Water Simulation

water.pde
xxxxxxxxxx
 
/* Processing Water Simulation 
* adapted by: Rodrigo Amaya
* 
* Based on "Java Water Simulation", by: Neil Wallis
* For more information visit the original article here: 
* http://neilwallis.com/projects/java/water/index.php
*
* How does it work? "2D Water"
* http://freespace.virgin.net/hugo.elias/graphics/x_water.htm
*
*/
​
//import processing.opengl.*;
​
PImage img;
​
int size;
int hwidth,hheight;
int riprad;
​
int ripplemap[];
int ripple[];
int texture[];
​
int oldind,newind, mapind;
​
int i,a,b; 
​
void setup(){
  img = loadImage("background.jpg");
  //width = img.width;
  //height = img.height;
  //size(width, height);
  size(300, 300);
  frameRate(40);
  
  hwidth = width>>1;
  hheight = height>>1;
  riprad=5; //test with 3
  
  size = width * (height+2) * 2;
  
  ripplemap = new int[size];
  ripple = new int[width*height];
  texture = new int[width*height];
  
  oldind = width;
  newind = width * (height+3);
  
  image(img, 0, 0); 
  loadPixels();
  
  smooth();
}
​
void draw() {
  image(img, 0, 0);
  
  loadPixels();
  texture = pixels;
  
  newframe();
    
  for (int i = 0; i < pixels.length; i++) {
    pixels[i] = ripple[i];
  }
   
  updatePixels();
}
​
public void disturb(int dx, int dy) {
  for (int j=dy-riprad;j<dy+riprad;j++) {
    for (int k=dx-riprad;k<dx+riprad;k++) {
      if (j>=0 && j<height && k>=0 && k<width) {
      ripplemap[oldind+(j*width)+k] += 128;   //test with 512         
      } 
    }
  }
}
​
void newframe() {
  //Toggle maps each frame
  i=oldind;
  oldind=newind;
  newind=i;
​
  i=0;
  mapind=oldind;
  for (int y=0;y<height;y++) {
    for (int x=0;x<width;x++) {
    short data = (short)((ripplemap[mapind-width]+ripplemap[mapind+width]+ripplemap[mapind-1]+ripplemap[mapind+1])>>1);
      data -= ripplemap[newind+i];
      data -= data >> 5;
      ripplemap[newind+i]=data;
​
    //where data=0 then still, where data>0 then wave
    data = (short)(1024-data);
​
      //offsets
    a=((x-hwidth)*data/1024)+hwidth;
      b=((y-hheight)*data/1024)+hheight;
​
    //bounds check
      if (a>=width) a=width-1;
      if (a<0) a=0;
      if (b>=height) b=height-1;
      if (b<0) b=0;
​
      ripple[i]=texture[a+(b*width)];
      mapind++;
    i++;
    }
  }
}
​
//Try switching between using the disturb method in mousePressed or mouseMoved
void mousePressed()
{
  //disturb(mouseX, mouseY);
}
​
void mouseMoved()
{
  disturb(mouseX, mouseY);
}
​
void mouseReleased()
{
}
​
Archived Sketch
