How to not click the applet to start

[litton1]

Hi all,
I have been going through a terrain generation program/tutorial. It works well and has facilities for zooming in and out as well as some other stuff but before anything can be done with the applet the user has to click the screen, I would like to remove this so that when the applet is loaded up it is good to go. Could someone please tell me what I am looking for? Sorry very new to java. Is there anything I should have told you but have not?
Thanks for your help in advance.


Binary Intelligence, true or false?

 

[sedj]

Just put the applet tag in the body of the html page ?

--------------------------------------------------
Free Java/J2EE Database Connection Pooling Software

http://www.primrose.org.uk

 

[litton1]

thx for the reply,
not sure what you mean by that sorry. If it wasn’t in the body how would it load?

I think that the applet is prevented from continuing from within the code. I tried commenting out a few bits

enableEvents (AWTEvent.KEY_EVENT_MASK | AWTEvent.MOUSE_EVENT_MASK);
	    requestFocus ();

just to see what happened but it just halted the whole thing. I cannot actually find on the web what this does?


Binary Intelligence, true or false?

 

[sedj]

Perhaps you should explain a little more about what you mean by "has to click the screen" - I imagined you were talking about clicking an HTML/Javascript option to load the Applet, not within the actual Java code ... if you think that the above code is "stopping the applet loading" then that is not the actual case - to have your applet "halt" on that code means by definition that the applet has actually loaded ...

--------------------------------------------------
Free Java/J2EE Database Connection Pooling Software

http://www.primrose.org.uk

 

[litton1]

Yes I will explain more and sorry for the confusion.

The applet loads a 3D terrain and renders to the frame but before you can zoom into the terrain (or do anything else for that matter) you must click the terrain in the applet. Hope that is clearer?


Binary Intelligence, true or false?

 

[litton1]

it could be this part as it is getting a mouse event and requesting focus (to the frame i guess)
so how would i bypass this so the frame has got the focus when the applet loads? i have tried putting the requestFocus() in the init() but that didnt work

protected void processMouseEvent (MouseEvent ev) 
	{
		if (ev.getID () == MouseEvent.MOUSE_PRESSED)
	    	requestFocus ();
	    super.processMouseEvent (ev);
	}

thanks again

Binary Intelligence, true or false?

 

[sedj]

So you need to work out then what method/event occurs when the mouse is clicked - once you find this, then you can add the method to the init().

--------------------------------------------------
Free Java/J2EE Database Connection Pooling Software

http://www.primrose.org.uk

 

[Diancecht]

Maybe you can look for focusGained method.

Cheers,
Dian

 

[litton1]

Thanks for the prompt but it was not there lol
I am stumped?
I am including the cut down code (sorry but there is still quite a bit which is the reason I haven’t already included it) just in case some guru can spot it at a quick glance

import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.awt.Graphics;
import java.awt.Font;
import java.awt.Color;

public class Landscape extends Applet 
{

	// lod = Level Of Detail
	// if step is 1 and lod is five then step becomes 32 
	// (binary shift 5 places) this is how 
	//the level of detail is organised.
	private static final int lod = 5, steps = 1 << lod;
	
	//was 0.5 how rough do we want the terrain .1 is 
	//very smooth but .5 is very very rough
	private static final double roughness = 0.2;
	
	//was  0.7, the exaggeration is 
	private static final double exaggeration = 0.2;
	
	//how bright?
	private static final double ambient = 0.2;
	
	//for the render was .7
	private static final double diffuse = 0.7;
	private static final double strength = 8.0;
	
	static final double hither = .1;
	
