Language Java Nosugar Graphics ME Code Mecanvas.java

//	MeCanvas clas
//	part of the set of documents known as Java no sugar.
//	Copyright (c) 1996,1997 Sunil Gupta, sunil@magnetic.demon.co.uk
//	placed into the public domain by the author
//
import java.awt.*;
import java.net.*;
import java.io.*;
import Context;

public class MeCanvas extends ThreadedCanvas
{
	//*******************************************************************
	// globals
	//*******************************************************************
	static final int MAX_DURATION =5;
	
	static final int DOING_NOTHING = -1;
	static final int LOADING_IMAGES = 0;
	static final int IMAGES_OK = 2;	
	
	static final int LOOK_LEFT =0;
	static final int LOOK_RIGHT =1;
	static final int TONGUE =2;
	static final int HIT =3;
	static final int AAGH =4;
	static final int SMUG1 =5;
	static final int SMUG2 =6;
	
	static final int N =  0;
	static final int NE = 1;
	static final int E =  2;
	static final int SE = 3;
	static final int S =  4;
	static final int SW = 5;
	static final int W =  6;
	static final int NW = 7;
	static final int STOP = 8;
	
	static final int IMAGE_WIDTH = 118;
	static final int IMAGE_HEIGHT = 186;
	
	static boolean images_loaded = false;
	static String status = "";
	static int doing_what = DOING_NOTHING;
	
	static Image img_look_left, img_look_right, img_tongue;
	static Image img_hit, img_aagh, img_smug1, img_smug2;
	static Image img_ne_aagh, img_nw_aagh, img_sw_aagh, img_se_aagh;
	static Image img_eyebrowse_aagh, img_hair_aagh, img_specs_aagh, img_mouth_aagh;
	
	static Image normal_images[] = null;
	static int current_id = 1;
	
	//*******************************************************************
	// instance variables
	//*******************************************************************
	int which_image = LOOK_LEFT;
	int x,y, direction, duration, time_spent;
	int explode_x, explode_y;
	boolean exploding = false, imploding = false;
	int explode_counter = 0;
		
	//###################################################################
	// Paint stuff
	//###################################################################
	public void addNotify()
	{
		Thread image_loader;
		
		super.addNotify();

		// -------load images asynchronously-----------
		if (doing_what == DOING_NOTHING)
		{
			image_loader = new Thread(this);
			image_loader.start();
		}
	}
			
	//*******************************************************************
	public Dimension minimumSize() 	
	{
		return ( new Dimension(200,200));
	}
	
	//*******************************************************************
	public boolean mouseDown( Event ev, int mouse_x, int mouse_y)
	{
		Rectangle rect;
		
		if (exploding)
			set_status ("Can't you see I'm breaking apart?");
		else
		{
			rect = new Rectangle(x,y,IMAGE_WIDTH, IMAGE_HEIGHT);
			if ( rect.inside(mouse_x, mouse_y))
			{
				set_status ("Hit");
				exploding = true;
				imploding = false;
				explode_counter = 0;
				explode_x = x + IMAGE_WIDTH/2;
				explode_y = y + IMAGE_HEIGHT/2;
			}
			else
				set_status ("You missed");
		}
		return true;
	}

	//###################################################################
	// THREADS 
	//###################################################################
	public void onRun( Graphics g)
	{
		x = (int) (Math.random() * size().width);
		y = (int) (Math.random() * size().height);
		choose_direction();
	}
			
	//*******************************************************************
	public void run()
	{
		if (doing_what == DOING_NOTHING)
		{
			doing_what = LOADING_IMAGES;
			try
			{
				load_images();
			}
			catch (Exception e) {}
		}
		else
			super.run();
	}
	
	//*******************************************************************
	public void onLoop( Graphics g)
	{
		Image img;
		int image_num, random;
		int font_width, font_height, font_x, font_y;
		FontMetrics metrics;

		if (doing_what != IMAGES_OK)
		{
			metrics = g.getFontMetrics();
			font_width = metrics.stringWidth(status);
			font_height = metrics.getHeight();
			
			random = (int) Math.round(Math.random() * 4.0);
			switch (random)
			{
				case 1:	
					g.setColor(Color.red);
					break;
				case 2:
					g.setColor(Color.blue);
					break;
				case 3:
					g.setColor(Color.green);
					break;
				default:
					g.setColor(Color.black);
			}
			
			font_x = size().width - font_width;
			font_y = (size().height - font_height)/2;
			g.drawString(status, font_x, font_y);
		}
		else if (exploding || imploding)
		{
			onExplodeLoop(g);
		}
		else
		{
			//----------------choose the image-------------
			image_num = choose_image(direction);
		
