[added] vec3.lua (very quick work, probably would benefit from tests)

This commit is contained in:
Max Cahill 2020-01-29 21:12:14 +11:00
parent 2069a4b3e7
commit 63448b5d5e
2 changed files with 658 additions and 42 deletions

View File

@ -14,8 +14,8 @@
]]
local vec2 = class()
vec2.x = 0
vec2.y = 0
vec2.type = "vec2"
--probably-too-flexible ctor
function vec2:new(x, y)
@ -24,8 +24,10 @@ function vec2:new(x, y)
elseif x then
if type(x) == "number" then
return vec2:filled(x)
elseif x.copy then
elseif x.type == "vec2" then
return x:copy()
elseif type(x) == "table" and x[1] and x[2] then
return vec2:xy(x[1], x[2])
end
end
return vec2:zero()
@ -187,46 +189,30 @@ end
--scalar
function vec2:saddi(x, y)
if y then
self.x = self.x + x
self.y = self.y + y
else
self.x = self.x + x
self.y = self.y + x
end
if not y then y = x end
self.x = self.x + x
self.y = self.y + y
return self
end
function vec2:ssubi(x, y)
if y then
self.x = self.x - x
self.y = self.y - y
else
self.x = self.x - x
self.y = self.y - x
end
if not y then y = x end
self.x = self.x - x
self.y = self.y - y
return self
end
function vec2:smuli(x, y)
if y then
self.x = self.x * x
self.y = self.y * y
else
self.x = self.x * x
self.y = self.y * x
end
if not y then y = x end
self.x = self.x * x
self.y = self.y * y
return self
end
function vec2:sdivi(x, y)
if y then
self.x = self.x / x
self.y = self.y / y
else
self.x = self.x / x
self.y = self.y / x
end
if not y then y = x end
self.x = self.x / x
self.y = self.y / y
return self
end
@ -351,19 +337,12 @@ end
vec2.rot180i = vec2.inversei --alias
function vec2:rotate_aroundi(angle, pivot)
local s = math.sin(angle)
local c = math.cos(angle)
local ox = self.x - pivot.x
local oy = self.y - pivot.y
self.x = (c * ox - s * oy) + pivot.x
self.y = (s * ox + c * oy) + pivot.y
self:vsubi(pivot)
self:rotatei(angle)
self:vaddi(pivot)
return self
end
function vec2:rotate_around(angle, pivot)
return self:copy():rotate_aroundi(angle, pivot)
end
--garbage mode
function vec2:normalised()
@ -394,6 +373,10 @@ end
vec2.rot180 = vec2.inverse --alias
function vec2:rotate_around(angle, pivot)
return self:copy():rotate_aroundi(angle, pivot)
end
function vec2:angle()
return math.atan2(self.y, self.x)
end
@ -560,7 +543,7 @@ function vec2:apply_friction(mu, dt)
end
--"gamey" friction in one dimension
function apply_friction_1d(v, mu, dt)
local function apply_friction_1d(v, mu, dt)
local friction = mu * v * dt
if math.abs(friction) > math.abs(v) then
return 0

633
vec3.lua Normal file
View File

@ -0,0 +1,633 @@
--[[
3d vector type
]]
--[[
notes:
depends on a class() function as in oo.lua
some methods depend on math library extensions
math.clamp(v, min, max) - return v clamped between min and max
math.round(v) - round v downwards if fractional part is < 0.5
]]
--defined globally? otherwise import vec2
if not vec2 then
local path = ...
