Fixed merge conflicts. Refactored reflect and refract.

This commit is contained in:
Matthew Blanchard 2015-12-22 18:05:39 -05:00
commit bb78a486b0
3 changed files with 299 additions and 299 deletions

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@ -1,359 +1,338 @@
--- Quaternions
-- @module quat
-- @alias quaternion
-- quaternions
-- @author Andrew Stacey
-- Website: http://www.math.ntnu.no/~stacey/HowDidIDoThat/iPad/Codea.html
-- Licence: CC0 http://wiki.creativecommons.org/CC0
--[[
This is a class for handling quaternion numbers. It was originally
designed as a way of encoding rotations of 3 dimensional space.
--]]
local current_folder = (...):gsub('%.[^%.]+$', '') .. "."
local constants = require(current_folder .. "constants")
local vec3 = require(current_folder .. "vec3")
local quaternion = {}
quaternion.__index = quaternion
local ffi = require "ffi"
local DOT_THRESHOLD = constants.DOT_THRESHOLD
local FLT_EPSILON = constants.FLT_EPSILON
local abs = math.abs
local acos = math.acos
local asin = math.asin
local atan2 = math.atan2
local cos = math.cos
local sin = math.sin
local min = math.min
local max = math.max
local pi = math.pi
local sqrt = math.sqrt
--[[
A quaternion can either be specified by giving the four coordinates as
real numbers or by giving the scalar part and the vector part.
--]]
ffi.cdef[[
typedef struct {
double x, y, z, w;
} cpml_quat;
]]
local function new(...)
local x, y, z, w
-- copy
local arg = { select(1, ...) or 0, select(2, ...) or 0, select(3, ...) or 0, select(4, ...) or 0 }
local n = select('#', ...)
if n == 1 and type(arg[1]) == "table" then
x = arg[1].x or arg[1][1]
y = arg[1].y or arg[1][2]
z = arg[1].z or arg[1][3]
w = arg[1].w or arg[1][4]
-- four numbers
elseif n == 4 then
x = arg[1]
y = arg[2]
z = arg[3]
w = arg[4]
-- real number plus vector
elseif n == 2 then
x = arg[1].x or arg[1][1]
y = arg[1].y or arg[1][2]
z = arg[1].z or arg[1][3]
w = arg[2]
else
print(string.format("%s %s %s %s", select(1, ...), select(2, ...), select(3, ...), select(4, ...)))
error("Incorrect number of arguments to quaternion")
end
local quat = {}
local cpml_quat = ffi.typeof("cpml_quat")
quat.new = cpml_quat
return setmetatable({ x = x or 0, y = y or 0, z = z or 0, w = w or 1 }, quaternion)
function quat.identity(out)
out.x = 0
out.y = 0
out.z = 0
out.w = 1
end
function quaternion.__add(a, b)
if type(b) == "number" then
return new(a.x, a.y, a.z, a.w + b)
end
return new(a.x + b.x, a.y + b.y, a.z + b.z, a.w + b.w)
function quat.clone(a)
local out = quat.new()
ffi.copy(out, a, ffi.sizeof(cpml_quat))
return out
end
function quaternion.__sub(a, b)
return new(a.x - b.x, a.y - b.y, a.z - b.z, a.w - b.w)
function quat.add(out, a, b)
out.x = a.x + b.x
out.y = a.y + b.y
out.z = a.z + b.z
out.w = a.w + b.w
end
function quaternion:__unm()
return self:scale(-1)
function quat.sub(out, a, b)
out.x = a.x - b.x
out.y = a.y - b.y
out.z = a.z - b.z
out.w = a.w - b.w
end
function quaternion.__mul(a, b)
-- quat * number
if type(b) == "number" then
return a:scale(b)
-- quat * quat
elseif type(b) == "table" and b.w then
local x, y, z, w
x = a.x * b.w + a.w * b.x + a.y * b.z - a.z * b.y
y = a.y * b.w + a.w * b.y + a.z * b.x - a.x * b.z
z = a.z * b.w + a.w * b.z + a.x * b.y - a.y * b.x
w = a.w * b.w - a.x * b.x - a.y * b.y - a.z * b.z
return new(x, y, z, w)
else
function quat.mul(out, a, b)
if type(b) == "table" and b.x and b.y and b.z and b.w then
out.x = a.x * b.w + a.w * b.x + a.y * b.z - a.z * b.y
