/*
 * OpenSimplex (Simplectic) Noise in Java.
 * by Kurt Spencer
 *
 * v1.1 (October 5, 2014)
 * - Added 2D and 4D implementations.
 * - Proper gradient sets for all dimensions, from a
 *   dimensionally-generalizable scheme with an actual
 *   rhyme and reason behind it.
 * - Removed default permutation array in favor of
 *   default seed.
 * - Changed seed-based constructor to be independent
 *   of any particular randomization library, so results
 *   will be the same when ported to other languages.
 */

/**
 * Ported to D by Brian Schott
 */

module opensimplexnoise;
import std.traits;

public class OpenSimplexNoise(T) if (isFloatingPoint!T) {

	enum T STRETCH_CONSTANT_2D = -0.211324865405187;    //(1/Math.sqrt(2+1)-1)/2;
	enum T SQUISH_CONSTANT_2D = 0.366025403784439;      //(Math.sqrt(2+1)-1)/2;
	enum T STRETCH_CONSTANT_3D = -1.0 / 6;              //(1/Math.sqrt(3+1)-1)/3;
	enum T SQUISH_CONSTANT_3D = 1.0 / 3;                //(Math.sqrt(3+1)-1)/3;
	enum T STRETCH_CONSTANT_4D = -0.138196601125011;    //(1/Math.sqrt(4+1)-1)/4;
	enum T SQUISH_CONSTANT_4D = 0.309016994374947;      //(Math.sqrt(4+1)-1)/4;

	enum T NORM_CONSTANT_2D = 47;
	enum T NORM_CONSTANT_3D = 103;
	enum T NORM_CONSTANT_4D = 30;

	enum long DEFAULT_SEED = 0;

	private short[] perm;
	private short[] permGradIndex3D;

	public this() {
		this(DEFAULT_SEED);
	}

	public this(short[] perm) {
		this.perm = perm;
		permGradIndex3D = new short[256];

		for (int i = 0; i < 256; i++) {
			//Since 3D has 24 gradients, simple bitmask won't work, so precompute modulo array.
			permGradIndex3D[i] = cast(short)((perm[i] % (gradients3D.length / 3)) * 3);
		}
	}

	//Initializes the class using a permutation array generated from a 64-bit seed.
	//Generates a proper permutation (i.e. doesn't merely perform N successive pair swaps on a base array)
	//Uses a simple 64-bit LCG.
	public this(long seed) {
		perm = new short[256];
		permGradIndex3D = new short[256];
		short[] source = new short[256];
		for (short i = 0; i < 256; i++)
			source[i] = i;
		seed = seed * 6_364_136_223_846_793_005L + 1_442_695_040_888_963_407L;
		seed = seed * 6_364_136_223_846_793_005L + 1_442_695_040_888_963_407L;
		seed = seed * 6_364_136_223_846_793_005L + 1_442_695_040_888_963_407L;
		for (int i = 255; i >= 0; i--) {
			seed = seed * 6_364_136_223_846_793_005L + 1_442_695_040_888_963_407L;
			int r = cast(int)((seed + 31) % (i + 1));
			if (r < 0)
				r += (i + 1);
			perm[i] = source[r];
			permGradIndex3D[i] = cast(short)((perm[i] % (gradients3D.length / 3)) * 3);
			source[r] = source[i];
		}
	}

	//2D OpenSimplex (Simplectic) Noise.
	public T eval(T x, T y) {

		//Place input coordinates onto grid.
		T stretchOffset = (x + y) * STRETCH_CONSTANT_2D;
		T xs = x + stretchOffset;
		T ys = y + stretchOffset;

		//Floor to get grid coordinates of rhombus (stretched square) super-cell origin.
		int xsb = fastFloor(xs);
		int ysb = fastFloor(ys);

		//Skew out to get actual coordinates of rhombus origin. We'll need these later.
		T squishOffset = (xsb + ysb) * SQUISH_CONSTANT_2D;
		T xb = xsb + squishOffset;
		T yb = ysb + squishOffset;

		//Compute grid coordinates relative to rhombus origin.
		T xins = xs - xsb;
		T yins = ys - ysb;

		//Sum those together to get a value that determines which region we're in.
		T inSum = xins + yins;

		//Positions relative to origin point.
		T dx0 = x - xb;
		T dy0 = y - yb;

		//We'll be defining these inside the next block and using them afterwards.
		T dx_ext, dy_ext;
		int xsv_ext, ysv_ext;

		T value = 0;

		//Contribution (1,0)
		T dx1 = dx0 - 1 - SQUISH_CONSTANT_2D;
		T dy1 = dy0 - 0 - SQUISH_CONSTANT_2D;
		T attn1 = 2 - dx1 * dx1 - dy1 * dy1;
		if (attn1 > 0) {
			attn1 *= attn1;
			value += attn1 * attn1 * extrapolate(xsb + 1, ysb + 0, dx1, dy1);
		}

		//Contribution (0,1)
		T dx2 = dx0 - 0 - SQUISH_CONSTANT_2D;
		T dy2 = dy0 - 1 - SQUISH_CONSTANT_2D;
		T attn2 = 2 - dx2 * dx2 - dy2 * dy2;
		if (attn2 > 0) {
			attn2 *= attn2;
			value += attn2 * attn2 * extrapolate(xsb + 0, ysb + 1, dx2, dy2);
		}

		if (inSum <= 1) { //We're inside the triangle (2-Simplex) at (0,0)
			T zins = 1 - inSum;
			if (zins > xins || zins > yins) { //(0,0) is one of the closest two triangular vertices
				if (xins > yins) {
					xsv_ext = xsb + 1;
					ysv_ext = ysb - 1;
					dx_ext = dx0 - 1;
					dy_ext = dy0 + 1;
				} else {
					xsv_ext = xsb - 1;
					ysv_ext = ysb + 1;
					dx_ext = dx0 + 1;
					dy_ext = dy0 - 1;
				}
			} else { //(1,0) and (0,1) are the closest two vertices.
				xsv_ext = xsb + 1;
				ysv_ext = ysb + 1;
				dx_ext = dx0 - 1 - 2 * SQUISH_CONSTANT_2D;
				dy_ext = dy0 - 1 - 2 * SQUISH_CONSTANT_2D;
			}
		} else { //We're inside the triangle (2-Simplex) at (1,1)
			T zins = 2 - inSum;
			if (zins < xins || zins < yins) { //(0,0) is one of the closest two triangular vertices
				if (xins > yins) {
					xsv_ext = xsb + 2;
					ysv_ext = ysb + 0;
					dx_ext = dx0 - 2 - 2 * SQUISH_CONSTANT_2D;
					dy_ext = dy0 + 0 - 2 * SQUISH_CONSTANT_2D;
				} else {
					xsv_ext = xsb + 0;
					ysv_ext = ysb + 2;
					dx_ext = dx0 + 0 - 2 * SQUISH_CONSTANT_2D;
					dy_ext = dy0 - 2 - 2 * SQUISH_CONSTANT_2D;
				}
			} else { //(1,0) and (0,1) are the closest two vertices.
				dx_ext = dx0;
				dy_ext = dy0;
				xsv_ext = xsb;
				ysv_ext = ysb;
			}
			xsb += 1;
			ysb += 1;
			dx0 = dx0 - 1 - 2 * SQUISH_CONSTANT_2D;
			dy0 = dy0 - 1 - 2 * SQUISH_CONSTANT_2D;
		}

