Updated simplex noise 3D

glm/gtx/noise.inl

@@ -17,11 +17,17 @@
 
 namespace glm
 {
-	template <typename T>
-	inline detail::tvec3<T> permute(detail::tvec3<T> const & x)
+	template <typename T, template<typename> class vecType>
+	inline vecType<T> permute(vecType<T> const & x)
 	{
 		return mod(((x * T(34)) + T(1)) * x, T(289));
 	}
+  
+	template <typename T, template<typename> class vecType>
+	inline vecType<T> taylorInvSqrt(vecType<T> const & r)
+	{
+		return T(1.79284291400159) - T(0.85373472095314) * r;
+	}
 
 namespace gtx{
 namespace noise
@@ -54,34 +60,123 @@ namespace noise
 		detail::tvec3<T> p = permute(
 			permute(i.y + detail::tvec3<T>(T(0), i1.y, T(1)))
 			+ i.x + detail::tvec3<T>(T(0), i1.x, T(1)));
-/*
+
 		detail::tvec3<T> m = max(T(0.5) - detail::tvec3<T>(
 			dot(x0, x0), 
 			dot(detail::tvec2<T>(x12.x, x12.y), detail::tvec2<T>(x12.x, x12.y)), 
-			dot(detail::tvec2<T>(x12.z, x12.w), detail::tvec2<T>(x12.z, x12.w)), T(0.0));
+			dot(detail::tvec2<T>(x12.z, x12.w), detail::tvec2<T>(x12.z, x12.w))), T(0));
 		m = m * m ;
 		m = m * m ;
 
 		// Gradients: 41 points uniformly over a line, mapped onto a diamond.
 		// The ring size 17*17 = 289 is close to a multiple of 41 (41*7 = 287)
 
-		detail::tvec3<T> x = 2.0 * fract(p * C.w) - 1.0;
-		detail::tvec3<T> h = abs(x) - 0.5;
-		detail::tvec3<T> ox = floor(x + 0.5);
+		detail::tvec3<T> x = T(2) * fract(p * C.w) - T(1);
+		detail::tvec3<T> h = abs(x) - T(0.5);
+		detail::tvec3<T> ox = floor(x + T(0.5));
 		detail::tvec3<T> a0 = x - ox;
 
 		// Normalise gradients implicitly by scaling m
 		// Inlined for speed: m *= taylorInvSqrt( a0*a0 + h*h );
-		m *= 1.79284291400159 - 0.85373472095314 * (a0 * a0 + h * h);
+		m *= T(1.79284291400159) - T(0.85373472095314) * (a0 * a0 + h * h);
 
 		// Compute final noise value at P
 		detail::tvec3<T> g;
 		g.x  = a0.x  * x0.x  + h.x  * x0.y;
-		g.yz = a0.yz * x12.xz + h.yz * x12.yw;
-		return 130.0 * dot(m, g);
-*/
+		//g.yz = a0.yz * x12.xz + h.yz * x12.yw;
+		g.y = a0.y * x12.x + h.y * x12.y;
+		g.z = a0.z * x12.z + h.z * x12.w;
+		return T(130) * dot(m, g);
+	}
+
+	template <typename T>
+	inline T snoise(glm::detail::tvec3<T> const & v)
+	{ 
+		detail::tvec2<T> const C = detail::tvec2<T>(1.0 / 6.0, 1.0 / 3.0);
+		detail::tvec4<T> const D = detail::tvec4<T>(0.0, 0.5, 1.0, 2.0);
+
+		// First corner
+		detail::tvec3<T> i  = floor(v + dot(v, C.y));
+		detail::tvec3<T> x0 =   v - i + dot(i, C.x);
+
+		// Other corners
+		detail::tvec3<T> g = step(x0.yzx, x0.xyz);
+		detail::tvec3<T> l = 1.0 - g;
+		detail::tvec3<T> i1 = min( g.xyz, l.zxy );
+		detail::tvec3<T> i2 = max( g.xyz, l.zxy );
+
+		//   x0 = x0 - 0.0 + 0.0 * C.xxx;
+		//   x1 = x0 - i1  + 1.0 * C.xxx;
+		//   x2 = x0 - i2  + 2.0 * C.xxx;
+		//   x3 = x0 - 1.0 + 3.0 * C.xxx;
+		detail::tvec3<T> x1 = x0 - i1 + C.x;
+		detail::tvec3<T> x2 = x0 - i2 + C.y; // 2.0*C.x = 1/3 = C.y
+		detail::tvec3<T> x3 = x0 - D.y;      // -1.0+3.0*C.x = -0.5 = -D.y
+
+		// Permutations
+		i = mod(i, T(289)); 
+		detail::tvec4<T> p = permute(permute(permute( 
+			i.z + detail::tvec4<T>(0.0, i1.z, i2.z, 1.0)) + 
+			i.y + detail::tvec4<T>(0.0, i1.y, i2.y, 1.0)) + 
+			i.x + detail::tvec4<T>(0.0, i1.x, i2.x, 1.0));
+
+		// Gradients: 7x7 points over a square, mapped onto an octahedron.
+		// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
+		T n_ = T(0.142857142857); // 1.0/7.0
+		detail::tvec3<T> ns = n_ * D.wyz - D.xzx;
+
+		detail::tvec4<T> j = p - T(49) * floor(p * ns.z * ns.z);  //  mod(p,7*7)
+
+		detail::tvec4<T> x_ = floor(j * ns.z);
+		detail::tvec4<T> y_ = floor(j - T(7) * x_ );    // mod(j,N)
+
+		detail::tvec4<T> x = x_ * ns.x + ns;
+		detail::tvec4<T> y = y_ * ns.x + ns;
+		detail::tvec4<T> h = T(1) - abs(x) - abs(y);
+
+		detail::tvec4<T> b0 = detail::tvec4<T>(x.xy, y.xy);
+		detail::tvec4<T> b1 = detail::tvec4<T>(x.zw, y.zw);
+
+		//vec4 s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0;
+		//vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;
+		detail::tvec4<T> s0 = floor(b0) * T(2) + T(1);
+		detail::tvec4<T> s1 = floor(b1) * T(2) + T(1);
+		detail::tvec4<T> sh = -step(h, detail::tvec4<T>(0));
+
+		detail::tvec4<T> a0 = b0 + s0 * sh.xxyy;
+		detail::tvec4<T> a1 = b1 + s1 * sh.zzww;
+
+		detail::tvec3<T> p0 = vec3(a0.xy, h.x);
+		detail::tvec3<T> p1 = vec3(a0.zw, h.y);
+		detail::tvec3<T> p2 = vec3(a1.xy, h.z);
+		detail::tvec3<T> p3 = vec3(a1.zw, h.w);
+
+		//Normalise gradients
+		detail::tvec4<T> norm = taylorInvSqrt(detail::tvec4<T>(
+			dot(p0, p0), 
+			dot(p1, p1), 
+			dot(p2, p2), 
+			dot(p3, p3)));
+		p0 *= norm.x;
+		p1 *= norm.y;
+		p2 *= norm.z;
+		p3 *= norm.w;
+
+		// Mix final noise value
+		vec4 m = max(T(0.6) - detail::tvec4<T>(
+			dot(x0, x0), 
+			dot(x1, x1), 
+			dot(x2, x2), 
+			dot(x3, x3)), T(0));
+		m = m * m;
+		return T(42) * dot(m * m, detail::tvec4<T>(
+			dot(p0, x0), 
+			dot(p1, x1), 
+			dot(p2, x2), 
+			dot(p3, x3)));
 	}
 
+
 }//namespace noise
 }//namespace gtx
 }//namespace glm