import java.awt.*;
import java.util.*;
import java.io.*;
import java.lang.*;

public class Renderer extends Object implements Serializable
{
    private World world;
    public Scanline line;
    
    public Renderer()
    {
	// System.out.println("Calling Renderer()...");
	world = new World();
	// System.out.println("Completed Renderer().");
    }
    
    public Renderer(World worldin)
    {
	// System.out.println("Calling Renderer()...");
	world = worldin;
	// System.out.println("Completed Renderer().");	
    }
    
    public void zbuffer(Graphics g, Graphics g2, Dimension bounds)
    {
	int maxj = bounds.height;		
	for (int j=0; j<maxj; j++)		
	{
	    
	}	
    }
    
    public Scanline calculateOneScanline(Dimension bounds, int j)
    {
	double[] zbuffer = new double[bounds.width];
	int[] whichbuffer = new int[bounds.width];
	double currentz;
	Color backdropColor = world.getBackdropColor();

	// long start = System.currentTimeMillis();
	// System.out.println("Start time is " + start);
	
	int maxi = bounds.width;
	int whalf = bounds.width/2;
	int hhalf = bounds.height/2;		

	if (line == null)
	{
	    line = new Scanline(bounds.width);
	}

	for (int i=0; i<maxi; i++)
	{
	    zbuffer[i] = Double.NEGATIVE_INFINITY;
	    whichbuffer[i] = -1;
	    for (int k=0; k<world.nItems; k++)
	    {
		if (world.items[k].contains(i-whalf,hhalf-j))
		{
		    try
		    {
			currentz = world.items[k].zIntersect(i-whalf,hhalf-j);
			if (currentz >= zbuffer[i])
			{
			    zbuffer[i] = currentz;
			    whichbuffer[i] = k;
			}
		    }
		    catch (ItemException pe)
		    {
			System.out.println("ItemException in zbuffer: "
			    + pe.getMessage());					
		    }
		}
	    }
	}
	
	for (int i=0; i<maxi; i++) 
	{
	    if (whichbuffer[i] == -1) 
	    {
		line.values[i] = backdropColor; 
	    }
	    else 
	    {
		line.values[i] = world.getColorAtItem(whichbuffer[i],
		    i-whalf, hhalf-j, zbuffer[i]);
	    }
	}

	// long stop = System.currentTimeMillis();
	// System.out.println("Total time is " + (stop-start));
	
	return line;
    }
}