149 lines
2.6 KiB
Lua
149 lines
2.6 KiB
Lua
local sqrt = math.sqrt
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local ffi = require "ffi"
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ffi.cdef[[
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typedef struct {
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double x, y, z;
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} cpml_vec3;
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]]
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local vec3 = {}
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local cpml_vec3 = ffi.typeof("cpml_vec3")
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vec3.new = cpml_vec3
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function vec3.clone(a)
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local out = vec3.new()
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ffi.copy(out, a, ffi.sizeof(cpml_vec3))
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return out
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end
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function vec3.add(out, a, b)
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out.x = a.x + b.x
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out.y = a.y + b.y
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out.z = a.z + b.z
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end
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function vec3.sub(out, a, b)
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out.x = a.x - b.x
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out.y = a.y - b.y
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out.z = a.z - b.z
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end
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function vec3.mul(out, a, b)
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out.x = a.x * b
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out.y = a.y * b
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out.z = a.z * b
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end
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function vec3.div(out, a, b)
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out.x = a.x / b
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out.y = a.y / b
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out.z = a.z / b
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end
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function vec3.cross(out, a, b)
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out.x = a.y * b.z - a.z * b.y
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out.y = a.z * b.x - a.x * b.z
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out.z = a.x * b.y - a.y * b.x
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end
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function vec3.dot(a, b)
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return a.x * b.x + a.y * b.y + a.z * b.z
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end
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function vec3.normalize(out, a)
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local l = vec3.len(a)
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out.x = a.x / l
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out.y = a.y / l
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out.z = a.z / l
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end
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function vec3.len(a)
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return sqrt(a.x * a.x + a.y * a.y + a.z * a.z)
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end
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function vec3.len2(a)
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return a.x * a.x + a.y * a.y + a.z * a.z
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end
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function vec3.dist(a, b)
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local dx = a.x - b.x
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local dy = a.y - b.y
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local dz = a.z - b.z
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return sqrt(dx * dx + dy * dy + dz * dz)
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end
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function vec3.dist2(a, b)
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local dx = a.x - b.x
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local dy = a.y - b.y
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local dz = a.z - b.z
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return dx * dx + dy * dy + dz * dz
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end
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function vec3.reflect(i, n)
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local tmp = vec3.new()
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vec3.mul(tmp, n, 2.0 * vec3.dot(n, i))
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vec3.sub(tmp, i, tmp)
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return tmp
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end
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function vec3.refract(i, n, ior)
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local tmp = vec3.new()
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local d = vec3.dot(n, i)
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local k = 1.0 - ior * ior * (1.0 - d * d)
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if k >= 0.0 then
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local tmp2 = vec3.new() -- Can this be avoided?
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vec3.mul(tmp, i, ior)
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vec3.mul(tmp2, n, ior * d + sqrt(k))
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vec3.sub(tmp, tmp, tmp2)
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end
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return tmp
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end
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function vec3.lerp(a, b, s)
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return a + s * (b - a)
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end
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function vec3.unpack(a)
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return a.x, a.y, a.z
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end
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function vec3.tostring(a)
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return string.format("(%+0.3f,%+0.3f,%+0.3f)", a.x, a.y, a.z)
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end
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local vec3_mt = {}
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vec3_mt.__index = vec3
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vec3_mt.__call = vec3.new
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vec3_mt.__tostring = vec3.tostring
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function vec3_mt.__unm(a)
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return vec3.new(-a.x, -a.y, -a.z)
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end
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function vec3_mt.__eq(a,b)
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return a.x == b.x and a.y == b.y and a.z == b.z
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end
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function vec3_mt.__add(a, b)
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local temp = vec3.new()
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vec3.add(temp, a, b)
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return temp
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end
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function vec3_mt.__mul(a, b)
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local temp = vec3.new()
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vec3.mul(temp, a, b)
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return temp
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end
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function vec3_mt.__div(a, b)
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local temp = vec3.new()
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vec3.div(temp, a, b)
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return temp
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end
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ffi.metatype(cpml_vec3, vec3_mt)
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return setmetatable({}, vec3_mt)
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