			//------------draw it-------------------------
			img = normal_images[image_num];
			g.drawImage( img,x,y,null);
		
			//---------get ready for next image-----------
			move_image();
		
			time_spent ++;
			duration --;
			if (duration <= 0)	choose_direction();
		}
		
		//----------------sleep-------------------------------
		try
		{
			Thread.sleep(50);
		}
		catch (Exception e){}
	}
	
	//*******************************************************************
	public void onExplodeLoop( Graphics g)
	{
		int delta;
		
		//-------------------draw the peices in place------------------
		if (explode_counter < 2)
		{
			g.drawImage( img_hit,x,y,null);
		}
		else if (explode_counter < 6)
		{
			g.drawImage( img_aagh,x,y,null);
		}
		else
		{
			delta = (explode_counter-5) * (explode_counter-5) * 2;
			g.drawImage(img_ne_aagh, explode_x-delta, explode_y+delta, null);
			g.drawImage(img_nw_aagh, explode_x+delta, explode_y+delta, null);
			g.drawImage(img_sw_aagh, explode_x-delta, explode_y+delta, null);				
			g.drawImage(img_se_aagh, explode_x-delta, explode_y-delta, null);
			g.drawImage(img_eyebrowse_aagh, explode_x+delta, explode_y, null);
			g.drawImage(img_hair_aagh, explode_x, explode_y-delta, null);
			g.drawImage(img_specs_aagh, explode_x-delta, explode_y, null);
			g.drawImage(img_mouth_aagh, explode_x, explode_y+delta, null);
		}
		
		//-------------------get ready for next step-------------------
		if (exploding)
		{
			explode_counter ++;
			if (explode_counter >= 15)
			{
				exploding = false;
				imploding = true;
				x = (int) (Math.random() * size().width);
				y = (int) (Math.random() * size().height);
				explode_x = x;
				explode_y = y;
			}
		}
		else
		{
			explode_counter --;
			if (explode_counter <= 0)
			{
				imploding = false;
				choose_direction();
			}
		}
	}
	
	//###################################################################
	// stuff
	//###################################################################
	void load_images() throws Exception
	{
		URL dir_url, img_url;
		MediaTracker tracker = new MediaTracker(this);
		
		System.out.println("Called load_images");
		
		//------------load main pictures---------------
		if (!images_loaded)
		{
			dir_url = new URL(Context.code_base, "pics/" );
		
			img_url = new URL(dir_url, "looklef.gif");
			img_look_left = getImage(img_url, tracker);
			img_url = new URL(dir_url, "lookrit.gif");
			img_look_right = getImage(img_url, tracker);
			img_url = new URL(dir_url, "tongue.gif");
			img_tongue = getImage(img_url, tracker);
			img_url = new URL(dir_url, "hit.gif");
			img_hit = getImage(img_url, tracker);
			img_url = new URL(dir_url, "aagh.gif");
			img_aagh = getImage(img_url, tracker);
			img_url = new URL(dir_url, "smug.gif");
			img_smug1 = getImage(img_url, tracker);
			img_url = new URL(dir_url, "smug2.gif");
			img_smug2 = getImage(img_url, tracker);
		
			//------------------populate array--------------------	
			normal_images = new Image[7];
			normal_images[0] = img_look_left;
			normal_images[1] = img_look_right;
			normal_images[2] = img_tongue;
			normal_images[3] = img_hit;
			normal_images[4] = img_aagh;
			normal_images[5] = img_smug1;
			normal_images[6] = img_smug2;
	