		//Contribution (0,0) or (1,1)
		T attn0 = 2 - dx0 * dx0 - dy0 * dy0;
		if (attn0 > 0) {
			attn0 *= attn0;
			value += attn0 * attn0 * extrapolate(xsb, ysb, dx0, dy0);
		}

		//Extra Vertex
		T attn_ext = 2 - dx_ext * dx_ext - dy_ext * dy_ext;
		if (attn_ext > 0) {
			attn_ext *= attn_ext;
			value += attn_ext * attn_ext * extrapolate(xsv_ext, ysv_ext, dx_ext, dy_ext);
		}

		return value / NORM_CONSTANT_2D;
	}

	//3D OpenSimplex (Simplectic) Noise.
	public T eval(T x, T y, T z) {

		//Place input coordinates on simplectic honeycomb.
		T stretchOffset = (x + y + z) * STRETCH_CONSTANT_3D;
		T xs = x + stretchOffset;
		T ys = y + stretchOffset;
		T zs = z + stretchOffset;

		//Floor to get simplectic honeycomb coordinates of rhombohedron (stretched cube) super-cell origin.
		int xsb = fastFloor(xs);
		int ysb = fastFloor(ys);
		int zsb = fastFloor(zs);

		//Skew out to get actual coordinates of rhombohedron origin. We'll need these later.
		T squishOffset = (xsb + ysb + zsb) * SQUISH_CONSTANT_3D;
		T xb = xsb + squishOffset;
		T yb = ysb + squishOffset;
		T zb = zsb + squishOffset;

		//Compute simplectic honeycomb coordinates relative to rhombohedral origin.
		T xins = xs - xsb;
		T yins = ys - ysb;
		T zins = zs - zsb;

		//Sum those together to get a value that determines which region we're in.
		T inSum = xins + yins + zins;

		//Positions relative to origin point.
		T dx0 = x - xb;
		T dy0 = y - yb;
		T dz0 = z - zb;

		//We'll be defining these inside the next block and using them afterwards.
		T dx_ext0, dy_ext0, dz_ext0;
		T dx_ext1, dy_ext1, dz_ext1;
		int xsv_ext0, ysv_ext0, zsv_ext0;
		int xsv_ext1, ysv_ext1, zsv_ext1;

		T value = 0;
		if (inSum <= 1) { //We're inside the tetrahedron (3-Simplex) at (0,0,0)

			//Determine which two of (0,0,1), (0,1,0), (1,0,0) are closest.
			byte aPoint = 0x01;
			T aScore = xins;
			byte bPoint = 0x02;
			T bScore = yins;
			if (aScore >= bScore && zins > bScore) {
				bScore = zins;
				bPoint = 0x04;
			} else if (aScore < bScore && zins > aScore) {
				aScore = zins;
				aPoint = 0x04;
			}

			//Now we determine the two lattice points not part of the tetrahedron that may contribute.
			//This depends on the closest two tetrahedral vertices, including (0,0,0)
			T wins = 1 - inSum;
			if (wins > aScore || wins > bScore) { //(0,0,0) is one of the closest two tetrahedral vertices.
				byte c = (bScore > aScore ? bPoint : aPoint); //Our other closest vertex is the closest out of a and b.

				if ((c & 0x01) == 0) {
					xsv_ext0 = xsb - 1;
					xsv_ext1 = xsb;
					dx_ext0 = dx0 + 1;
					dx_ext1 = dx0;
				} else {
					xsv_ext0 = xsv_ext1 = xsb + 1;
					dx_ext0 = dx_ext1 = dx0 - 1;
				}

				if ((c & 0x02) == 0) {
					ysv_ext0 = ysv_ext1 = ysb;
					dy_ext0 = dy_ext1 = dy0;
					if ((c & 0x01) == 0) {
						ysv_ext1 -= 1;
						dy_ext1 += 1;
					} else {
						ysv_ext0 -= 1;
						dy_ext0 += 1;
					}
				} else {
					ysv_ext0 = ysv_ext1 = ysb + 1;
					dy_ext0 = dy_ext1 = dy0 - 1;
				}

				if ((c & 0x04) == 0) {
					zsv_ext0 = zsb;
					zsv_ext1 = zsb - 1;
					dz_ext0 = dz0;
					dz_ext1 = dz0 + 1;
				} else {
					zsv_ext0 = zsv_ext1 = zsb + 1;
					dz_ext0 = dz_ext1 = dz0 - 1;
				}
			} else { //(0,0,0) is not one of the closest two tetrahedral vertices.
				byte c = cast(byte)(aPoint | bPoint); //Our two extra vertices are determined by the closest two.

				if ((c & 0x01) == 0) {
					xsv_ext0 = xsb;
					xsv_ext1 = xsb - 1;
					dx_ext0 = dx0 - 2 * SQUISH_CONSTANT_3D;
					dx_ext1 = dx0 + 1 - SQUISH_CONSTANT_3D;
				} else {
					xsv_ext0 = xsv_ext1 = xsb + 1;
					dx_ext0 = dx0 - 1 - 2 * SQUISH_CONSTANT_3D;
					dx_ext1 = dx0 - 1 - SQUISH_CONSTANT_3D;
				}

				if ((c & 0x02) == 0) {
					ysv_ext0 = ysb;
					ysv_ext1 = ysb - 1;
					dy_ext0 = dy0 - 2 * SQUISH_CONSTANT_3D;
					dy_ext1 = dy0 + 1 - SQUISH_CONSTANT_3D;
				} else {
					ysv_ext0 = ysv_ext1 = ysb + 1;
					dy_ext0 = dy0 - 1 - 2 * SQUISH_CONSTANT_3D;
					dy_ext1 = dy0 - 1 - SQUISH_CONSTANT_3D;
				}

				if ((c & 0x04) == 0) {
					zsv_ext0 = zsb;
					zsv_ext1 = zsb - 1;
					dz_ext0 = dz0 - 2 * SQUISH_CONSTANT_3D;
					dz_ext1 = dz0 + 1 - SQUISH_CONSTANT_3D;
				} else {
					zsv_ext0 = zsv_ext1 = zsb + 1;
					dz_ext0 = dz0 - 1 - 2 * SQUISH_CONSTANT_3D;
					dz_ext1 = dz0 - 1 - SQUISH_CONSTANT_3D;
				}
			}

			//Contribution (0,0,0)
			T attn0 = 2 - dx0 * dx0 - dy0 * dy0 - dz0 * dz0;
			if (attn0 > 0) {
				attn0 *= attn0;
				value += attn0 * attn0 * extrapolate(xsb + 0, ysb + 0, zsb + 0, dx0, dy0, dz0);
			}

			//Contribution (1,0,0)
			T dx1 = dx0 - 1 - SQUISH_CONSTANT_3D;
			T dy1 = dy0 - 0 - SQUISH_CONSTANT_3D;
			T dz1 = dz0 - 0 - SQUISH_CONSTANT_3D;
			T attn1 = 2 - dx1 * dx1 - dy1 * dy1 - dz1 * dz1;
			if (attn1 > 0) {
				attn1 *= attn1;
				value += attn1 * attn1 * extrapolate(xsb + 1, ysb + 0, zsb + 0, dx1, dy1, dz1);
			}

			//Contribution (0,1,0)
			T dx2 = dx0 - 0 - SQUISH_CONSTANT_3D;
			T dy2 = dy0 - 1 - SQUISH_CONSTANT_3D;
			T dz2 = dz1;
			T attn2 = 2 - dx2 * dx2 - dy2 * dy2 - dz2 * dz2;
			if (attn2 > 0) {
				attn2 *= attn2;
				value += attn2 * attn2 * extrapolate(xsb + 0, ysb + 1, zsb + 0, dx2, dy2, dz2);
			}

