2D游戏编程7—星空案例

// INCLUDES ///////////////////////////////////////////////
#define WIN32_LEAN_AND_MEAN  // just say no to MFC

#include <windows.h>   // include important windows stuff
#include <windowsx.h>
#include <mmsystem.h>
#include <iostream.h> // 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>

// DEFINES ////////////////////////////////////////////////

// defines for windows
#define WINDOW_CLASS_NAME "WINCLASS1"
#define WINDOW_WIDTH      400
#define WINDOW_HEIGHT     300

// starfield defines
#define NUM_STARS            256

// MACROS /////////////////////////////////////////////////

#define KEYDOWN(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0)
#define KEYUP(vk_code)   ((GetAsyncKeyState(vk_code) & 0x8000) ? 0 : 1)

// TYPES //////////////////////////////////////////////////

typedef struct STAR_TYP
        {
        int x,y;        // position of star
        int vel;        // horizontal velocity of star
        COLORREF col;   // color of star
        } STAR, *STAR_PTR;

// PROTOTYPES /////////////////////////////////////////////

void Erase_Stars(void);
void Draw_Stars(void);
void Move_Stars(void);
void Init_Stars(void);

// GLOBALS ////////////////////////////////////////////////

HWND      main_window_handle = NULL; // globally track main window
HINSTANCE hinstance_app      = NULL; // globally track hinstance

HDC       global_dc          = NULL; // tracks a global dc

char buffer[80];                     // general printing buffer

STAR stars[256];                     // holds the starfield

// 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

///////////////////////////////////////////////////////////

void Init_Stars(void)
{
// this function initializes all the stars

for (int index=0; index < NUM_STARS; index++)
    {
    // select random position
    stars[index].x = rand()%WINDOW_WIDTH;
    stars[index].y = rand()%WINDOW_HEIGHT;

    // set random velocity
    stars[index].vel = 1 + rand()%16;

    // set intensity which is inversely prop to velocity for 3D effect
    // note, I am mixing equal amounts of RGB to make black -> bright white
    int intensity = 15*(17 - stars[index].vel);
    stars[index].col = RGB(intensity, intensity, intensity); 

    } // end for index

} // end Init_Stars

////////////////////////////////////////////////////////////

void Erase_Stars(void)
{
// this function erases all the stars
for (int index=0; index < NUM_STARS; index++)
    SetPixel(global_dc, stars[index].x, stars[index].y, RGB(0,0,0));

} // end Erase_Stars

////////////////////////////////////////////////////////////

void Draw_Stars()
{
// this function draws all the stars
for (int index=0; index < NUM_STARS; index++)
    SetPixel(global_dc, stars[index].x, stars[index].y, stars[index].col);

} // end Draw_Stars

////////////////////////////////////////////////////////////

void Move_Stars(void)
{
// this function moves all the stars and wraps them around the
// screen boundaries
for (int index=0; index < NUM_STARS; index++)
    {
    // move the star and test for edge
    stars[index].x+=stars[index].vel;

    if (stars[index].x >= WINDOW_WIDTH)
        stars[index].x -= WINDOW_WIDTH;

    } // end for index

} // end Move_Stars

////////////////////////////////////////////////////////////

int Game_Main(void *parms = NULL, int num_parms = 0)
{
// this is the main loop of the game, do all your processing
// here

// get the time
DWORD start_time = GetTickCount();

// erase the stars
Erase_Stars();

// move the stars
Move_Stars();

// draw the stars
Draw_Stars();

// lock to 30 fps
while((start_time - GetTickCount() < 33));

// for now test if user is hitting ESC and send WM_CLOSE
if (KEYDOWN(VK_ESCAPE))
   SendMessage(main_window_handle,WM_CLOSE,0,0);

// 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

// first get the dc to the window
global_dc = GetDC(main_window_handle);

// initialize the star field here
Init_Stars();

// 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

// release the global dc
ReleaseDC(main_window_handle, global_dc);

// 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    = 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
                            WINDOW_CLASS_NAME,     // class
                            "T3D Game Console Star Demo", // title
                            WS_OVERLAPPEDWINDOW | WS_VISIBLE,
                             0,0,      // initial x,y
                            400,300,  // 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

///////////////////////////////////////////////////////////