			//------------load aargh pictures---------------
			dir_url = new URL(Context.code_base,"aaghpart/" );
			
			img_url = new URL(dir_url, "aagh_ne.gif");
			img_ne_aagh = getImage(img_url, tracker);
			img_url = new URL(dir_url, "aagh_nw.gif");
			img_nw_aagh = getImage(img_url, tracker);
			img_url = new URL(dir_url, "aagh_sw.gif");
			img_sw_aagh = getImage(img_url, tracker);
			img_url = new URL(dir_url, "aagh_se.gif");
			img_se_aagh = getImage(img_url, tracker);
			img_url = new URL(dir_url, "eyebrows.gif");
			img_eyebrowse_aagh = getImage(img_url, tracker);
			img_url = new URL(dir_url, "hair.gif");
			img_hair_aagh = getImage(img_url, tracker);
			img_url = new URL(dir_url, "specs.gif");
			img_specs_aagh = getImage(img_url, tracker);
			img_url = new URL(dir_url, "mouth.gif");
			img_mouth_aagh = getImage(img_url, tracker);
		
			images_loaded = true;
			doing_what = IMAGES_OK;
			set_status("Images were fine");
		}
	}
	
	//*******************************************************************
	synchronized int get_id()
	{
		int old_id;
		
		old_id = current_id;
		current_id ++;
		return old_id;
		
	}

	//*******************************************************************
	synchronized Image getImage( URL url, MediaTracker tracker) throws Exception
	{
		int ID;
		Image image;
		

		Thread.yield();
		
		// -----------------------------------------------
		// tell the toolkit to load an image, no point checking for
		// null as the images are loaded asynchronously
		image = getToolkit().getImage(url);
		
		// -----------------------------------------------
		// you have to use a media tracker to find out whether
		// the image was loaded
		
		ID = get_id();
		tracker.addImage(image, ID);
		tracker.waitForID(ID);
		if ( tracker.isErrorID(ID) )
		{	
			set_status("Unable to or couldnt find image:\n '" + url +"'");
			throw new IOException("Unable to or couldnt find image: '" + url +"'") ;
		}
		
		// -----------------------------------------------
		set_status( url);
		return image;
	}
	
	//*******************************************************************
	int choose_image( int the_direction)
	{
		int image_num, mutate_image;
		double normality_level;
		
		//------------------current image--------------------
		switch (the_direction)
		{
			case N:
			case S:
				image_num = SMUG1;
				break;
				
			case NE:
			case SE:
			case E:
				image_num = LOOK_LEFT;
				break;
				
			case NW:
			case W:
			case SW:
				image_num = LOOK_RIGHT;
				break;
				
			default:
				image_num = SMUG2;
				break;
		}
		
		//----------------random one -------------
		normality_level = Math.random() * 5.0;
		if (normality_level <= 1.0)
		{
			mutate_image = (int) Math.round(Math.random() * 2.0);
			switch (mutate_image)
			{
				case 0:
					image_num = LOOK_LEFT;
					break;
				case 1:
					image_num = LOOK_RIGHT;
					break;
				case 2:
					image_num = TONGUE;
					break;
			}
			
		}
		
		//----------------and the jury says--------
		return image_num;
	}
	
	//*******************************************************************
	void move_image()
	{
		int delta;
		delta = 4 * time_spent;
		switch (direction)
		{
			case N:	 			y+=delta; 	break;
			case NE: x+=delta;	y+=delta; 	break;
			case E:	 x+=delta; 				break;
			case SE: x+=delta;	y-=delta; 	break;
			case S:	 			y-=delta; 	break;
			case SW: x-=delta;	y-=delta;	break;
			case W:  x-=delta; 				break;
			case NW: x-=delta;	y+=delta; 	break;
		}
		
		if (	(x <= 0) || ( (x+IMAGE_WIDTH) >= size().width))
			x = (int) Math.round(Math.random() * (size().width - IMAGE_WIDTH) );
		
		if (	(y <= 0) || ( (y+IMAGE_HEIGHT) >= size().height))
			y = (int) Math.round(Math.random() * (size().height - IMAGE_HEIGHT));
	}
	
	//*******************************************************************
	void choose_direction()
	{
		direction = (int) Math.round((Math.random() * STOP));
		duration = (int) (Math.random() * MAX_DURATION);
		time_spent = 1;
	}
	
	//*******************************************************************
	void set_status(String message)
	{
		status = message;
		System.out.println(message);
	}
}

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