			//Contribution (0,0,1)
			T dx3 = dx2;
			T dy3 = dy1;
			T dz3 = dz0 - 1 - SQUISH_CONSTANT_3D;
			T attn3 = 2 - dx3 * dx3 - dy3 * dy3 - dz3 * dz3;
			if (attn3 > 0) {
				attn3 *= attn3;
				value += attn3 * attn3 * extrapolate(xsb + 0, ysb + 0, zsb + 1, dx3, dy3, dz3);
			}
		} else if (inSum >= 2) { //We're inside the tetrahedron (3-Simplex) at (1,1,1)

			//Determine which two tetrahedral vertices are the closest, out of (1,1,0), (1,0,1), (0,1,1) but not (1,1,1).
			byte aPoint = 0x06;
			T aScore = xins;
			byte bPoint = 0x05;
			T bScore = yins;
			if (aScore <= bScore && zins < bScore) {
				bScore = zins;
				bPoint = 0x03;
			} else if (aScore > bScore && zins < aScore) {
				aScore = zins;
				aPoint = 0x03;
			}

			//Now we determine the two lattice points not part of the tetrahedron that may contribute.
			//This depends on the closest two tetrahedral vertices, including (1,1,1)
			T wins = 3 - inSum;
			if (wins < aScore || wins < bScore) { //(1,1,1) is one of the closest two tetrahedral vertices.
				byte c = (bScore < aScore ? bPoint : aPoint); //Our other closest vertex is the closest out of a and b.

				if ((c & 0x01) != 0) {
					xsv_ext0 = xsb + 2;
					xsv_ext1 = xsb + 1;
					dx_ext0 = dx0 - 2 - 3 * SQUISH_CONSTANT_3D;
					dx_ext1 = dx0 - 1 - 3 * SQUISH_CONSTANT_3D;
				} else {
					xsv_ext0 = xsv_ext1 = xsb;
					dx_ext0 = dx_ext1 = dx0 - 3 * SQUISH_CONSTANT_3D;
				}

				if ((c & 0x02) != 0) {
					ysv_ext0 = ysv_ext1 = ysb + 1;
					dy_ext0 = dy_ext1 = dy0 - 1 - 3 * SQUISH_CONSTANT_3D;
					if ((c & 0x01) != 0) {
						ysv_ext1 += 1;
						dy_ext1 -= 1;
					} else {
						ysv_ext0 += 1;
						dy_ext0 -= 1;
					}
				} else {
					ysv_ext0 = ysv_ext1 = ysb;
					dy_ext0 = dy_ext1 = dy0 - 3 * SQUISH_CONSTANT_3D;
				}

				if ((c & 0x04) != 0) {
					zsv_ext0 = zsb + 1;
					zsv_ext1 = zsb + 2;
					dz_ext0 = dz0 - 1 - 3 * SQUISH_CONSTANT_3D;
					dz_ext1 = dz0 - 2 - 3 * SQUISH_CONSTANT_3D;
				} else {
					zsv_ext0 = zsv_ext1 = zsb;
					dz_ext0 = dz_ext1 = dz0 - 3 * SQUISH_CONSTANT_3D;
				}
			} else { //(1,1,1) is not one of the closest two tetrahedral vertices.
				byte c = cast(byte)(aPoint & bPoint); //Our two extra vertices are determined by the closest two.

				if ((c & 0x01) != 0) {
					xsv_ext0 = xsb + 1;
					xsv_ext1 = xsb + 2;
					dx_ext0 = dx0 - 1 - SQUISH_CONSTANT_3D;
					dx_ext1 = dx0 - 2 - 2 * SQUISH_CONSTANT_3D;
				} else {
					xsv_ext0 = xsv_ext1 = xsb;
					dx_ext0 = dx0 - SQUISH_CONSTANT_3D;
					dx_ext1 = dx0 - 2 * SQUISH_CONSTANT_3D;
				}

				if ((c & 0x02) != 0) {
					ysv_ext0 = ysb + 1;
					ysv_ext1 = ysb + 2;
					dy_ext0 = dy0 - 1 - SQUISH_CONSTANT_3D;
					dy_ext1 = dy0 - 2 - 2 * SQUISH_CONSTANT_3D;
				} else {
					ysv_ext0 = ysv_ext1 = ysb;
					dy_ext0 = dy0 - SQUISH_CONSTANT_3D;
					dy_ext1 = dy0 - 2 * SQUISH_CONSTANT_3D;
				}

				if ((c & 0x04) != 0) {
					zsv_ext0 = zsb + 1;
					zsv_ext1 = zsb + 2;
					dz_ext0 = dz0 - 1 - SQUISH_CONSTANT_3D;
					dz_ext1 = dz0 - 2 - 2 * SQUISH_CONSTANT_3D;
				} else {
					zsv_ext0 = zsv_ext1 = zsb;
					dz_ext0 = dz0 - SQUISH_CONSTANT_3D;
					dz_ext1 = dz0 - 2 * SQUISH_CONSTANT_3D;
				}
			}

			//Contribution (1,1,0)
			T dx3 = dx0 - 1 - 2 * SQUISH_CONSTANT_3D;
			T dy3 = dy0 - 1 - 2 * SQUISH_CONSTANT_3D;
			T dz3 = dz0 - 0 - 2 * SQUISH_CONSTANT_3D;
			T attn3 = 2 - dx3 * dx3 - dy3 * dy3 - dz3 * dz3;
			if (attn3 > 0) {
				attn3 *= attn3;
				value += attn3 * attn3 * extrapolate(xsb + 1, ysb + 1, zsb + 0, dx3, dy3, dz3);
			}

			//Contribution (1,0,1)
			T dx2 = dx3;
			T dy2 = dy0 - 0 - 2 * SQUISH_CONSTANT_3D;
			T dz2 = dz0 - 1 - 2 * SQUISH_CONSTANT_3D;
			T attn2 = 2 - dx2 * dx2 - dy2 * dy2 - dz2 * dz2;
			if (attn2 > 0) {
				attn2 *= attn2;
				value += attn2 * attn2 * extrapolate(xsb + 1, ysb + 0, zsb + 1, dx2, dy2, dz2);
			}

			//Contribution (0,1,1)
			T dx1 = dx0 - 0 - 2 * SQUISH_CONSTANT_3D;
			T dy1 = dy3;
			T dz1 = dz2;
			T attn1 = 2 - dx1 * dx1 - dy1 * dy1 - dz1 * dz1;
			if (attn1 > 0) {
				attn1 *= attn1;
				value += attn1 * attn1 * extrapolate(xsb + 0, ysb + 1, zsb + 1, dx1, dy1, dz1);
			}

			//Contribution (1,1,1)
			dx0 = dx0 - 1 - 3 * SQUISH_CONSTANT_3D;
			dy0 = dy0 - 1 - 3 * SQUISH_CONSTANT_3D;
			dz0 = dz0 - 1 - 3 * SQUISH_CONSTANT_3D;
			T attn0 = 2 - dx0 * dx0 - dy0 * dy0 - dz0 * dz0;
			if (attn0 > 0) {
				attn0 *= attn0;
				value += attn0 * attn0 * extrapolate(xsb + 1, ysb + 1, zsb + 1, dx0, dy0, dz0);
			}
		} else { //We're inside the octahedron (Rectified 3-Simplex) in between.
			T aScore;
			byte aPoint;
			bool aIsFurtherSide;
			T bScore;
			byte bPoint;
			bool bIsFurtherSide;

