raze-gles/polymer/eduke32/source/lunatic/test/test_dists.lua
2013-06-28 14:07:41 +00:00

89 lines
2 KiB
Lua
Executable file

#!/usr/bin/env luajit
local ffi = require "ffi"
local math = require "math"
local os = require "os"
local xmath = require "xmath"
local ldist = xmath.ldist
local sqrt = math.sqrt
local function printf(fmt, ...)
print(string.format(fmt, ...))
end
local function edist(p1, p2)
return sqrt(p1.x*p1.x + p2.x*p2.x)
end
-- z dummy is so that there's no error with xmath.rotate()
local vec2 = ffi.typeof("struct { int32_t x, y, z /* dummy */; }")
local numpoints = tonumber(arg[1]) or 1e4
local Nsq = numpoints*numpoints
printf("number of points: %d, testing %d distances", numpoints, Nsq)
local B = 8192
local pts = {}
for i=1,numpoints do
pts[i] = vec2(math.random(-B, B), math.random(B, -B))
end
-- test edist
local t = os.clock()
local sum = 0
for i=1,numpoints do
for j=1,numpoints do
sum = sum+edist(pts[i], pts[j])
end
end
t = os.clock()-t
printf("edist: %.03fns per call, mean=%.03f", (1e9*t)/Nsq, sum/Nsq)
-- test ldist
t = os.clock()
local sum = 0
for i=1,numpoints do
for j=1,numpoints do
sum = sum+ldist(pts[i], pts[j])
end
end
t = os.clock()-t
printf("ldist: %.03fns per call, mean=%.03f", (1e9*t)/Nsq, sum/Nsq)
-- test rotation
t = os.clock()
-- from control.lua (the CON version of rotatepoint)
local function _rotatepoint(pivotx, pivoty, posx, posy, ang)
local pos = xmath.ivec3(posx, posy)
local pivot = xmath.ivec3(pivotx, pivoty)
pos = xmath.rotate(pos, pivot, ang):toivec3()
return pos.x, pos.y
end
sum = 0
for i=1,numpoints do
for j=1,numpoints do
-- local p = xmath.rotate(pts[i], pts[j], j)
-- sum = sum+p.x
sum = sum + _rotatepoint(pts[j].x, pts[j].y, pts[i].x, pts[i].y, j)
end
end
t = os.clock()-t
printf("rotate: %.03fns per call", (1e9)/Nsq)
-- Results (helixhorned x86, x86_64)
-- number of points: 10000, testing 100000000 distances
-- edist: 6.300ns per call, mean=6286.597
-- ldist: 17.600ns per call, mean=8692.612
-- rotate: 10.000ns per call [even with _rotatepoint()!]