+++ /dev/null
-"""
-A Bounding Box object and assorted utilities , subclassed from a numpy array
-
-"""
-
-import numpy as N
-
-class BBox(N.ndarray):
- """
- A Bounding Box object:
-
- Takes Data as an array. Data is any python sequence that can be turned into a
- 2x2 numpy array of floats:
-
- [[MinX, MinY ],
- [MaxX, MaxY ]]
-
- It is a subclass of numpy.ndarray, so for the most part it can be used as
- an array, and arrays that fit the above description can be used in its place.
-
- Usually created by the factory functions:
-
- asBBox
-
- and
-
- fromPoints
-
- """
- def __new__(subtype, data):
- """
- Takes Data as an array. Data is any python sequence that can be turned into a
- 2x2 numpy array of floats:
-
- [[MinX, MinY ],
- [MaxX, MaxY ]]
-
- You don't usually call this directly. BBox objects are created with the factory functions:
-
- asBBox
-
- and
-
- fromPoints
-
- """
- arr = N.array(data, N.float)
- arr.shape = (2,2)
- if arr[0,0] > arr[1,0] or arr[0,1] > arr[1,1]:
- # note: zero sized BB OK.
- raise ValueError("BBox values not aligned: \n minimum values must be less that maximum values")
- return N.ndarray.__new__(BBox, shape=arr.shape, dtype=arr.dtype, buffer=arr)
-
- def Overlaps(self, BB):
- """
- Overlap(BB):
-
- Tests if the given Bounding Box overlaps with this one.
- Returns True is the Bounding boxes overlap, False otherwise
- If they are just touching, returns True
- """
-
- if ( (self[1,0] >= BB[0,0]) and (self[0,0] <= BB[1,0]) and
- (self[1,1] >= BB[0,1]) and (self[0,1] <= BB[1,1]) ):
- return True
- else:
- return False
-
- def Inside(self, BB):
- """
- Inside(BB):
-
- Tests if the given Bounding Box is entirely inside this one.
-
- Returns True if it is entirely inside, or touching the
- border.
-
- Returns False otherwise
- """
- if ( (BB[0,0] >= self[0,0]) and (BB[1,0] <= self[1,0]) and
- (BB[0,1] >= self[0,1]) and (BB[1,1] <= self[1,1]) ):
- return True
- else:
- return False
-
- def Merge(self, BB):
- """
- Joins this bounding box with the one passed in, maybe making this one bigger
-
- """
-
- if BB[0,0] < self[0,0]: self[0,0] = BB[0,0]
- if BB[0,1] < self[0,1]: self[0,1] = BB[0,1]
- if BB[1,0] > self[1,0]: self[1,0] = BB[1,0]
- if BB[1,1] > self[1,1]: self[1,1] = BB[1,1]
-
- ### This could be used for a make BB from a bunch of BBs
-
- #~ def _getboundingbox(bboxarray): # lrk: added this
- #~ # returns the bounding box of a bunch of bounding boxes
- #~ upperleft = N.minimum.reduce(bboxarray[:,0])
- #~ lowerright = N.maximum.reduce(bboxarray[:,1])
- #~ return N.array((upperleft, lowerright), N.float)
- #~ _getboundingbox = staticmethod(_getboundingbox)
-
-
- ## Save the ndarray __eq__ for internal use.
- Array__eq__ = N.ndarray.__eq__
- def __eq__(self, BB):
- """
- __eq__(BB) The equality operator
-
- A == B if and only if all the entries are the same
-
- """
- return N.all(self.Array__eq__(BB))
-
-
-def asBBox(data):
- """
- returns a BBox object.
-
- If object is a BBox, it is returned unaltered
-
- If object is a numpy array, a BBox object is returned that shares a
- view of the data with that array
-
- """
-
- if isinstance(data, BBox):
- return data
- arr = N.asarray(data, N.float)
- return N.ndarray.__new__(BBox, shape=arr.shape, dtype=arr.dtype, buffer=arr)
-
-def fromPoints(Points):
- """
- fromPoints (Points).
-
- reruns the bounding box of the set of points in Points. Points can
- be any python object that can be turned into a numpy NX2 array of Floats.
-
- If a single point is passed in, a zero-size Bounding Box is returned.
-
- """
- Points = N.asarray(Points, N.float).reshape(-1,2)
-
- arr = N.vstack( (Points.min(0), Points.max(0)) )
- return N.ndarray.__new__(BBox, shape=arr.shape, dtype=arr.dtype, buffer=arr)
-
-def fromBBArray(BBarray):
- """
- Builds a BBox object from an array of Bounding Boxes.
- The resulting Bounding Box encompases all the included BBs.
-
- The BBarray is in the shape: (Nx2x2) where BBarray[n] is a 2x2 array that represents a BBox
- """
-
- #upperleft = N.minimum.reduce(BBarray[:,0])
- #lowerright = N.maximum.reduce(BBarray[:,1])
-
-# BBarray = N.asarray(BBarray, N.float).reshape(-1,2)
-# arr = N.vstack( (BBarray.min(0), BBarray.max(0)) )
- BBarray = N.asarray(BBarray, N.float).reshape(-1,2,2)
- arr = N.vstack( (BBarray[:,0,:].min(0), BBarray[:,1,:].max(0)) )
- return asBBox(arr)
- #return asBBox( (upperleft, lowerright) ) * 2
-
-
-
-
projects / wxWidgets.git / blobdiff