out.y = a.y * b.w + a.w * b.y + a.z * b.x - a.x * b.z
out.z = a.z * b.w + a.w * b.z + a.x * b.y - a.y * b.x
out.w = a.w * b.w - a.x * b.x - a.y * b.y - a.z * b.z
elseif type(b) == "table" and b.x and b.y and b.z then
local qv = vec3(a.x, a.y, a.z)
local uv = qv:cross(b)
local uuv = qv:cross(uv)
return b + ((uv * a.w) + uuv) * 2
local uv, uuv = vec3(), vec3()
vec3.cross(uv, qv, b)
vec3.cross(uuv, qv, uv)
vec3.mul(out, uv, a.w)
vec3.add(out, out, uuv)
vec3.mul(out, out, 2)
vec3.add(out, b, out)
end
end
function quaternion.__div(a, b)
function quat.div(out, a, b)
if type(b) == "number" then
return a:scale(1 / b)
elseif type(b) == "table" then
return a * b:reciprocal()
quat.scale(out, a, 1 / b)
elseif type(b) == "table" and b.x and b.y and b.z and b.w then
quat.reciprocal(out, b)
quat.mul(out, a, out)
end
end
function quaternion:__pow(n)
function quat.pow(out, a, n)
if n == 0 then
return self.unit()
quat.identity(out)
elseif n > 0 then
return self * self^(n-1)
out.x = a.x^(n-1)
out.y = a.y^(n-1)
out.z = a.z^(n-1)
out.w = a.w^(n-1)
quat.mul(out, a, out)
elseif n < 0 then
return self:reciprocal()^(-n)
quat.reciprocal(out, a)
out.x = out.x^(-n)
out.y = out.y^(-n)
out.z = out.z^(-n)
out.w = out.w^(-n)
end
end
function quaternion.__eq(a, b)
if a.x ~= b.x or a.y ~= b.y or a.z ~= b.z or a.w ~= b.w then
return false
end
return true
function quat.cross(out, a, b)
out.x = a.w * b.x + a.x * b.w + a.y * b.z - a.z * b.y
out.y = a.w * b.y + a.y * b.w + a.z * b.x - a.x * b.z
out.z = a.w * b.z + a.z * b.w + a.x * b.y - a.y * b.x
out.w = a.w * b.w - a.x * b.x - a.y * b.y - a.z * b.z
end
function quaternion:__tostring()
return string.format("(%0.3f,%0.3f,%0.3f,%0.3f)", self.x, self.y, self.z, self.w)
end
function quaternion:unpack()
return self.x, self.y, self.z, self.w
end
function quaternion.unit()
return new(0, 0, 0, 1)
end
function quaternion:to_axis_angle()
if self.w > 1 or self.w < -1 then
self = self:normalize()
end
local angle = 2 * math.acos(self.w)
local s = math.sqrt(1-self.w*self.w)
local x, y, z
if s < constants.FLT_EPSILON then
x = self.x
y = self.y
z = self.z
else
x = self.x / s -- normalize axis
y = self.y / s
z = self.z / s
end
return angle, vec3(x, y, z)
end
-- Test if we are zero
function quaternion:is_zero()
-- are we the zero vector
if self.x ~= 0 or self.y ~= 0 or self.z ~= 0 or self.w ~= 0 then
return false
end
return true
end
-- Test if we are real
function quaternion:is_real()
-- are we the zero vector
if self.x ~= 0 or self.y ~= 0 or self.z ~= 0 then
return false
end
return true
end
-- Test if the real part is zero
function quaternion:is_imaginary()
-- are we the zero vector
if self.w ~= 0 then
return false
end
return true
end
-- The dot product of two quaternions
function quaternion.dot(a, b)
function quat.dot(a, b)
return a.x * b.x + a.y * b.y + a.z * b.z + a.w * b.w
end
function quaternion.cross(a, b)
return new(
a.w * b.x + a.x * b.w + a.y * b.z - a.z * b.y,
a.w * b.y + a.y * b.w + a.z * b.x - a.x * b.z,
a.w * b.z + a.z * b.w + a.x * b.y - a.y * b.x,
a.w * b.w - a.x * b.x - a.y * b.y - a.z * b.z
)
end
-- Length of a quaternion
function quaternion:len()
return math.sqrt(self:len2())
end
-- Length squared of a quaternion
function quaternion:len2()
return self:dot(self)
end
-- Normalize a quaternion to have length 1
function quaternion:normalize()
if self:is_zero() then
error("Unable to normalize a zero-length quaternion")
function quat.normalize(out, a)
if quat.is_zero(a) then
error("Cannot normalize a zero-length quaternion.")
