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|
| local EPSILON = 0.0001
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| local function isNearZero(f)
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| return math.abs(f) < EPSILON
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| end
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|
|
| Vector3D = function(x, y, z)
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| local mt = {}
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| local obj = {
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| x = x,
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| y = y,
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| z = z
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| }
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|
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| function obj:get()
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| return self.x, self.y, self.z
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| end
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|
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| function obj:length()
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| return math.sqrt(self.x * self.x + self.y * self.y + self.z * self.z)
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| end
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|
|
| function obj:normalize()
|
| local len = self:length()
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| if len < EPSILON then return 0 end
|
| self.x = self.x / len
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| self.y = self.y / len
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| self.z = self.z / len
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| return len
|
| end
|
|
|
| function obj:zeroNearZero()
|
| if isNearZero(self.x) then self.x = 0 end
|
| if isNearZero(self.y) then self.y = 0 end
|
| if isNearZero(self.z) then self.z = 0 end
|
| end
|
|
|
| function obj:dotProduct(v)
|
| return self.x * v.x + self.y * v.y + self.z * v.z
|
| end
|
|
|
| function obj:crossProduct(v)
|
| local x, y, z = self.x, self.y, self.z
|
| self.x = y * v.z - v.y * z
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| self.y = z * v.x - v.z * x
|
| self.z = x * v.y - v.x * y
|
| end
|
|
|
| obj.zero_near_zero = obj.zeroNearZero
|
| obj.dot_product = obj.dotProduct
|
| obj.cross_product = obj.crossProduct
|
|
|
|
|
| function mt:__add(v)
|
| return Vector3D(self.x + v.x, self.y + v.y, self.z + v.z)
|
| end
|
|
|
| function mt:__mul(v)
|
| if type(v) == "number" then
|
| return Vector3D(self.x * v, self.y * v, self.z * v)
|
| end
|
| return Vector3D(self.x * v.x, self.y * v.y, self.z * v.z)
|
| end
|
|
|
| function mt:__sub(v)
|
| return Vector3D(self.x - v.x, self.y - v.y, self.z - v.z)
|
| end
|
|
|
| setmetatable(obj, mt)
|
| return obj
|
| end
|
|
|
| return Vector3D
|
|
|