			//Decide between point (0,0,1) and (1,1,0) as closest
			T p1 = xins + yins;
			if (p1 > 1) {
				aScore = p1 - 1;
				aPoint = 0x03;
				aIsFurtherSide = true;
			} else {
				aScore = 1 - p1;
				aPoint = 0x04;
				aIsFurtherSide = false;
			}

			//Decide between point (0,1,0) and (1,0,1) as closest
			T p2 = xins + zins;
			if (p2 > 1) {
				bScore = p2 - 1;
				bPoint = 0x05;
				bIsFurtherSide = true;
			} else {
				bScore = 1 - p2;
				bPoint = 0x02;
				bIsFurtherSide = false;
			}

			//The closest out of the two (1,0,0) and (0,1,1) will replace the furthest out of the two decided above, if closer.
			T p3 = yins + zins;
			if (p3 > 1) {
				T score = p3 - 1;
				if (aScore <= bScore && aScore < score) {
					aScore = score;
					aPoint = 0x06;
					aIsFurtherSide = true;
				} else if (aScore > bScore && bScore < score) {
					bScore = score;
					bPoint = 0x06;
					bIsFurtherSide = true;
				}
			} else {
				T score = 1 - p3;
				if (aScore <= bScore && aScore < score) {
					aScore = score;
					aPoint = 0x01;
					aIsFurtherSide = false;
				} else if (aScore > bScore && bScore < score) {
					bScore = score;
					bPoint = 0x01;
					bIsFurtherSide = false;
				}
			}

			//Where each of the two closest points are determines how the extra two vertices are calculated.
			if (aIsFurtherSide == bIsFurtherSide) {
				if (aIsFurtherSide) { //Both closest points on (1,1,1) side

					//One of the two extra points is (1,1,1)
					dx_ext0 = dx0 - 1 - 3 * SQUISH_CONSTANT_3D;
					dy_ext0 = dy0 - 1 - 3 * SQUISH_CONSTANT_3D;
					dz_ext0 = dz0 - 1 - 3 * SQUISH_CONSTANT_3D;
					xsv_ext0 = xsb + 1;
					ysv_ext0 = ysb + 1;
					zsv_ext0 = zsb + 1;

					//Other extra point is based on the shared axis.
					byte c = cast(byte)(aPoint & bPoint);
					if ((c & 0x01) != 0) {
						dx_ext1 = dx0 - 2 - 2 * SQUISH_CONSTANT_3D;
						dy_ext1 = dy0 - 2 * SQUISH_CONSTANT_3D;
						dz_ext1 = dz0 - 2 * SQUISH_CONSTANT_3D;
						xsv_ext1 = xsb + 2;
						ysv_ext1 = ysb;
						zsv_ext1 = zsb;
					} else if ((c & 0x02) != 0) {
						dx_ext1 = dx0 - 2 * SQUISH_CONSTANT_3D;
						dy_ext1 = dy0 - 2 - 2 * SQUISH_CONSTANT_3D;
						dz_ext1 = dz0 - 2 * SQUISH_CONSTANT_3D;
						xsv_ext1 = xsb;
						ysv_ext1 = ysb + 2;
						zsv_ext1 = zsb;
					} else {
						dx_ext1 = dx0 - 2 * SQUISH_CONSTANT_3D;
						dy_ext1 = dy0 - 2 * SQUISH_CONSTANT_3D;
						dz_ext1 = dz0 - 2 - 2 * SQUISH_CONSTANT_3D;
						xsv_ext1 = xsb;
						ysv_ext1 = ysb;
						zsv_ext1 = zsb + 2;
					}
				} else {//Both closest points on (0,0,0) side

					//One of the two extra points is (0,0,0)
					dx_ext0 = dx0;
					dy_ext0 = dy0;
					dz_ext0 = dz0;
					xsv_ext0 = xsb;
					ysv_ext0 = ysb;
					zsv_ext0 = zsb;

					//Other extra point is based on the omitted axis.
					byte c = cast(byte)(aPoint | bPoint);
					if ((c & 0x01) == 0) {
						dx_ext1 = dx0 + 1 - SQUISH_CONSTANT_3D;
						dy_ext1 = dy0 - 1 - SQUISH_CONSTANT_3D;
						dz_ext1 = dz0 - 1 - SQUISH_CONSTANT_3D;
						xsv_ext1 = xsb - 1;
						ysv_ext1 = ysb + 1;
						zsv_ext1 = zsb + 1;
					} else if ((c & 0x02) == 0) {
						dx_ext1 = dx0 - 1 - SQUISH_CONSTANT_3D;
						dy_ext1 = dy0 + 1 - SQUISH_CONSTANT_3D;
						dz_ext1 = dz0 - 1 - SQUISH_CONSTANT_3D;
						xsv_ext1 = xsb + 1;
						ysv_ext1 = ysb - 1;
						zsv_ext1 = zsb + 1;
					} else {
						dx_ext1 = dx0 - 1 - SQUISH_CONSTANT_3D;
						dy_ext1 = dy0 - 1 - SQUISH_CONSTANT_3D;
						dz_ext1 = dz0 + 1 - SQUISH_CONSTANT_3D;
						xsv_ext1 = xsb + 1;
						ysv_ext1 = ysb + 1;
						zsv_ext1 = zsb - 1;
					}
				}
			} else { //One point on (0,0,0) side, one point on (1,1,1) side
				byte c1, c2;
				if (aIsFurtherSide) {
					c1 = aPoint;
					c2 = bPoint;
				} else {
					c1 = bPoint;
					c2 = aPoint;
				}

				//One contribution is a permutation of (1,1,-1)
				if ((c1 & 0x01) == 0) {
					dx_ext0 = dx0 + 1 - SQUISH_CONSTANT_3D;
					dy_ext0 = dy0 - 1 - SQUISH_CONSTANT_3D;
					dz_ext0 = dz0 - 1 - SQUISH_CONSTANT_3D;
					xsv_ext0 = xsb - 1;
					ysv_ext0 = ysb + 1;
					zsv_ext0 = zsb + 1;
				} else if ((c1 & 0x02) == 0) {
					dx_ext0 = dx0 - 1 - SQUISH_CONSTANT_3D;
					dy_ext0 = dy0 + 1 - SQUISH_CONSTANT_3D;
					dz_ext0 = dz0 - 1 - SQUISH_CONSTANT_3D;
					xsv_ext0 = xsb + 1;
					ysv_ext0 = ysb - 1;
					zsv_ext0 = zsb + 1;
				} else {
					dx_ext0 = dx0 - 1 - SQUISH_CONSTANT_3D;
					dy_ext0 = dy0 - 1 - SQUISH_CONSTANT_3D;
					dz_ext0 = dz0 + 1 - SQUISH_CONSTANT_3D;
					xsv_ext0 = xsb + 1;
					ysv_ext0 = ysb + 1;
					zsv_ext0 = zsb - 1;
				}

				//One contribution is a permutation of (0,0,2)
				dx_ext1 = dx0 - 2 * SQUISH_CONSTANT_3D;
				dy_ext1 = dy0 - 2 * SQUISH_CONSTANT_3D;
				dz_ext1 = dz0 - 2 * SQUISH_CONSTANT_3D;
				xsv_ext1 = xsb;
				ysv_ext1 = ysb;
				zsv_ext1 = zsb;
				if ((c2 & 0x01) != 0) {
					dx_ext1 -= 2;
					xsv_ext1 += 2;
				} else if ((c2 & 0x02) != 0) {
					dy_ext1 -= 2;
					ysv_ext1 += 2;
				} else {
					dz_ext1 -= 2;
					zsv_ext1 += 2;
				}
			}

