Refactored the vec3 class.

modules/vec3.lua

@@ -1,86 +1,50 @@
---[[
-Copyright (c) 2010-2013 Matthias Richter
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in
-all copies or substantial portions of the Software.
-
-Except as contained in this notice, the name(s) of the above copyright holders
-shall not be used in advertising or otherwise to promote the sale, use or
-other dealings in this Software without prior written authorization.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-THE SOFTWARE.
-]]--
-
--- Modified to include 3D capabilities by Bill Shillito, April 2014
--- Various bug fixes by Colby Klein, October 2014
-
---- 3 dimensional vectors.
--- @module vec3
--- @alias vector
-
-local assert = assert
-local sqrt, cos, sin, atan2, acos = math.sqrt, math.cos, math.sin, math.atan2, math.acos
-
-local vector = {}
-vector.__index = vector
-
---- Instance a new vec3.
--- @param x X value, table containing 3 elements, or another vector.
--- @param y Y value
--- @param z Z value
--- @return vec3
-local function new(x,y,z)
-	-- allow construction via vec3(a, b, c), vec3 { a, b, c } or vec3 { x = a, y = b, z = c }
-	if type(x) == "table" then
-		return setmetatable({x=x.x or x[1] or 0, y=x.y or x[2] or 0, z=x.z or x[3] or 0}, vector)
-	end
-	return setmetatable({x = x or 0, y = y or 0, z = z or 0}, vector)
-end
+local sqrt= math.sqrt
+local ffi = require "ffi"
 
-local function isvector(v)
-	return getmetatable(v) == vector or type(v.x and v.y and v.z) == "number"
-end
+ffi.cdef[[
+typedef struct {
+	double x, y, z;
+} cpml_vec3;
+]]
 
-local zero = new(0,0,0)
-local unit_x = new(1,0,0)
-local unit_y = new(0,1,0)
-local unit_z = new(0,0,1)
+local vec3 = {}
+local cpml_vec3 = ffi.typeof("cpml_vec3")
+vec3.new = cpml_vec3
 
---- Create a new vector containing the same data.
--- @return vec3
-function vector:clone()
-	return new(self.x, self.y, self.z)
+function vec3.clone(a)
+	ffi.copy(vec3.new(), a, ffi.sizeof(out))
 end
 
---- Unpack the vector into its components.
--- @return number
--- @return number
--- @return number
-function vector:unpack()
-	return self.x, self.y, self.z
+function vec3.add(out, a, b)
+	out.x = a.x + b.x
+	out.y = a.y + b.y
+	out.z = a.z + b.z
 end
 
-function vector:__tostring()
-	return string.format("(%+0.3f,%+0.3f,%+0.3f)", self.x, self.y, self.z)
+function vec3.sub(out, a, b)
+	out.x = a.x - b.x
+	out.y = a.y - b.y
+	out.z = a.z - b.z
 end
 
-function vector.__unm(a)
-	return new(-a.x, -a.y, -a.z)
+function vec3.mul(out, a, b)
+	out.x = a.x * b
+	out.y = a.y * b
+	out.z = a.z * b
 end
 
+<<<<<<< HEAD
+function vec3.div(out, a, b)
+	out.x = a.x / b
+	out.y = a.y / b
+	out.z = a.z / b
+end
+
+function vec3.cross(out, a, b)
+	out.x = a.y*b.z - a.z*b.y
+	out.y = a.z*b.x - a.x*b.z
+	out.z = a.x*b.y - a.y*b.x
+=======
 function vector.__add(a,b)
 	if type(a) == "number" then
 		return new(a+b.x, a+b.y, a+b.z)
@@ -127,190 +91,86 @@ end
 
 function vector.__eq(a,b)
 	return a.x == b.x and a.y == b.y and a.z == b.z
+>>>>>>> refs/remotes/excessive/master
 end
 
