import java.applet.*; 
import java.awt.*; 
import java.awt.image.*; 
import java.awt.event.*;
import java.io.*; 
import java.net.*; 
import java.text.*; 
import java.util.*; 
import java.util.zip.*; 

public class zombies extends BApplet {
// Zombie Infection Simulation
// Kevan Davis, 16/8/03

int freeze;
int num=1000;
int numweps = 6;
int speed=1;
int panic=5;
int human;
int panichuman;
int zombie;
int wall;
int armedhuman, corpse, chainsaw;
Being[] beings = new Being[4000];
Weapon[] weapons = new Weapon[10];

void setup() 
{ 
  int x,y; 
  size(250,250); 
  human=color(200,0,200);
  panichuman=color(255,120,255);
	 zombie=color(0,255,0);
  wall=color(50,50,60);
	chainsaw = color(0,0,255);
	armedhuman = color(255,255,255);
	corpse = color(100, 100, 100);

  noBackground(); 

  fill(color(0,0,0));
  rect(0,0,width,height); 
  fill(wall);
  stroke(color(0,0,0));
  for (int i=0; i<100; i++)
  {
    rect((int)random(width-1)+1, (int)random(height-1)+1,
         (int)random(60)+10, (int)random(60)+10); 
  }
  fill(color(0,0,0));
  for (int i=0; i<30; i++)
  {
    rect((int)random(width-1)+1, (int)random(height-1)+1,
         (int)random(20)+20,(int)random(20)+20); 

    x=(int)random(width-1)+1;
    y=(int)random(height-1)+1;
  }

  for(int i=0; i<4000; i++)
  { beings[i] = new Being(); beings[i].position(); }
	for(int i = 0; i < numweps; i ++ ) {
		weapons[i] = new Weapon();
		weapons[i].position();
	}
  beings[1].infect();
  freeze=0;
} 
 
void loop() 
{ 
  if (freeze==0)
  {
    for(int i=0; i<num; i++) { 
      beings[i].move(); 
    } 
		for(int i = 0; i < numweps; i++) {
			weapons[i].move();
		}
    if (speed==2) { delay(20); }
    else if (speed==3) { delay(50); }
    else if (speed==4) { delay(100); }
  }
} 


int look(int x, int y,int d,int dist)
{
	float ratio = 0.25f;
	int vx=0, vy=0;
	boolean seenWall = false;
  for(int i=1; i<=dist; i++)
  {
		for(int j = (int)(-ratio * i); j <= (int)(ratio * i); j++) {
			switch(d) {
				case 1:
					vx = x + j;
					vy = y - i;
					break;
				case 2:
					vx = x + i;
					vy = y + j;
					break;
				case 3:
					vx = x + j;
					vy = y + i;
					break;
				case 4:
					vx = x - i;
					vy = y + j;
			}

			if (vx>width-1 || vx<1 || vy>height-1 || vy<1) {
				seenWall = true;
				continue;
			}
			int seeing = getPixel(vx,vy);
			if(seeing == chainsaw) 
				return 6;
			if(seeing == armedhuman)
				return 5;
			if(seeing == panichuman)
				return 4;
			if(seeing == human)
				return 2;
			if(seeing == zombie)
				return 1;
			if(seeing == wall)
				seenWall = true;
  	}
	}
  return seenWall ? 3 : 0;
}

void keyPressed() 
{ 
  if(key == ' ')
  {
    for(int i=0; i<num; i++)
    { beings[i].uninfect(); }
    beings[1].infect();
  } 
  if(key == 's' || key == 'S')
  {
    speed++;
    if (speed>4) { speed=1; }
  }
  if(key == 'p' || key == 'P')
  {
    panic = 5 - panic;
  }
  if(key == 'g' || key == 'G')
  {
    if (zombie==color(155,155,155))
    { zombie=color(0,255,0); }
    else
    { zombie=color(155,155,155); }
  }
  if(key == '+' && num < 4000) { num += 100; key='z'; }
  if(key == '-' && num > 100) { num -= 100; key='z'; }
  if(key == 'z' || key == 'Z')
  {
    freeze=1;
    setup(); 
  }
	if(key == 'b' || key == 'B') {
		for(int i = 0; i < num; i ++) {
			if(beings[i].type == 2) {
				beings[i].type = 5;
			}
		}
	}
}

class Being
{ 
  int xpos, ypos, dir;
	int avoid;
  int type, active;
	int panicimmunity;