	// PI=3.14159265 /6 = 0.523598775
	//set the zoom on start up of applet
	static final double fov = Math.PI / 6;
	
	private Terrain terrain;
	private int width, height;
	
	private Triple[][] map;
	private RGB[][] colors;
	private double[][] shade;
	private Triple[][] normals;
	private Triple[][] eyeMap;
	private XY[][] scrMap;
	
	private int numTriangles = steps * steps * 2;
	private Triangle[] triangles;
	
	private Triple sun = new Triple (3.6, 1.5, 0.6);
	private Triple loc = new Triple (0.4, 2.4, -1.6);
	private Quaternion rot = Quaternion.newRotation (-.82, 1.0, 0.0, 0.0);
	
	private Rasteriser rasteriser;
	Font f = new Font("TimesRoman",Font.BOLD,12);
	String name;
	String message;

	public void init () 
  	{
  		//pick the frame background colour, white is good :)
    	setBackground (Color.white);
	
		//make a map
	    map = new Triple[steps + 1][steps + 1];
	   	colors = new RGB[steps + 1][steps + 1];
	    shade = new double[steps + 1][steps + 1];
	    normals = new Triple[steps + 1][steps + 1];
	    eyeMap = new Triple[steps + 1][steps + 1];
	    scrMap = new XY[steps + 1][steps + 1];
	    triangles = new Triangle[numTriangles];
	
	    terrain = new FractalTerrain (lod, roughness);

    	// fill in vertices
	    for (int i = 0; i <= steps; ++ i) {
	      for (int j = 0; j <= steps; ++ j) {
	        double x = 1.0 * i / steps, z = 1.0 * j / steps;
	        double altitude = exaggeration * terrain.getAltitude (x, z);
	        map[i][j] = new Triple (x, altitude, z);
	        colors[i][j] = terrain.getColor (x, z);
	        shade[i][j] = 1.0;
	        normals[i][j] = new Triple (0.0, 0.0, 0.0);
	      }
	    }

	    // set up tessellation
	    int triangle = 0;
	    for (int i = 0; i < steps; ++ i) {
	      for (int j = 0; j < steps; ++ j) {
	        triangles[triangle ++] = new Triangle (i, j, i + 1, j, i, j + 1);
	        triangles[triangle ++] = new Triangle (i + 1, j, i + 1, j + 1, i, j + 1);
	      }
	    }

	    // compute triangle and vertex normals
	    for (int i = 0; i < numTriangles; ++ i) {
	      Triple v0 = map[triangles[i].i[0]][triangles[i].j[0]],
	        v1 = map[triangles[i].i[1]][triangles[i].j[1]],
	        v2 = map[triangles[i].i[2]][triangles[i].j[2]];
	      Triple normal = v0.subtract (v1).cross (v2.subtract (v1)).normalise ();
	      triangles[i].n = normal;
	      for (int j = 0; j < 3; ++ j) {
	        normals[triangles[i].i[j]][triangles[i].j[j]] =
	          normals[triangles[i].i[j]][triangles[i].j[j]].add (normal);
	      }
	    }

	    // compute vertex shadows
	    for (int i = 0; i <= steps; ++ i) 
	    {
	 		for (int j = 0; j <= steps; ++ j) 
	 		{
	        	shade[i][j] = 1.0;
	        	Triple vertex = map[i][j];
	        	Triple ray = sun.subtract (vertex);
	        	double distance = steps * Math.sqrt (ray.x * ray.x + ray.z * ray.z);
	        	/* step along ray in horizontal units of grid width */
	        	for (double place = 1.0; place < distance; place += 1.0) 
	        	{
	          		Triple sample = vertex.add (ray.scale (place / distance));
	          		double sx = sample.x, sy = sample.y, sz = sample.z;
	          		if ((sx < 0.0) || (sx > 1.0) || (sz < 0.0) || (sz > 1.0))
	            		break; /* stepped off terrain */
	          		double ground = exaggeration * terrain.getAltitude (sx, sz);
	          		if (ground >= sy) 
	          		{
	            		shade[i][j] = 0.0;
	            		break;
	          		}
	        	}
	      	}
	    }

