InitGraph();
rows=31;cols=31;
ScaleWindow(0, 0,cols+1, rows+1);
Colour(Black);
BoxFill(0,0,cols+1,rows+1);

pic1=new Array(cols);pic2=new Array(cols);
for(var i = 0;i<=cols;i++){
   pic1[i]=new Array(rows);pic2[i]=new Array(rows);
}

filt=new Array(3);
filt[0]=new Array( 0,-1, 0);
filt[1]=new Array(-1, 4,-1);
filt[2]=new Array( 0,-1, 0);
window.showpic1=function() {         //and copy to pic1
 for(var i = 0;i<=cols;i++){
   for(var j = 0;j<=rows;j++) {
      if (pic1[i][j]>0){
         Colour(Red)}else{Colour(Black)};
      BoxFill(i, j,.8, .8);
//      pic1[i][j]=pic2[i][j];
   }
 }
}

window.showpic2=function() {         //and copy to pic1
 for(var i = 0;i<=cols;i++){
   for(var j = 0;j<=rows;j++) {
      if (pic2[i][j]>0){
         Colour(Red)}else{Colour(Black)};
      BoxFill(i, j,.8, .8);
      pic1[i][j]=pic2[i][j];
   }
 }
}

function smooth() {
 for(var i = 1;i<cols;i++){    //for each point
   for(var j = 1;j<rows;j++) { //except edge
      m = 0;
      for (k = i - 1;k<=i + 1;k++) {
         for (l = j - 1;l<= j + 1;l++) {
            m = m + pic1 [k][l]; //add 9 values in 3x3 block
         }
      }
      if (m > 4) {        //If majority are set
         pic2 [i][j] = 1; //set pixel of pic2 to red
      }else{
         pic2 [i][j] = 0; //set pixel of pic2 to black
      };
   Colour(White);
   Label(m,i,j);          //show count
   }
 }
}

function filter() {
 Colour("yellow");
 for(var i = 1;i<cols;i++){    //for each point
   for(var j = 1;j<rows;j++) { //except edge
      m = 0;
      for (k = 0;k<=2;k++) {
         for (l = 0;l<= 2;l++) {
            m = m + pic1 [i+k-1][j+l-1]*filt[l][k]; 
         }
      }
      if (m >=1) {        //If total is positive
         pic2 [i][j] = 1; //set pixel of pic2 to red
      }else{
         pic2 [i][j] = 0; //set pixel of pic2 to black
      };
   Label(m,i,j);
   }
 }
}

//Set up picture with a ragged diamond
for (i = 0;i<= cols;i++){ 
   for (j = 0; j<=rows;j++) {
      k = Math.abs(i - rows/2) + Math.abs(j - cols/2);
      if (k + 6 * Math.random() < 14) { 
         pic2[i][j] = 1;}
      else {
         pic2 [i][j] = 0;
      };
   }
}

showpic2();
n=0;

setTimeout('eval(document.panels.step.value);',3000);