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local class = require'r.class'
local Pos = class()
function Pos.new(cls)
return setmetatable({},cls)
end
function Pos.init(self,x,y)
self.x = x
self.y = y
return self
end
function Pos.make(cls,...)
return cls:new():init(...)
end
function Pos.__add(self,other)
return Pos:make(self.x+other.x,self.y+other.y)
end
function Pos.__sub(self,other)
return Pos:make(self.x-other.x,self.y-other.y)
end
function Pos.__mul(a,b)
if type(a) == "number" then
return Pos:make(a*b.x,a*b.y)
elseif type(b) == "number" then
return Pos:make(a.x*b,a.y*b)
else
error("can only multiply Pos by scalar")
end
end
function Pos.__div(a,b)
assert(type(b) == "number","can only divide Pos by scalar")
return a*(1/b)
end
function Pos.__eq(a,b) return a.x==b.x and a.y==b.y end
function Pos.lensq(self) return self.x^2 + self.y^2 end
function Pos.len(self) return math.sqrt(self:lensq()) end
function Pos.norm(self) return self/self:len() end
function Pos.dot(self,other) return self.x*other.x+self.y*other.y end
function Pos.vals(self) return self.x, self.y end
function Pos.__tostring(self)
return string.format("(%.2f,%.2f)",self.x,self.y)
end
return Pos
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