Unity 之 Lua使用Vector3遇到的问题
【摘要】
Unity 之 Lua使用Vector3遇到的问题
1.正常使用2.遇到问题3.原来如此4.ToLua中的V3实现表
1.正常使用
在Lua使用的形式和C#中大致相同，只是Lua使用表的形式来模拟V3类型,原来C#中各种常用的属性和方法也都相应的被实现了。（详情可查看文末源码）
使用示例：
local V3;
V3 = Vector3(0,0,0...
1.正常使用
在Lua使用的形式和C#中大致相同，只是Lua使用表的形式来模拟V3类型,原来C#中各种常用的属性和方法也都相应的被实现了。（详情可查看文末源码）
使用示例：
local V3;
V3 = Vector3(0,0,0);
V3 = Vector3.zero;
V3 = Vector3.left * 10;
V3 = Vector3.left * 10 + Vector3.down * 10;
2.遇到问题
当将一个number类型放到乘号左边时，则程序执行到这一行就不会向下执行了；【思考一下】
V3 = 10 * Vector3.left;
原来在C#中是没有这种限制的，想下面这种代码随便怎么放位置都可以，只要满足你的需求，写法随便；
V3 = (hang - 1) / 2 * Vector3.down * hangGao;
V3 = Vector3.down * hangGao* (hang - 1) / 2;
但是在Lua中就只能将模拟 V3类型的变量放到前面来写；
3.原来如此
后知后觉：在Lua中V3是个表，而这个表的加，减，乘，除 这写运算操作试Lua使用原方法帮我们实现的，打开源码：
V3表乘法操作部分：
Vector3.__mul = function(va, d)
if type(d) == "number" then
return _new(va.x * d, va.y * d, va.z * d)
else
local vec = va:Clone()
vec:MulQuat(d)
return vec
end
end
这下明白了吧，这个原方法定义的时候，第一个参数是模拟V3类型，第二个是参数是Number类型；所有就会有上面的问题，当我们将V3类型的变量放到后面写的时候，当然执行不下去了。
结论：使用V3变量时，放到表达式的最左侧书写
4.ToLua中的V3实现表
local math = math
local acos = math.acos
local sqrt = math.sqrt
local max = math.max
local min = math.min
local clamp = Mathf.Clamp
local cos = math.cos
local sin = math.sin
local abs = math.abs
local sign = Mathf.Sign
local setmetatable = setmetatable
local rawset = rawset
local rawget = rawget
local type = type
local rad2Deg = 57.295779513082
local deg2Rad = 0.017453292519943
local Vector3 = {}
local get = tolua.initget(Vector3)
Vector3.__index = function(t,k)
local var = rawget(Vector3, k) if var == nil then var = rawget(get, k) if var ~= nil then return var(t) end end return var
end
function Vector3.New(x, y, z) local t = {x = x or 0, y = y or 0, z = z or 0}
setmetatable(t, Vector3) return t
end
local _new = Vector3.New
Vector3.__call = function(t,x,y,z)
local t = {x = x or 0, y = y or 0, z = z or 0}
setmetatable(t, Vector3) return t
end
function Vector3:Set(x,y,z)
self.x = x or 0
self.y = y or 0
self.z = z or 0
end
function Vector3.Get(v) return v.x, v.y, v.z
end
function Vector3:Clone()
return setmetatable({x = self.x, y = self.y, z = self.z}, Vector3)
end
function Vector3.Distance(va, vb)
return sqrt((va.x - vb.x)^2 + (va.y - vb.y)^2 + (va.z - vb.z)^2)
end
function Vector3.Dot(lhs, rhs)
return lhs.x * rhs.x + lhs.y * rhs.y + lhs.z * rhs.z
end
function Vector3.Lerp(from, to, t)
t = clamp(t, 0, 1)
return _new(from.x + (to.x - from.x) * t, from.y + (to.y - from.y) * t, from.z + (to.z - from.z) * t)
end
function Vector3:Magnitude()
return sqrt(self.x * self.x + self.y * self.y + self.z * self.z)
end
function Vector3.Max(lhs, rhs)
return _new(max(lhs.x, rhs.x), max(lhs.y, rhs.y), max(lhs.z, rhs.z))
end
function Vector3.Min(lhs, rhs)
return _new(min(lhs.x, rhs.x), min(lhs.y, rhs.y), min(lhs.z, rhs.z))
end
function Vector3.Normalize(v)
local x,y,z = v.x, v.y, v.z local num = sqrt(x * x + y * y + z * z) if num > 1e-5 then return setmetatable({x = x / num, y = y / num, z = z / num}, Vector3) end return setmetatable({x = 0, y = 0, z = 0}, Vector3)
end
function Vector3:SetNormalize()
local num = sqrt(self.x * self.x + self.y * self.y + self.z * self.z) if num > 1e-5 then self.x = self.x / num
self.y = self.y / num
self.z = self.z /num else self.x = 0
self.y = 0
self.z = 0
end return self
end
function Vector3:SqrMagnitude()
return self.x * self.x + self.y * self.y + self.z * self.z
end
local dot = Vector3.Dot
function Vector3.Angle(from, to)
return acos(clamp(dot(from:Normalize(), to:Normalize()), -1, 1)) * rad2Deg
end
function Vector3:ClampMagnitude(maxLength)
if self:SqrMagnitude() > (maxLength * maxLength) then self:SetNormalize()
self:Mul(maxLength) end return self
end
function Vector3.OrthoNormalize(va, vb, vc)
