120 lines
1.8 KiB
Lua
120 lines
1.8 KiB
Lua
local sqrt= math.sqrt
|
|
local ffi = require "ffi"
|
|
|
|
ffi.cdef[[
|
|
typedef struct {
|
|
double x, y;
|
|
} cpml_vec2;
|
|
]]
|
|
|
|
local vec2 = {}
|
|
local cpml_vec2 = ffi.typeof("cpml_vec2")
|
|
vec2.new = cpml_vec2
|
|
|
|
function vec2.clone(a)
|
|
local out = vec2.new()
|
|
ffi.copy(out, a, ffi.sizeof(cpml_vec2))
|
|
return out
|
|
end
|
|
|
|
function vec2.add(out, a, b)
|
|
out.x = a.x + b.x
|
|
out.y = a.y + b.y
|
|
end
|
|
|
|
function vec2.sub(out, a, b)
|
|
out.x = a.x - b.x
|
|
out.y = a.y - b.y
|
|
end
|
|
|
|
function vec2.mul(out, a, b)
|
|
out.x = a.x * b
|
|
out.y = a.y * b
|
|
end
|
|
|
|
function vec2.div(out, a, b)
|
|
out.x = a.x / b
|
|
out.y = a.y / b
|
|
end
|
|
|
|
function vec2.cross(a, b)
|
|
return a.x * b.y - a.y * b.x
|
|
end
|
|
|
|
function vec2.dot(a, b)
|
|
return a.x * b.x + a.y * b.y
|
|
end
|
|
|
|
function vec2.normalize(out, a)
|
|
local l = vec2.len(a)
|
|
out.x = a.x / l
|
|
out.y = a.y / l
|
|
end
|
|
|
|
function vec2.len(a)
|
|
return sqrt(a.x * a.x + a.y * a.y)
|
|
end
|
|
|
|
function vec2.len2(a)
|
|
return a.x * a.x + a.y * a.y
|
|
end
|
|
|
|
function vec2.dist(a, b)
|
|
local dx = a.x - b.x
|
|
local dy = a.y - b.y
|
|
return sqrt(dx * dx + dy * dy)
|
|
end
|
|
|
|
function vec2.dist2(a, b)
|
|
local dx = a.x - b.x
|
|
local dy = a.y - b.y
|
|
return dx * dx + dy * dy
|
|
end
|
|
|
|
function vec2.lerp(a, b, s)
|
|
return a + s * (b - a)
|
|
end
|
|
|
|
function vec2.unpack(a)
|
|
return a.x, a.y
|
|
end
|
|
|
|
function vec2.tostring(a)
|
|
return string.format("(%+0.3f,%+0.3f)", a.x, a.y)
|
|
end
|
|
|
|
local vec2_mt = {}
|
|
|
|
vec2_mt.__index = vec2
|
|
vec2_mt.__call = vec2.new
|
|
vec2_mt.__tostring = vec2.tostring
|
|
|
|
function vec2_mt.__unm(a)
|
|
return vec2.new(-a.x, -a.y)
|
|
end
|
|
|
|
function vec2_mt.__eq(a,b)
|
|
return a.x == b.x and a.y == b.y
|
|
end
|
|
|
|
function vec2_mt.__add(a, b)
|
|
local temp = vec2.new()
|
|
vec2.add(temp, a, b)
|
|
return temp
|
|
end
|
|
|
|
function vec2_mt.__mul(a, b)
|
|
local temp = vec2.new()
|
|
vec2.mul(temp, a, b)
|
|
return temp
|
|
end
|
|
|
|
function vec2_mt.__div(a, b)
|
|
local temp = vec2.new()
|
|
vec2.div(temp, a, b)
|
|
return temp
|
|
end
|
|
|
|
ffi.metatype(cpml_vec2, vec2_mt)
|
|
return setmetatable({}, vec2_mt)
|