local vec2_path = path:sub(1, path:len() - 1) .. "2"
local vec2 = require(vec2_path)
end
local vec3 = class()
vec3.type = "vec3"
--probably-too-flexible ctor
function vec3:new(x, y, z)
if x and y then
return vec3:xyz(x, y, z)
elseif x then
if type(x) == "number" then
return vec3:filled(x)
elseif x.type == "vec3" then
return x:copy()
elseif type(x) == "table" and x[1] and x[2] and x[3] then
return vec3:xyz(x[1], x[2], x[3])
end
end
return vec3:zero()
end
--explicit ctors
function vec3:copy()
return self:init({
x = self.x, y = self.y, z = self.z
})
end
function vec3:xyz(x, y, z)
return self:init({
x = x, y = y, z = z
})
end
function vec3:filled(v)
return self:init({
x = v, y = v, z = v
})
end
function vec3:zero()
return vec3:filled(0)
end
--shared pooled storage
local _vec3_pool = {}
--size limit for tuning memory upper bound
local _vec3_pool_limit = 128
function vec3.pool_size()
return #_vec3_pool
end
--flush the entire pool
function vec3.flush_pool()
if vec3.pool_size() > 0 then
_vec3_pool = {}
end
end
--drain one element from the pool, if it exists
function vec3.drain_pool()
if #_vec3_pool > 0 then
return table.remove(_vec3_pool)
end
return nil
end
--get a pooled vector (initialise it yourself)
function vec3:pooled()
return vec3.drain_pool() or vec3:zero()
end
--get a pooled copy of an existing vector
function vec3:pooled_copy()
return vec3:pooled():vset(self)
end
--release a vector to the pool
function vec3:release()
if vec3.pool_size() < _vec3_pool_limit then
table.insert(_vec3_pool, self)
end
end
--unpack for multi-args
function vec3:unpack()
return self.x, self.y, self.z
end
--pack when a sequence is needed
--(not particularly useful)
function vec3:pack()
return {self:unpack()}
end
--modify
function vec3:sset(x, y, z)
if not y then y = x end
if not z then z = y end
self.x = x
self.y = y
self.z = z
return self
end
function vec3:vset(v)
self.x = v.x
self.y = v.y
self.z = v.z
return self
end
function vec3:swap(v)
local sx, sy, sz = self.x, self.y, self.z
self:vset(v)
v:sset(sx, sy, sz)
return self
end
-----------------------------------------------------------
--equality comparison
-----------------------------------------------------------
--threshold for equality in each dimension
local EQUALS_EPSILON = 1e-9
--true if a and b are functionally equivalent
function vec3.equals(a, b)
return (
math.abs(a.x - b.x) <= EQUALS_EPSILON and
math.abs(a.y - b.y) <= EQUALS_EPSILON and
math.abs(a.z - b.z) <= EQUALS_EPSILON
)
end
--true if a and b are not functionally equivalent
--(very slightly faster than `not vec3.equals(a, b)`)
function vec3.nequals(a, b)
return (
math.abs(a.x - b.x) > EQUALS_EPSILON or
math.abs(a.y - b.y) > EQUALS_EPSILON or
math.abs(a.z - b.z) > EQUALS_EPSILON
)
end
-----------------------------------------------------------
--arithmetic
-----------------------------------------------------------
--immediate mode
--vector
function vec3:vaddi(v)
self.x = self.x + v.x
self.y = self.y + v.y
self.z = self.z + v.z
return self
end
function vec3:vsubi(v)
self.x = self.x - v.x
self.y = self.y - v.y
self.z = self.z - v.z
return self
end
function vec3:vmuli(v)
self.x = self.x * v.x
self.y = self.y * v.y
self.z = self.z * v.z
return self
end
function vec3:vdivi(v)
self.x = self.x / v.x
self.y = self.y / v.y
self.z = self.z / v.z
return self
end
--scalar
function vec3:saddi(x, y, z)
if not y then y = x end
if not z then z = y end
self.x = self.x + x
self.y = self.y + y
self.z = self.z + z
return self
end
function vec3:ssubi(x, y, z)
if not y then y = x end
if not z then z = y end
self.x = self.x - x
self.y = self.y - y
self.z = self.z - z
return self
end
function vec3:smuli(x, y, z)
if not y then y = x end
if not z then z = y end
self.x = self.x * x
self.y = self.y * y
self.z = self.z * z
return self
end
function vec3:sdivi(x, y, z)
if not y then y = x end
if not z then z = y end
