import java.applet.*;
import java.awt.*;
import java.io.*;
import java.net.*;
import Point3D;
import Matrix3D;

public class MyTestMatrix extends Applet {
  final static int CHUNKSIZE = 100;
  Raster raster;
  Image screen;
  Point3D vertList[];
  Point3D worldList[];
  Point3D tranList[];
  int vertices;
  Matrix3D view;
  Matrix3D model;
  String me;
  String me2;
  float eyex, eyey, eyez;
  float lookatx, lookaty, lookatz;
  float upx, upy, upz;
  float fov;
  
  public void init() {
    raster = new Raster(size().width, size().height);
    raster.fill(getBackground());
    screen = raster.toImage();
    
    eyex = 0;        eyey = 0;        eyez = -10;
    lookatx = 0;     lookaty = 0;     lookatz = 0;
    upx = 0;         upy = 1;         upz = 0;
    fov = 30;
    
    vertList = new Point3D[CHUNKSIZE];
    vertices = 0;
    
    String filename = getParameter("datafile");
    showStatus("Reading "+filename);
    InputStream is = null;
    try {
      is = new URL(getDocumentBase(), filename).openStream();
      ReadInput(is);
      is.close();
    } catch (IOException e) {
      showStatus("Error reading "+filename);
    }
    
    worldList = new Point3D[vertList.length];
    tranList = new Point3D[vertList.length];
    for (int i = 0; i < vertices; i++) {
      worldList[i] = new Point3D();
      tranList[i] = new Point3D();
    }
    
    view = new Matrix3D(raster);
    me2 = view.toString();
    float t = (float) Math.sin(Math.PI*(fov/2)/180);
    float s = (t*size().height)/size().width;
    
    view.perspective(-t, t, -s, s, -1, -200);
    view.lookAt(eyex, eyey, eyez, lookatx, lookaty, lookatz, upx, upy, upz);
    me2 = view.toString();
    
    model = new Matrix3D();
    me = model.toString();
    long time = System.currentTimeMillis();
    model.transform(vertList, worldList, 0, vertices);
    view.transform(worldList, tranList, 0, vertices);
    DrawObject();
    time = System.currentTimeMillis() - time;
    showStatus("Time = "+time+" ms");
    screen = raster.toImage();
  }
  
  private double getNumber(StreamTokenizer st) throws IOException
  {
    if (st.nextToken() != StreamTokenizer.TT_NUMBER) {
      System.err.println("ERROR: line "+st.lineno()+": expected number");
      throw new IOException(st.toString());
    }
    return st.nval;
  }
  
  public void ReadInput(InputStream is) throws IOException
  {
    StreamTokenizer st = new StreamTokenizer(is);
    st.commentChar('#');
  scan: while (true) {
    switch (st.nextToken()) {
    default:
      break scan;
    case StreamTokenizer.TT_WORD:
      if (st.sval.equals("v")) {
	float x = (float) getNumber(st);
	float y = (float) getNumber(st);
	float z = (float) getNumber(st);
	if (vertices == vertList.length) {
	  Point3D newList[] = new Point3D[vertList.length+CHUNKSIZE];
	  System.arraycopy(vertList, 0, newList, 0, vertList.length);
	  vertList = newList;
	}
	vertList[vertices++] = new Point3D(x, y, z);
      } else
	if (st.sval.equals("eye")) {
	  eyex = (float) getNumber(st);
	  eyey = (float) getNumber(st);
	  eyez = (float) getNumber(st);
	} else
	  if (st.sval.equals("look")) {
	    lookatx = (float) getNumber(st);
	    lookaty = (float) getNumber(st);
	    lookatz = (float) getNumber(st);
	  } else
	    if (st.sval.equals("up")) {
	      upx = (float) getNumber(st);
	      upy = (float) getNumber(st);
	      upz = (float) getNumber(st);
	    } else
	      if (st.sval.equals("fov")) {
		fov = (float) getNumber(st);
	      } else {
		System.err.println("ERROR: line "+st.lineno()+": unexpected token :"+st.sval);
		break scan;
	      }
      break;
    }
    if (vertices % 100 == 0) showStatus("vertices = " + vertices);
  }
  is.close();
  if (st.ttype != StreamTokenizer.TT_EOF) {
    throw new IOException(st.toString());
  }
  }
  
  public void paint(Graphics g)
  {
    g.drawImage(screen, 0, 0, this);
    showStatus(me2);
  }
  
  public void update(Graphics g)
  {
    paint(g);
  }
  
  float v0x, v0y, v0z;

  public boolean mouseDown(Event e, int x, int y)
  {
    if (e.metaDown()) {
      showStatus("Resetting model matrix");
      model.loadIdentity();
    }
    v0x = (float) (x - (size().width / 2));
    v0y = (float) ((size().height / 2) - y);
    v0z = (float) size().width;
    float l0 = (float) (1 / Math.sqrt(v0x*v0x + v0y*v0y + v0z*v0z));
    v0x *= l0;
    v0y *= l0;
    v0z *= l0;
    return true;
  }
  
  public boolean mouseDrag(Event e, int x, int y)
  {
    if (e.metaDown()) {
      showStatus("Resetting model matrix");
    }
    else {
      float v1x = (float) (x - (size().width / 2));
      float v1y = (float) ((size().height / 2) - y);
      float v1z = (float) size().width;
      if (e.controlDown() && e.shiftDown()) {
	// control and shift keys = skew
	showStatus("Skewing...");
      }
      else if (e.controlDown()) {
	// control key = scale
	showStatus("Scaling...");
      }
      else if (e.shiftDown()) {
	// shift key = translate
	showStatus("Translating...");
      }
      else {
	// no keys = rotate
	float l = (float) (1 / Math.sqrt(v1x*v1x + v1y*v1y + v1z*v1z));
	v1x *= l;
	v1y *= l;
	v1z *= l;
	
	float ax = v0y*v1z - v0z*v1y;
	float ay = v0z*v1x - v0x*v1z;
	float az = v0x*v1y - v0y*v1x;
	l = (float) Math.sqrt(ax*ax + ay*ay + az*az);
	float theta = (float) Math.asin(l);
	if (v0x*v1x + v0y*v1y + v0z*v1z < 0)
	  theta += (float) Math.PI / 2;
	model.rotate(ax, ay, az, theta);
	showStatus("Rotating...");
      }
      v0x = v1x;
      v0y = v1y;
      v0z = v1z;
      model.transform(vertList, worldList, 0, vertices);
      view.transform(worldList, tranList, 0, vertices);
      DrawObject();
    }
    screen = raster.toImage();
    repaint();
    return true;
  }
  
  void DrawObject()
  {
    int ix, iy;
    int w, h;
    w = raster.width;
    h = raster.height;
    raster.fill(getBackground());
    for (int i = 0; i < vertices; i++) {
      ix = (int) tranList[i].x;
      iy = (int) tranList[i].y;
      if (ix >= 0 && iy >= 0 && ix < w && iy < h)
	raster.setPixel(0xffa000a0, ix, iy);
    }
  }
  
}