va:SetNormalize()
vb:Sub(vb:Project(va))
vb:SetNormalize() if vc == nil then
return va, vb
end vc:Sub(vc:Project(va))
vc:Sub(vc:Project(vb))
vc:SetNormalize() return va, vb, vc
end
function Vector3.MoveTowards(current, target, maxDistanceDelta)
local delta = target - current local sqrDelta = delta:SqrMagnitude()
local sqrDistance = maxDistanceDelta * maxDistanceDelta if sqrDelta > sqrDistance then local magnitude = sqrt(sqrDelta) if magnitude > 1e-6 then delta:Mul(maxDistanceDelta / magnitude) delta:Add(current) return delta
else return current:Clone()
end end return target:Clone()
end
function ClampedMove(lhs, rhs, clampedDelta)
local delta = rhs - lhs if delta > 0 then
return lhs + min(delta, clampedDelta)
else
return lhs - min(-delta, clampedDelta)
end
end
local overSqrt2 = 0.7071067811865475244008443621048490
local function OrthoNormalVector(vec)
local res = _new() if abs(vec.z) > overSqrt2 then local a = vec.y * vec.y + vec.z * vec.z
local k = 1 / sqrt (a)
res.x = 0
res.y = -vec.z * k
res.z = vec.y * k
else local a = vec.x * vec.x + vec.y * vec.y
local k = 1 / sqrt (a)
res.x = -vec.y * k
res.y = vec.x * k
res.z = 0
end return res
end
function Vector3.RotateTowards(current, target, maxRadiansDelta, maxMagnitudeDelta)
local len1 = current:Magnitude()
local len2 = target:Magnitude() if len1 > 1e-6 and len2 > 1e-6 then local from = current / len1
local to = target / len2 local cosom = dot(from, to) if cosom > 1 - 1e-6 then return Vector3.MoveTowards (current, target, maxMagnitudeDelta) elseif cosom < -1 + 1e-6 then local axis = OrthoNormalVector(from) local q = Quaternion.AngleAxis(maxRadiansDelta * rad2Deg, axis) local rotated = q:MulVec3(from) local delta = ClampedMove(len1, len2, maxMagnitudeDelta) rotated:Mul(delta) return rotated
else local angle = acos(cosom) local axis = Vector3.Cross(from, to) axis:SetNormalize () local q = Quaternion.AngleAxis(min(maxRadiansDelta, angle) * rad2Deg, axis) local rotated = q:MulVec3(from) local delta = ClampedMove(len1, len2, maxMagnitudeDelta) rotated:Mul(delta) return rotated
end
end return Vector3.MoveTowards(current, target, maxMagnitudeDelta)
end
function Vector3.SmoothDamp(current, target, currentVelocity, smoothTime)
local maxSpeed = Mathf.Infinity
local deltaTime = Time.deltaTime smoothTime = max(0.0001, smoothTime) local num = 2 / smoothTime local num2 = num * deltaTime local num3 = 1 / (1 + num2 + 0.48 * num2 * num2 + 0.235 * num2 * num2 * num2) local vector2 = target:Clone() local maxLength = maxSpeed * smoothTime
local vector = current - target vector:ClampMagnitude(maxLength) target = current - vector local vec3 = (currentVelocity + (vector * num)) * deltaTime currentVelocity = (currentVelocity - (vec3 * num)) * num3 local vector4 = target + (vector + vec3) * num3 if Vector3.Dot(vector2 - current, vector4 - vector2) > 0 then vector4 = vector2 currentVelocity:Set(0,0,0) end return vector4, currentVelocity
end function Vector3.Scale(a, b)
local x = a.x * b.x
local y = a.y * b.y
local z = a.z * b.z
return _new(x, y, z)
end
function Vector3.Cross(lhs, rhs)
local x = lhs.y * rhs.z - lhs.z * rhs.y
local y = lhs.z * rhs.x - lhs.x * rhs.z
local z = lhs.x * rhs.y - lhs.y * rhs.x
return _new(x,y,z)
end
function Vector3:Equals(other)
return self.x == other.x and self.y == other.y and self.z == other.z
end function Vector3.Reflect(inDirection, inNormal)
local num = -2 * dot(inNormal, inDirection)
inNormal = inNormal * num
inNormal:Add(inDirection)
return inNormal
end function Vector3.Project(vector, onNormal)
local num = onNormal:SqrMagnitude() if num < 1.175494e-38 then return _new(0,0,0)
end local num2 = dot(vector, onNormal)
local v3 = onNormal:Clone()
v3:Mul(num2/num)
return v3
end