			//Contribution (1,0,0)
			T dx1 = dx0 - 1 - SQUISH_CONSTANT_3D;
			T dy1 = dy0 - 0 - SQUISH_CONSTANT_3D;
			T dz1 = dz0 - 0 - SQUISH_CONSTANT_3D;
			T attn1 = 2 - dx1 * dx1 - dy1 * dy1 - dz1 * dz1;
			if (attn1 > 0) {
				attn1 *= attn1;
				value += attn1 * attn1 * extrapolate(xsb + 1, ysb + 0, zsb + 0, dx1, dy1, dz1);
			}

			//Contribution (0,1,0)
			T dx2 = dx0 - 0 - SQUISH_CONSTANT_3D;
			T dy2 = dy0 - 1 - SQUISH_CONSTANT_3D;
			T dz2 = dz1;
			T attn2 = 2 - dx2 * dx2 - dy2 * dy2 - dz2 * dz2;
			if (attn2 > 0) {
				attn2 *= attn2;
				value += attn2 * attn2 * extrapolate(xsb + 0, ysb + 1, zsb + 0, dx2, dy2, dz2);
			}

			//Contribution (0,0,1)
			T dx3 = dx2;
			T dy3 = dy1;
			T dz3 = dz0 - 1 - SQUISH_CONSTANT_3D;
			T attn3 = 2 - dx3 * dx3 - dy3 * dy3 - dz3 * dz3;
			if (attn3 > 0) {
				attn3 *= attn3;
				value += attn3 * attn3 * extrapolate(xsb + 0, ysb + 0, zsb + 1, dx3, dy3, dz3);
			}

			//Contribution (1,1,0)
			T dx4 = dx0 - 1 - 2 * SQUISH_CONSTANT_3D;
			T dy4 = dy0 - 1 - 2 * SQUISH_CONSTANT_3D;
			T dz4 = dz0 - 0 - 2 * SQUISH_CONSTANT_3D;
			T attn4 = 2 - dx4 * dx4 - dy4 * dy4 - dz4 * dz4;
			if (attn4 > 0) {
				attn4 *= attn4;
				value += attn4 * attn4 * extrapolate(xsb + 1, ysb + 1, zsb + 0, dx4, dy4, dz4);
			}

			//Contribution (1,0,1)
			T dx5 = dx4;
			T dy5 = dy0 - 0 - 2 * SQUISH_CONSTANT_3D;
			T dz5 = dz0 - 1 - 2 * SQUISH_CONSTANT_3D;
			T attn5 = 2 - dx5 * dx5 - dy5 * dy5 - dz5 * dz5;
			if (attn5 > 0) {
				attn5 *= attn5;
				value += attn5 * attn5 * extrapolate(xsb + 1, ysb + 0, zsb + 1, dx5, dy5, dz5);
			}

			//Contribution (0,1,1)
			T dx6 = dx0 - 0 - 2 * SQUISH_CONSTANT_3D;
			T dy6 = dy4;
			T dz6 = dz5;
			T attn6 = 2 - dx6 * dx6 - dy6 * dy6 - dz6 * dz6;
			if (attn6 > 0) {
				attn6 *= attn6;
				value += attn6 * attn6 * extrapolate(xsb + 0, ysb + 1, zsb + 1, dx6, dy6, dz6);
			}
		}

		//First extra vertex
		T attn_ext0 = 2 - dx_ext0 * dx_ext0 - dy_ext0 * dy_ext0 - dz_ext0 * dz_ext0;
		if (attn_ext0 > 0)
		{
			attn_ext0 *= attn_ext0;
			value += attn_ext0 * attn_ext0 * extrapolate(xsv_ext0, ysv_ext0, zsv_ext0, dx_ext0, dy_ext0, dz_ext0);
		}

		//Second extra vertex
		T attn_ext1 = 2 - dx_ext1 * dx_ext1 - dy_ext1 * dy_ext1 - dz_ext1 * dz_ext1;
		if (attn_ext1 > 0)
		{
			attn_ext1 *= attn_ext1;
			value += attn_ext1 * attn_ext1 * extrapolate(xsv_ext1, ysv_ext1, zsv_ext1, dx_ext1, dy_ext1, dz_ext1);
		}

		return value / NORM_CONSTANT_3D;
	}

	//4D OpenSimplex (Simplectic) Noise.
	public T eval(T x, T y, T z, T w) {

		//Place input coordinates on simplectic honeycomb.
		T stretchOffset = (x + y + z + w) * STRETCH_CONSTANT_4D;
		T xs = x + stretchOffset;
		T ys = y + stretchOffset;
		T zs = z + stretchOffset;
		T ws = w + stretchOffset;

		//Floor to get simplectic honeycomb coordinates of rhombo-hypercube super-cell origin.
		int xsb = fastFloor(xs);
		int ysb = fastFloor(ys);
		int zsb = fastFloor(zs);
		int wsb = fastFloor(ws);

		//Skew out to get actual coordinates of stretched rhombo-hypercube origin. We'll need these later.
		T squishOffset = (xsb + ysb + zsb + wsb) * SQUISH_CONSTANT_4D;
		T xb = xsb + squishOffset;
		T yb = ysb + squishOffset;
		T zb = zsb + squishOffset;
		T wb = wsb + squishOffset;

		//Compute simplectic honeycomb coordinates relative to rhombo-hypercube origin.
		T xins = xs - xsb;
		T yins = ys - ysb;
		T zins = zs - zsb;
		T wins = ws - wsb;

		//Sum those together to get a value that determines which region we're in.
		T inSum = xins + yins + zins + wins;

		//Positions relative to origin point.
		T dx0 = x - xb;
		T dy0 = y - yb;
		T dz0 = z - zb;
		T dw0 = w - wb;

		//We'll be defining these inside the next block and using them afterwards.
		T dx_ext0, dy_ext0, dz_ext0, dw_ext0;
		T dx_ext1, dy_ext1, dz_ext1, dw_ext1;
		T dx_ext2, dy_ext2, dz_ext2, dw_ext2;
		int xsv_ext0, ysv_ext0, zsv_ext0, wsv_ext0;
		int xsv_ext1, ysv_ext1, zsv_ext1, wsv_ext1;
		int xsv_ext2, ysv_ext2, zsv_ext2, wsv_ext2;

		T value = 0;
		if (inSum <= 1) { //We're inside the pentachoron (4-Simplex) at (0,0,0,0)

			//Determine which two of (0,0,0,1), (0,0,1,0), (0,1,0,0), (1,0,0,0) are closest.
			byte aPoint = 0x01;
			T aScore = xins;
			byte bPoint = 0x02;
			T bScore = yins;
			if (aScore >= bScore && zins > bScore) {
				bScore = zins;
				bPoint = 0x04;
			} else if (aScore < bScore && zins > aScore) {
				aScore = zins;
				aPoint = 0x04;
			}
			if (aScore >= bScore && wins > bScore) {
				bScore = wins;
				bPoint = 0x08;
			} else if (aScore < bScore && wins > aScore) {
				aScore = wins;
				aPoint = 0x08;
			}

