Delphi 與 DirectX 之 DelphiX(19): 繪圖表面(TDirectDrawSurface)如何載入圖片

上個例子中 TDirectDrawSurface 是從 TDXImageList 中擷取的圖片,
其實 TDirectDrawSurface 自己擷取圖片的方法有很多:

TDirectDrawSurface.LoadFromFile();TDirectDrawSurface.LoadFromStream();TDirectDrawSurface.LoadFromGraphic();TDirectDrawSurface.LoadFromGraphicRect();TDirectDrawSurface.LoadFromDIB();TDirectDrawSurface.LoadFromDIBRect();

本例分別測試了它們, 運行:

代碼檔案:

unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, DXDraws, StdCtrls, DIB;type  TForm1 = class(TForm)    DXDraw1: TDXDraw;    Button1: TButton;    Button2: TButton;    Button3: TButton;    Button4: TButton;    Button5: TButton;    Button6: TButton;    procedure Button1Click(Sender: TObject);    procedure Button2Click(Sender: TObject);    procedure Button3Click(Sender: TObject);    procedure Button4Click(Sender: TObject);    procedure Button5Click(Sender: TObject);    procedure Button6Click(Sender: TObject);  end;var  Form1: TForm1;implementation{$R *.dfm}const  ImgPath1 = 'C:\Temp\DelphiX.bmp';procedure TForm1.Button1Click(Sender: TObject);var  MySurface: TDirectDrawSurface;begin  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);  MySurface.LoadFromFile(ImgPath1);  DXDraw1.Surface.Fill($EEEEEE);  DXDraw1.Surface.Draw(0, 0, MySurface);  DXDraw1.Flip;  FreeAndNil(MySurface);end;procedure TForm1.Button2Click(Sender: TObject);var  MySurface: TDirectDrawSurface;  stream: TMemoryStream;begin  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);  stream := TMemoryStream.Create;  stream.LoadFromFile(ImgPath1);  MySurface.LoadFromStream(stream);  DXDraw1.Surface.Fill($CCCCCC);  DXDraw1.Surface.Draw(0, 0, MySurface);  DXDraw1.Flip;  FreeAndNil(stream);  FreeAndNil(MySurface);end;procedure TForm1.Button3Click(Sender: TObject);var  MySurface: TDirectDrawSurface;  bit: TGraphic;begin  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);  bit := TBitmap.Create;  bit.LoadFromFile(ImgPath1);  MySurface.LoadFromGraphic(bit);  DXDraw1.Surface.Fill($999999);  DXDraw1.Surface.Draw(0, 0, MySurface);  DXDraw1.Flip;  FreeAndNil(bit);  FreeAndNil(MySurface);end;procedure TForm1.Button4Click(Sender: TObject);var  MySurface: TDirectDrawSurface;  bit: TBitmap;begin  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);  bit := TBitmap.Create;  bit.LoadFromFile(ImgPath1);  MySurface.LoadFromGraphicRect(bit,                                bit.Width div 2, bit.Height div 2,                                Rect(0, 0, bit.Width, bit.Height));  DXDraw1.Surface.Fill($666666);  DXDraw1.Surface.Draw(0, 0, MySurface);  DXDraw1.Flip;  FreeAndNil(bit);  FreeAndNil(MySurface);end;{使用 TDIB 需要 uses DIB 單元}procedure TForm1.Button5Click(Sender: TObject);var  MySurface: TDirectDrawSurface;  dib: TDIB;begin  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);  dib := TDIB.Create;  dib.LoadFromFile(ImgPath1);  MySurface.LoadFromDIB(dib);  DXDraw1.Surface.Fill($333333);  DXDraw1.Surface.Draw(0, 0, MySurface);  DXDraw1.Flip;  FreeAndNil(dib);  FreeAndNil(MySurface);end;procedure TForm1.Button6Click(Sender: TObject);var  MySurface: TDirectDrawSurface;  dib: TDIB;begin  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);  dib := TDIB.Create;  dib.LoadFromFile(ImgPath1);  MySurface.LoadFromDIBRect(dib,                            DXDraw1.Width, DXDraw1.Height,                            Rect(0, 0, dib.Width, dib.Height));  DXDraw1.Surface.Fill(0);  DXDraw1.Surface.Draw(0, 0, MySurface);  DXDraw1.Flip;  FreeAndNil(dib);  FreeAndNil(MySurface);end;end.