change hash function, remove caching of noise vectors; noise won't use unbounded memory now

1 files changed, 5 insertions, 11 deletions

diff --git a/server/noise.lua b/server/noise.lua
index bf7ac2e..c0ca57c 100644
--- a/server/noise.lua
+++ b/server/noise.lua
@@ -9,8 +9,8 @@ math.randomseed(os.time())
 local function hash_list(t)
 	local h = #t
 	for _,x in ipairs(t) do
-		x = bit.bxor(bit.rshift(x,16),x) * 0x45d9f3b
-		x = bit.bxor(bit.rshift(x,16),x) * 0x45d9f3b
+		x = bit.bxor(bit.rshift(x,16),x) * 0x7feb352d
+		x = bit.bxor(bit.rshift(x,15),x) * 0x846ca68b
 		x = bit.bxor(bit.rshift(x,16),x)
 		h = bit.bxor(h,x + 0x9e3779b9 + bit.lshift(h,6) + bit.rshift(h,2))
 	end
@@ -33,17 +33,11 @@ end
 local function slerp(a,b,t) return lerp(a,b,smoothstep(t)) end
 
 local PerlinNoise = class()
-function PerlinNoise.make(cls,ind_seed)
-	local grid = {}
-	setmetatable(grid,{__index=function(t,k) t[k] = {} return t[k] end})
-	return setmetatable({grid=grid,ind_seed=ind_seed},cls)
+function PerlinNoise.make(cls,seed)
+	return setmetatable({seed=seed},cls)
 end
 function PerlinNoise.vertex(self,ix,iy)
-	local v = self.grid[ix][iy]
-	if v then return v end
-	local vv = hash_to_unit_vec{ix,iy,self.ind_seed}
-	self.grid[ix][iy] = vv
-	return vv
+	return hash_to_unit_vec{ix,iy,self.seed}
 end
 
 function PerlinNoise.at(self,x,y)