			//Now we determine the three lattice points not part of the pentachoron that may contribute.
			//This depends on the closest two pentachoron vertices, including (0,0,0,0)
			T uins = 1 - inSum;
			if (uins > aScore || uins > bScore) { //(0,0,0,0) is one of the closest two pentachoron vertices.
				byte c = (bScore > aScore ? bPoint : aPoint); //Our other closest vertex is the closest out of a and b.
				if ((c & 0x01) == 0) {
					xsv_ext0 = xsb - 1;
					xsv_ext1 = xsv_ext2 = xsb;
					dx_ext0 = dx0 + 1;
					dx_ext1 = dx_ext2 = dx0;
				} else {
					xsv_ext0 = xsv_ext1 = xsv_ext2 = xsb + 1;
					dx_ext0 = dx_ext1 = dx_ext2 = dx0 - 1;
				}

				if ((c & 0x02) == 0) {
					ysv_ext0 = ysv_ext1 = ysv_ext2 = ysb;
					dy_ext0 = dy_ext1 = dy_ext2 = dy0;
					if ((c & 0x01) == 0x01) {
						ysv_ext0 -= 1;
						dy_ext0 += 1;
					} else {
						ysv_ext1 -= 1;
						dy_ext1 += 1;
					}
				} else {
					ysv_ext0 = ysv_ext1 = ysv_ext2 = ysb + 1;
					dy_ext0 = dy_ext1 = dy_ext2 = dy0 - 1;
				}

				if ((c & 0x04) == 0) {
					zsv_ext0 = zsv_ext1 = zsv_ext2 = zsb;
					dz_ext0 = dz_ext1 = dz_ext2 = dz0;
					if ((c & 0x03) != 0) {
						if ((c & 0x03) == 0x03) {
							zsv_ext0 -= 1;
							dz_ext0 += 1;
						} else {
							zsv_ext1 -= 1;
							dz_ext1 += 1;
						}
					} else {
						zsv_ext2 -= 1;
						dz_ext2 += 1;
					}
				} else {
					zsv_ext0 = zsv_ext1 = zsv_ext2 = zsb + 1;
					dz_ext0 = dz_ext1 = dz_ext2 = dz0 - 1;
				}

				if ((c & 0x08) == 0) {
					wsv_ext0 = wsv_ext1 = wsb;
					wsv_ext2 = wsb - 1;
					dw_ext0 = dw_ext1 = dw0;
					dw_ext2 = dw0 + 1;
				} else {
					wsv_ext0 = wsv_ext1 = wsv_ext2 = wsb + 1;
					dw_ext0 = dw_ext1 = dw_ext2 = dw0 - 1;
				}
			} else { //(0,0,0,0) is not one of the closest two pentachoron vertices.
				byte c = cast(byte)(aPoint | bPoint); //Our three extra vertices are determined by the closest two.

				if ((c & 0x01) == 0) {
					xsv_ext0 = xsv_ext2 = xsb;
					xsv_ext1 = xsb - 1;
					dx_ext0 = dx0 - 2 * SQUISH_CONSTANT_4D;
					dx_ext1 = dx0 + 1 - SQUISH_CONSTANT_4D;
					dx_ext2 = dx0 - SQUISH_CONSTANT_4D;
				} else {
					xsv_ext0 = xsv_ext1 = xsv_ext2 = xsb + 1;
					dx_ext0 = dx0 - 1 - 2 * SQUISH_CONSTANT_4D;
					dx_ext1 = dx_ext2 = dx0 - 1 - SQUISH_CONSTANT_4D;
				}

				if ((c & 0x02) == 0) {
					ysv_ext0 = ysv_ext1 = ysv_ext2 = ysb;
					dy_ext0 = dy0 - 2 * SQUISH_CONSTANT_4D;
					dy_ext1 = dy_ext2 = dy0 - SQUISH_CONSTANT_4D;
					if ((c & 0x01) == 0x01) {
						ysv_ext1 -= 1;
						dy_ext1 += 1;
					} else {
						ysv_ext2 -= 1;
						dy_ext2 += 1;
					}
				} else {
					ysv_ext0 = ysv_ext1 = ysv_ext2 = ysb + 1;
					dy_ext0 = dy0 - 1 - 2 * SQUISH_CONSTANT_4D;
					dy_ext1 = dy_ext2 = dy0 - 1 - SQUISH_CONSTANT_4D;
				}

				if ((c & 0x04) == 0) {
					zsv_ext0 = zsv_ext1 = zsv_ext2 = zsb;
					dz_ext0 = dz0 - 2 * SQUISH_CONSTANT_4D;
					dz_ext1 = dz_ext2 = dz0 - SQUISH_CONSTANT_4D;
					if ((c & 0x03) == 0x03) {
						zsv_ext1 -= 1;
						dz_ext1 += 1;
					} else {
						zsv_ext2 -= 1;
						dz_ext2 += 1;
					}
				} else {
					zsv_ext0 = zsv_ext1 = zsv_ext2 = zsb + 1;
					dz_ext0 = dz0 - 1 - 2 * SQUISH_CONSTANT_4D;
					dz_ext1 = dz_ext2 = dz0 - 1 - SQUISH_CONSTANT_4D;
				}

				if ((c & 0x08) == 0) {
					wsv_ext0 = wsv_ext1 = wsb;
					wsv_ext2 = wsb - 1;
					dw_ext0 = dw0 - 2 * SQUISH_CONSTANT_4D;
					dw_ext1 = dw0 - SQUISH_CONSTANT_4D;
					dw_ext2 = dw0 + 1 - SQUISH_CONSTANT_4D;
				} else {
					wsv_ext0 = wsv_ext1 = wsv_ext2 = wsb + 1;
					dw_ext0 = dw0 - 1 - 2 * SQUISH_CONSTANT_4D;
					dw_ext1 = dw_ext2 = dw0 - 1 - SQUISH_CONSTANT_4D;
				}
			}

			//Contribution (0,0,0,0)
			T attn0 = 2 - dx0 * dx0 - dy0 * dy0 - dz0 * dz0 - dw0 * dw0;
			if (attn0 > 0) {
				attn0 *= attn0;
				value += attn0 * attn0 * extrapolate(xsb + 0, ysb + 0, zsb + 0, wsb + 0, dx0, dy0, dz0, dw0);
			}

			//Contribution (1,0,0,0)
			T dx1 = dx0 - 1 - SQUISH_CONSTANT_4D;
			T dy1 = dy0 - 0 - SQUISH_CONSTANT_4D;
			T dz1 = dz0 - 0 - SQUISH_CONSTANT_4D;
			T dw1 = dw0 - 0 - SQUISH_CONSTANT_4D;
			T attn1 = 2 - dx1 * dx1 - dy1 * dy1 - dz1 * dz1 - dw1 * dw1;
			if (attn1 > 0) {
				attn1 *= attn1;
				value += attn1 * attn1 * extrapolate(xsb + 1, ysb + 0, zsb + 0, wsb + 0, dx1, dy1, dz1, dw1);
			}

			//Contribution (0,1,0,0)
			T dx2 = dx0 - 0 - SQUISH_CONSTANT_4D;
			T dy2 = dy0 - 1 - SQUISH_CONSTANT_4D;
			T dz2 = dz1;
			T dw2 = dw1;
			T attn2 = 2 - dx2 * dx2 - dy2 * dy2 - dz2 * dz2 - dw2 * dw2;
			if (attn2 > 0) {
				attn2 *= attn2;
				value += attn2 * attn2 * extrapolate(xsb + 0, ysb + 1, zsb + 0, wsb + 0, dx2, dy2, dz2, dw2);
			}

			//Contribution (0,0,1,0)
			T dx3 = dx2;
			T dy3 = dy1;
			T dz3 = dz0 - 1 - SQUISH_CONSTANT_4D;
			T dw3 = dw1;
			T attn3 = 2 - dx3 * dx3 - dy3 * dy3 - dz3 * dz3 - dw3 * dw3;
			if (attn3 > 0) {
				attn3 *= attn3;
				value += attn3 * attn3 * extrapolate(xsb + 0, ysb + 0, zsb + 1, wsb + 0, dx3, dy3, dz3, dw3);
			}