	    // compute triangle and vertex colors
	    for (int i = 0; i < numTriangles; ++ i) 
	    {
	    	RGB average = new RGB (0.0, 0.0, 0.0);
	      	for (int j = 0; j < 3; ++ j) 
	      	{
	        	int k = triangles[i].i[j], l = triangles[i].j[j];
	        	Triple vertex = map[k][l];
	        	RGB color = colors[k][l];
	        	double shadow = shade[k][l];
	        	Triple normal = normals[k][l].normalise ();
	        	Triple light = vertex.subtract (sun);
	        	double distance2 = light.length2 ();
	        	double dot = light.normalise ().dot (normal);
	        	double lighting = ambient;
	        	if (dot < 0.0) // add diffuse lighting
	          		lighting -= strength * diffuse * dot * shadow / distance2;
	        	color = color.scale (lighting);
	        	triangles[i].rgb[j] = color;
	        	average = average.add (color);
	      	}
	      	triangles[i].color = new Color (average.scale (1.0 / 3.0).toRGB ());
	    }

	    width = getSize ().width / 2;
	    height = getSize ().height;
	
	    worldToEye ();
	    eyeToScreen ();

	    //check that rasterizer width and height are not empty if they
	    //are then pass in the width and height(NOTE: the width is half 
	    //the applet width). 
		if (rasteriser == null) 
	    {
	    	rasteriser = new Rasteriser (width, height);
	     	//create a canvas to draw the high quality picture to
	     	
	       	Viewer viewer = new Viewer (rasteriser);
	       	
	       	//make a flowlayout and put it on the right side of the applet 
	      	setLayout (new FlowLayout (FlowLayout.RIGHT, 0, 0));
	      	add (viewer);
	    }
	    else
	    {
	    	rasteriser = new Rasteriser (width + width, height);
	     	//create a canvas to draw the high quality picture to
	     	
	       	Viewer viewer = new Viewer (rasteriser);
	       	
	       	//make a flowlayout and put it on the right side of the applet 
	      	setLayout (new FlowLayout (FlowLayout.LEFT, 0, 0));
	      	add (viewer);
	    }
	    
	    enableEvents (AWTEvent.KEY_EVENT_MASK | AWTEvent.MOUSE_EVENT_MASK);
	    requestFocus ();
    
		this.name = getParameter("name");
		if (this.name == null)
			this.name = "Tony";
		
		this.name = "Hello " + this.name + "!";
		this.message = "paint called";
		repaint ();
		requestFocus ();
	
  	}
  	
  	public void start()
  	{
  		requestFocus ();
  	}

	protected void processMouseEvent (MouseEvent ev) 
	{
		if (ev.getID () == MouseEvent.MOUSE_PRESSED)
	    	requestFocus ();
	    super.processMouseEvent (ev);
	}

  	protected void processKeyEvent (KeyEvent ev) 
  	{
  		double r, x, y, z;
    	if (ev.getID () != KeyEvent.KEY_PRESSED) 
    	{
      		super.processKeyEvent (ev);
      		return;
    	}
    
    	int key = ev.getKeyCode ();
    	// rotate but which way
    	if ((key == KeyEvent.VK_UP) || (key == KeyEvent.VK_DOWN) || (key == KeyEvent.VK_LEFT) || (key == KeyEvent.VK_RIGHT) || (key == KeyEvent.VK_COMMA) || (key == KeyEvent.VK_PERIOD)) 
    	{
      		r = ((key == KeyEvent.VK_DOWN) || (key == KeyEvent.VK_RIGHT) || (key == KeyEvent.VK_PERIOD)) ?  - Math.PI / 64 : Math.PI / 64;
                  
      		x = ((key == KeyEvent.VK_UP) || (key == KeyEvent.VK_DOWN)) ? 1.0 : 0.0;
        	y = ((key == KeyEvent.VK_LEFT) || (key == KeyEvent.VK_RIGHT)) ? 1.0 : 0.0;
        	z = ((key == KeyEvent.VK_COMMA) || (key == KeyEvent.VK_PERIOD)) ? 1.0 : 0.0;
      		Quaternion delta = Quaternion.newRotation (r, x, y, z);
			
