You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

380 lines
10 KiB

"""Routines for calculating bounding boxes, point in rectangle calculations and
so on.
"""
from fontTools.misc.roundTools import otRound
from fontTools.misc.vector import Vector as _Vector
import math
import warnings
def calcBounds(array):
"""Calculate the bounding rectangle of a 2D points array.
Args:
array: A sequence of 2D tuples.
Returns:
A four-item tuple representing the bounding rectangle ``(xMin, yMin, xMax, yMax)``.
"""
if len(array) == 0:
return 0, 0, 0, 0
xs = [x for x, y in array]
ys = [y for x, y in array]
return min(xs), min(ys), max(xs), max(ys)
def calcIntBounds(array, round=otRound):
"""Calculate the integer bounding rectangle of a 2D points array.
Values are rounded to closest integer towards ``+Infinity`` using the
:func:`fontTools.misc.fixedTools.otRound` function by default, unless
an optional ``round`` function is passed.
Args:
array: A sequence of 2D tuples.
round: A rounding function of type ``f(x: float) -> int``.
Returns:
A four-item tuple of integers representing the bounding rectangle:
``(xMin, yMin, xMax, yMax)``.
"""
return tuple(round(v) for v in calcBounds(array))
def updateBounds(bounds, p, min=min, max=max):
"""Add a point to a bounding rectangle.
Args:
bounds: A bounding rectangle expressed as a tuple
``(xMin, yMin, xMax, yMax)``.
p: A 2D tuple representing a point.
min,max: functions to compute the minimum and maximum.
Returns:
The updated bounding rectangle ``(xMin, yMin, xMax, yMax)``.
"""
(x, y) = p
xMin, yMin, xMax, yMax = bounds
return min(xMin, x), min(yMin, y), max(xMax, x), max(yMax, y)
def pointInRect(p, rect):
"""Test if a point is inside a bounding rectangle.
Args:
p: A 2D tuple representing a point.
rect: A bounding rectangle expressed as a tuple
``(xMin, yMin, xMax, yMax)``.
Returns:
``True`` if the point is inside the rectangle, ``False`` otherwise.
"""
(x, y) = p
xMin, yMin, xMax, yMax = rect
return (xMin <= x <= xMax) and (yMin <= y <= yMax)
def pointsInRect(array, rect):
"""Determine which points are inside a bounding rectangle.
Args:
array: A sequence of 2D tuples.
rect: A bounding rectangle expressed as a tuple
``(xMin, yMin, xMax, yMax)``.
Returns:
A list containing the points inside the rectangle.
"""
if len(array) < 1:
return []
xMin, yMin, xMax, yMax = rect
return [(xMin <= x <= xMax) and (yMin <= y <= yMax) for x, y in array]
def vectorLength(vector):
"""Calculate the length of the given vector.
Args:
vector: A 2D tuple.
Returns:
The Euclidean length of the vector.
"""
x, y = vector
return math.sqrt(x**2 + y**2)
def asInt16(array):
"""Round a list of floats to 16-bit signed integers.
Args:
array: List of float values.
Returns:
A list of rounded integers.
"""
return [int(math.floor(i+0.5)) for i in array]
def normRect(rect):
"""Normalize a bounding box rectangle.
This function "turns the rectangle the right way up", so that the following
holds::
xMin <= xMax and yMin <= yMax
Args:
rect: A bounding rectangle expressed as a tuple
``(xMin, yMin, xMax, yMax)``.
Returns:
A normalized bounding rectangle.
"""
(xMin, yMin, xMax, yMax) = rect
return min(xMin, xMax), min(yMin, yMax), max(xMin, xMax), max(yMin, yMax)
def scaleRect(rect, x, y):
"""Scale a bounding box rectangle.
Args:
rect: A bounding rectangle expressed as a tuple
``(xMin, yMin, xMax, yMax)``.
x: Factor to scale the rectangle along the X axis.
Y: Factor to scale the rectangle along the Y axis.
Returns:
A scaled bounding rectangle.
"""
(xMin, yMin, xMax, yMax) = rect
return xMin * x, yMin * y, xMax * x, yMax * y
def offsetRect(rect, dx, dy):
"""Offset a bounding box rectangle.
Args:
rect: A bounding rectangle expressed as a tuple
``(xMin, yMin, xMax, yMax)``.
dx: Amount to offset the rectangle along the X axis.
dY: Amount to offset the rectangle along the Y axis.
Returns:
An offset bounding rectangle.
"""
(xMin, yMin, xMax, yMax) = rect
return xMin+dx, yMin+dy, xMax+dx, yMax+dy
def insetRect(rect, dx, dy):
"""Inset a bounding box rectangle on all sides.
Args:
rect: A bounding rectangle expressed as a tuple
``(xMin, yMin, xMax, yMax)``.
dx: Amount to inset the rectangle along the X axis.
dY: Amount to inset the rectangle along the Y axis.
Returns:
An inset bounding rectangle.
