c言語による水波紋表示の実現

/****************************************************
 *     ：              *
 *     ：Visual C++ 6.0，EasyX 20130114(beta) *
 *  　　 ：  (QQ: 415051674)      *
 *     ：             *
 *     ：2013/3/20        *
 ****************************************************/


#include <graphics.h>     
#include <conio.h>
#include <stdio.h>

#define PIC_HEIGHT 600
#define PIC_WIDTH  800

void FrameFun();									//      ，        
void RenderFun();									//      ，          

IMAGE src_img;										//      
IMAGE dest_img(PIC_WIDTH, PIC_HEIGHT);				//         
DWORD *img_ptr1;									//         
DWORD *img_ptr2;									//             


//      buf         ，       ，           。
short *buf  = new short[PIC_HEIGHT*PIC_WIDTH+PIC_WIDTH];
short *buf2 = new short[PIC_HEIGHT*PIC_WIDTH+PIC_WIDTH];


void main()
{
	//      ，    
    initgraph(PIC_WIDTH, PIC_HEIGHT); 
	SetWindowText(GetHWnd(), "Wave-     （         。           ）");
    loadimage(&src_img, "water.jpg");		//     ，  ：800*600
	setbkmode(TRANSPARENT);
	settextcolor(BLACK);
	setfont(25, 0, "Arial");

	//       
	img_ptr1 = GetImageBuffer(&src_img);
	img_ptr2 = GetImageBuffer(&dest_img);

	//        
	memset(buf,  0, (PIC_HEIGHT*PIC_WIDTH+PIC_WIDTH) * sizeof(short));
	memset(buf2, 0, (PIC_HEIGHT*PIC_WIDTH+PIC_WIDTH) * sizeof(short));

	// Let's Go!
	BeginBatchDraw();		//    ，     
	while(true) 
	{
		FrameFun();
		RenderFun();
		FlushBatchDraw();
		Sleep(1);
	}
	EndBatchDraw();
}

//               
void nextFrame()
{
	for(int i = PIC_WIDTH; i < PIC_HEIGHT*(PIC_WIDTH-1); i++)
	{
		//   ：X0'= (X1+X2+X3+X4) / 2 - X0
		buf2[i] = ((buf[i-PIC_WIDTH] + buf[i+PIC_WIDTH] + buf[i-1] + buf[i+1]) >> 1) - buf2[i];

		//     
		buf2[i] -= buf2[i] >> 5;
	}

	short *ptmp = buf;
	buf  = buf2;
	buf2 = ptmp;
}

//                ，    dest_img  
void RenderRipple()
{
	int i = 0;
	for (int y = 0; y < PIC_HEIGHT; y++) 
	{
			for (int x = 0; x < PIC_WIDTH; x++) 
			{
				short data = 1024 - buf[i];

				//   
				int a = ((x - PIC_WIDTH  / 2) * data / 1024) + PIC_WIDTH  / 2;
				int b = ((y - PIC_HEIGHT / 2) * data / 1024) + PIC_HEIGHT / 2;

				//     
				if (a >= PIC_WIDTH)		a = PIC_WIDTH - 1;
				if (a < 0)				a = 0;
				if (b >= PIC_HEIGHT)	b = PIC_HEIGHT - 1;
				if (b < 0)				b = 0;
				
				//      
				img_ptr2[i] = img_ptr1[a + (b * PIC_WIDTH)];
				i++;
			}
		}
}

//        
//     ：
// (x, y):     
// stonesize: “  ”   
// stoneweight:  “  ”   
// Ps:       ，          ，     “  ”    “  ”   
void disturb(int x, int y, int stonesize, int stoneweight) 
{
	//        
	if ((x >= PIC_WIDTH - stonesize) ||
		(x < stonesize) ||
		(y >= PIC_HEIGHT - stonesize) ||
		(y < stonesize))
		return;

	for (int posx=x-stonesize; posx<x+stonesize; posx++)
	{
		for (int posy=y-stonesize; posy<y+stonesize; posy++)
		{
			if ((posx-x)*(posx-x) + (posy-y)*(posy-y) < stonesize*stonesize)
			{
				buf[PIC_WIDTH*posy+posx] += stoneweight;
			}
		}
	}
}

//   fps
float getFps()
{
#define FPS_COUNT 8
	static i = 0;
	static oldTime = GetTickCount();
	static float fps;

	if (i > FPS_COUNT)
	{
		i = 0;
		int newTime = GetTickCount();
		int elapsedTime = newTime - oldTime;
		fps = FPS_COUNT / (elapsedTime / 1000.0f);
		oldTime = newTime;
	}
	i++;
	return fps;
}

//   
void RenderFun()
{
	RenderRipple();
	putimage(0, 0, &dest_img);

	char s[5];
	sprintf(s, "%.1f", getFps());
	outtextxy(0, 0, s);
}

//   
void FrameFun() 
{
	//   
	if(MouseHit())
	{
		MOUSEMSG msg = GetMouseMsg();
		if(msg.uMsg == WM_MOUSEMOVE)
		{
			disturb(msg.x, msg.y, 3, 256);
		}
		else if(msg.uMsg == WM_LBUTTONDOWN)
		{
			disturb(msg.x, msg.y, 3, 2560);
		}
		FlushMouseMsgBuffer();
	}

	//         
	nextFrame();
}