src/main/java/eu/svjatoslav/sixth/e3d/gui/UserRelativityTracker.java

   1 /*
   2  * Sixth 3D engine. Author: Svjatoslav Agejenko.
   3  * This project is released under Creative Commons Zero (CC0) license.
   4  */
   5 package eu.svjatoslav.sixth.e3d.gui;
   6
   7 import eu.svjatoslav.sixth.e3d.geometry.Point3D;
   8 import eu.svjatoslav.sixth.e3d.math.TransformsStack;
   9 import eu.svjatoslav.sixth.e3d.math.Vertex;
  10
  11 /**
  12  * Tracks the position of the user in the 3D space.
  13  * <p>
  14  * It can be used to determine the angle between the user and the object.
  15  * Also, it can be used to determine the distance between the user and the object.
  16  */
  17
  18 public class UserRelativityTracker {
  19
  20     private final static int minimalSliceFactor = 5;
  21     public Vertex center = new Vertex();
  22     public Vertex right;
  23     public Vertex down;
  24
  25     public UserRelativityTracker() {
  26
  27     }
  28
  29     public void analyze(final TransformsStack transformPipe,
  30                         final RenderingContext renderingContext) {
  31
  32         center.calculateLocationRelativeToViewer(transformPipe, renderingContext);
  33
  34         if (right != null) {
  35             right.calculateLocationRelativeToViewer(transformPipe, renderingContext);
  36             down.calculateLocationRelativeToViewer(transformPipe, renderingContext);
  37         }
  38     }
  39
  40     public void enableOrientationTracking() {
  41         right = new Vertex(new Point3D(10, 0, 0));
  42         down = new Vertex(new Point3D(0, 10, 0));
  43     }
  44
  45     public double getAngleXY() {
  46         return center.transformedCoordinate
  47                 .getAngleXY(down.transformedCoordinate);
  48     }
  49
  50     public double getAngleXZ() {
  51         return center.transformedCoordinate
  52                 .getAngleXZ(right.transformedCoordinate);
  53     }
  54
  55     public double getAngleYZ() {
  56         return center.transformedCoordinate
  57                 .getAngleYZ(down.transformedCoordinate);
  58     }
  59
  60     public double getDistanceToUser() {
  61         return center.transformedCoordinate.getVectorLength();
  62     }
  63
  64     public double proposeSliceFactor() {
  65         final double distanceToCamera = getDistanceToUser();
  66
  67         double proposedSliceFactor = distanceToCamera / 5;
  68
  69         if (proposedSliceFactor < minimalSliceFactor)
  70             proposedSliceFactor = minimalSliceFactor;
  71
  72         return proposedSliceFactor;
  73     }
  74
  75 }