Delphi 与 DirectX 之 DelphiX(18): TDXDraw 中描绘图片的命令

前面的绘图命令都是来自 TDXImageList,
准确地说是来自 TDXImageList.Items 所包含的 TPictureCollectionItem 对象.

那 TDXDraw 本身有没有绘图命令呢?
TDXDraw 本身没有绘图命令, 但它的有绘图表面(TDirectDrawSurface), 譬如: Surface、Primary;
TDXDraw 的绘图表面有更多的绘图命令, 另外 TDXDraw 可以多个绘图表面.

TDirectDrawSurface 的绘图命令和 TPictureCollectionItem 的绘图命令最大的区别是它们的图像来源;
TDirectDrawSurface 的图像来源必须是另一个已绘制好的 TDirectDrawSurface 对象.

这里列举的只是 TDirectDrawSurface 和 TPictureCollectionItem 类似的描绘图片的命令:

TDirectDrawSurface.Draw();
TDirectDrawSurface.StretchDraw();
TDirectDrawSurface.DrawAdd();
TDirectDrawSurface.DrawAlpha();
TDirectDrawSurface.DrawSub();
TDirectDrawSurface.DrawAddCol();
TDirectDrawSurface.DrawAlphaCol();
TDirectDrawSurface.DrawSubCol();
TDirectDrawSurface.DrawRotate();
TDirectDrawSurface.DrawRotateAdd();
TDirectDrawSurface.DrawRotateAdd();
TDirectDrawSurface.DrawRotateAlpha();
TDirectDrawSurface.DrawRotateSub();
TDirectDrawSurface.DrawRotateAddCol();
TDirectDrawSurface.DrawRotateAlphaCol();
TDirectDrawSurface.DrawRotateCol();
TDirectDrawSurface.DrawRotateSubCol();
TDirectDrawSurface.DrawWaveX();
TDirectDrawSurface.DrawWaveXAdd();
TDirectDrawSurface.DrawWaveXAlpha();
TDirectDrawSurface.DrawWaveXSub();
TDirectDrawSurface.DrawWaveY();
TDirectDrawSurface.DrawWaveYAdd();
TDirectDrawSurface.DrawWaveYAlpha();
TDirectDrawSurface.DrawWaveYSub();

本例效果图:

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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;

type
  TForm1 = class(TForm)
    DXDraw1: TDXDraw;
    DXImageList1: TDXImageList;
    Button1: TButton;
    Button2: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

var
  PicItem: TPictureCollectionItem;

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

procedure TForm1.Button1Click(Sender: TObject);
var
  MySurface: TDirectDrawSurface;
begin
  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);
  PicItem.Restore; {Surface.Draw 的矩形范围好像能直接作用到列表中的图片, 需要恢复一下}
  MySurface.SetSize(PicItem.Width, PicItem.Height);
  MySurface.Fill(0);
  PicItem.Draw(MySurface, 0, 0, 0);

  DXDraw1.Surface.Fill(0);
  DXDraw1.Surface.Draw((DXDraw1.Width - MySurface.Width) div 2,
                       (DXDraw1.Height - MySurface.Height) div 2,
                       MySurface);
  DXDraw1.Flip;
  FreeAndNil(MySurface);
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  MySurface: TDirectDrawSurface;
  m,n: Integer;
begin
  m := 40; n := 15;
  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);
  PicItem.Restore; {Surface.Draw 的矩形范围好像能直接作用到列表中的图片, 需要恢复一下}
  MySurface.SetSize(PicItem.Width, PicItem.Height);
  MySurface.Fill(0);
  PicItem.Draw(MySurface, 0, 0, 0);

  DXDraw1.Surface.Fill(0);
  DXDraw1.Surface.Draw((DXDraw1.Width - MySurface.Width) div 2 + m,
                       (DXDraw1.Height - MySurface.Height) div 2 + n,
                       Bounds(m, n, MySurface.Width - m*2, MySurface.Height - n*2),
                       MySurface);
  DXDraw1.Flip;
  FreeAndNil(MySurface);
end;

end.