			// rot is rotation
      		rot = delta.multiply (rot);
    
      		worldToEye ();
      		eyeToScreen ();
      		repaint ();
    	} 
    	//z = bigger x = smaller
    	else if ((key == KeyEvent.VK_Z) || (key == KeyEvent.VK_X)) 
    	{	//make bigger: move the map closer or smaller
      		z = (key == KeyEvent.VK_Z) ? 1.0 / 8: -1.0 / 8;
      		Triple delta = new Triple (0.0, 0.0, z);
      		Quaternion tmp = rot.inverse ();
      		Triple deltar = tmp.rotate (delta);
      		loc = loc.add (deltar);
      
      		worldToEye ();
      		eyeToScreen ();
      		repaint ();
    		// rasterize
    	} 
    	else if (key == KeyEvent.VK_ENTER) //rasterise it
    	{
      		rasteriser.clear ();
      		enterKeyPressed();
      		rasteriser.update ();  
      		//rasteriser.savePPM("c:\terrain\testoutput.txt");  	
    	} 
    	else if (key == KeyEvent.VK_SPACE) // make a new landscape
    	{
    		initalSetup ();
    		
    		//this is sort of a clipping affect as it 
    		// only paints half the applet
   	 		repaint (0, 0, width, height);
		}
    	super.processKeyEvent (ev);
    }

 	private void worldToEye () 
 	{
    	for (int i = 0; i <= steps; ++ i) 
    	{
      		for (int j = 0; j <= steps; ++ j) 
      		{
        		Triple p = map[i][j];
        		Triple t = p.subtract (loc);
        		Triple r = rot.rotate (t);
        		eyeMap[i][j] = r;
      		}
    	}
  	}

	private void eyeToScreen () 
	{
    	double scale = width / 2 / Math.tan (fov / 2);
    	for (int i = 0; i <= steps; ++ i) 
    	{
      		for (int j = 0; j <= steps; ++ j) 
      		{
        		Triple p = eyeMap[i][j];
        		double x = p.x, y = p.y, z = p.z;
        		if (z >= hither) 
        		{
          			double tmp = scale / z;
          			scrMap[i][j] = new XY (width / 2 + (int) (x * tmp), height / 2 - (int) (y * tmp));
        		} 
        		else 
        		{
          			scrMap[i][j] = null;
        		}
      		}
    	}
  	}

  	public void paint (Graphics g) 
 	{
 		g.setFont(f);
 		g.setColor(Color.black);
 		
		g.drawString(this.name, 5, 50);
		
		//draw the map :)
 		for (int i = 0; i < numTriangles; ++ i) 
    	{
      		XY xy0 = scrMap[triangles[i].i[0]][triangles[i].j[0]],
        	xy1 = scrMap[triangles[i].i[1]][triangles[i].j[1]],
        	xy2 = scrMap[triangles[i].i[2]][triangles[i].j[2]];
      		double dot =- map[triangles[i].i[0]][triangles[i].j[0]].subtract (loc).normalise ().dot (triangles[i].n);
      		if ((dot > 0.0) && (xy0 != null) && (xy1 != null) && (xy2 != null)) 
      		{
        		int[] x = { xy0.x, xy1.x, xy2.x }, y = { xy0.y, xy1.y, xy2.y };
        		g.setColor (triangles[i].color);
        		g.fillPolygon (x, y, 3);
      		}
    	}    
    
