
//
//
//  Java Plasma written 1997 Martin Steen
//
//

import java.awt.*;
import java.awt.image.*;

public class ms_plasma extends java.applet.Applet implements Runnable
{
  Image img;
  int w;
  int h;
  Thread Timer;

  byte[] pix;
  byte[] newpal;
  byte[][] ptab;
  IndexColorModel icm;
  short[] pl1,pl2;
  byte[] data;
  int plastime = 0;
  int plasma_size;

  public void init()
  {
    w = size().width;
    h = size().height;

    resize(w,h);

    plasma_size = 1;
    switch(w)
    {
      case 80:  plasma_size = 0; break;
      case 320: plasma_size = 2; break;
    }

    pix = new byte[w*h];
    newpal = new byte[768];
    ptab = new byte[3][256];
    make_palette();
    init_data();

    img = createImage(new MemoryImageSource(w,h,icm,pix,0,w));
  }

  public void init_data()
  {
     int t,x,y;

     pl1 = new short[30000];
     pl2 = new short[30000];
     data = new byte[70000];

     for (y = 0; y < 256; y++)
     {
       int offs = y * 256;
       int ym = y - 128;

       for (x = 0; x < 256; x++)
       {
         int xm = x - 128;
         data[offs+x] = (byte) (83 * (3+(Math.cos(0.09*Math.sqrt(xm*xm + ym*ym))) + Math.cos(x/21.0)+Math.cos(y/26.0)));
       }
     }

     for (t = 0; t < 30000; t++)
     {
       pl1[t] = (short) (48+Math.cos(t/37.0)*47.0+256*(short)(48+47*(Math.sin(t/31.0))));
       pl2[t] = (short) (48+Math.sin(t/24.0)*47.0+256*(short)(48+47*(Math.cos(t/19.0)))-pl1[t]);
     }
  }

  public void make_palette()
  {
    int j = 0, i = 0;

    for (int r = 0; r < 256; r++)
    {
      for (int t = 64; t <= 256; t <<= 1)
      {
        newpal[i++] = (byte) ((Math.sin(r * Math.PI * 2 / t) * 31.0 + 31)*4);
      }
    }
    for (i = 0; i < 256; i++)
    {
      ptab[0][i] = newpal[j++];
      ptab[1][i] = newpal[j++];
      ptab[2][i] = newpal[j++];
    }
    icm = new  IndexColorModel(8,256,ptab[0],ptab[1],ptab[2]);
  }

  public void calc_plasma(int t)
  {
    short p2 = pl2[t];
    short x,y;
    int si = 0;
    int di;

    di = (int) pl1[t];
    si = 0;

    switch (plasma_size)
    {
      case 2:
      {
        byte p;

        for (y = 0; y < 100; y++)
        {
          for (x = 0; x < 160; x++)
          {
            p = (byte) (data[di++] + data[di+p2]);

            pix[si+320] = p;
            pix[si+321] = p;
            pix[si++]   = p;
            pix[si++]   = p;
          }
          di += 96;
          si += 320;
        }
      }
      break;

      case 1:
      {
        for (y = 0; y < 100; y++)
        {
          for (x = 0; x < 160; x++)
          {
            pix[si++] = (byte) (data[di++] + data[di+p2]);
          }
          di += 96;
        }
      }
      break;

      case 0:
      {
        for (y = 0; y < 100; y += 2)
        {
          for (x = 0; x < 160; x += 2)
          {
            pix[si++] = (byte) (data[di++] + data[di+p2]); di++;
          }
          di += 96 + 256;
        }
      }
      break;
    }
  }

  public void start()
  {
    if (Timer == null)
    {
      Timer = new Thread(this);
      Timer.start();
    }
  }

  public void run()
  {
    int x,y,red,blue,index,gr;

    Timer.setPriority(Thread.MIN_PRIORITY);

    while (true)
    {
      repaint();
      try{Thread.sleep(10);}
      catch (InterruptedException e){}
    }
  }


  public void update(Graphics g)
  {
    calc_plasma(plastime++);
    if (plastime == 30000) plastime = 0;
    img.flush();
    g.drawImage(img,0,0,this);
  }

  public void paint(Graphics g)
  {
    img.flush();
    g.drawImage(img,0,0,this);
  }
}