-function vector.__lt(a,b)
-	-- This is a lexicographical order.
-	return a.x < b.x or (a.x == b.x and a.y < b.y) or (a.x == b.x and a.y == b.y and a.z < b.z)
-end
-
-function vector.__le(a,b)
-	-- This is a lexicographical order.
-	return a.x <= b.x and a.y <= b.y and a.z <= b.z
+function vec3.dot(a, b)
+	return a.x * b.x + a.y * b.y + a.z * b.z
 end
 
---- Dot product.
--- @param a first vec3 to dot with
--- @param b second vec3 to dot with
--- @return number
-function vector.dot(a,b)
-	assert(isvector(a) and isvector(b), "dot: wrong argument types (<vector> expected)")
-	return a.x*b.x + a.y*b.y + a.z*b.z
+function vec3.normalize(out, a)
+	local l = vec3.len(a)
+	out.x, out.y, out.z = a.x / l, a.y / l, a.z / l
 end
 
-function vector:len2()
-	return self.x * self.x + self.y * self.y + self.z * self.z
+function vec3.len2(a)
+	return a.x * a.x + a.y * a.y + a.z * a.z
 end
 
---- Vector length/magnitude.
--- @return number
-function vector:len()
-	return sqrt(self.x * self.x + self.y * self.y + self.z * self.z)
+function vec3.len(a)
+	return sqrt(a.x * a.x + a.y * a.y + a.z * a.z)
 end
 
---- Distance between two points.
--- @param a first point
--- @param b second point
--- @return number
-function vector.dist(a, b)
-	assert(isvector(a) and isvector(b), "dist: wrong argument types (<vector> expected)")
+function vec3.dist(a, b)
 	local dx = a.x - b.x
 	local dy = a.y - b.y
 	local dz = a.z - b.z
 	return sqrt(dx * dx + dy * dy + dz * dz)
 end
 
---- Squared distance between two points.
--- @param a first point
--- @param b second point
--- @return number
-function vector.dist2(a, b)
-	assert(isvector(a) and isvector(b), "dist: wrong argument types (<vector> expected)")
+function vec3.dist2(a, b)
 	local dx = a.x - b.x
 	local dy = a.y - b.y
 	local dz = a.z - b.z
 	return (dx * dx + dy * dy + dz * dz)
 end
 
---- Normalize vector.
--- Scales the vector in place such that its length is 1.
--- @return vec3
-function vector:normalize_inplace()
-	local l = self:len()
-	if l > 0 then
-		self.x, self.y, self.z = self.x / l, self.y / l, self.z / l
-	end
-	return self
-end
-
---- Normalize vector.
--- Returns a copy of the vector scaled such that its length is 1.
--- @return vec3
-function vector:normalize()
-	return self:clone():normalize_inplace()
-end
-
---- Rotate vector about an axis.
--- @param phi Amount to rotate, in radians
--- @param axis Axis to rotate by
--- @return vec3
-function vector:rotate(phi, axis)
-	if axis == nil then return self end
-
-	local u = axis:normalize() or Vector(0,0,1) -- default is to rotate in the xy plane
-	local c, s = cos(phi), sin(phi)
 
-	-- Calculate generalized rotation matrix
-	local m1 = new((c + u.x * u.x * (1-c)),       (u.x * u.y * (1-c) - u.z * s), (u.x * u.z * (1-c) + u.y * s))
-	local m2 = new((u.y * u.x * (1-c) + u.z * s), (c + u.y * u.y * (1-c)),       (u.y * u.z * (1-c) - u.x * s))
-	local m3 = new((u.z * u.x * (1-c) - u.y * s), (u.z * u.y * (1-c) + u.x * s), (c + u.z * u.z * (1-c))      )
-
-	-- Return rotated vector
-	return new( m1:dot(self), m2:dot(self), m3:dot(self) )
-end
-
-function vector:rotate_inplace(phi, axis)
-	self = self:rotated(phi, axis)
+function vec3.lerp(a, b, s)
+	return a + s * (b - a)
 end
 
