2015-12-19 23:56:56 -05:00

127 lines
2.1 KiB
Lua

local sqrt= math.sqrt
local ffi = require "ffi"
ffi.cdef[[
typedef struct {
double x, y, z;
} cpml_vec3;
]]
local vec3 = {}
local cpml_vec3 = ffi.typeof("cpml_vec3")
vec3.new = cpml_vec3
function vec3.clone(a)
ffi.copy(vec3.new(), a, ffi.sizeof(out))
end
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 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 vec3.mul(out, a, b)
out.x = a.x * b
out.y = a.y * b
out.z = a.z * b
end
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
end
function vec3.dot(a, b)
return a.x * b.x + a.y * b.y + a.z * b.z
end
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 vec3.len2(a)
return a.x * a.x + a.y * a.y + a.z * a.z
end
function vec3.len(a)
return sqrt(a.x * a.x + a.y * a.y + a.z * a.z)
end
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
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
function vec3.lerp(a, b, s)
return a + s * (b - a)
end
function vec3.unpack(a)
return a.x, a.y, a.z
end
function vec3.tostring(a)
return string.format("(%+0.3f,%+0.3f,%+0.3f)", a.x, a.y, a.z)
end
local vec3_mt = {}
vec3_mt.__index = vec3
vec3_mt.__call = vec3.new
vec3_mt.__tostring = vec3.tostring
function vec3_mt.__unm(a)
return vec3.new(-a.x, -a.y, -a.z)
end
function vec3_mt.__eq(a,b)
return a.x == b.x and a.y == b.y and a.z == b.z
end
function vec3_mt.__add(a, b)
local temp = vec3.new()
vec3.add(temp, a, b)
return temp
end
function vec3_mt.__mul(a, b)
local temp = vec3.new()
vec3.mul(temp, a, b)
return temp
end
function vec3_mt.__div(a, b)
local temp = vec3.new()
vec3.div(temp, a, b)
return temp
end
ffi.metatype(cpml_vec3, vec3_mt)
return setmetatable({}, vec3_mt)