C language realizes water ripple effect

This paper shares the concrete code of C language to realize the effect of water ripple for your reference. The specific content is as follows

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

#define PIC_HEIGHT 600
#define PIC_WIDTH 800

void FrameFun();     //  Frame logic function that handles each 1 The logic of the frame 
void RenderFun();     //  Frame rendering function, output each 1 Frame to display device 

IMAGE src_img;     //  In situ figure  
IMAGE dest_img(PIC_WIDTH, PIC_HEIGHT);  //  The bitmap displayed after processing 
DWORD *img_ptr1;     //  Original slice memory pointer 
DWORD *img_ptr2;     //  The bitmap memory pointer displayed after processing 


//  The following two  buf  For each 1 The amplitude of a point, the former is the current amplitude, the latter is the bottom amplitude 1 The amplitude of a moment. 
short *buf = new short[PIC_HEIGHT*PIC_WIDTH+PIC_WIDTH];
short *buf2 = new short[PIC_HEIGHT*PIC_WIDTH+PIC_WIDTH];


void main()
{
 //  Initialize the device and load the image 
  initgraph(PIC_WIDTH, PIC_HEIGHT); 
 SetWindowText(GetHWnd(), "Wave- Water ripple effect (click to create 1 A ripple of water. Continuously generate water ripples by moving the mouse) ");
  loadimage(&src_img, "water.jpg"); //  Load picture, size: 800*600
 setbkmode(TRANSPARENT);
 settextcolor(BLACK);
 setfont(25, 0, "Arial");

 //  Get a memory pointer 
 img_ptr1 = GetImageBuffer(&src_img);
 img_ptr2 = GetImageBuffer(&dest_img);

 //  Initializes the amplitude array 
 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(); //  Double buffering is required for flash screen 
 while(true) 
 {
 FrameFun();
 RenderFun();
 FlushBatchDraw();
 Sleep(1);
 }
 EndBatchDraw();
}

//  To calculate the 1 The amplitude of waves at all points in time 
void nextFrame()
{
 for(int i = PIC_WIDTH; i < PIC_HEIGHT*(PIC_WIDTH-1); i++)
 {
 //  Formula: 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];

 //  Wave energy attenuation 
 buf2[i] -= buf2[i] >> 5;
 }

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

//  Handle the current moment after the amplitude effect of the bitmap, save in  dest_img  In the 
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];

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

  //  Boundary processing 
  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;
  
  //  Deal with deviation  
  img_ptr2[i] = img_ptr1[a + (b * PIC_WIDTH)];
  i++;
  }
 }
}

//  Mouse simulation throw stone 
//  Parameter description: 
// (x, y):  The mouse coordinates 
// stonesize:  The size of the rock 
// stoneweight:  The force of a rock 
// Ps:  If an error occurs, 1 General is the array caused by the boundary, please adjust the size of the "stone" and the strength of the "stone" 
void disturb(int x, int y, int stonesize, int stoneweight) 
{
 //  Crossing the boundary is not handled 
 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;
  }
 }
 }
}

//  To calculate 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;
}

//  Apply colours to a drawing 
void RenderFun()
{
 RenderRipple();
 putimage(0, 0, &dest_img);

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

//  logic 
void FrameFun() 
{
 //  The mouse 
 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();
 }

 //  Under the calculation 1 The frame of the amplitude 
 nextFrame();
}