placing tiles where the user clicks. How will I determine the X and Y coordinates where the user clicked? And also how do I check if the user cliked on a tile that is inside map boundaries? I have gone through the tutorial given on DelphiGameDev, but to be honest, it lacks explanation...

Once again a big thanks to those who helped!

PS. I use tiles of 128x64 and my current map size is 50x50.


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Below is the new code. Sorry for changing, but I have found a MUCH easier way...

Unit LoD;

Interface

Uses
 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
 Dialogs, DXDraws, DIB, DXClass, DXSprite, DXPlay, DXInput;

Type
  TTile = Record
    TileImage: Integer;
  End;

  TTileMap = Record
    MapArray: Array[0..49, 0..49] Of TTile;
  End;

  TForm1 = Class( TDXForm )
    DXDraw1: TDXDraw;
    DXImageList1: TDXImageList;
    DXTimer1: TDXTimer;
    DXInput1: TDXInput;
    Procedure FormCreate( Sender: TObject );
    Function CartesianToIsometric( CartPoint: TPoint ): TPoint;
    Function IsomectricToCartesian( IsoPoint: TPoint ): TPoint;
    Procedure PlaceTile( PatternIndex: Integer );
    Procedure DXTimer1Timer( Sender: TObject; LagCount: Integer );
    Procedure FormKeyDown( Sender: TObject; var Key: Word; Shift: TShiftState );
  Private
    { Private Declarations }
  Public
    { Public Declarations }
  End;

Var
 Form1: TForm1;
 Map: TTileMap;
 StartX, StartY: Integer;

Implementation

{$R *.dfm}

Procedure TForm1.FormCreate( Sender: TObject );
Var
 X, Y: Integer;
Begin
  DXDraw1.Display.Width := Screen.Width;
  DXDraw1.Display.Height := Screen.Height;

  StartX := 0;
  StartY := 0;

  For X := 0 To 49 Do
   Begin
     For Y := 0 To 49 Do
      Begin
        Map.MapArray[X, Y].TileImage := 0;
      End;{ For }
   End;{ For }

  DXTimer1.Enabled := True;
End;

Function TForm1.CartesianToIsometric( CartPoint: TPoint ): TPoint;
Var
 IsoPoint: TPoint;
Begin
  Result := Point( 0, 0 );

  IsoPoint.X := CartPoint.X - CartPoint.Y;
  IsoPoint.Y := Round( ( CartPoint.X + CartPoint.Y ) / 2 );

  Result := IsoPoint;
End;

Function TForm1.IsomectricToCartesian( IsoPoint: TPoint ): TPoint;
Var
 CartPoint: TPoint;
Begin
  Result := Point( 0, 0 );

  CartPoint.X := Round( ( 2 * IsoPoint.Y + IsoPoint.X ) / 2 );
  CartPoint.Y := Round( ( 2 * IsoPoint.Y - IsoPoint.X ) / 2 );

  Result := CartPoint;
End;

Procedure TForm1.PlaceTile( PatternIndex: Integer );
Var
 i, j: Integer;
 X, Y: Integer;
 TileImage: Integer;
Begin
  If DXDraw1.CanDraw
  Then
   Begin
     For i := 0 To 49 Do { Loop through rows }
      Begin
        For j := 0 To 49 Do { Loop through columns }
         Begin
           X := J * 66; // Change to 64
           Y := i * 66; // Change to 64
           TileImage := Map.MapArray[i, j].TileImage;
           DXImageList1.Items[TileImage].Draw( DXDraw1.Surface, StartX + CartesianToIsometric( Point( X, Y ) ).X, StartY + CartesianToIsometric( Point( X, Y ) ).Y, PatternIndex );
         End;{ For }
      End;{ For }
   End
  Else Exit;
End;

Procedure TForm1.DXTimer1Timer( Sender: TObject; LagCount: Integer );
Begin
  DXDraw1.Surface.Fill( 0 );
  PlaceTile( 0 );
  DXDraw1.Flip;

  DXInput1.Update;
  If IsLeft In DXInput1.States
  Then StartX := StartX + 16;
  If IsRight In DXInput1.States
  Then StartX := StartX - 16;
  If IsUp In DXInput1.States
  Then StartY := StartY + 8;
  If IsDown In DXInput1.States
  Then StartY := StartY - 8;
End;

Procedure TForm1.FormKeyDown( Sender: TObject; Var Key: Word; Shift: TShiftState );
Begin
  If Key = VK_ESCAPE
  Then Application.Terminate;
End;

End.

Here's the source for those who wish to compile the code.


Game.zip