  	}

	public Dimension getPreferredSize () 	
	{
    	//set size of the black area
    	//return new Dimension (512, 256);
    	return new Dimension (1000, 500);
  	}
  	
  	private void enterKeyPressed()
  	{
		for (int i = 0; i < numTriangles; ++ i) 
  		{
    		XY xy0 = scrMap[triangles[i].i[0]][triangles[i].j[0]],
      			xy1 = scrMap[triangles[i].i[1]][triangles[i].j[1]],
      			xy2 = scrMap[triangles[i].i[2]][triangles[i].j[2]];
    		double dot = - map[triangles[i].i[0]][triangles[i].j[0]].subtract (loc).normalise ().dot (triangles[i].n);
    		dot = 1.0;
    		if ((dot > 0.0) && (xy0 != null) && (xy1 != null) && (xy2 != null)) 
    		{
      			double z0 = eyeMap[triangles[i].i[0]][triangles[i].j[0]].z,
        		z1 = eyeMap[triangles[i].i[1]][triangles[i].j[1]].z,
        		z2 = eyeMap[triangles[i].i[2]][triangles[i].j[2]].z;
      				Vertex v0 = new Vertex (xy0, z0, triangles[i].rgb[0]),
        			v1 = new Vertex (xy1, z1, triangles[i].rgb[1]),
        		v2 = new Vertex (xy2, z2, triangles[i].rgb[2]);
      			rasteriser.rasterise (v0, v1, v2);
    		}
  		}
  	}
  	
	public void	initalSetup()
  	{
  		
  	}
  	
	//start the program
  	public static void main (String[] args) 
  	{
  		//create a frame to paint on
    	Frame frame = new Frame ("Landscape");
    	
    	//make an instance of landscape
    	Landscape landscape = new Landscape ();
    	
    	//add the landscape to the frame
    	frame.add (landscape, "Center");
    	
    	frame.pack ();
    	
    	// call init() in the landscape object 
    	landscape.init ();
    	
    	// make the frame visible
    	frame.setVisible (true);
    	
  	}
}

Binary Intelligence, true or false?

 

[litton1]

just to finish the post with a solution

i have changed this

    protected void processMouseEvent (MouseEvent ev) 
    {
        if (ev.getID () == MouseEvent.MOUSE_PRESSED)
            requestFocus ();
        super.processMouseEvent (ev);
    }

            protected void processKeyEvent (KeyEvent ev) 
      {
          double r, x, y, z;
        if (ev.getID () != KeyEvent.KEY_PRESSED) 
        {
              super.processKeyEvent (ev);
              return;
        }
    
        int key = ev.getKeyCode ();
        // rotate but which way
        if ((key == KeyEvent.VK_UP) || (key == KeyEvent.VK_DOWN) || (key == KeyEvent.VK_LEFT) || (key == KeyEvent.VK_RIGHT) || (key == KeyEvent.VK_COMMA) || (key == KeyEvent.VK_PERIOD)) 
        {
              r = ((key == KeyEvent.VK_DOWN) || (key == KeyEvent.VK_RIGHT) || (key == KeyEvent.VK_PERIOD)) ?  - Math.PI / 64 : Math.PI / 64;
                  
              x = ((key == KeyEvent.VK_UP) || (key == KeyEvent.VK_DOWN)) ? 1.0 : 0.0;
            y = ((key == KeyEvent.VK_LEFT) || (key == KeyEvent.VK_RIGHT)) ? 1.0 : 0.0;
            z = ((key == KeyEvent.VK_COMMA) || (key == KeyEvent.VK_PERIOD)) ? 1.0 : 0.0;

to this

 public boolean keyDown( Event e, int key ) 
 {
    // rotate but which way
    if ((key == Event.UP) || (key == Event.DOWN) || (key == Event.LEFT) || (key == Event.RIGHT) || (key == ',') || (key == '.')) 
    	{
      		double r = ((key == Event.DOWN) || (key == Event.RIGHT) || (key == '.')) ?  - Math.PI / 64 : Math.PI / 64;
                  
      		double x = ((key == Event.UP) || (key == Event.DOWN)) ? 1.0 : 0.0,
        	y = ((key == Event.LEFT) || (key == Event.RIGHT)) ? 1.0 : 0.0,
        	z = ((key == ',') || (key == '.')) ? 1.0 : 0.0;

this now prevents me from having to click the applet

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