gov/nasa/worldwind/geom/Frustum.java

   1 /*
   2 Copyright (C) 2001, 2006 United States Government
   3 as represented by the Administrator of the
   4 National Aeronautics and Space Administration.
   5 All Rights Reserved.
   6 */
   7 package gov.nasa.worldwind.geom;
   8
   9 import gov.nasa.worldwind.*;
  10
  11 //todo: check javadoc accuracy,
  12
  13 /**
  14  * Instances of <code>Frustum</code> are immutable. </p>
  15  *
  16  * @author Tom Gaskins
  17  * @version $Id: Frustum.java 1774 2007-05-08 01:03:37Z dcollins $
  18  */
  19 public class Frustum
  20 {
  21     private final Plane left;
  22     private final Plane right;
  23     private final Plane bottom;
  24     private final Plane top;
  25     private final Plane near;
  26     private final Plane far;
  27
  28     /**
  29      * Create a default frustum with six <code>Plane</code>s. This defines a box of dimension (2, 2, 2) centered at the
  30      * origin.
  31      */
  32     public Frustum()
  33     {
  34         this.near = new Plane(0d, 0d, 1d, 1d);
  35         this.far = new Plane(0d, 0d, 0d - 1d, 1d);
  36         this.left = new Plane(1d, 0d, 0d, 1d);
  37         this.right = new Plane(0d - 1d, 0d, 0d, 1d);
  38         this.bottom = new Plane(0d, 1d, 0d, 1d);
  39         this.top = new Plane(0d, 0d - 1d, 0d, 1d);
  40     }
  41
  42     /**
  43      * Create a frustum from six <code>Plane</code>s, which define its boundaries. Does not except null arguments.
  44      *
  45      * @param near   the near plane
  46      * @param far    the far plane
  47      * @param left   the left side of the view frustum
  48      * @param right  the right side of the view frustm
  49      * @param top    the top of the view frustum
  50      * @param bottom the bottom of the view frustum
  51      * @throws IllegalArgumentException if any argument is null
  52      */
  53     public Frustum(Plane near, Plane far, Plane left, Plane right, Plane bottom, Plane top)
  54     {
  55         if (near == null || far == null || left == null || right == null || bottom == null || top == null)
  56         {
  57             String message = WorldWind.retrieveErrMsg("nullValue.PlaneIsNull");
  58             WorldWind.logger().log(java.util.logging.Level.FINE, message);
  59             throw new IllegalArgumentException(message);
  60         }
  61         this.near = near;
  62         this.far = far;
  63         this.left = left;
  64         this.right = right;
  65         this.bottom = bottom;
  66         this.top = top;
  67     }
  68
  69     /**
  70      * Obtain the near <code>Plane</code>.
  71      *
  72      * @return the near <code>Plane</code>
  73      */
  74     public final Plane getNear()
  75     {
  76         return this.near;
  77     }
  78
  79     /**
  80      * Obtain the far <code>Plane</code>.
  81      *
  82      * @return the far <code>Plane</code>
  83      */
  84     public final Plane getFar()
  85     {
  86         return this.far;
  87     }
  88
  89     /**
  90      * Obtain the left <code>Plane</code>.
  91      *
  92      * @return the left <code>Plane</code>
  93      */
  94     public final Plane getLeft()
  95     {
  96         return this.left;
  97     }
  98
  99     /**
 100      * Obtain the right <code>Plane</code>.
 101      *
 102      * @return the right <code>Plane</code>
 103      */
 104     public final Plane getRight()
 105     {
 106         return this.right;
 107     }
 108
 109     /**
 110      * Obtain the bottom <code>Plane</code>.
 111      *
 112      * @return the bottom <code>Plane</code>
 113      */
 114     public final Plane getBottom()
 115     {
 116         return this.bottom;
 117     }
 118
 119     /**
 120      * Obtain the top <code>Plane</code>.
 121      *
 122      * @return the top <code>Plane</code>
 123      */
 124     public final Plane getTop()
 125     {
 126         return this.top;
 127     }
 128
 129     /**
 130      * @param m
 131      * @return
 132      * @throws IllegalArgumentException if <code>m</code> is null
 133      */
 134     public final Frustum getInverseTransformed(Matrix m)
 135     {
 136         if (m == null)
 137         {
 138             String message = WorldWind.retrieveErrMsg("nullValue.MatrixIsNull");
 139             WorldWind.logger().log(java.util.logging.Level.FINE, message);
 140             throw new IllegalArgumentException(message);
 141         }
 142
 143         // Assumes orthogonal matrices with translation.