			//Contribution (0,0,0,1)
			T dx4 = dx2;
			T dy4 = dy1;
			T dz4 = dz1;
			T dw4 = dw0 - 1 - SQUISH_CONSTANT_4D;
			T attn4 = 2 - dx4 * dx4 - dy4 * dy4 - dz4 * dz4 - dw4 * dw4;
			if (attn4 > 0) {
				attn4 *= attn4;
				value += attn4 * attn4 * extrapolate(xsb + 0, ysb + 0, zsb + 0, wsb + 1, dx4, dy4, dz4, dw4);
			}
		} else if (inSum >= 3) { //We're inside the pentachoron (4-Simplex) at (1,1,1,1)
			//Determine which two of (1,1,1,0), (1,1,0,1), (1,0,1,1), (0,1,1,1) are closest.
			byte aPoint = 0x0E;
			T aScore = xins;
			byte bPoint = 0x0D;
			T bScore = yins;
			if (aScore <= bScore && zins < bScore) {
				bScore = zins;
				bPoint = 0x0B;
			} else if (aScore > bScore && zins < aScore) {
				aScore = zins;
				aPoint = 0x0B;
			}
			if (aScore <= bScore && wins < bScore) {
				bScore = wins;
				bPoint = 0x07;
			} else if (aScore > bScore && wins < aScore) {
				aScore = wins;
				aPoint = 0x07;
			}

			//Now we determine the three lattice points not part of the pentachoron that may contribute.
			//This depends on the closest two pentachoron vertices, including (0,0,0,0)
			T uins = 4 - inSum;
			if (uins < aScore || uins < bScore) { //(1,1,1,1) is one of the closest two pentachoron vertices.
				byte c = (bScore < aScore ? bPoint : aPoint); //Our other closest vertex is the closest out of a and b.

				if ((c & 0x01) != 0) {
					xsv_ext0 = xsb + 2;
					xsv_ext1 = xsv_ext2 = xsb + 1;
					dx_ext0 = dx0 - 2 - 4 * SQUISH_CONSTANT_4D;
					dx_ext1 = dx_ext2 = dx0 - 1 - 4 * SQUISH_CONSTANT_4D;
				} else {
					xsv_ext0 = xsv_ext1 = xsv_ext2 = xsb;
					dx_ext0 = dx_ext1 = dx_ext2 = dx0 - 4 * SQUISH_CONSTANT_4D;
				}

				if ((c & 0x02) != 0) {
					ysv_ext0 = ysv_ext1 = ysv_ext2 = ysb + 1;
					dy_ext0 = dy_ext1 = dy_ext2 = dy0 - 1 - 4 * SQUISH_CONSTANT_4D;
					if ((c & 0x01) != 0) {
						ysv_ext1 += 1;
						dy_ext1 -= 1;
					} else {
						ysv_ext0 += 1;
						dy_ext0 -= 1;
					}
				} else {
					ysv_ext0 = ysv_ext1 = ysv_ext2 = ysb;
					dy_ext0 = dy_ext1 = dy_ext2 = dy0 - 4 * SQUISH_CONSTANT_4D;
				}

				if ((c & 0x04) != 0) {
					zsv_ext0 = zsv_ext1 = zsv_ext2 = zsb + 1;
					dz_ext0 = dz_ext1 = dz_ext2 = dz0 - 1 - 4 * SQUISH_CONSTANT_4D;
					if ((c & 0x03) != 0x03) {
						if ((c & 0x03) == 0) {
							zsv_ext0 += 1;
							dz_ext0 -= 1;
						} else {
							zsv_ext1 += 1;
							dz_ext1 -= 1;
						}
					} else {
						zsv_ext2 += 1;
						dz_ext2 -= 1;
					}
				} else {
					zsv_ext0 = zsv_ext1 = zsv_ext2 = zsb;
					dz_ext0 = dz_ext1 = dz_ext2 = dz0 - 4 * SQUISH_CONSTANT_4D;
				}

				if ((c & 0x08) != 0) {
					wsv_ext0 = wsv_ext1 = wsb + 1;
					wsv_ext2 = wsb + 2;
					dw_ext0 = dw_ext1 = dw0 - 1 - 4 * SQUISH_CONSTANT_4D;
					dw_ext2 = dw0 - 2 - 4 * SQUISH_CONSTANT_4D;
				} else {
					wsv_ext0 = wsv_ext1 = wsv_ext2 = wsb;
					dw_ext0 = dw_ext1 = dw_ext2 = dw0 - 4 * SQUISH_CONSTANT_4D;
				}
			} else { //(1,1,1,1) is not one of the closest two pentachoron vertices.
				byte c = cast(byte)(aPoint & bPoint); //Our three extra vertices are determined by the closest two.

				if ((c & 0x01) != 0) {
					xsv_ext0 = xsv_ext2 = xsb + 1;
					xsv_ext1 = xsb + 2;
					dx_ext0 = dx0 - 1 - 2 * SQUISH_CONSTANT_4D;
					dx_ext1 = dx0 - 2 - 3 * SQUISH_CONSTANT_4D;
					dx_ext2 = dx0 - 1 - 3 * SQUISH_CONSTANT_4D;
				} else {
					xsv_ext0 = xsv_ext1 = xsv_ext2 = xsb;
					dx_ext0 = dx0 - 2 * SQUISH_CONSTANT_4D;
					dx_ext1 = dx_ext2 = dx0 - 3 * SQUISH_CONSTANT_4D;
				}

				if ((c & 0x02) != 0) {
					ysv_ext0 = ysv_ext1 = ysv_ext2 = ysb + 1;
					dy_ext0 = dy0 - 1 - 2 * SQUISH_CONSTANT_4D;
					dy_ext1 = dy_ext2 = dy0 - 1 - 3 * SQUISH_CONSTANT_4D;
					if ((c & 0x01) != 0) {
						ysv_ext2 += 1;
						dy_ext2 -= 1;
					} else {
						ysv_ext1 += 1;
						dy_ext1 -= 1;
					}
				} else {
					ysv_ext0 = ysv_ext1 = ysv_ext2 = ysb;
					dy_ext0 = dy0 - 2 * SQUISH_CONSTANT_4D;
					dy_ext1 = dy_ext2 = dy0 - 3 * SQUISH_CONSTANT_4D;
				}

				if ((c & 0x04) != 0) {
					zsv_ext0 = zsv_ext1 = zsv_ext2 = zsb + 1;
					dz_ext0 = dz0 - 1 - 2 * SQUISH_CONSTANT_4D;
					dz_ext1 = dz_ext2 = dz0 - 1 - 3 * SQUISH_CONSTANT_4D;
					if ((c & 0x03) != 0) {
						zsv_ext2 += 1;
						dz_ext2 -= 1;
					} else {
						zsv_ext1 += 1;
						dz_ext1 -= 1;
					}
				} else {
					zsv_ext0 = zsv_ext1 = zsv_ext2 = zsb;
					dz_ext0 = dz0 - 2 * SQUISH_CONSTANT_4D;
					dz_ext1 = dz_ext2 = dz0 - 3 * SQUISH_CONSTANT_4D;
				}

				if ((c & 0x08) != 0) {
					wsv_ext0 = wsv_ext1 = wsb + 1;
					wsv_ext2 = wsb + 2;
					dw_ext0 = dw0 - 1 - 2 * SQUISH_CONSTANT_4D;
					dw_ext1 = dw0 - 1 - 3 * SQUISH_CONSTANT_4D;
					dw_ext2 = dw0 - 2 - 3 * SQUISH_CONSTANT_4D;
				} else {
					wsv_ext0 = wsv_ext1 = wsv_ext2 = wsb;
					dw_ext0 = dw0 - 2 * SQUISH_CONSTANT_4D;
					dw_ext1 = dw_ext2 = dw0 - 3 * SQUISH_CONSTANT_4D;
				}
			}

