Windows粒子系统

#include <windows.h>
#include <tchar.h>    //swprintf_s函数所需的头文件
#include  <time.h>

#pragma comment(lib, "winmm.lib")    //playSound
#pragma comment(lib, "Msimg32.lib")    //TransparentBlt

#define WINDOW_WIDTH    950
#define WINDOW_HEIGHT    710
#define WINDOW_TITLE    L"Windows粒子系统"
// 表示粒子数量
#define FLYSTAR_NUMBER    100    
// 表示粒子持续帧数,修改每次星光绽放持续的时间   
#define FLYSTAR_LASTED_FRAME 60                    


struct FLYSTAR
{
    int x;       //星光所在的x坐标
    int y;       //星光所在的y坐标
    int vx;      //星光x方向的速度
    int vy;      //星光y方向的速度
    int lasted;  //星光存在的时间
    BOOL exist;  //星光是否存在
};
// 环境，内存句柄
HDC    g_hdc = NULL, g_mdc = NULL, g_bufdc = NULL;
HBITMAP g_hStar = NULL, g_hBackGround = NULL;
DWORD g_tPre = 0, g_tNow = 0;
// 储存内部窗口区域的坐标
RECT g_rect;
FLYSTAR FlyStars[FLYSTAR_NUMBER]; 
int g_StarNum = 0; 

// 回调函数,窗口过程函数
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);
BOOL Game_Init(HWND hwnd);
VOID Game_Paint(HWND hwnd);
BOOL Game_CleanUp(HWND hwnd);


int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
    WNDCLASSEX wndClass = { 0 };
    wndClass.cbSize = sizeof(WNDCLASSEX);
    wndClass.style = CS_HREDRAW | CS_VREDRAW;
    wndClass.lpfnWndProc = WndProc;
    wndClass.cbClsExtra = 0;
    wndClass.cbWndExtra = 0;
    wndClass.hInstance = hInstance;
    wndClass.hIcon = 0;
    wndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
    // 白色画刷句柄
    wndClass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    // 用一个以空终止的字符串，指定菜单资源的名字
    wndClass.lpszMenuName = NULL;
    //窗口类的名字
    wndClass.lpszClassName = L"Game Develop";

    if (!RegisterClassEx(&wndClass))
        return -1;

    // 正式创建窗口
    HWND hwnd = CreateWindow(L"Game Develop", WINDOW_TITLE,
        WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, WINDOW_WIDTH,
        WINDOW_HEIGHT, NULL, NULL, hInstance, NULL);

    MoveWindow(hwnd, 150, 50, WINDOW_WIDTH, WINDOW_HEIGHT, true);
    ShowWindow(hwnd, nShowCmd);
    UpdateWindow(hwnd);

    if (!Game_Init(hwnd))
    {
        MessageBox(hwnd, L"资源初始化失败", L"消息窗口", 0);
        return FALSE;
    }

    PlaySound(L"music.wav", NULL, SND_FILENAME | SND_ASYNC | SND_LOOP);

    MSG msg = { 0 };
    while (msg.message != WM_QUIT)
    {
        // 查看应用程序消息队列，有消息时将队列中的消息派发出去
        if (PeekMessage(&msg, 0, 0, 0, PM_REMOVE))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
        else
        {
            g_tNow = GetTickCount();
            // 重绘
            if (g_tNow - g_tPre >= 40)
                Game_Paint(hwnd);
        }
    }

    // 程序准备结束，注销窗口类
    UnregisterClass(L"Game Develop", wndClass.hInstance);
    return 0;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_KEYDOWN:
        if (wParam == VK_ESCAPE)
            PostQuitMessage(0);
        break;
        
    case WM_DESTROY:
        Game_CleanUp(hwnd);
        PostQuitMessage(0);
        break;

        //调用缺省的窗口过程
    default:
        return DefWindowProc(hwnd, message, wParam, lParam);
    }
    return 0;
}

BOOL Game_Init(HWND hwnd)
{
    // 用系统时间初始化 
    // 随机数发生器的初始化函数
    srand((unsigned)time(NULL));