 144         Matrix it = m.getTranspose();
 145
 146         Plane n = new Plane(it.transform(this.near.getVector()));
 147         Plane f = new Plane(it.transform(this.far.getVector()));
 148         Plane l = new Plane(it.transform(this.left.getVector()));
 149         Plane r = new Plane(it.transform(this.right.getVector()));
 150         Plane b = new Plane(it.transform(this.bottom.getVector()));
 151         Plane t = new Plane(it.transform(this.top.getVector()));
 152
 153         return new Frustum(n, f, l, r, b, t);
 154     }
 155
 156     /**
 157      * @param extent
 158      * @return
 159      * @throws IllegalArgumentException if <code>extent</code> is null
 160      */
 161     public final boolean intersects(Extent extent)
 162     {
 163         if (extent == null)
 164         {
 165             String message = WorldWind.retrieveErrMsg("nullValue.ExtentIsNull");
 166             WorldWind.logger().log(java.util.logging.Level.FINE, message);
 167             throw new IllegalArgumentException(message);
 168         }
 169
 170         // See if the extent's bounding sphere is within or intersects the frustum.
 171         Point c = extent.getCenter();
 172         double nr = -extent.getRadius();
 173
 174         if (this.far.dot(c) <= nr)
 175             return false;
 176         if (this.left.dot(c) <= nr)
 177             return false;
 178         if (this.right.dot(c) <= nr)
 179             return false;
 180         if (this.top.dot(c) <= nr)
 181             return false;
 182         if (this.bottom.dot(c) <= nr)
 183             return false;
 184         //noinspection RedundantIfStatement
 185         if (this.near.dot(c) <= nr)
 186             return false;
 187
 188         return true;
 189     }
 190
 191     /**
 192      * @param point
 193      * @return
 194      * @throws IllegalArgumentException if <code>point</code> is null
 195      */
 196     public final boolean contains(Point point)
 197     {
 198         if (point == null)
 199         {
 200             String message = WorldWind.retrieveErrMsg("nullValue.PointIsNull");
 201             WorldWind.logger().log(java.util.logging.Level.FINE, message);
 202             throw new IllegalArgumentException(message);
 203         }
 204
 205         if (this.far.dot(point) < 0)
 206             return false;
 207         if (this.left.dot(point) < 0)
 208             return false;
 209         if (this.right.dot(point) < 0)
 210             return false;
 211         if (this.top.dot(point) < 0)
 212             return false;
 213         if (this.bottom.dot(point) < 0)
 214             return false;
 215         //noinspection RedundantIfStatement
 216         if (this.near.dot(point) < 0)
 217             return false;
 218
 219         return true;
 220     }
 221
 222     @Override
 223     public String toString()
 224     {
 225         return "near: " + near.toString() + "... far: " + far.toString() + "... left: " + left.toString()
 226             + "... right: " + right.toString() + "... bottom: " + bottom.toString() + "... top: " + top.toString();
 227     }
 228
 229     @Override
 230     public boolean equals(Object o)
 231     {
 232         if (this == o)
 233             return true;
 234         if (o == null || getClass() != o.getClass())
 235             return false;
 236
 237         final gov.nasa.worldwind.geom.Frustum frustum = (gov.nasa.worldwind.geom.Frustum) o;
 238
 239         if (!bottom.equals(frustum.bottom))
 240             return false;
 241         if (!far.equals(frustum.far))
 242             return false;
 243         if (!left.equals(frustum.left))
 244             return false;
 245         if (!near.equals(frustum.near))
 246             return false;
 247         if (!right.equals(frustum.right))
 248             return false;
 249         //noinspection RedundantIfStatement
 250         if (!top.equals(frustum.top))
 251             return false;
 252
 253         return true;
 254     }
 255
 256     @Override
 257     public int hashCode()
 258     {
 259         int result;
 260         result = near.hashCode();
 261         result = 31 * result + far.hashCode();
 262         result = 29 * result + left.hashCode();
 263         result = 23 * result + right.hashCode();
 264         result = 19 * result + bottom.hashCode();
 265         result = 17 * result + top.hashCode();
 266         return result;
 267     }
 268 }