self.x = self.x / x
self.y = self.y / y
self.z = self.z / z
return self
end
--garbage mode
function vec3:vadd(v)
return self:copy():vaddi(v)
end
function vec3:vsub(v)
return self:copy():vsubi(v)
end
function vec3:vmul(v)
return self:copy():vmuli(v)
end
function vec3:vdiv(v)
return self:copy():vdivi(v)
end
function vec3:sadd(x, y, z)
return self:copy():saddi(x, y, z)
end
function vec3:ssub(x, y, z)
return self:copy():ssubi(x, y, z)
end
function vec3:smul(x, y, z)
return self:copy():smuli(x, y, z)
end
function vec3:sdiv(x, y, z)
return self:copy():sdivi(x, y, z)
end
--fused multiply-add (a + (b * t))
function vec3:fmai(v, t)
self.x = self.x + (v.x * t)
self.y = self.y + (v.y * t)
self.z = self.z + (v.z * t)
return self
end
function vec3:fma(v, t)
return self:copy():fmai(v, t)
end
-----------------------------------------------------------
-- geometric methods
-----------------------------------------------------------
function vec3:length_squared()
return self.x * self.x + self.y * self.y + self.z * self.z
end
function vec3:length()
return math.sqrt(self:length_squared())
end
function vec3:distance_squared(other)
local dx = self.x - other.x
local dy = self.y - other.y
local dz = self.z - other.z
return dx * dx + dy * dy + dz * dz
end
function vec3:distance(other)
return math.sqrt(self:distance_squared(other))
end
--immediate mode
function vec3:normalisei_both()
local len = self:length()
if len == 0 then
return self, 0
end
return self:sdivi(len), len
end
function vec3:normalisei()
local v, len = self:normalisei_both()
return v
end
function vec3:normalisei_len()
local v, len = self:normalisei_both()
return len
end
function vec3:inversei()
return self:smuli(-1)
end
--swizzle extraction
--not as nice as property accessors so might be worth doing that later :)
local _allowed_swizzle = {
x = true,
y = true,
z = true,
}
function vec3:extract_single(swizzle)
if _allowed_swizzle[swizzle] then
return self[swizzle]
end
return 0
end
function vec3:infuse_single(swizzle, v)
if _allowed_swizzle[swizzle] then
self[swizzle] = v
end
return self
end
function vec3:extract_vec2(swizzle, into)
if not into then into = vec2:zero() end
local x = self:extract_single(swizzle:sub(1, 1))
local y = self:extract_single(swizzle:sub(2, 2))
return into:sset(x, y)
end
function vec3:infuse_vec2(swizzle, v)
self:infuse_single(swizzle:sub(1, 1), v.x)
self:infuse_single(swizzle:sub(2, 2), v.y)
return self
end
--rotate around a swizzle
function vec3:rotatei(swizzle, angle)
local v = vec2:pooled()
self:extract_vec2(swizzle, v)
v:rotatei(angle)
self:infuse_vec2(swizzle, v)
v:release()
return self
end
local _euler_macro = {
"yz",
"xz",
"xy",
}
function vec3:rotate_euleri(angle_x_axis, angle_y_axis, angle_z_axis)
for i, swizzle in ipairs(_euler_macro) do
local angle =
i == 1 and angle_x_axis
or i == 2 and angle_y_axis
or i == 3 and angle_z_axis
self:rotatei(swizzle, angle)
end
return self
end
--todo: 90deg rotations
vec3.rot180i = vec3.inversei --alias
function vec3:rotate_aroundi(swizzle, angle, pivot)
self:vsubi(pivot)
self:rotatei(swizzle, angle)
self:vaddi(pivot)
return self
end
--garbage mode
function vec3:normalised()
return self:copy():normalisei()
end
function vec3:normalised_len()
local v = self:copy()
local len = v:normalisei_len()
return v, len
end
function vec3:inverse()
return self:copy():inversei()
end
function vec3:rotate(angle)
return self:copy():rotatei(angle)
end
function vec3:rot90r()
return self:copy():rot90ri()
end
function vec3:rot90l()
return self:copy():rot90li()
end
vec3.rot180 = vec3.inverse --alias
function vec3:rotate_around(swizzle, angle, pivot)
return self:copy():rotate_aroundi(swizzle, angle, pivot)
end
-----------------------------------------------------------
-- per-component clamping ops
-----------------------------------------------------------
function vec3:mini(v)
self.x = math.min(self.x, v.x)
