Vector2/vector2.lua at master · AngeloYazar/Vector2 · GitHub

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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
--[[ Vector2 by Angelo Yazar ]]--
local math = math
local setmetatable = setmetatable
local assert = assert
local Vector2 = {}
setfenv(1, Vector2)
mt = {}
mt.__index = Vector2

function new( i, j )
	local v = { i, j }
	setmetatable( v, mt )
	return v
end

function get( a )
	return a[1], a[2]
end

function set( v, a, b )
	v[1], v[2] = a, b or v[2]
end

function add( a, b )
	return new( a[1]+b[1], a[2]+b[2] )
end

function sub( a, b )
	return new( a[1]-b[1], a[2]-b[2] )
end

function mul( a, b )
	return new( a[1]*b, a[2]*b )
end

function div( a, b )
	assert( b, "Vector2: Can't divide by 0" )
	return new( a[1]/b, a[2]/b )
end

function copy( a )
	return new( a[1], a[2] )
end

function dot( a, b )
	return a[1]*b[1] + a[2]*b[2]
end

function magnitude( a )
	return math.sqrt(a[1]^2 + a[2]^2)
end

function sqrMagnitude( a )
	return a[1]^2 + a[2]^2
end

function project( a, b )
	return b:mul( a:dot(b)/b:sqrMagnitude() )
end

function normalized( a )
	local m = a:magnitude()
	if m and m > 0 then return new(a[1]/m,a[2]/m)
	else return new(0,0,0) end
end

function normalize( a )
	local m = a:magnitude()
	if m then
		a[1] = a[1] / m
		a[2] = a[2] / m
	end
	return a
end

function clampMagnitude( a, maxLength )
	local m = a:magnitude()
	if m > maxLength then
		return  ( a:normalized() ):mul( maxLength )
	else return a:copy() end
end

function scale( a, s )
	a[1] = a[1] * s
	a[2] = a[2] * s
	return a
end

function angle( a, b )
	return math.deg( math.atan2(b[2]-a[2],b[1]-a[1]) )
end

function reflect( a, n )
	local nu = n:normalized()
	local anu = a:dot(nu) * 2
	nu:scale(anu)
	return new( -a[1]+nu[1], -a[2]+nu[2] )
end

function distance( a, b )
	return math.sqrt((b[1]-a[1])^2+(b[2]-a[2])^2)
end

function lerp( a, b, t )
	local t1 = 1-t
	return new( a[1]*t1+b[1]*t, a[2]*t1+b[2]*t )
end

function min( a, b )
	local i,j = a[1], a[2]
	if i > b[1] then i = b[1] end
	if j > b[2] then j = b[2] end
	return new(i,j)
end

function max( a, b )
	local i,j = a[1], a[2]
	if i < b[1] then i = b[1] end
	if j < b[2] then j = b[2] end
	return new(i,j)
end

local function sign( x )
	if x < 0 then
		return -1
	else
		return 1
	end
end

function quadrant( a )
	return new(sign(a[1]),sign(a[2]))
end

function tostring ( a )
	return "Vector2: " .. a[1] .. ", " .. a[2]
end

mt.__add = add
mt.__sub = sub
mt.__mul = mul
mt.__div = div
mt.__tostring = tostring

mt.__le = function( a, b )
	return a:magnitude() <= b:magnitude()
end

mt.__lt = function( a, b )
	return a:magnitude() < b:magnitude()
end

mt.__eq = function( a, b )
	return ( a[1] == b[1] and a[2] == b[2] )
end

return Vector2