Delphi 与 DirectX 之 DelphiX(13): TPictureCollectionItem.DrawRotate

本例效果图(实际效果是相当流畅的, gif 只能说明个动作趋势):

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代码文件:

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unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DXDraws, StdCtrls, DXClass, ComCtrls;

type
  TForm1 = class(TForm)
    DXDraw1: TDXDraw;
    DXImageList1: TDXImageList;
    DXTimer1: TDXTimer;
    procedure FormCreate(Sender: TObject);
    procedure DXTimer1Timer(Sender: TObject; LagCount: Integer);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

var
  PicItem: TPictureCollectionItem;
  Angle: Cardinal;

procedure TForm1.FormCreate(Sender: TObject);
const
  ImgPath1 = 'C:\Temp\DelphiX.bmp';
begin
  DXDraw1.Align := alClient;
  DXTimer1.Interval := 0;
  DXImageList1.DXDraw := DXDraw1;
  PicItem := TPictureCollectionItem(DXImageList1.Items.Add);
  PicItem.Picture.LoadFromFile(ImgPath1);
end;

procedure TForm1.DXTimer1Timer(Sender: TObject; LagCount: Integer);
begin
  DXDraw1.Surface.Fill(0);
  PicItem.DrawRotate(DXDraw1.Surface,
                     DXDraw1.Width div 2, DXDraw1.Height div 2, {位置}
                     PicItem.Width, PicItem.Height,             {大小}
                     0,                                         {调色板}
                     0.5, 0.5,                                  {旋转中心: 0..1}
                     Byte(Angle));                              {旋转角度 0..255}
  Inc(Angle);
  DXDraw1.Flip;
end;

end.