return false
end
local l = 1 / self:len()
return self:scale(l)
local l = 1 / quat.len(a)
quat.scale(out, a, l)
end
-- Scale the quaternion
function quaternion:scale(l)
return new(self.x * l, self.y * l, self.z * l, self.w * l)
function quat.len(a)
return sqrt(a.x * a.x + a.y * a.y + a.z * a.z + a.w * a.w)
end
-- Conjugation (corresponds to inverting a rotation)
function quaternion:conjugate()
return new(-self.x, -self.y, -self.z, self.w)
function quat.len2(a)
return a.x * a.x + a.y * a.y + a.z * a.z + a.w * a.w
end
function quaternion:inverse()
return self:conjugate():normalize()
function quat.lerp(out, a, b, s)
quat.sub(out, b, a)
quat.mul(out, out, s)
quat.add(out, a, out)
quat.normalize(out, out)
end
-- Reciprocal: 1/q
function quaternion:reciprocal()
if self.is_zero() then
error("Cannot reciprocate a zero quaternion")
return false
function quat.slerp(out, a, b, s)
local function clamp(n, low, high) return min(max(n, low), high) end
local dot = quat.dot(a, b)
if dot < 0 then
quat.scale(a, a, -1)
dot = -dot
end
local q = self:conjugate()
local l = self:len2()
q = q:scale(1 / l)
if dot > DOT_THRESHOLD then
quat.lerp(out, a, b, s)
return
end
return q
clamp(dot, -1, 1)
local temp = quat.new()
local theta = acos(dot) * s
quat.scale(out, a, dot)
quat.sub(out, b, out)
quat.normalize(out, out)
quat.scale(out, out, sin(theta))
quat.scale(temp, a, cos(theta))
quat.add(out, temp, out)
end
-- Returns the real part
function quaternion:real()
return self.w
end
function quat.rotate(out, angle, axis)
local len = vec3.len(axis)
function quaternion:clone()
return new(self.x, self.y, self.z, self.w)
end
-- Returns the vector (imaginary) part as a Vec3 object
function quaternion:to_vec3()
return vec3(self.x, self.y, self.z)
end
--[[
Converts a rotation to a quaternion. The first argument is the angle
to rotate, the second must specify an axis as a Vec3 object.
--]]
local function rotate(angle, axis)
local len = axis:len()
if math.abs(len - 1) > 0.001 then
if abs(len - 1) > FLT_EPSILON then
axis.x = axis.x / len
axis.y = axis.y / len
axis.z = axis.z / len
end
local sin = math.sin(angle * 0.5)
local cos = math.cos(angle * 0.5)
local s = sin(angle * 0.5)
local c = cos(angle * 0.5)
return new(axis.x * sin, axis.y * sin, axis.z * sin, cos)
out.x = axis.x * s
out.y = axis.y * s
out.z = axis.z * s
out.w = c
end
--- Create a quaternion from a direction + up vector.