self.y = math.min(self.y, v.y)
self.z = math.min(self.z, v.z)
return self
end
function vec3:maxi(v)
self.x = math.max(self.x, v.x)
self.y = math.max(self.y, v.y)
self.z = math.max(self.z, v.z)
return self
end
function vec3:clampi(min, max)
self.x = math.clamp(self.x, min.x, max.x)
self.y = math.clamp(self.y, min.y, max.y)
self.z = math.clamp(self.z, min.z, max.z)
return self
end
function vec3:min(v)
return self:copy():mini(v)
end
function vec3:max(v)
return self:copy():maxi(v)
end
function vec3:clamp(min, max)
return self:copy():clampi(min, max)
end
-----------------------------------------------------------
-- absolute value
-----------------------------------------------------------
function vec3:absi()
self.x = math.abs(self.x)
self.y = math.abs(self.y)
self.z = math.abs(self.z)
return self
end
function vec3:abs()
return self:copy():absi()
end
-----------------------------------------------------------
-- truncation/rounding
-----------------------------------------------------------
function vec3:floori()
self.x = math.floor(self.x)
self.y = math.floor(self.y)
self.z = math.floor(self.z)
return self
end
function vec3:ceili()
self.x = math.ceil(self.x)
self.y = math.ceil(self.y)
self.z = math.ceil(self.z)
return self
end
function vec3:roundi()
self.x = math.round(self.x)
self.y = math.round(self.y)
self.z = math.round(self.z)
return self
end
function vec3:floor()
return self:copy():floori()
end
function vec3:ceil()
return self:copy():ceili()
end
function vec3:round()
return self:copy():roundi()
end
-----------------------------------------------------------
-- interpolation
-----------------------------------------------------------
function vec3:lerpi(other, amount)
self.x = math.lerp(self.x, other.x, amount)
self.y = math.lerp(self.y, other.y, amount)
self.z = math.lerp(self.z, other.z, amount)
return self
end
function vec3:lerp(other, amount)
return self:copy():lerpi(other, amount)
end
-----------------------------------------------------------
-- vector products and projections
-----------------------------------------------------------
function vec3.dot(a, b)
return a.x * b.x + a.y * b.y + a.z * b.z
end
function vec3.cross(a, b, into)
if not into then into = vec3:zero() end
return into:sset(
a.y * b.z - a.z * b.y,
a.z * b.x - a.x * b.z,
a.x * b.y - a.y * b.x
)
end
--scalar projection a onto b
function vec3.sproj(a, b)
local len = b:length()
if len == 0 then
return 0
end
return a:dot(b) / len
end
--vector projection a onto b (writes into a)
function vec3.vproji(a, b)
local div = b:dot(b)
if div == 0 then
return a:sset(0, 0, 0)
end
local fac = a:dot(b) / div
return a:vset(b):smuli(fac)
end
function vec3.vproj(a, b)
return a:copy():vproji(b)
end
--vector rejection a onto b (writes into a)
function vec3.vreji(a, b)
local tx, ty, tz = a.x, a.y, a.z
a:vproji(b)
a:sset(tx - a.x, ty - a.y, tz - a.z)
return a
end
function vec3.vrej(a, b)
return a:copy():vreji(b)
end
-----------------------------------------------------------
-- vector extension methods for special purposes
-- (any common vector ops worth naming)
-----------------------------------------------------------
--"physical" friction
local _v_friction = vec3:zero() --avoid alloc
function vec3:apply_friction(mu, dt)
_v_friction:vset(self):smuli(mu * dt)
if _v_friction:length_squared() > self:length_squared() then
self:sset(0, 0)
else
self:vsubi(_v_friction)
end
return self
end
--"gamey" friction in one dimension
local function apply_friction_1d(v, mu, dt)
local friction = mu * v * dt
if math.abs(friction) > math.abs(v) then
return 0
else
return v - friction
end
end
--"gamey" friction in both dimensions
function vec3:apply_friction_xy(mu_x, mu_y, dt)
self.x = apply_friction_1d(self.x, mu_x, dt)
self.y = apply_friction_1d(self.y, mu_y, dt)
self.z = apply_friction_1d(self.z, mu_y, dt)
return self
end
return vec3