"""
(xMin, yMin, xMax, yMax) = rect
return xMin+dx, yMin+dy, xMax-dx, yMax-dy
def sectRect(rect1, rect2):
"""Test for rectangle-rectangle intersection.
Args:
rect1: First bounding rectangle, expressed as tuples
``(xMin, yMin, xMax, yMax)``.
rect2: Second bounding rectangle.
Returns:
A boolean and a rectangle.
If the input rectangles intersect, returns ``True`` and the intersecting
rectangle. Returns ``False`` and ``(0, 0, 0, 0)`` if the input
rectangles don't intersect.
"""
(xMin1, yMin1, xMax1, yMax1) = rect1
(xMin2, yMin2, xMax2, yMax2) = rect2
xMin, yMin, xMax, yMax = (max(xMin1, xMin2), max(yMin1, yMin2),
min(xMax1, xMax2), min(yMax1, yMax2))
if xMin >= xMax or yMin >= yMax:
return False, (0, 0, 0, 0)
return True, (xMin, yMin, xMax, yMax)
def unionRect(rect1, rect2):
"""Determine union of bounding rectangles.
Args:
rect1: First bounding rectangle, expressed as tuples
``(xMin, yMin, xMax, yMax)``.
rect2: Second bounding rectangle.
Returns:
The smallest rectangle in which both input rectangles are fully
enclosed.
"""
(xMin1, yMin1, xMax1, yMax1) = rect1
(xMin2, yMin2, xMax2, yMax2) = rect2
xMin, yMin, xMax, yMax = (min(xMin1, xMin2), min(yMin1, yMin2),
max(xMax1, xMax2), max(yMax1, yMax2))
return (xMin, yMin, xMax, yMax)
def rectCenter(rect):
"""Determine rectangle center.
Args:
rect: Bounding rectangle, expressed as tuples
``(xMin, yMin, xMax, yMax)``.
Returns:
A 2D tuple representing the point at the center of the rectangle.
"""
(xMin, yMin, xMax, yMax) = rect
return (xMin+xMax)/2, (yMin+yMax)/2
def rectArea(rect):
"""Determine rectangle area.
Args:
rect: Bounding rectangle, expressed as tuples
``(xMin, yMin, xMax, yMax)``.
Returns:
The area of the rectangle.
"""
(xMin, yMin, xMax, yMax) = rect
return (yMax - yMin) * (xMax - xMin)
def intRect(rect):
"""Round a rectangle to integer values.
Guarantees that the resulting rectangle is NOT smaller than the original.
Args:
rect: Bounding rectangle, expressed as tuples
``(xMin, yMin, xMax, yMax)``.
Returns:
A rounded bounding rectangle.
"""
(xMin, yMin, xMax, yMax) = rect
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)
class Vector(_Vector):
def __init__(self, *args, **kwargs):
warnings.warn(
"fontTools.misc.arrayTools.Vector has been deprecated, please use "
"fontTools.misc.vector.Vector instead.",
DeprecationWarning,
)
def pairwise(iterable, reverse=False):
"""Iterate over current and next items in iterable.
Args:
iterable: An iterable
reverse: If true, iterate in reverse order.
Returns:
A iterable yielding two elements per iteration.
Example:
>>> tuple(pairwise([]))
()
>>> tuple(pairwise([], reverse=True))
()
>>> tuple(pairwise([0]))
((0, 0),)
>>> tuple(pairwise([0], reverse=True))
((0, 0),)
>>> tuple(pairwise([0, 1]))
((0, 1), (1, 0))
>>> tuple(pairwise([0, 1], reverse=True))
((1, 0), (0, 1))
>>> tuple(pairwise([0, 1, 2]))
((0, 1), (1, 2), (2, 0))
>>> tuple(pairwise([0, 1, 2], reverse=True))
((2, 1), (1, 0), (0, 2))
>>> tuple(pairwise(['a', 'b', 'c', 'd']))
(('a', 'b'), ('b', 'c'), ('c', 'd'), ('d', 'a'))
>>> tuple(pairwise(['a', 'b', 'c', 'd'], reverse=True))
(('d', 'c'), ('c', 'b'), ('b', 'a'), ('a', 'd'))
"""
if not iterable:
return
if reverse:
it = reversed(iterable)
else:
it = iter(iterable)
first = next(it, None)
a = first
for b in it:
yield (a, b)
a = b
yield (a, first)
def _test():
"""
>>> import math
>>> calcBounds([])
(0, 0, 0, 0)
>>> 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)))
[True, True, True, False]
>>> vectorLength((3, 4))
5.0
>>> vectorLength((1, 1)) == math.sqrt(2)
True
>>> list(asInt16([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))
(50.0, 100.0)
>>> rectCenter((0, 0, 100, 199.0))
(50.0, 99.5)
>>> intRect((0.9, 2.9, 3.1, 4.1))
(0, 2, 4, 5)
"""
if __name__ == "__main__":
import sys
import doctest
sys.exit(doctest.testmod().failed)