diff --git a/c++/perspective/src/common.h b/c++/perspective/src/common.h
index d3bea9c..2c5e843 100644
--- a/c++/perspective/src/common.h
+++ b/c++/perspective/src/common.h
@@ -42,7 +42,6 @@ public:
 		r(r), g(g), b(b), a(a) { }
 };
 
-
 inline int clz(const Int &x)
 	{ return x ? __builtin_clz(x) : 32; }
 inline int clz(const UInt &x)
diff --git a/c++/perspective/src/generator.cpp b/c++/perspective/src/generator.cpp
index 8fb0116..4457cf5 100644
--- a/c++/perspective/src/generator.cpp
+++ b/c++/perspective/src/generator.cpp
@@ -27,10 +27,10 @@ Generator::set_seed(ULongInt x) {
 
 Real
 Generator::random(const ULongIntVector2 &coord, int index) const {
-	ULongInt seed = ULongInt(rand()) ^ (ULongInt(rand()) << 16) ^ (ULongInt(rand()) << 32) ^ (ULongInt(rand()) << 48);
-	//ULongInt seed = random(coord.x ^ seeds_x()[index]);
-	//seed = random(seed ^ coord.y ^ seeds_y()[index]);
-	return Real(seed)/Real(ULLONG_MAX);
+	ULongInt seed = random(random(coord.x) ^ seeds_x()[index]);
+	seed = random(seed ^ random(coord.y) ^ seeds_y()[index]);
+	seed = random(seed ^ random(coord.x) ^ random(coord.y));
+	return Real(seed)/Real(ULLONG_MAX)*Real(2) - Real(1);
 }
 
 Vector4
@@ -78,19 +78,19 @@ Generator::generate(const ULongIntVector2 &coord, bool shrink_cache) const {
 		ULongInt level = (level_x < level_y ? level_x : level_y) + 1;
 
 		if (level < one) {
-			value /= (one/level);
+			value /= one/level;
 			if (level_x == level_y) {
 				// square corners
 				value += ( generate(ULongIntVector2(coord.x - level, coord.y - level))
-						+ generate(ULongIntVector2(coord.x - level, coord.y + level))
-						+ generate(ULongIntVector2(coord.x + level, coord.y - level))
-						+ generate(ULongIntVector2(coord.x + level, coord.y + level)) )*0.25;
+						 + generate(ULongIntVector2(coord.x - level, coord.y + level))
+						 + generate(ULongIntVector2(coord.x + level, coord.y - level))
+						 + generate(ULongIntVector2(coord.x + level, coord.y + level)) )*0.25;
 			} else {
 				// diamond corners
 				value += ( generate(ULongIntVector2(coord.x - level, coord.y))
-						+ generate(ULongIntVector2(coord.x + level, coord.y))
-						+ generate(ULongIntVector2(coord.x, coord.y - level))
-						+ generate(ULongIntVector2(coord.x, coord.y + level)) )*0.25;
+						 + generate(ULongIntVector2(coord.x + level, coord.y))
+						 + generate(ULongIntVector2(coord.x, coord.y - level))
+						 + generate(ULongIntVector2(coord.x, coord.y + level)) )*0.25;
 			}
 		}
 	}
diff --git a/c++/perspective/src/generator.h b/c++/perspective/src/generator.h
index affe538..e53476a 100644
--- a/c++/perspective/src/generator.h
+++ b/c++/perspective/src/generator.h
@@ -21,9 +21,26 @@ public:
 	};
 	
 	static inline ULongInt random(ULongInt x) {
+		++x;
+		x ^= x >> 2;
+		x ^= x << 3;
+		x ^= x >> 5;
+		x ^= x << 7;
+		x ^= x >> 11;
 		x ^= x << 13;
-		x ^= x >> 7;
-		x ^= x << 17;
+		x ^= x >> 17;
+		x ^= x << 19;
+		x ^= x >> 23;
+		x ^= x << 29;
+		x ^= x >> 31;
+		x ^= x << 37;
+		x ^= x >> 41;
+		x ^= x << 43;
+		x ^= x >> 47;
+		x ^= x << 53;
+		x ^= x >> 59;
+		x ^= x << 61;
+		++x;
 		return x;
 	}
 	static inline Real random_to_real(ULongInt x)