Computer Graphics for Java Programmers, Second Edition

Appendix D. Class CvHLines.java

The following class is used in program HLines.java, listed in Section 6.8:

// CvHLines.java: Used in the file HLines.java.
import java.awt.*;
import java.util.*;

class CvHLines extends Canvas3D
{  private int maxX, maxY, centerX, centerY, nTria, nVertices;
   private Obj3D obj;
   private Point2D imgCenter;
   private Tria[] tr;
   private HPGL hpgl;
   private int[] refPol;
   private int[][] connect;
   private int[] nConnect;
   private int chunkSize = 4;
   private double hLimit;
   private Vector polyList;
   private float maxScreenRange;

   Obj3D getObj(){return obj;}
   void setObj(Obj3D obj){this.obj = obj;}

void setHPGL(HPGL hpgl){this.hpgl = hpgl;} public void paint(Graphics g) { if (obj == null) return; Vector polyList = obj.getPolyList(); if (polyList == null) return; int nFaces = polyList.size(); if (nFaces == 0) return; float xe, ye, ze; Dimension dim = getSize(); maxX = dim.width - 1; maxY = dim.height - 1; centerX = maxX/2; centerY = maxY/2; // ze-axis towards eye, so ze-coordinates of // object points are all negative. Since screen // coordinates x and y are used to interpolate for // the z-direction, we have to deal with 1/z instead // of z. With negative z, a small value of 1/z means // a small value of |z| for a nearby point. // obj is a java object that contains all data, // with w, e and vScr parallel (with vertex numbers // as index values): // - Vector w (with Point3D elements) // - Array e (with Point3D elements) // - Array vScr (with Point2D elements) // - Vector ...