    HBITMAP bmp;
    g_hdc = GetDC(hwnd);
    g_mdc = CreateCompatibleDC(g_hdc);
    g_bufdc = CreateCompatibleDC(g_hdc);
    bmp = CreateCompatibleBitmap(g_hdc, WINDOW_WIDTH, WINDOW_HEIGHT);
    
    SelectObject(g_mdc, bmp);
    g_hBackGround = (HBITMAP)LoadImage(NULL, L"bg.bmp", IMAGE_BITMAP, WINDOW_WIDTH, WINDOW_HEIGHT, LR_LOADFROMFILE);
    g_hStar = (HBITMAP)LoadImage(NULL, L"star.bmp", IMAGE_BITMAP, 30, 30, LR_LOADFROMFILE);

    // 取得内部窗口大小
    GetClientRect(hwnd, &g_rect);

    Game_Paint(hwnd);
    return TRUE;
}

VOID Game_Paint(HWND hwnd)
{
    // 先在mdc中贴上背景图
    SelectObject(g_bufdc, g_hBackGround);
    // 将源矩形区域直接拷贝到目标矩形区域
    BitBlt(g_mdc, 0, 0, WINDOW_WIDTH, WINDOW_HEIGHT, g_bufdc, 0, 0, SRCCOPY);

    // 创建粒子
    if (g_StarNum == 0)
    {
        // 随机设置爆炸点
        int x = rand() % g_rect.right;
        int y = rand() % g_rect.bottom;

        for (int i = 0; i < FLYSTAR_NUMBER; i++)
        {
            FlyStars[i].x = x;
            FlyStars[i].y = y;
            FlyStars[i].lasted = 0;
            // x，y方向的移动速度随机为1—15之间的一个值
            if (i % 4 == 0)
            {
                FlyStars[i].vx = -(1 + rand() % 15);
                FlyStars[i].vy = -(1 + rand() % 15);
            }
            if (i % 4 == 1)
            {
                FlyStars[i].vx = (1 + rand() % 15);
                FlyStars[i].vy = (1 + rand() % 15);
            }
            if (i % 4 == 2)
            {
                FlyStars[i].vx = -(1 + rand() % 15);
                FlyStars[i].vy = (1 + rand() % 15);
            }
            if (i % 4 == 3)
            {
                FlyStars[i].vx = (1 + rand() % 15);
                FlyStars[i].vy = -(1 + rand() % 15);
            }
            FlyStars[i].exist = true;
        }
        g_StarNum = FLYSTAR_NUMBER;
    }

    // 显示粒子
    for (int i = 0; i < FLYSTAR_NUMBER; i++)
    {
        if (FlyStars[i].exist)
        {
            SelectObject(g_bufdc, g_hStar);
            TransparentBlt(g_mdc, FlyStars[i].x, FlyStars[i].y, 30, 30, g_bufdc, 0, 0, 30, 30, RGB(0, 0, 0));

            // 下一次坐标
            FlyStars[i].x += FlyStars[i].vx;
            FlyStars[i].y += FlyStars[i].vy;
            // 在每进行一次贴图后，将粒子的存在时间累加1.
            FlyStars[i].lasted++;
            // 进行条件判断，若某粒子跑出窗口区域一定的范围，则将该粒子设为不存在，且粒子数随之递减
            if (FlyStars[i].x <= -10 || FlyStars[i].x>g_rect.right || FlyStars[i].y <= -10 || FlyStars[i].y>g_rect.bottom || FlyStars[i].lasted>FLYSTAR_LASTED_FRAME)
            {
                FlyStars[i].exist = false;  //删除星光粒子 
                g_StarNum--;                    //递减星光总数
            }
        }
    }
    BitBlt(g_hdc, 0, 0, WINDOW_WIDTH, WINDOW_HEIGHT, g_mdc, 0, 0, SRCCOPY);
    g_tPre = GetTickCount();
}

BOOL Game_CleanUp(HWND hwnd)
{
    // 释放资源对象
    DeleteObject(g_hBackGround);
    DeleteObject(g_hStar);
    DeleteDC(g_bufdc);
    DeleteDC(g_mdc);
    ReleaseDC(hwnd, g_hdc);
    return TRUE;
}