// <applet code="Plasma" width=800 height=600></applet>
// Plasma.java
// FB - 201003254
// Moving plasma fractal
import java.applet.Applet;
import java.awt.*;
import java.awt.image.*;
import java.util.Random;
public class Plasma extends Applet
{
Image img;int pix[],col[];
int w,h,alpha,ctr;
float roughness;
Random rng=new Random();
public void putpixel(int x,int y,int c) //c:0 to 767
{
c=(c%256)<<((int)(c/256)*8) & 16777215;
pix[w*y+x]=(alpha<<24)|c;
}
public int getpixel(int x,int y) //:0 to 767
{
int c=pix[w*y+x] & 16777215;
if(c>65535) c=(c>>16)+512;
else if(c>255) c=(c>>8)+256;
return c;
}
public void adjust(int xa,int ya,int x,int y,int xb,int yb)
{
int c,d;float v;
if(getpixel(x,y)==0)
{
d=(int)(Math.abs(xa-xb)+Math.abs(ya-yb));
v=(getpixel(xa,ya)+getpixel(xb,yb))/2+(rng.nextFloat()-0.5f)*d*roughness;
c=((int)Math.abs(v))%768;putpixel(x,y,c);
}
}
public void subdivide(int x1,int y1,int x2,int y2)
{
int x,y;float v;
if(!((x2-x1<2) && (y2-y1<2)))
{
x=(int)((x1+x2)/2);y=(int)((y1+y2)/2);
adjust(x1,y1,x,y1,x2,y1);adjust(x2,y1,x2,y,x2,y2);
adjust(x1,y2,x,y2,x2,y2);adjust(x1,y1,x1,y,x1,y2);
if(getpixel(x,y)==0)
{
v=(getpixel(x1,y1)+getpixel(x2,y1)+getpixel(x2,y2)+getpixel(x1,y2))/4;
putpixel(x,y,(int)v);
}
subdivide(x1,y1,x,y);subdivide(x,y1,x2,y);
subdivide(x,y,x2,y2);subdivide(x1,y,x,y2);
}
}
public void init()
{
roughness=rng.nextInt(10)+2; ctr=0;
w=getSize().width;h=getSize().height;
alpha=255; pix=new int[w*h]; col=new int[h];
putpixel(0,0,rng.nextInt(768));
putpixel(w-1,0,rng.nextInt(768));
putpixel(w-1,h-1,rng.nextInt(768));
putpixel(0,h-1,rng.nextInt(768));
subdivide(0,0,w-1,h-1);
img=createImage(new MemoryImageSource(w,h,pix,0,w));
}
public void paint(Graphics g)
{
int sh=w/2;
if(ctr==0)
{
g.drawImage(img,0,0,this);
// shift the image data to the left
for(int x=sh;x<w;x++)
for(int y=0;y<h;y++)
{
pix[w*y+x-sh]=pix[w*y+x];
if(x>w-1-sh) pix[w*y+x]=0;
}
putpixel(w-1,0,rng.nextInt(768));
putpixel(w-1,h-1,rng.nextInt(768));
subdivide(0,0,w-1,h-1);
}
else
{
// shift the graph area 1 pixel to the left
g.copyArea(1,0,w-1,h,-1,0);
for(int y=0;y<h;y++) col[y]=pix[w*y+sh+ctr];
img=createImage(new MemoryImageSource(1,h,col,0,1));
g.drawImage(img,w-1,0,this);
}
ctr++;ctr%=sh;
// slowdown the sliding speed
long ctm=System.currentTimeMillis();
while((System.currentTimeMillis()-ctm)<10) {;}
repaint();
}
public void update(Graphics g) { paint(g); }
}