  Being()
  {
    dir = (int)random(4)+1;
		avoid = -1;
    type = 2;
    active = 0;
  }

  void position()
  {
    for (int ok=0; ok<100; ok++)
    {
      xpos = (int)random(width-1)+1; 
      ypos = (int)random(height-1)+1;
      if (getPixel(xpos,ypos)==color(0,0,0)) break;
    }
  }

  boolean infect(int x, int y)
  {
    if (x==xpos && y==ypos)
    { 
			type = 1; 
			return true;
		}
		return false;
  }

	boolean attack(int x, int y, Being attacker)
	{
		if(type == 1) {
/*			// There's a 10% chance that the zombie will kill the attacker
			if(random(100) <= 10) {
				// BRAINS!
				attacker.infect();
			} else { */
				type = 7; // Corpse
				setPixel(xpos, ypos, corpse);
				return true;
//			}
		}
		return false;
	}

  boolean infect()
  { 
		type = 1; 
		setPixel(xpos, ypos, zombie); 
		avoid = -1;
		return true;
	}

  void uninfect()
  { type = 2; }

  void move()
  {
		// Corpses don't move
		if(type == 7) {
			setPixel(xpos, ypos, corpse);
			return;
		}
    int r = (int)random(10);
    if (((type==2 || type == 5) && (active>0 || r>panic)) ||
        r==1)
    {
      setPixel(xpos, ypos, color(0,0,0));

      if (look(xpos,ypos,dir,1)==0)
      {
        if (dir==1) { ypos--; }
        if (dir==2) { xpos++; }
        if (dir==3) { ypos++; }
        if (dir==4) { xpos--; }
      }
      else // We're blocked, so change direction
      {
				do {
	        dir = (int)random(4)+1; 
				} while(dir == avoid);
      }

      if (type == 1)
      { setPixel(xpos, ypos, zombie); }
      else if (type == 2 && active > 0)
      { setPixel(xpos, ypos, panichuman); }
			else if (type == 5) {
				setPixel(xpos, ypos, armedhuman); 
			}
      else
      { setPixel(xpos, ypos, human); }
      if (active>0) {
				active--;
				if(active == 0) {
					avoid = -1;
				}
			}
    }

    int target = look(xpos,ypos,dir,10);

		switch(type) {
			case 1: // Zombie
      	if (target==2 || target==4 || target == 5) { active = 10; }

	      if (active==0 && target!=1) { dir = (int)random(4)+1; }
 
  	    int victim = look(xpos,ypos,dir,1);
    	  if (victim == 2 || victim==4 || victim == 5)
      	{
        	int ix = xpos; int iy = ypos;
	        if (dir==1) { iy--; }
  	      if (dir==2) { ix++; }
    	    if (dir==3) { iy++; }
      	  if (dir==4) { ix--; }
        	for(int i=0; i<num; i++)
	        { 
  	        if(beings[i].infect(ix,iy)) break; 
    	    }
      	}
				break;
			case 2: // Unarmed Human
				// If we've spotted a zombie or a panicked human
  	    if (target==1 || target==4) {
    	  	active = 10;
				}
      	if (target==1) {       
	        dir = dir + 2; if (dir>4) { dir = dir - 4; } 
					avoid = dir;
					panicimmunity = 0;
    	  } else if (target == 4) {
					panicimmunity += 10;
					if(panicimmunity > 1000) {
						// We've gotten used to panicking people and have calmed down again
						active = 0;
					}
				} else {
					panicimmunity -= 1;
				}
      	if ((int)random(8)==1) { dir = (int)random(4)+1; }
				victim = look(xpos, ypos, dir, 1);
				if (victim == 6) { // Chainsaw!
					int ix = xpos, iy = ypos;
					switch(dir) {
						case 1: iy--; break;
						case 2: ix++; break;
						case 3: iy++; break;
						case 4: ix--; break;
					}
					for(int i = 0; i < numweps; i++) {
						if(weapons[i].pickup(ix, iy) == true) {
							type = 5;
							break;
						}
					}
				}
				break;
			case 5: // Armed human
				if (target == 1) {
					active = 10;
				}
				victim = look(xpos, ypos, dir, 1);
				if (victim == 1) { // Zombie sighted
					int ix = xpos, iy = ypos;
					switch(dir) {
						case 1: iy--; break;
						case 2: ix++; break;
						case 3: iy++; break;
						case 4: ix--; break;
					}
					for(int i = 0; i< num; i++) {
						if(beings[i].attack(ix, iy, this)) break;
					}
				}
				break;
		}
  }
}
	public class Weapon extends Being {
		boolean pickup(int x, int y) {
			if(x == xpos && y == ypos) {
				setPixel(xpos, ypos, color(0,0,0));
				position();
				move();
				return true;
			}
			return false;
		}

  Weapon()
  {
    dir = (int)random(4)+1;
		avoid = -1;
    type = 6;
    active = 0;
  }

		void move() {
			setPixel(xpos, ypos, chainsaw);
		}
	}
}