Lib/fontTools/misc/arrayTools.py

#
# Various array and rectangle tools, but mostly rectangles, hence the
# name of this module (not).
#

import Numeric

def calcBounds(array):
	"""Return the bounding rectangle of a 2D points array as a tuple:
	(xMin, yMin, xMax, yMax)
	"""
	if len(array) == 0:
		return 0, 0, 0, 0
	xMin, yMin = Numeric.minimum.reduce(array)
	xMax, yMax = Numeric.maximum.reduce(array)
	return xMin, yMin, xMax, yMax

def updateBounds(bounds, (x, y), min=min, max=max):
	"""Return the bounding recangle of rectangle bounds and point (x, y)."""
	xMin, yMin, xMax, yMax = bounds
	return min(xMin, x), min(yMin, y), max(xMax, x), max(yMax, y)

def pointInRect((x, y), rect):
	"""Return True when point (x, y) is inside rect."""
	xMin, yMin, xMax, yMax = rect
	return (xMin <= x <= xMax) and (yMin <= y <= yMax)

def pointsInRect(array, rect):
	"""Find out which points or array are inside rect. 
	Returns an array with a boolean for each point.
	"""
	if len(array) < 1:
		return []
	lefttop = rect[:2]
	rightbottom = rect[2:]
	condition = Numeric.logical_and(
			Numeric.greater_equal(array, lefttop), 
			Numeric.less_equal(array, rightbottom))
	return Numeric.logical_and.reduce(condition, -1)

def vectorLength(vector):
	"""Return the length of the given vector."""
	return Numeric.sqrt(vector[0]**2 + vector[1]**2)

def asInt16(array):
	"""Round and cast to 16 bit integer."""
	return Numeric.floor(array + 0.5).astype(Numeric.Int16)
	

def normRect((xMin, yMin, xMax, yMax)):
	"""Normalize the rectangle so that the following holds:
		xMin <= xMax and yMin <= yMax
	"""
	return min(xMin, xMax), min(yMin, yMax), max(xMin, xMax), max(yMin, yMax)

def scaleRect((xMin, yMin, xMax, yMax), x, y):
	"""Scale the rectangle by x, y."""
	return xMin * x, yMin * y, xMax * x, yMax * y

def offsetRect((xMin, yMin, xMax, yMax), dx, dy):
	"""Offset the rectangle by dx, dy."""
	return xMin+dx, yMin+dy, xMax+dx, yMax+dy

def insetRect((xMin, yMin, xMax, yMax), dx, dy):
	"""Inset the rectangle by dx, dy on all sides."""
	return xMin+dx, yMin+dy, xMax-dx, yMax-dy

def sectRect((xMin1, yMin1, xMax1, yMax1), (xMin2, yMin2, xMax2, yMax2)):
	"""Return a boolean and a rectangle. If the input rectangles intersect, return
	True and the intersecting rectangle. Return False and (0, 0, 0, 0) if the input
	rectangles don't intersect.
	"""
	xMin, yMin, xMax, yMax = (max(xMin1, xMin2), max(yMin1, yMin2),
	                          min(xMax1, xMax2), min(yMax1, yMax2))
	if xMin >= xMax or yMin >= yMax:
		return 0, (0, 0, 0, 0)
	return 1, (xMin, yMin, xMax, yMax)

def unionRect((xMin1, yMin1, xMax1, yMax1), (xMin2, yMin2, xMax2, yMax2)):
	"""Return the smallest rectangle in which both input rectangles are fully
	enclosed. In other words, return the total bounding rectangle of both input
	rectangles.
	"""
	xMin, yMin, xMax, yMax = (min(xMin1, xMin2), min(yMin1, yMin2),
	                          max(xMax1, xMax2), max(yMax1, yMax2))
	return (xMin, yMin, xMax, yMax)

def rectCenter((xMin, yMin, xMax, yMax)):
	"""Return the center of the rectangle as an (x, y) coordinate."""
	return (xMin+xMax)/2, (yMin+yMax)/2

def intRect((xMin, yMin, xMax, yMax)):
	"""Return the rectangle, rounded off to integer values, but guaranteeing that
	the resulting rectangle is NOT smaller than the original.
	"""
	import math
	xMin = int(math.floor(xMin))
	yMin = int(math.floor(yMin))
	xMax = int(math.ceil(xMax))
	yMax = int(math.ceil(yMax))
	return (xMin, yMin, xMax, yMax)


def _test():
	"""
	>>> import math
	>>> calcBounds([(0, 40), (0, 100), (50, 50), (80, 10)])
	(0, 10, 80, 100)
	>>> updateBounds((0, 0, 0, 0), (100, 100))
	(0, 0, 100, 100)
	>>> pointInRect((50, 50), (0, 0, 100, 100))
	True
	>>> pointInRect((0, 0), (0, 0, 100, 100))
	True
	>>> pointInRect((100, 100), (0, 0, 100, 100))
	True
	>>> not pointInRect((101, 100), (0, 0, 100, 100))
	True
	>>> list(pointsInRect([(50, 50), (0, 0), (100, 100), (101, 100)], (0, 0, 100, 100)))
	[1, 1, 1, 0]
	>>> vectorLength((3, 4))
	5.0
	>>> vectorLength((1, 1)) == math.sqrt(2)
	True
	>>> list(asInt16(Numeric.array([0, 0.1, 0.5, 0.9])))
	[0, 0, 1, 1]
	>>> normRect((0, 10, 100, 200))
	(0, 10, 100, 200)
	>>> normRect((100, 200, 0, 10))
	(0, 10, 100, 200)
	>>> scaleRect((10, 20, 50, 150), 1.5, 2)
	(15.0, 40, 75.0, 300)
	>>> offsetRect((10, 20, 30, 40), 5, 6)
	(15, 26, 35, 46)
	>>> insetRect((10, 20, 50, 60), 5, 10)
	(15, 30, 45, 50)
	>>> insetRect((10, 20, 50, 60), -5, -10)
	(5, 10, 55, 70)
	>>> intersects, rect = sectRect((0, 10, 20, 30), (0, 40, 20, 50))
	>>> not intersects
	True
	>>> intersects, rect = sectRect((0, 10, 20, 30), (5, 20, 35, 50))
	>>> intersects
	1
	>>> rect
	(5, 20, 20, 30)
	>>> unionRect((0, 10, 20, 30), (0, 40, 20, 50))
	(0, 10, 20, 50)
	>>> rectCenter((0, 0, 100, 200))
	(50, 100)
	>>> rectCenter((0, 0, 100, 199.0))
	(50, 99.5)
	>>> intRect((0.9, 2.9, 3.1, 4.1))
	(0, 2, 4, 5)
	"""

if __name__ == "__main__":
	import doctest
	doctest.testmod()