remove C library dependency

simplex.lua

@@ -9,7 +9,6 @@ local table = table
 local tonumber = tonumber
 local ipairs = ipairs
 local error = error
-local bit = require("bit")
 
 local simplex = {}
 
@@ -137,8 +136,8 @@ function simplex.Noise2D(xin, yin)
 	local y2 = y0 - 1.0 + 2.0 * G2;
 
 	-- Work out the hashed gradient indices of the three simplex corners
-	local ii = bit.band(i , 255)
-	local jj = bit.band(j , 255)
+	local ii = math.floor(i % 255)
+	local jj = math.floor(j % 255)
 	local gi0 = perm[ii+perm[jj]] % 12;
 	local gi1 = perm[ii+i1+perm[jj+j1]] % 12;
 	local gi2 = perm[ii+1+perm[jj+1]] % 12;
@@ -250,9 +249,9 @@ function simplex.Noise3D(xin, yin, zin)
 	local z3 = z0 - 1.0 + 3.0*G3;
 	
 	-- Work out the hashed gradient indices of the four simplex corners
-	local ii = bit.band(i , 255)
-	local jj = bit.band(j , 255)
-	local kk = bit.band(k , 255)
+	local ii = math.floor(i % 255)
+	local jj = math.floor(j % 255)
+	local kk = math.floor(k % 255)
 	
 	local gi0 = perm[ii+perm[jj+perm[kk]]] % 12;
 	local gi1 = perm[ii+i1+perm[jj+j1+perm[kk+k1]]] % 12;
@@ -394,10 +393,10 @@ function simplex.Noise4D(x,y,z,w)
 	local w4 = w0 - 1.0 + 4.0*G4;
 	
 	-- Work out the hashed gradient indices of the five simplex corners
-	local ii = bit.band(i , 255)
-	local jj = bit.band(j , 255)
-	local kk = bit.band(k , 255)
-	local ll = bit.band(l , 255)
+	local ii = math.floor(i % 255)
+	local jj = math.floor(j % 255)
+	local kk = math.floor(k % 255)
+	local ll = math.floor(l % 255)
 	local gi0 = perm[ii+perm[jj+perm[kk+perm[ll]]]] % 32;
 	local gi1 = perm[ii+i1+perm[jj+j1+perm[kk+k1+perm[ll+l1]]]] % 32;
 	local gi2 = perm[ii+i2+perm[jj+j2+perm[kk+k2+perm[ll+l2]]]] % 32;