//javac -classpath ../jogl-1.1.1-rc7-linux-i586/lib/jogl.jar:../jogl-1.1.1-rc7-linux-i586/lib/gluegen-rt.jar:. J1_1_Point.java
//java -classpath ../jogl-1.1.1-rc7-linux-i586/lib/jogl.jar:../jogl-1.1.1-rc7-linux-i586/lib/gluegen-rt.jar:. -Djava.library.path=../jogl-1.1.1-rc7-linux-i586/lib/ J1_1_Point

//Windows:

//C:\Program Files\Java\joglprogs>javac -classpath jogl.jar;gluegen-rt.jar;. J1_1_Point.java
//C:\Program Files\Java\joglprogs>java -classpath jogl.jar;gluegen-rt.jar;. -Djava.library.path=. J1_1_Point


// gluegen-rt.dll This dll's not needed yet
// gluegen-rt.jar
// jogl.dll
// jogl.jar
// jogl_awt.dll
// jogl_cg.dll

import java.awt.*;
//import net.java.games.jogl.*;       //**Removed
import javax.media.opengl.GL;
import javax.media.opengl.*;
import javax.media.opengl.glu.GLU;

public class J1_3_Line extends J1_2_Line {

  public void display(GLAutoDrawable drawable) {
    int x0 = (int) (Math.random()*WIDTH);
    int y0 = (int) (Math.random()*HEIGHT);
    int xn = (int) (Math.random()*WIDTH);
    int yn = (int) (Math.random()*HEIGHT);

    gl.glColor3f(1,1,1);
    bresenhamLine(x0, y0, xn,yn);
  }

  void bresenhamLine(int x0, int y0, int xn, int yn) {
    int dx, dy, incrE, incrNE, d, x, y, flag=0;

    if (xn < x0) {
      int temp = x0;
      x0 = xn; xn = temp;
      temp = y0; y0 = yn; yn = temp;
    }
    if (yn < y0) {
      y0 = -y0; yn = -yn;
      flag = 10;
    }

    dy = yn - y0;
    dx = xn - x0;

    if (dx < dy) {
      int temp = x0;
      x0 = y0; y0 = temp;

      temp = xn; xn = yn; yn = temp;
      flag++;
    }

    x = x0; 
    y = y0;
    d = 2*dy - dx;
    incrE = 2*dy;
    incrNE = 2*(dy-dx);

    while (x < xn+1) {
      writepixel(x, y, flag);
      x++;
      
      if (d <= 0) {
        d += incrE;
      } else {
        y++;
	d += incrNE;
      }
    }
  }

  void writepixel(int x, int y, int flag) {
    gl.glBegin(GL.GL_POINTS);
    if (flag==0) {
      gl.glVertex2i(x, y);
    } else if (flag == -1) {
      gl.glVertex2i(y, x);    
    } else if (flag == 10) {
      gl.glVertex2i(x, -y);
    } else { //if (flag == 11) {
      gl.glVertex2i(y, -x);        
    }
    gl.glEnd();
  }
/*
 * OpenGL version:
  gl.glBegin(GL.GL_LINES);
    gl.glVertex2i(x0, y0);
    gl.glVertex2i(xn, yn);  
  gl.glEnd();
*/

  public static void main(String[] args) {
    J1_3_Line f = new J1_3_Line();
    
    f.setTitle("JOGL J1_3_Line");
    f.setSize(WIDTH, HEIGHT);
    f.setVisible(true);
  }
}