Delphix And Fps Problem

I've recently acquired DelphiX and have gone through multiple tutorials on how to use it efficiently. However, through programming, I've come across code from a tutorial that was discontinued and I'd like to finish it for learning. The code's for an isometric tiling engine for a game, but the problem is that the FPS rate is EXTREMELY slow come rendering extremely large maps. It crawls at a rate of 5-7FPS, even on pretty powerful machines. (I'll include the code below.)

Now, the code itself draws out at each interval of the timer (which I know is a bad way to do things) but there are animated tiles (6 frames each tile), so I don't know any alternative method to bypass the drawing of unupdated tiles. I know that it should only redraw when it needs to, but this is for a game so it should be redrawing quite often.

I have looked elsewhere, but found no solutions and I have probed at the code for a few days now. Any suggestions/fixes/sample code would be nice.

Code:

unit uGame;interfaceuses  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,  DXDraws, StdCtrls, ExtCtrls, DXInput, DXClass;const TileHeight=15;type TTile = Record               TileImage:Integer;               Marked:Boolean;             end;type TTileMap = Record                  Map:array[1..50,1..50]of TTile;                end;type  TMainForm = class(TDXForm)    DXDraw: TDXDraw;    TileMaps: TDXImageList;    DXTimer: TDXTimer;    DXInput: TDXInput;    Panel: TPanel;    Markers: TDXImageList;    procedure DXTimerTimer(Sender: TObject; LagCount: Integer);    procedure FormCreate(Sender: TObject);    procedure DrawTiles(StartX,StartY:Integer);    procedure CheckTiles(X,Y:Integer; var XTile, YTile: Integer);    procedure DXDrawMouseMove(Sender: TObject; Shift: TShiftState; X,      Y: Integer);    procedure FormKeyDown(Sender: TObject; var Key: Word;      Shift: TShiftState);  private    { Private declarations }  public    { Public declarations }  end;var  Frame:Integer;  MainForm: TMainForm;  Map:TTileMap;  StartX,StartY:Integer;  TileX,TileY:Integer;implementation{$R *.DFM}procedure TMainForm.DrawTiles(StartX,StartY:Integer);var PosX,PosY,LoopX,LoopY,XTile,YTile,NumOfTilesY,TileImage:Integer;begin  PosY:=0;  PosX:=1;  NumOfTilesY := 0;  for LoopY := 1 to 49 do  begin    NumOfTilesY := NumOfTilesY + 1;    XTile:=1;    YTile:=LoopY;    for LoopX := 1 to NumOfTilesY do    begin      TileImage:=Map.Map[XTile,YTile].TileImage;      TileMaps.Items[TileImage].Draw(DXDraw.Surface,StartX+PosX+LoopX*64,StartY+LoopY*15,Frame);      if Map.Map[XTile,YTile].Marked then      begin        //Markers.Items[0].Draw(DXDraw.Surface,StartX+PosX+LoopX*64,StartY+LoopY*15,0);      end;      XTile:=XTile+1;      YTile:=YTile-1;    end;    PosX:=PosX-32;    PosY:=PosY+15;  end;  for LoopY := 1 to 50 do  begin    XTile:=LoopY;    YTile:=50;    for LoopX := 1 to NumOfTilesY do    begin      TileImage:=Map.Map[XTile,YTile].TileImage;      TileMaps.Items[TileImage].Draw(DXDraw.Surface,StartX+PosX+LoopX*64,StartY+PosY+LoopY*15,Frame);      if Map.Map[XTile,YTile].Marked then      begin        //Markers.Items[0].Draw(DXDraw.Surface,StartX+PosX+LoopX*64,StartY+PosY+LoopY*15,0);      end;      XTile:=XTile+1;      YTile:=YTile-1;    end;    NumOfTilesY:=NumOfTilesY-1;    PosX:=PosX+32;  end;  // draw map marker here, above all tiles...  //Markers.Items[0].Draw(DXDraw.Surface,StartX+PosX+LoopX*64,StartY+PosY+LoopY*15,0);  end;procedure TMainForm.DXTimerTimer(Sender: TObject; LagCount: Integer);begin  if not DXDraw.CanDraw then Exit;  DXDraw.Surface.Fill(0);  Panel.Caption:='FPS: '+IntToStr(DXTimer.FrameRate) +' TileX: '+IntToStr(TileX) +' TileY: '+IntToStr(TileY);  DrawTiles(StartX,StartY);  DXDraw.Flip;  DXInput.Update;  { Check for mouse input here }  If isLeft in DXInput.States then StartX:=StartX+16;  If isRight in DXInput.States then StartX:=StartX-16;  If isUp in DXInput.States then StartY:=StartY+8;  If isDown in DXInput.States then StartY:=StartY-8;  If (Frame=5) then    Frame:=0  else    Frame:=Frame+1;end;procedure TMainForm.FormCreate(Sender: TObject);var i,ii: integer;begin  Frame:=0;  StartX:=0;  StartY:=0;  for i := 1 to 50 do    for ii := 1 to 50 do      Map.Map[i,ii].TileImage := Random(16); // 0-12  DXTimer.Enabled:=True;end;procedure TMainForm.CheckTiles(X,Y:Integer; var XTile,YTile:Integer);var LoopX,LoopY:Integer;begin  for LoopY := 1 to 50 do  begin    if (Y-((0.46875)*(X-StartX)+StartY+(LoopY*30))<15) and (Y-((0.46875)*(X-StartX)+StartY+(LoopY*30))>(-15)) then    begin      YTile:=LoopY;    end;  end;  for LoopX := 1 to 50 do  begin    if (-(0.46875)*(X-StartX)+StartY+(LoopX*30)-Y<15) and ((-0.46875)*(X-StartX)+StartY+(LoopX*30)-Y>(-15)) then    begin      XTile:=LoopX;    end;  end;end;procedure TMainForm.DXDrawMouseMove(Sender: TObject; Shift: TShiftState; X,  Y: Integer);begin  Map.Map[TileX,TileY].Marked:=False;  CheckTiles(X-96,Y,TileX,TileY);  Map.Map[TileX,TileY].Marked:=True;end;procedure TMainForm.FormKeyDown(Sender: TObject; var Key: Word;  Shift: TShiftState);begin  if key = 27 then Application.Terminate();end;end.

Note: I've added the onKeyDown method for exiting. There used to be two buttons on the form, but that messed the control up when it came to scrolling with the keys.

Note2: If anyone knows how to scroll with the mouse, I'd really like to learn that.

Thanks to anyone that helps!
kvarnerexpress