-- @param normal
-- @param up
-- @return quat
local function from_direction(normal, up)
local a = up:cross(normal)
local d = up:dot(normal)
return new(a.x, a.y, a.z, d + 1)
function quat.scale(out, a, s)
out.x = a.x * s
out.y = a.y * s
out.z = a.z * s
out.w = a.w * s
end
function quaternion:to_euler()
local sqx = self.x*self.x
local sqy = self.y*self.y
local sqz = self.z*self.z
local sqw = self.w*self.w
function quat.conjugate(out, a)
out.x = -a.x
out.y = -a.y
out.z = -a.z
out.w = a.w
end
function quat.inverse(out, a)
quat.conjugate(out, a)
quat.normalize(out, out)
end
function quat.reciprocal(out, a)
if quat.is_zero(a) then
error("Cannot reciprocate a zero-length quaternion.")
return false
end
local l = quat.len2(a)
quat.conjugate(out, a)
quat.scale(out, out, 1 / l)
end
function quat.is_zero(a)
return a.x == 0 and a.y == 0 and a.z == 0 and a.w == 0 then
end
function quat.is_real(a)
return a.x == 0 and a.y == 0 and a.z == 0 then
end
function quat.is_imaginary(a)
return a.w == 0 then
end
function quat.real(a)
return a.w
end
function quat.imaginary(a)
return vec3(a.x, a.y, a.z)
end
function quat.from_direction(out, normal, up)
local d = vec3.dot(up, normal)
local a = vec3()
vec3.cross(a, up, normal)
out.x = a.x
out.y = a.y
out.z = a.z
out.w = d + 1
end
function quat.to_angle_axis(a)
if a.w > 1 or a.w < -1 then
quat.normalize(a, a)
end
local angle = 2 * acos(a.w)
local s = sqrt(1 - a.w * a.w)
local x, y, z
if s < FLT_EPSILON then
x = a.x
y = a.y
z = a.z
else
x = a.x / s
y = a.y / s
z = a.z / s
end
return angle, vec3(x, y, z)
end
function quat.to_euler(a)
local sqx = a.x * a.x
local sqy = a.y * a.y
local sqz = a.z * a.z
local sqw = a.w * a.w
-- if normalised is one, otherwise is correction factor
local unit = sqx + sqy + sqz + sqw
local test = self.x*self.y + self.z*self.w
local test = a.x * a.y + a.z * a.w
local pitch, yaw, roll
-- singularity at north pole
if test > 0.499*unit then
yaw = 2 * math.atan2(self.x,self.w)
pitch = math.pi/2
roll = 0
return pitch, yaw, roll
if test > 0.499 * unit then
pitch = pi / 2
yaw = 2 * atan2(a.x, a.w)
roll = 0
elseif test < -0.499 * unit then
pitch = -pi / 2
yaw = -2 * atan2(a.x, a.w)
roll = 0
else
pitch = asin(2 * test / unit)
yaw = atan2(2 * a.y * a.w - 2 * a.x * a.z, sqx - sqy - sqz + sqw)
roll = atan2(2 * a.x * a.w - 2 * a.y * a.z, -sqx + sqy - sqz + sqw)
end
-- singularity at south pole
if test < -0.499*unit then
yaw = -2 * math.atan2(self.x,self.w)
pitch = -math.pi/2
roll = 0
return pitch, yaw, roll
end
yaw = math.atan2(2*self.y*self.w-2*self.x*self.z , sqx - sqy - sqz + sqw)
pitch = math.asin(2*test/unit)
roll = math.atan2(2*self.x*self.w-2*self.y*self.z , -sqx + sqy - sqz + sqw)
return pitch, roll, yaw
return pitch, yaw, roll
end
-- http://keithmaggio.wordpress.com/2011/02/15/math-magician-lerp-slerp-and-nlerp/
-- non-normalized rotations do not work out for quats!
