D3DX8指南01_CreateDevice

根据 DirectX 8.1 SDK  samples/Multimedia/Direct3D/Tutorials/Tut01_CreateDevice 翻译
保留原文档的所有注释

//-----------------------------------------------------------------------------
// File: CreateDevice.cpp
//
// Desc: This is the first tutorial for using Direct3D. In this tutorial, all
//       we are doing is creating a Direct3D device and using it to clear the
//       window.
//-----------------------------------------------------------------------------
program Tut01_CreateDevice;

uses
  Windows,
  Messages,
  Direct3D8 in 'JEDI/Direct3D8.pas',
  DXTypes in 'JEDI/DXTypes.pas';

const
  NULL=nil;

//-----------------------------------------------------------------------------
// Global variables
//-----------------------------------------------------------------------------
var
g_pD3D      :IDirect3D8       = NULL; // Used to create the D3DDevice
g_pd3dDevice:IDirect3DDevice8 = NULL; // Our rendering device

//-----------------------------------------------------------------------------
// Name: InitD3D()
// Desc: Initializes Direct3D
//-----------------------------------------------------------------------------
function InitD3D( hWnd: HWND ) :HRESULT;
var
 d3ddm :TD3DDisplayMode;
 d3dpp :TD3DPresentParameters;
begin
 // Create the D3D object.
 g_pD3D:=Direct3DCreate8(D3D_SDK_VERSION);
 if g_pD3D=nil then begin
   Result:=E_FAIL;
   exit;
 end;

 // Get the current desktop display mode
 if not (g_pD3D.GetAdapterDisplayMode( D3DADAPTER_DEFAULT, d3ddm )=S_OK) then begin
   Result:=E_FAIL;
   exit;
 end;

 // Set up the structure used to create the D3DDevice. Most parameters are
 // zeroed out. We set Windowed to TRUE, since we want to do D3D in a
 // window, and then set the SwapEffect to "discard", which is the most
 // efficient method of presenting the back buffer to the display.  And
 // we request a back buffer format that matches the current desktop display
 // format.
 Fillchar( d3dpp, sizeof(d3dpp), 0 );
 d3dpp.Windowed := TRUE;
 d3dpp.SwapEffect := D3DSWAPEFFECT_DISCARD;
 d3dpp.BackBufferFormat := d3ddm.Format;

 // Create the Direct3D device. Here we are using the default adapter (most
 // systems only have one, unless they have multiple graphics hardware cards
 // installed) and requesting the HAL (which is saying we want the hardware
 // device rather than a software one). Software vertex processing is
 // specified since we know it will work on all cards. On cards that support
 // hardware vertex processing, though, we would see a big performance gain
 // by specifying hardware vertex processing.
 // Create the D3DDevice
 if not ( g_pD3D.CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,
                                      D3DCREATE_SOFTWARE_VERTEXPROCESSING,
                                      d3dpp, g_pd3dDevice )=S_OK) then begin
   Result:=E_FAIL;
   exit;
  end;

  // Device state would normally be set here

  Result:=S_OK;
end;

//-----------------------------------------------------------------------------
// Name: Cleanup()
// Desc: Releases all previously initialized objects
//-----------------------------------------------------------------------------
procedure Cleanup;
begin
 g_pd3dDevice:=nil;
 g_pD3D      :=nil;
end;

//-----------------------------------------------------------------------------
// Name: Render()
// Desc: Draws the scene
//-----------------------------------------------------------------------------
procedure Render;
begin
  if( NULL = g_pd3dDevice ) then exit;

  // Clear the backbuffer to a blue color
  g_pd3dDevice.Clear( 0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0,0,255), 1.0, 0 );

  // Begin the scene
  g_pd3dDevice.BeginScene();

  // Rendering of scene objects can happen here

  // End the scene
  g_pd3dDevice.EndScene();

  // Present the backbuffer contents to the display
  g_pd3dDevice.Present( NULL, NULL, 0, NULL );
end;

//-----------------------------------------------------------------------------
// Name: MsgProc()
// Desc: The window's message handler
//-----------------------------------------------------------------------------
function MsgProc( h_Wnd : THandle; aMSG : Cardinal; wParam : Cardinal; lParam : Integer ) : LRESULT; stdcall;
begin
  case aMSG of
    WM_DESTROY:
       PostQuitMessage( 0 );
    WM_PAINT  :
       begin
        Render;
        ValidateRect( h_Wnd, NULL);
       end;
  end;

  Result :=DefWindowProc(h_Wnd, aMSG, wParam, lParam);
end;

//-----------------------------------------------------------------------------
// Name: WinMain()
// Desc: The application's entry point
//-----------------------------------------------------------------------------
function WinMain( hInst :LongWord  ) :Integer;
var
 wc   :TWndClassEx;
 hWnd :THandle;
 aMsg :TMsg;
begin
 // Register the window class
 FillChar(wc,sizeof(wc),0);
 wc.cbSize:=sizeof(wc);
 wc.style:=CS_CLASSDC;
 wc.lpfnWndProc:=@MsgProc;
 wc.cbClsExtra:=0;
 wc.cbWndExtra:=0;
 wc.hInstance:=hInst;
 wc.hIcon:=0;//LoadIcon(hInstance, 'MAINICON');
 wc.hCursor:=0;//LoadCursor(hInstance, MakeIntResource(200));
 wc.hbrBackground:=0;
 wc.lpszMenuName:=nil;
 wc.lpszClassName:='D3D Tutorial';
 wc.hIconSm:=0;//LoadIcon(hInstance, 'MAINICON');
 RegisterClassEx(wc);

 // Create the application's window
 hWnd := CreateWindow('D3D Tutorial', 'D3D Tutorial 01: CreateDevice',
                      WS_OVERLAPPEDWINDOW, 100, 100, 300, 300,
                      GetDesktopWindow(), 0, wc.hInstance, NULL );

 // Initialize Direct3D
 if SUCCEEDED(InitD3D(hWnd)) then begin
     // Show the window
     ShowWindow( hWnd, SW_SHOWDEFAULT );
     UpdateWindow( hWnd );

     // Enter the message loop
     while GetMessage(aMsg, 0, 0, 0) do begin
        TranslateMessage(aMsg);
        DispatchMessage(aMsg);
     end
 end;

 // Clean up everything and exit the app
 Cleanup;
 UnregisterClass( 'D3D Tutorial', wc.hInstance );
 Result:=0;
end;

begin
  WinMain(hInstance);
  Halt(0);
end.