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Rename vector:angle(). Shorter implementation. Add vector.zero

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Matthias Richter 2013-07-30 11:54:24 +02:00
parent 51c31f70b2
commit 1f9a7f1f52
1 changed files with 8 additions and 12 deletions
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20
vector.lua
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@ -25,7 +25,7 @@ THE SOFTWARE.
]]-- ]]--
local assert = assert local assert = assert
local sqrt, cos, sin = math.sqrt, math.cos, math.sin local sqrt, cos, sin, atan2 = math.sqrt, math.cos, math.sin, math.atan2
local vector = {} local vector = {}
vector.__index = vector vector.__index = vector
@ -33,6 +33,7 @@ vector.__index = vector
local function new(x,y) local function new(x,y)
return setmetatable({x = x or 0, y = y or 0}, vector) return setmetatable({x = x or 0, y = y or 0}, vector)
end end
local zero = new(0,0)
local function isvector(v) local function isvector(v)
return getmetatable(v) == vector return getmetatable(v) == vector
@ -135,16 +136,6 @@ function vector:rotated(phi)
return new(c * self.x - s * self.y, s * self.x + c * self.y) return new(c * self.x - s * self.y, s * self.x + c * self.y)
end end
function vector:angle()
local a = new(1,0)
local angle = math.acos((a*self)/(a:len()*self:len()))
if self.y < 0 then
return -angle
else
return angle
end
end
function vector:perpendicular() function vector:perpendicular()
return new(-self.y, self.x) return new(-self.y, self.x)
end end
@ -176,11 +167,16 @@ function vector:trim_inplace(maxLen)
return self return self
end end
function vector:angleTo(other)
other = other or zero
return atan2(self.y - other.y, self.x - other.x)
end
function vector:trimmed(maxLen) function vector:trimmed(maxLen)
return self:clone():trim_inplace(maxLen) return self:clone():trim_inplace(maxLen)
end end
-- the module -- the module
return setmetatable({new = new, isvector = isvector}, return setmetatable({new = new, isvector = isvector, zero = zero},
{__call = function(_, ...) return new(...) end}) {__call = function(_, ...) return new(...) end})