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
|
# Various mathematical calculations extracted from the PDF::Writer for Ruby gem.
# - http://rubyforge.org/projects/ruby-pdf
# - Copyright 2003 - 2005 Austin Ziegler.
# - Licensed under a MIT-style licence.
#
module RFPDF::Math
PI2 = ::Math::PI * 2.0
# One degree of arc measured in terms of radians.
DR = PI2 / 360.0
# One radian of arc, measured in terms of degrees.
RD = 360 / PI2
# One degree of arc, measured in terms of gradians.
DG = 400 / 360.0
# One gradian of arc, measured in terms of degrees.
GD = 360 / 400.0
# One radian of arc, measured in terms of gradians.
RG = 400 / PI2
# One gradian of arc, measured in terms of radians.
GR = PI2 / 400.0
# Truncate the remainder.
def remt(num, den)
num - den * (num / den.to_f).to_i
end
# Wrap radian values within the range of radians (0..PI2).
def rad2rad(rad)
remt(rad, PI2)
end
# Wrap degree values within the range of degrees (0..360).
def deg2deg(deg)
remt(deg, 360)
end
# Wrap gradian values within the range of gradians (0..400).
def grad2grad(grad)
remt(grad, 400)
end
# Convert degrees to radians. The value will be constrained to the
# range of radians (0..PI2) unless +wrap+ is false.
def deg2rad(deg, wrap = true)
rad = DR * deg
rad = rad2rad(rad) if wrap
rad
end
# Convert degrees to gradians. The value will be constrained to the
# range of gradians (0..400) unless +wrap+ is false.
def deg2grad(deg, wrap = true)
grad = DG * deg
grad = grad2grad(grad) if wrap
grad
end
# Convert radians to degrees. The value will be constrained to the
# range of degrees (0..360) unless +wrap+ is false.
def rad2deg(rad, wrap = true)
deg = RD * rad
deg = deg2deg(deg) if wrap
deg
end
# Convert radians to gradians. The value will be constrained to the
# range of gradians (0..400) unless +wrap+ is false.
def rad2grad(rad, wrap = true)
grad = RG * rad
grad = grad2grad(grad) if wrap
grad
end
# Convert gradians to degrees. The value will be constrained to the
# range of degrees (0..360) unless +wrap+ is false.
def grad2deg(grad, wrap = true)
deg = GD * grad
deg = deg2deg(deg) if wrap
deg
end
# Convert gradians to radians. The value will be constrained to the
# range of radians (0..PI2) unless +wrap+ is false.
def grad2rad(grad, wrap = true)
rad = GR * grad
rad = rad2rad(rad) if wrap
rad
end
end
|