function quaternion.lerp(a, b, s)
local v = a + (b - a) * s
return v:normalize()
function quat.unpack(a)
return a.x, a.y, a.z, a.w
end
-- http://number-none.com/product/Understanding%20Slerp,%20Then%20Not%20Using%20It/
function quaternion.slerp(a, b, s)
local function clamp(n, low, high) return math.min(math.max(n, low), high) end
local dot = a:dot(b)
-- http://www.gamedev.net/topic/312067-shortest-slerp-path/#entry2995591
if dot < 0 then
a = -a
dot = -dot
end
if dot > constants.DOT_THRESHOLD then
return quaternion.lerp(a, b, s)
end
clamp(dot, -1, 1)
local theta = math.acos(dot) * s
local c = (b - a * dot):normalize()
return a * math.cos(theta) + c * math.sin(theta)
function quat.tostring(a)
return string.format("(%+0.3f,%+0.3f,%+0.3f,%+0.3f)", a.x, a.y, a.z, a.w)
end
-- return quaternion
-- the module
return setmetatable({ new = new, rotate = rotate, from_direction = from_direction },
{ __call = function(_, ...) return new(...) end })
local quat_mt = {}
quat_mt.__index = quat
quat_mt.__call = quat.new
quat_mt.__tostring = quat.tostring
function quat_mt.__unm(a)
local temp = quat.new()
quat.scale(temp, a, -1)
return temp
end
function quat_mt.__eq(a,b)
return a.x == b.x and a.y == b.y and a.z == b.z and a.w == b.w
end
function quat_mt.__add(a, b)
local temp = quat.new()
quat.add(temp, a, b)
return temp
end
function quat_mt.__mul(a, b)
local temp = quat.new()
quat.mul(temp, a, b)
return temp
end
function quat_mt.__div(a, b)
local temp = quat.new()
quat.div(temp, a, b)
return temp
end
function quat_mt.__pow(a, n)
local temp = quat.new()
quat.pow(temp, a, n)
return temp
end
ffi.metatype(cpml_quat, quat_mt)
return setmetatable({}, quat_mt)

View File

@ -12,7 +12,9 @@ local cpml_vec2 = ffi.typeof("cpml_vec2")
vec2.new = cpml_vec2
function vec2.clone(a)
ffi.copy(vec2.new(), a, ffi.sizeof(out))
local out = vec2.new()
ffi.copy(out, a, ffi.sizeof(cpml_vec2))
return out
end
function vec2.add(out, a, b)

View File

@ -62,7 +62,9 @@ end
--- Clone a vector.
-- @tparam @{vec3} vec vector to be cloned
function vec3.clone(a)
ffi.copy(vec3.new(), a, ffi.sizeof(out))
local out = vec3.new()
ffi.copy(out, a, ffi.sizeof(cpml_vec3))
return out
end
--- Add two vectors.
@ -115,16 +117,6 @@ function vec3.cross(out, a, b)
out.z = a.x * b.y - a.y * b.x
end
--- Get the dot product of two vectors.
-- @tparam @{vec3} a Left hand operant
-- @tparam @{vec3} b Right hand operant
-- @treturn number
function vec3.dot(a, b)
return a.x * b.x + a.y * b.y + a.z * b.z
end
--- Get the normal of a vector.
-- @tparam @{vec3} out vector to store the result
-- @tparam @{vec3} a vector to normalize
@ -135,6 +127,33 @@ function vec3.normalize(out, a)
out.z = a.z / l
end
function vec3.reflect(out, i, n)
vec3.mul(out, n, 2.0 * vec3.dot(n, i))
vec3.sub(out, i, out)
return out
end
local tmp = vec3.__new(0, 0, 0)
function vec3.refract(out, i, n, ior)
local d = vec3.dot(n, i)
local k = 1.0 - ior * ior * (1.0 - d * d)
if k >= 0.0 then
vec3.mul(out, i, ior)
vec3.mul(tmp, n, ior * d + sqrt(k))
vec3.sub(out, out, tmp)
end
return out
end
--- Get the dot product of two vectors.
-- @tparam @{vec3} a Left hand operant
-- @tparam @{vec3} b Right hand operant
-- @treturn number
function vec3.dot(a, b)
return a.x * b.x + a.y * b.y + a.z * b.z
end
--- Get the length of a vector.
-- @tparam @{vec3} a vector to get the length of
-- @treturn number