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geometry

Timestamp:

Jun 24, 2010, 10:38:40 PM (15 years ago)

Author:

James Hudson

Message:

Fixed a few unit test errors.

Location:

trunk/anuga_core/source/anuga/geometry

Files:

-                      r7861
+                      r7872
 class AABB:
+    """Axially-aligned bounding box class.
+       Defines a box which can check for intersections with other boxes,
+       or if a point lies within it.
+    """ Axially-aligned bounding box class.
+        An axially aligned bounding box (or AABB) defines a box-shaped region
+        of the plane which contains any other arbitrary geometry.
+        It is useful because intersections can be tested against it very
+        rapidly. Once all misses are trivially rejected, a more expensive
+        collision detection can be done against the remaining geometry.
+        This class defines a box which can check for intersections with other
+        boxes, or points. It can also subdivide itself, returning
+        smaller AABBs. This can be used as the basis of a recursive tree
+        structure for optimising geometry searches.
     """

-                      r7866
+                      r7872
 class Cell():
     """class Cell
     One cell in the plane.
+    """ One cell in the plane.
+        A cell is defined by an AABB, and can have smaller AABB children.
+        The children can be rapidly searched for intersections in log(n) time.
     """
 …
     def __repr__(self):
+        """ String representation of the quadtree. """
         ret_str = '%s: leaves: %d' \
                % (self.name , len(self.leaves))
 …
                     #return
+            # option 2 - try splitting 2 ways - no diff noticed in practise
+            # option 2 - try splitting 2 ways - no performance difference
+            # noticed in practise between this and the above option.
             if subregion1.is_trivial_in(new_region):
                 self.children = [Cell(subregion1, self), \
 …
     def test_leaves(self, point):
+        """ Test all leaves to see if they intersect x.
+        """ Test all leaves on this node to see if they intersect x.
+            Does not recurse into children.
             x is a point to test
             return a list of leaves that intersect x

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