function Vector3.ProjectOnPlane(vector, planeNormal)
local v3 = Vector3.Project(vector, planeNormal)
v3:Mul(-1)
v3:Add(vector)
return v3
end function Vector3.Slerp(from, to, t)
local omega, sinom, scale0, scale1
if t <= 0 then return from:Clone()
elseif t >= 1 then return to:Clone()
end local v2 = to:Clone()
local v1 = from:Clone()
local len2 = to:Magnitude()
local len1 = from:Magnitude()
v2:Div(len2)
v1:Div(len1)
local len = (len2 - len1) * t + len1
local cosom = v1.x * v2.x + v1.y * v2.y + v1.z * v2.z if cosom > 1 - 1e-6 then
scale0 = 1 - t
scale1 = t
elseif cosom < -1 + 1e-6 then local axis = OrthoNormalVector(from) local q = Quaternion.AngleAxis(180.0 * t, axis) local v = q:MulVec3(from)
v:Mul(len) return v
else
omega = acos(cosom)
sinom = sin(omega)
scale0 = sin((1 - t) * omega) / sinom
scale1 = sin(t * omega) / sinom
end
v1:Mul(scale0)
v2:Mul(scale1)
v2:Add(v1)
v2:Mul(len)
return v2
end
function Vector3:Mul(q)
if type(q) == "number" then
self.x = self.x * q
self.y = self.y * q
self.z = self.z * q
else
self:MulQuat(q)
end return self
end
function Vector3:Div(d)
self.x = self.x / d
self.y = self.y / d
self.z = self.z / d return self
end
function Vector3:Add(vb)
self.x = self.x + vb.x
self.y = self.y + vb.y
self.z = self.z + vb.z return self
end
function Vector3:Sub(vb)
self.x = self.x - vb.x
self.y = self.y - vb.y
self.z = self.z - vb.z return self
end
function Vector3:MulQuat(quat) local num = quat.x * 2
local num2 = quat.y * 2
local num3 = quat.z * 2
local num4 = quat.x * num
local num5 = quat.y * num2
local num6 = quat.z * num3
local num7 = quat.x * num2
local num8 = quat.x * num3
local num9 = quat.y * num3
local num10 = quat.w * num
local num11 = quat.w * num2
local num12 = quat.w * num3 local x = (((1 - (num5 + num6)) * self.x) + ((num7 - num12) * self.y)) + ((num8 + num11) * self.z)
local y = (((num7 + num12) * self.x) + ((1 - (num4 + num6)) * self.y)) + ((num9 - num10) * self.z)
local z = (((num8 - num11) * self.x) + ((num9 + num10) * self.y)) + ((1 - (num4 + num5)) * self.z) self:Set(x, y, z)
return self
end
function Vector3.AngleAroundAxis (from, to, axis) from = from - Vector3.Project(from, axis)
to = to - Vector3.Project(to, axis) local angle = Vector3.Angle (from, to) return angle * (Vector3.Dot (axis, Vector3.Cross (from, to)) < 0 and -1 or 1)
end
Vector3.__tostring = function(self)
return "["..self.x..","..self.y..","..self.z.."]"
end
Vector3.__div = function(va, d)
return _new(va.x / d, va.y / d, va.z / d)
end
Vector3.__mul = function(va, d)
if type(d) == "number" then
return _new(va.x * d, va.y * d, va.z * d)
else
local vec = va:Clone()
vec:MulQuat(d)
return vec
end
end
Vector3.__add = function(va, vb)
return _new(va.x + vb.x, va.y + vb.y, va.z + vb.z)
end
Vector3.__sub = function(va, vb)
return _new(va.x - vb.x, va.y - vb.y, va.z - vb.z)
end
Vector3.__unm = function(va)
return _new(-va.x, -va.y, -va.z)
end
Vector3.__eq = function(a,b)
local v = a - b
local delta = v:SqrMagnitude()
return delta < 1e-10
end
get.up = function() return _new(0,1,0) end
get.down = function() return _new(0,-1,0) end
get.right = function() return _new(1,0,0) end
get.left = function() return _new(-1,0,0) end
get.forward = function() return _new(0,0,1) end
get.back = function() return _new(0,0,-1) end
get.zero = function() return _new(0,0,0) end
get.one = function() return _new(1,1,1) end
get.magnitude = Vector3.Magnitude
get.normalized = Vector3.Normalize
get.sqrMagnitude= Vector3.SqrMagnitude
UnityEngine.Vector3 = Vector3
setmetatable(Vector3, Vector3)
return Vector3
文章来源: czhenya.blog.csdn.net，作者：陈言必行，版权归原作者所有，如需转载，请联系作者。
原文链接：czhenya.blog.csdn.net/article/details/107716442
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