7.1.首次接触DirectDraw

下面,将简单介绍用这些界面如何创建一个DirectDraw应该程序:

1.创建主DirectDraw对象,得到一个IDirectDraw4界面.在此界上,设置协同等级和视频模式.

2.在IDirectDrawSurface界面上,创建至少一个主画面,基于画面的色深及视频模式,如果视频模式为每像素8位或更少,则需要使用调色版.

3.在IDirectDrawPalette界面上创建一个调色板,用RGB三元初始化调色板,并把调色板附在界面上.

4.如果DirectDraw程序带有一个窗体,或对一个可能出了DirectDraw可视界面边界的位图进行着色时,你就需要一个剪切工具,并把它调整到可视窗体的区域中.

5.在主画面上画图.

当然,上述步聚省去了许多细节,但这是使用不同界面的精髓. 具体细节请参见WINDOWS游戏编程大师第6章.
// DEMO6_3.CPP basic full-screen pixel plotting DirectDraw demo // INCLUDES /////////////////////////////////////////////// #define WIN32_LEAN_AND_MEAN // just say no to MFC #define INITGUID // make sure directX guids are included #include <windows.h> // include important windows stuff #include <windowsx.h> #include <mmsystem.h> #include <iostream> // include important C/C++ stuff #include <conio.h> #include <stdlib.h> #include <malloc.h> #include <memory.h> #include <string.h> #include <stdarg.h> #include <stdio.h> #include <math.h> #include <io.h> #include <fcntl.h> #include <ddraw.h> // include directdraw // DEFINES //////////////////////////////////////////////// // defines for windows #define WINDOW_CLASS_NAME "WINCLASS1" // default screen size #define SCREEN_WIDTH 640 // size of screen #define SCREEN_HEIGHT 480 #define SCREEN_BPP 8 // bits per pixel #define MAX_COLORS 256 // maximum colors // TYPES ////////////////////////////////////////////////////// // basic unsigned types typedef unsigned short USHORT; typedef unsigned short WORD; typedef unsigned char UCHAR; typedef unsigned char BYTE; // MACROS ///////////////////////////////////////////////// #define KEYDOWN(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0) #define KEYUP(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 0 : 1) // initializes a direct draw struct #define DD_INIT_STRUCT(ddstruct) { memset(&ddstruct,0,sizeof(ddstruct)); ddstruct.dwSize=sizeof(ddstruct); } // GLOBALS //////////////////////////////////////////////// HWND main_window_handle = NULL; // globally track main window HINSTANCE hinstance_app = NULL; // globally track hinstance // directdraw stuff LPDIRECTDRAW7 lpdd = NULL; // dd object LPDIRECTDRAWSURFACE7 lpddsprimary = NULL; // dd primary surface LPDIRECTDRAWSURFACE7 lpddsback = NULL; // dd back surface LPDIRECTDRAWPALETTE lpddpal = NULL; // a pointer to the created dd palette LPDIRECTDRAWCLIPPER lpddclipper = NULL; // dd clipper PALETTEENTRY palette[256]; // color palette PALETTEENTRY save_palette[256]; // used to save palettes DDSURFACEDESC2 ddsd; // a direct draw surface description struct DDBLTFX ddbltfx; // used to fill DDSCAPS2 ddscaps; // a direct draw surface capabilities struct HRESULT ddrval; // result back from dd calls DWORD start_clock_count = 0; // used for timing // these defined the general clipping rectangle int min_clip_x = 0, // clipping rectangle max_clip_x = SCREEN_WIDTH-1, min_clip_y = 0, max_clip_y = SCREEN_HEIGHT-1; // these are overwritten globally by DD_Init() int screen_width = SCREEN_WIDTH, // width of screen screen_height = SCREEN_HEIGHT, // height of screen screen_bpp = SCREEN_BPP; // bits per pixel char buffer[80]; // general printing buffer // FUNCTIONS ////////////////////////////////////////////// LRESULT CALLBACK WindowProc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam) { // this is the main message handler of the system PAINTSTRUCT ps; // used in WM_PAINT HDC hdc; // handle to a device context char buffer[80]; // used to print strings // what is the message switch(msg) { case WM_CREATE: { // do initialization stuff here // return success return(0); } break; case WM_PAINT: { // simply validate the window hdc = BeginPaint(hwnd,&ps); // end painting EndPaint(hwnd,&ps); // return success return(0); } break; case WM_DESTROY: { // kill the application, this sends a WM_QUIT message PostQuitMessage(0); // return success return(0); } break; default:break; } // end switch // process any messages that we didn't take care of return (DefWindowProc(hwnd, msg, wparam, lparam)); } // end WinProc /////////////////////////////////////////////////////////// int Game_Main(void *parms = NULL, int num_parms = 0) { // this is the main loop of the game, do all your processing // here // for now test if user is hitting ESC and send WM_CLOSE if (KEYDOWN(VK_ESCAPE)) SendMessage(main_window_handle,WM_CLOSE,0,0); // plot 1000 random pixels to the primary surface and return // clear ddsd and set size, never assume it's clean memset(&ddsd,0,sizeof(ddsd)); ddsd.dwSize = sizeof(ddsd); if (FAILED(lpddsprimary->Lock(NULL, &ddsd, DDLOCK_SURFACEMEMORYPTR | DDLOCK_WAIT, NULL))) { // error return(0); } // end if // now ddsd.lPitch is valid and so is ddsd.lpSurface // make a couple aliases to make code cleaner, so we don't // have to cast int mempitch = (int)ddsd.lPitch; UCHAR *video_buffer = (UCHAR *)ddsd.lpSurface; // plot 1000 random pixels with random colors on the // primary surface, they will be instantly visible for (int index=0; index < 1000; index++) { // select random position and color for 640x480x8 UCHAR color = rand()%256; int x = rand()%640; int y = rand()%480; // plot the pixel video_buffer[x+y*mempitch] = color; } // end for index // now unlock the primary surface if (FAILED(lpddsprimary->Unlock(NULL))) return(0); // sleep a bit Sleep(30); // return success or failure or your own return code here return(1); } // end Game_Main //////////////////////////////////////////////////////////// int Game_Init(void *parms = NULL, int num_parms = 0) { // this is called once after the initial window is created and // before the main event loop is entered, do all your initialization // here // create IDirectDraw interface 7.0 object and test for error if (FAILED(DirectDrawCreateEx(NULL, (void **)&lpdd, IID_IDirectDraw7, NULL))) return(0); // set cooperation to full screen if (FAILED(lpdd->SetCooperativeLevel(main_window_handle, DDSCL_FULLSCREEN | DDSCL_ALLOWMODEX | DDSCL_EXCLUSIVE | DDSCL_ALLOWREBOOT))) { // error return(0); } // end if // set display mode to 640x480x8 if (FAILED(lpdd->SetDisplayMode(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP,0,0))) { // error return(0); } // end if // clear ddsd and set size memset(&ddsd,0,sizeof(ddsd)); ddsd.dwSize = sizeof(ddsd); // enable valid fields ddsd.dwFlags = DDSD_CAPS; // request primary surface ddsd.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE; // create the primary surface if (FAILED(lpdd->CreateSurface(&ddsd, &lpddsprimary, NULL))) { // error return(0); } // end if // build up the palette data array for (int color=1; color < 255; color++) { // fill with random RGB values palette[color].peRed = rand()%256; palette[color].peGreen = rand()%256; palette[color].peBlue = rand()%256; // set flags field to PC_NOCOLLAPSE palette[color].peFlags = PC_NOCOLLAPSE; } // end for color // now fill in entry 0 and 255 with black and white palette[0].peRed = 0; palette[0].peGreen = 0; palette[0].peBlue = 0; palette[0].peFlags = PC_NOCOLLAPSE; palette[255].peRed = 255; palette[255].peGreen = 255; palette[255].peBlue = 255; palette[255].peFlags = PC_NOCOLLAPSE; // create the palette object if (FAILED(lpdd->CreatePalette(DDPCAPS_8BIT | DDPCAPS_ALLOW256 | DDPCAPS_INITIALIZE, palette,&lpddpal, NULL))) { // error return(0); } // end if // finally attach the palette to the primary surface if (FAILED(lpddsprimary->SetPalette(lpddpal))) { // error return(0); } // end if // return success or failure or your own return code here return(1); } // end Game_Init ///////////////////////////////////////////////////////////// int Game_Shutdown(void *parms = NULL, int num_parms = 0) { // this is called after the game is exited and the main event // loop while is exited, do all you cleanup and shutdown here // first the palette if (lpddpal) { lpddpal->Release(); lpddpal = NULL; } // end if // now the primary surface if (lpddsprimary) { lpddsprimary->Release(); lpddsprimary = NULL; } // end if // now blow away the IDirectDraw4 interface if (lpdd) { lpdd->Release(); lpdd = NULL; } // end if // return success or failure or your own return code here return(1); } // end Game_Shutdown // WINMAIN //////////////////////////////////////////////// int WINAPI WinMain( HINSTANCE hinstance, HINSTANCE hprevinstance, LPSTR lpcmdline, int ncmdshow) { WNDCLASSEX winclass; // this will hold the class we create HWND hwnd; // generic window handle MSG msg; // generic message HDC hdc; // graphics device context // first fill in the window class stucture winclass.cbSize = sizeof(WNDCLASSEX); winclass.style = CS_DBLCLKS | CS_OWNDC | CS_HREDRAW | CS_VREDRAW; winclass.lpfnWndProc = WindowProc; winclass.cbClsExtra = 0; winclass.cbWndExtra = 0; winclass.hInstance = hinstance; winclass.hIcon = LoadIcon(NULL, IDI_APPLICATION); winclass.hCursor = LoadCursor(NULL, IDC_ARROW); winclass.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH); winclass.lpszMenuName = NULL; winclass.lpszClassName = (LPCWSTR)WINDOW_CLASS_NAME; winclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION); // save hinstance in global hinstance_app = hinstance; // register the window class if (!RegisterClassEx(&winclass)) return(0); // create the window if (!(hwnd = CreateWindowEx(NULL, // extended style (LPCWSTR)WINDOW_CLASS_NAME, // class L"DirectDraw Full-Screen Demo", // title WS_POPUP | WS_VISIBLE, 0,0, // initial x,y SCREEN_WIDTH,SCREEN_HEIGHT, // initial width, height NULL, // handle to parent NULL, // handle to menu hinstance,// instance of this application NULL))) // extra creation parms return(0); // save main window handle main_window_handle = hwnd; // initialize game here Game_Init(); // enter main event loop while(TRUE) { // test if there is a message in queue, if so get it if (PeekMessage(&msg,NULL,0,0,PM_REMOVE)) { // test if this is a quit if (msg.message == WM_QUIT) break; // translate any accelerator keys TranslateMessage(&msg); // send the message to the window proc DispatchMessage(&msg); } // end if // main game processing goes here Game_Main(); } // end while // closedown game here Game_Shutdown(); // return to Windows like this return(msg.wParam); } // end WinMain ///////////////////////////////////////////////////////////