/*
     Simple 3D graphics routines - academic use only - by Chuck Liang,
     Hofstra University Computer Science
*/


import java.awt.*;
import java.awt.Graphics;

class point3
{
    public int x;
    public int y;
    public int z;
    public point3(int a, int b, int c) {x=a; y=b; z=c;}
}

public class boxworld
{
    public int XDIM = 800;
    public int YDIM = 600;
    public int ZDIM = 400;   
// zoom ratio - right now, not tied to ZDIM, but probably should!
    private double ZR = 0.5;
    private double tiltR = Math.PI/2;  // tilt angle in radians
// shortening ratio (scales z axis): usually should set to one:
    private double SR = 1.0;
    public final int xshift; // static display shift values
    public final int yshift;

    public void SR(double s) {SR = s;}
    public void ZR(double z) {ZR=z;}
    public void tilt(int d) {tiltR=Math.toRadians(d);}


    public boxworld(int xd, int yd, int zd, double zr0, int trd)
    {
	XDIM=xd; YDIM=yd; ZDIM=zd;
	ZR=zr0; tiltR = Math.toRadians(trd);
        xshift = (int)(ZDIM * Math.cos(tiltR) * SR);
        yshift = (int)(ZDIM * Math.sin(tiltR) * SR);
    }

    public boxworld(int xd, int yd, int zd, double zr0, int trd, double sr0)
    {
	XDIM=xd; YDIM=yd; ZDIM=zd;
	ZR=zr0; tiltR = Math.toRadians(trd);
	SR = sr0;
        xshift = (int)(ZDIM * Math.cos(tiltR) * SR);
        yshift = (int)(ZDIM * Math.sin(tiltR) * SR);
    }

// critical function to convert 3d coordinate to 2d coordinate
    public Point point32(int x, int y, int z)
    {
      double s;  int x2; int y2;
      s = (1-((1-ZR)*(double)z/((double)ZDIM)));
      x2 = (int) ((s*x) + (z * Math.cos(tiltR) * SR));
      y2 = (int) ((s*y) + (z * Math.sin(tiltR) * SR));
      y2 += 30 + Math.abs(yshift);
      if(xshift<0) x2 -= (int)xshift;  x2 += 10;
      return new Point(x2,y2);
    } // point32

public void drawbox(Graphics brush, int x0, int y0, int z0, 
		    int xd, int yd, int zd, Color mc)
{
  int a, b, u, v, x, y, p, q;
  Point ab, xy, uv, pq;
  brush.setColor(mc);
  ab = point32(x0,y0,z0);
  xy = point32(x0+xd,y0,z0);
  uv = point32(x0,y0+yd,z0);
  pq = point32(x0+xd,y0+yd,z0);
  a = ab.x;  b = ab.y;
  x = xy.x;  y= xy.y;
  u = uv.x; v = uv.y;
  p = pq.x;  q=pq.y;
  // front
  brush.drawLine(a,b,x,y);
  brush.drawLine(a,b,u,v);
  brush.drawLine(u,v,p,q);
  brush.drawLine(p,q,x,y);
  // sides
  xy = point32(x0,y0,z0+zd);
  pq = point32(x0,y0+yd,z0+zd);
  brush.drawLine(a,b,xy.x,xy.y);
  brush.drawLine(u,v,pq.x,pq.y);
  brush.drawLine(xy.x,xy.y,pq.x,pq.y);
  ab = point32(x0+xd,y0,z0+zd);
  uv = point32(x0+xd,y0+yd,z0+zd);
  brush.drawLine(xy.x,xy.y,ab.x,ab.y);
  brush.drawLine(pq.x,pq.y,uv.x,uv.y);
  brush.drawLine(ab.x,ab.y,uv.x,uv.y);
  xy = point32(x0+xd,y0,z0);
  pq = point32(x0+xd,y0+yd,z0);
  brush.drawLine(ab.x,ab.y,xy.x,xy.y);
  brush.drawLine(uv.x,uv.y,pq.x,pq.y);
} //drawbox

public void drawline(Graphics brush, int x0, int y0, int z0, 
	      int x1, int y1, int z1, Color mc)
{  
   Point ab = point32(x0,y0,z0);
   Point xy = point32(x1,y1,z1);
   brush.setColor(mc);
   brush.drawLine(ab.x,ab.y,xy.x,xy.y);
}

// fill circle with scaled radius
public void fillcircle(Graphics brush, int x0, int y0, int z0, double r, Color mc)
{
  int x, y, rs;
  Point xy = point32(x0,y0,z0);  x = xy.x; y=xy.y;
  rs = (int) ((1-((1-ZR)*((double)z0)/ZDIM)) * r);
  if (rs<1) rs = 1; // radius can't be too small.
  brush.setColor(mc);
  brush.fillOval(x-rs,y-rs,2*rs,2*rs);
  //  MPE_Draw_circle(graph,x,y,(int)rs-2,MPE_BLACK);  // 3d effect?
}

// draw circle with scaled radius
public void drawcircle(Graphics brush, int x0, int y0, int z0, double r, Color mc)
{
  int x, y, rs;
  Point xy = point32(x0,y0,z0);  x = xy.x; y=xy.y;
  rs = (int) ((1-((1-ZR)*((double)z0)/ZDIM)) * r);
  if (rs<1) rs = 1; // radius can't be too small.
  brush.setColor(mc);
  brush.drawOval(x-rs,y-rs,2*rs,2*rs);
  //  MPE_Draw_circle(graph,x,y,(int)rs-2,MPE_BLACK);  // 3d effect?
}

// draw image to scale - w and h represent the original dimensions of the
// image
public void drawimage(Graphics brush, Image im, 
		      int x, int y, int z, int w, int h)
{
    int ws, hs;
    Point xy = point32(x,y,z);
    ws = (int)dscale(w,z);  hs = (int)dscale(h,z);
    brush.drawImage(im,xy.x,xy.y,ws,hs,null);
}

public void drawimage(Graphics brush, Image im, int x, int y, int z)
{
    int w, h, ws, hs;
    Point xy = point32(x,y,z);
    w = im.getWidth(null);
    h = im.getHeight(null);
    ws = (int)dscale(w,z);  hs = (int)dscale(h,z);
    brush.drawImage(im,xy.x,xy.y,ws,hs,null);
}

// scale size x based on z coordinate z0:
public double dscale(double x, double z0)
{
  return (1-((1-ZR)*((double)z0)/ZDIM)) * x;
}

/* monte carlo method 
public void drawmc(Graphics brush, int i, montecarlo mtc,Color mc)
{
    double x, y, z;  int a, b, c;
   for (;i>0;i--)
    {
	x = (Math.random() * XDIM) - (XDIM/2);
	y = (Math.random() * YDIM) - (YDIM/2);
	z = (Math.random() * ZDIM) - (ZDIM/2);
	a = (int) (x+ (XDIM/2));
	b = (int) (y+ (YDIM/2));
	c = (int) (z+ (ZDIM/2));
	if (mtc.p(x,y,z)) fillcircle(brush,a,b,c,2.0,mc);
    }
} // drawmc
*/


// suggested window width and height
public int wwidth() 
{ return XDIM+Math.abs(xshift)+20;}
public int wheight()
{ return YDIM+Math.abs(yshift)+40;}


}// boxworld