1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
#!/usr/bin/env python
"""
ffgeom.py
Copyright (C) 2005 Aaron Cyril Spike, aaron@ekips.org
This file is part of FretFind 2-D.
FretFind 2-D is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
FretFind 2-D is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with FretFind 2-D; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
"""
import math
class Point:
precision = 5
def __init__(self, x, y):
self.__coordinates = {'x' : float(x), 'y' : float(y)}
def __getitem__(self, key):
return self.__coordinates[key]
def __setitem__(self, key, value):
self.__coordinates[key] = float(value)
def __repr__(self):
return '(%s, %s)' % (round(self['x'],self.precision),round(self['y'],self.precision))
def copy(self):
return Point(self['x'],self['y'])
def translate(self, x, y):
self['x'] += x
self['y'] += y
def move(self, x, y):
self['x'] = float(x)
self['y'] = float(y)
class Segment:
def __init__(self, e0, e1):
self.__endpoints = [e0, e1]
def __getitem__(self, key):
return self.__endpoints[key]
def __setitem__(self, key, value):
self.__endpoints[key] = value
def __repr__(self):
return repr(self.__endpoints)
def copy(self):
return Segment(self[0],self[1])
def translate(self, x, y):
self[0].translate(x,y)
self[1].translate(x,y)
def move(self,e0,e1):
self[0] = e0
self[1] = e1
def delta_x(self):
return self[1]['x'] - self[0]['x']
def delta_y(self):
return self[1]['y'] - self[0]['y']
#alias functions
run = delta_x
rise = delta_y
def slope(self):
if self.delta_x() != 0:
return self.delta_x() / self.delta_y()
return math.nan
def intercept(self):
if self.delta_x() != 0:
return self[1]['y'] - (self[0]['x'] * self.slope())
return math.nan
def distanceToPoint(self, p):
s2 = Segment(self[0],p)
c1 = dot(s2,self)
if c1 <= 0:
return Segment(p,self[0]).length()
c2 = dot(self,self)
if c2 <= c1:
return Segment(p,self[1]).length()
return self.perpDistanceToPoint(p)
def perpDistanceToPoint(self, p):
len = self.length()
if len == 0:
return math.nan
return math.fabs(((self[1]['x'] - self[0]['x']) * (self[0]['y'] - p['y'])) - \
((self[0]['x'] - p['x']) * (self[1]['y'] - self[0]['y']))) / len
def angle(self):
return math.pi * (math.atan2(self.delta_y(), self.delta_x())) / 180
def length(self):
return math.sqrt((self.delta_x() ** 2) + (self.delta_y() ** 2))
def pointAtLength(self, len):
if self.length() == 0: return Point(math.nan, math.nan)
ratio = len / self.length()
x = self[0]['x'] + (ratio * self.delta_x())
y = self[0]['y'] + (ratio * self.delta_y())
return Point(x, y)
def pointAtRatio(self, ratio):
if self.length() == 0: return Point(math.nan, math.nan)
x = self[0]['x'] + (ratio * self.delta_x())
y = self[0]['y'] + (ratio * self.delta_y())
return Point(x, y)
def createParallel(self, p):
return Segment(Point(p['x'] + self.delta_x(), p['y'] + self.delta_y()), p)
def intersect(self, s):
return intersectSegments(self, s)
def intersectSegments(s1, s2):
x1 = s1[0]['x']
x2 = s1[1]['x']
x3 = s2[0]['x']
x4 = s2[1]['x']
y1 = s1[0]['y']
y2 = s1[1]['y']
y3 = s2[0]['y']
y4 = s2[1]['y']
denom = ((y4 - y3) * (x2 - x1)) - ((x4 - x3) * (y2 - y1))
num1 = ((x4 - x3) * (y1 - y3)) - ((y4 - y3) * (x1 - x3))
num2 = ((x2 - x1) * (y1 - y3)) - ((y2 - y1) * (x1 - x3))
num = num1
if denom != 0:
x = x1 + ((num / denom) * (x2 - x1))
y = y1 + ((num / denom) * (y2 - y1))
return Point(x, y)
return Point(math.nan, math.nan)
def dot(s1, s2):
return s1.delta_x() * s2.delta_x() + s1.delta_y() * s2.delta_y()
# vim: expandtab shiftwidth=4 tabstop=8 softtabstop=4 fileencoding=utf-8 textwidth=99
|
