Delphi与DirectX之DelphiX(8) 第一个简单动画

本例效果图(用 gif 动画演示, 无论如何也出不来 DirectX 的流畅效果):

代码文件:

unit Unit1;
interface
uses
　Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
　Dialogs, DXDraws, StdCtrls, DXClass;
type
　TForm1 = class(TForm)
　　DXDraw1: TDXDraw;
　　DXImageList1: TDXImageList;
　　DXTimer1: TDXTimer;
　　Button1: TButton;
　　Button2: TButton;
　　procedure FormCreate(Sender: TObject);
　　procedure DXTimer1Timer(Sender: TObject; LagCount: Integer);
　　procedure Button1Click(Sender: TObject);
　　procedure Button2Click(Sender: TObject);
　end;
var
　Form1: TForm1;
implementation
{$R *.dfm}
var
　arr: array of record X,Y,a,b: Integer; end;
　PicItem: TPictureCollectionItem;
procedure TForm1.FormCreate(Sender: TObject);
const
　ImgPath1 = 'C:\Temp\DelphiX.bmp';
begin
　DXDraw1.Align := alClient;
　DXImageList1.DXDraw := DXDraw1;
　DXImageList1.Items.Add;
　PicItem := DXImageList1.Items[DXImageList1.Items.Count-1];
　PicItem.Picture.LoadFromFile(ImgPath1);
　SetLength(arr, 1);
　arr[0].X := Random(DXDraw1.Width - PicItem.Width);
　arr[0].Y := Random(DXDraw1.Height - PicItem.Height);
　arr[0].a := 1;
　arr[0].b := 1;
　Button1.Caption := '-';
　Button2.Caption := '+';
　DXTimer1.Interval := 10;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
　if Length(arr) > 1 then SetLength(arr, Length(arr)-1);
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
　SetLength(arr, Length(arr)+1);
　arr[High(arr)].X := Random(DXDraw1.Width - PicItem.Width);
　arr[High(arr)].Y := Random(DXDraw1.Height - PicItem.Height);
　arr[High(arr)].a := 1;
　arr[High(arr)].b := 1;
end;
procedure TForm1.DXTimer1Timer(Sender: TObject; LagCount: Integer);
var
　i: Integer;
begin
　DXDraw1.Surface.Fill(0);
　for i := 0 to Length(arr) - 1 do
　begin
　　if arr[i].X > DXDraw1.Width - PicItem.Width then arr[i].a := -1;
　　if arr[i].Y > DXDraw1.Height - PicItem.Height then arr[i].b := -1;
　　if arr[i].X = 0 then arr[i].a := 1;
　　if arr[i].Y = 0 then arr[i].b := 1;
　　Inc(arr[i].X, arr[i].a);
　　Inc(arr[i].Y, arr[i].b);
　　PicItem.Draw(DXDraw1.Surface, arr[i].X, arr[i].Y, 0);
　end;
　DXDraw1.Flip;
end;
end.