【游戏程序设计】粒子系统-烟花

运行结果：

源代码：

#include 
#pragma comment(lib, "winmm.lib")									//调用PlaySound函数所需库文件t

#define WINDOW_WIDTH 640
#define WINDOW_HEIGHT 480
#define WINDOW_TITLE L"【游戏程序设计】粒子系统-烟花"

//粒子星星
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
};

HINSTANCE hInst;
HDC hdc, mdc, bufdc;
HBITMAP hBg, hMask, hFlyStar;															//贴图的三个HBITMAP变量
int count;																				//计数
Flystar flystar[50];
RECT rect;																				//用户区矩形

int  MyWindowClass(HINSTANCE);
BOOL InitInstance(HINSTANCE, int);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
void MyDraw(HDC);

/*****************************************************************************************************************
在不同的应用程序中，在此处添加相关的全局变量
******************************************************************************************************************/
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPreInstace,
									LPSTR lpCmdLine, int nCmdShow) 
{
	MyWindowClass(hInstance);
	PlaySound(L"sound.wav", NULL, SND_FILENAME| SND_ASYNC| SND_LOOP);	//循环播放背景音乐
	if(!InitInstance(hInstance, nCmdShow))
		return FALSE;
	MSG msg;
	while(GetMessage(&msg, NULL, 0, 0)) 
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}

	return msg.wParam;
}

int MyWindowClass(HINSTANCE hInstance)
{
	WNDCLASSEX wcex;
	wcex.cbSize = sizeof(WNDCLASSEX);
	wcex.style = CS_HREDRAW | CS_VREDRAW;
	wcex.lpfnWndProc = WndProc;
	wcex.cbClsExtra = 0;
	wcex.cbWndExtra = 0;
	wcex.hInstance = hInstance;
	wcex.hIcon = NULL;
	wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
	wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
	wcex.lpszMenuName = NULL;
	wcex.lpszClassName = L"gamebase";
	wcex.hIconSm = NULL;

	return RegisterClassEx(&wcex); 
}

BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
	hInst = hInstance;
	HWND hwnd = CreateWindow(L"gamebase", WINDOW_TITLE, WS_OVERLAPPEDWINDOW, 
		CW_USEDEFAULT, CW_USEDEFAULT, WINDOW_WIDTH, WINDOW_HEIGHT, NULL, NULL, hInstance, NULL);
	if(!hwnd)
		return FALSE;
	MoveWindow(hwnd, 10, 10, WINDOW_WIDTH, WINDOW_HEIGHT, true);
	ShowWindow(hwnd, nCmdShow);
	UpdateWindow(hwnd);

	hdc = GetDC(hwnd);
	mdc = CreateCompatibleDC(hdc);
	bufdc = CreateCompatibleDC(hdc);

	hBg = (HBITMAP)LoadImage(NULL, L"bg.bmp", IMAGE_BITMAP, WINDOW_WIDTH, WINDOW_HEIGHT, LR_LOADFROMFILE);
	hMask = (HBITMAP)LoadImage(NULL, L"mask.bmp", IMAGE_BITMAP, 20, 20, LR_LOADFROMFILE);
	hFlyStar = (HBITMAP)LoadImage(NULL, L"flystar.bmp", IMAGE_BITMAP, 20, 20, LR_LOADFROMFILE);
	HBITMAP bmp = CreateCompatibleBitmap(hdc, WINDOW_WIDTH, WINDOW_HEIGHT);
	SelectObject(mdc, bmp);

	count = 0;
	GetClientRect(hwnd, &rect);															//获取用户区矩形
	SetTimer(hwnd, 1, 100, NULL);
	
	return TRUE;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	PAINTSTRUCT ps;

	switch(message)
	{
	//时间消息
	//在消息循环中加入处理WM_TIMER消息，当接收到此消息时使用MyDraw函数进行窗口绘图
	case WM_TIMER:
		MyDraw(hdc);
		break;
/**************************************************************************************************************
在退出程序前，往往在此处删除创建的相关资源
***************************************************************************************************************/
	case WM_DESTROY:																			//窗口结束消息
		DeleteObject(hBg);
		DeleteObject(hMask);
		DeleteObject(hFlyStar);
		DeleteDC(mdc);
		DeleteDC(bufdc);
		ReleaseDC(hwnd, hdc);
		KillTimer(hwnd, 1);																		//窗口结束时，删除所建立的定时器
		PostQuitMessage(0);
		break;
	default:
		return DefWindowProc(hwnd, message, wParam, lParam);
	}
	return 0;
}
/***************************************************************************************************************
在函数MyDraw（）中进行相关绘制工作
****************************************************************************************************************/
void MyDraw(HDC hdc)
{
	
	if(count == 0)
	{
		//随机设置爆炸点
		int x = rand() % rect.right;
		int y = rand() % rect.bottom;
		//产生星光粒子
		for(int i = 0; i < 50; ++i)
		{
			flystar[i].exist = true;
			flystar[i].x = x;
			flystar[i].y = y;
			//按粒子编号i来决定粒子在那个象限运动，且x，y方向的移动速度
			//随机为1-15的一个值，有1+rand()%15来完成
			switch(i % 4)
			{
			case 0:
				flystar[i].vx = -(1 + rand()%15);
				flystar[i].vy = -(1 + rand()%15);
				break;
			case 1:
				flystar[i].vx = 1 + rand()%15;
				flystar[i].vy = -(1 + rand()%15);
				break;
			case 2:
				flystar[i].vx = -(1 + rand()%15);
				flystar[i].vy = 1 + rand()%15;
				break;
			case 3:
				flystar[i].vx = 1 + rand()%15;
				flystar[i].vy = 1 + rand()%15;
				break;
			}
			//设定粒子的存在的时间为0
			flystar[i].lasted = 0;
		}
		//50个粒子由for循环设置完成后，我们将粒子的数量设为50，代表目前有50颗星光
		count = 50;
	}
	//先在内存dc中贴上背景图片
	SelectObject(bufdc, hBg);
	BitBlt(mdc, 0, 0, WINDOW_WIDTH, WINDOW_HEIGHT, bufdc, 0, 0, SRCCOPY);
	for(int i = 0; i < 50; ++i)
		//判断粒子是否还存在，若存在，则根据其坐标进行贴图操作
		if(flystar[i].exist)
		{
			SelectObject(bufdc, hMask);
			BitBlt(mdc, flystar[i].x, flystar[i].y, 20, 20, bufdc, 0, 0, SRCAND);
			SelectObject(bufdc, hFlyStar);
			BitBlt(mdc, flystar[i].x, flystar[i].y, 20, 20, bufdc, 0, 0, SRCPAINT);

			//计算下一次贴图的坐标
			flystar[i].x += flystar[i].vx;
			flystar[i].y += flystar[i].vy;
			//每一次贴图后，粒子的存在时间累加1
			++flystar[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(flystar[i].x < 0 || flystar[i].x > rect.right || flystar[i].y < 0 
					|| flystar[i].y > rect.bottom || flystar[i].lasted > 50)
			{
				flystar[i].exist = false;												//删除星光粒子
				--count;																//递减星光总数
			}
		}
	//将mdc的全部内容贴到hdc中
	BitBlt(hdc, 0, 0, WINDOW_WIDTH, WINDOW_HEIGHT, mdc, 0, 0, SRCCOPY);
}