-function vector:perpendicular()
-	return new(-self.y, self.x, 0)
-end
 
-function vector:project_on(v)
-	assert(isvector(v), "invalid argument: cannot project vector on " .. type(v))
-	-- (self * v) * v / v:len2()
-	local s = (self.x * v.x + self.y * v.y + self.z * v.z) / (v.x * v.x + v.y * v.y + v.z * v.z)
-	return new(s * v.x, s * v.y, s * v.z)
+function vec3.unpack(a)
+	return a.x, a.y, a.z
 end
 
-function vector:project_from(v)
-	assert(isvector(v), "invalid argument: cannot project vector on " .. type(v))
-	-- Does the reverse of projectOn.
-	local s = (v.x * v.x + v.y * v.y + v.z * v.z) / (self.x * v.x + self.y * v.y + self.z * v.z)
-	return new(s * v.x, s * v.y, s * v.z)
-end
 
-function vector:mirror_on(v)
-	assert(isvector(v), "invalid argument: cannot mirror vector on " .. type(v))
-	local s = 2 * (self.x * v.x + self.y * v.y + self.z * v.z) / (v.x * v.x + v.y * v.y + v.z * v.z)
-	return new(s * v.x - self.x, s * v.y - self.y, s * v.z - self.z)
+function vec3.tostring(a)
+	return string.format("(%+0.3f,%+0.3f,%+0.3f)", a.x, a.y, a.z)
 end
 
---- Cross product.
--- @param v vec3 to cross with
--- @return vec3
-function vector:cross(v)
-	assert(isvector(v), "cross: wrong argument types (<vector> expected)")
-	return new(self.y*v.z - self.z*v.y, self.z*v.x - self.x*v.z, self.x*v.y - self.y*v.x)
-end
+local vec3_mt = {}
 
--- @return vec3
-function vector:trim_inplace(maxLen)
-	-- ref.: http://blog.signalsondisplay.com/?p=336
-	local s = maxLen * maxLen / self:len2()
-	s = (s > 1 and 1) or math.sqrt(s)
-	self.x, self.y, self.z = self.x * s, self.y * s, self.z * s
-	return self
-end
+vec3_mt.__index = vec3
+vec3_mt.__call = vec3.new
+vec3_mt.__tostring = vec3.tostring
 
--- @return vec3
-function vector:trim(maxLen)
-	return self:clone():trim_inplace(maxLen)
+function vec3_mt.__unm(a)
+	return vec3.new(-a.x, -a.y, -a.z)
 end
 
--- @return number
-function vector:angle_to(other)
-	-- Only makes sense in 2D.
-	if other then
-		return atan2(self.y-other.y, self.x-other.x)
-	end
-	return atan2(self.y, self.x)
+function vec3_mt.__eq(a,b)
+	return a.x == b.x and a.y == b.y and a.z == b.z
 end
 
--- @return number
-function vector:angle_between(other)
-	if other then
-		return acos(self:dot(other) / (self:len() * other:len()))
-	end
-	return 0
+function vec3_mt.__add(a, b)
+	local temp = vec3.new()
+	vec3.add(temp, a, b)
+	return temp
 end
 
--- @return vec3
-function vector:orientation_to_direction(orientation)
-	orientation = orientation or new(0, 1, 0)
-	return orientation
-		:rotated(self.z, unit_z)
-		:rotated(self.y, unit_y)
-		:rotated(self.x, unit_x)
+function vec3_mt.__mul(a, b)
+	local temp = vec3.new()
+	vec3.mul(temp, a, b)
+	return temp
 end
 
--- http://keithmaggio.wordpress.com/2011/02/15/math-magician-lerp-slerp-and-nlerp/
-function vector.lerp(a, b, s)
-	return a + s * (b - a)
+function vec3_mt.__div(a, b)
+	local temp = vec3.new()
+	vec3.div(temp, a, b)
+	return temp
 end
 
--- the module
-return setmetatable(
-	{
-		new      = new,
-		lerp     = lerp,
-		isvector = isvector,
-		zero     = zero,
-		unit_x   = unit_x,
-		unit_y   = unit_y,
-		unit_z   = unit_z
-	}, {
-		__call = function(_, ...) return new(...) end
-	}
-)
+ffi.metatype(cpml_vec3, vec3_mt)
+return setmetatable({}, vec3_mt)