			//Contribution (1,1,1,0)
			T dx4 = dx0 - 1 - 3 * SQUISH_CONSTANT_4D;
			T dy4 = dy0 - 1 - 3 * SQUISH_CONSTANT_4D;
			T dz4 = dz0 - 1 - 3 * SQUISH_CONSTANT_4D;
			T dw4 = dw0 - 3 * SQUISH_CONSTANT_4D;
			T attn4 = 2 - dx4 * dx4 - dy4 * dy4 - dz4 * dz4 - dw4 * dw4;
			if (attn4 > 0) {
				attn4 *= attn4;
				value += attn4 * attn4 * extrapolate(xsb + 1, ysb + 1, zsb + 1, wsb + 0, dx4, dy4, dz4, dw4);
			}

			//Contribution (1,1,0,1)
			T dx3 = dx4;
			T dy3 = dy4;
			T dz3 = dz0 - 3 * SQUISH_CONSTANT_4D;
			T dw3 = dw0 - 1 - 3 * SQUISH_CONSTANT_4D;
			T attn3 = 2 - dx3 * dx3 - dy3 * dy3 - dz3 * dz3 - dw3 * dw3;
			if (attn3 > 0) {
				attn3 *= attn3;
				value += attn3 * attn3 * extrapolate(xsb + 1, ysb + 1, zsb + 0, wsb + 1, dx3, dy3, dz3, dw3);
			}

			//Contribution (1,0,1,1)
			T dx2 = dx4;
			T dy2 = dy0 - 3 * SQUISH_CONSTANT_4D;
			T dz2 = dz4;
			T dw2 = dw3;
			T attn2 = 2 - dx2 * dx2 - dy2 * dy2 - dz2 * dz2 - dw2 * dw2;
			if (attn2 > 0) {
				attn2 *= attn2;
				value += attn2 * attn2 * extrapolate(xsb + 1, ysb + 0, zsb + 1, wsb + 1, dx2, dy2, dz2, dw2);
			}

			//Contribution (0,1,1,1)
			T dx1 = dx0 - 3 * SQUISH_CONSTANT_4D;
			T dz1 = dz4;
			T dy1 = dy4;
			T dw1 = dw3;
			T attn1 = 2 - dx1 * dx1 - dy1 * dy1 - dz1 * dz1 - dw1 * dw1;
			if (attn1 > 0) {
				attn1 *= attn1;
				value += attn1 * attn1 * extrapolate(xsb + 0, ysb + 1, zsb + 1, wsb + 1, dx1, dy1, dz1, dw1);
			}

			//Contribution (1,1,1,1)
			dx0 = dx0 - 1 - 4 * SQUISH_CONSTANT_4D;
			dy0 = dy0 - 1 - 4 * SQUISH_CONSTANT_4D;
			dz0 = dz0 - 1 - 4 * SQUISH_CONSTANT_4D;
			dw0 = dw0 - 1 - 4 * SQUISH_CONSTANT_4D;
			T attn0 = 2 - dx0 * dx0 - dy0 * dy0 - dz0 * dz0 - dw0 * dw0;
			if (attn0 > 0) {
				attn0 *= attn0;
				value += attn0 * attn0 * extrapolate(xsb + 1, ysb + 1, zsb + 1, wsb + 1, dx0, dy0, dz0, dw0);
			}
		} else if (inSum <= 2) { //We're inside the first dispentachoron (Rectified 4-Simplex)
			T aScore;
			byte aPoint;
			bool aIsBiggerSide = true;
			T bScore;
			byte bPoint;
			bool bIsBiggerSide = true;

			//Decide between (1,1,0,0) and (0,0,1,1)
			if (xins + yins > zins + wins) {
				aScore = xins + yins;
				aPoint = 0x03;
			} else {
				aScore = zins + wins;
				aPoint = 0x0C;
			}

			//Decide between (1,0,1,0) and (0,1,0,1)
			if (xins + zins > yins + wins) {
				bScore = xins + zins;
				bPoint = 0x05;
			} else {
				bScore = yins + wins;
				bPoint = 0x0A;
			}

			//Closer between (1,0,0,1) and (0,1,1,0) will replace the further of a and b, if closer.
			if (xins + wins > yins + zins) {
				T score = xins + wins;
				if (aScore >= bScore && score > bScore) {
					bScore = score;
					bPoint = 0x09;
				} else if (aScore < bScore && score > aScore) {
					aScore = score;
					aPoint = 0x09;
				}
			} else {
				T score = yins + zins;
				if (aScore >= bScore && score > bScore) {
					bScore = score;
					bPoint = 0x06;
				} else if (aScore < bScore && score > aScore) {
					aScore = score;
					aPoint = 0x06;
				}
			}

			//Decide if (1,0,0,0) is closer.
			T p1 = 2 - inSum + xins;
			if (aScore >= bScore && p1 > bScore) {
				bScore = p1;
				bPoint = 0x01;
				bIsBiggerSide = false;
			} else if (aScore < bScore && p1 > aScore) {
				aScore = p1;
				aPoint = 0x01;
				aIsBiggerSide = false;
			}

			//Decide if (0,1,0,0) is closer.
			T p2 = 2 - inSum + yins;
			if (aScore >= bScore && p2 > bScore) {
				bScore = p2;
				bPoint = 0x02;
				bIsBiggerSide = false;
			} else if (aScore < bScore && p2 > aScore) {
				aScore = p2;
				aPoint = 0x02;
				aIsBiggerSide = false;
			}

			//Decide if (0,0,1,0) is closer.
			T p3 = 2 - inSum + zins;
			if (aScore >= bScore && p3 > bScore) {
				bScore = p3;
				bPoint = 0x04;
				bIsBiggerSide = false;
			} else if (aScore < bScore && p3 > aScore) {
				aScore = p3;
				aPoint = 0x04;
				aIsBiggerSide = false;
			}

			//Decide if (0,0,0,1) is closer.
			T p4 = 2 - inSum + wins;
			if (aScore >= bScore && p4 > bScore) {
				bScore = p4;
				bPoint = 0x08;
				bIsBiggerSide = false;
			} else if (aScore < bScore && p4 > aScore) {
				aScore = p4;
				aPoint = 0x08;
				aIsBiggerSide = false;
			}

			//Where each of the two closest points are determines how the extra three vertices are calculated.
			if (aIsBiggerSide == bIsBiggerSide) {
				if (aIsBiggerSide) { //Both closest points on the bigger side
					byte c1 = cast(byte)(aPoint | bPoint);
					byte c2 = cast(byte)(aPoint & bPoint);
					if ((c1 & 0x01) == 0) {
						xsv_ext0 = xsb;
						xsv_ext1 = xsb - 1;
						dx_ext0 = dx0 - 3 * SQUISH_CONSTANT_4D;
						dx_ext1 = dx0 + 1 - 2 * SQUISH_CONSTANT_4D;
					} else {
						xsv_ext0 = xsv_ext1 = xsb + 1;
						dx_ext0 = dx0 - 1 - 3 * SQUISH_CONSTANT_4D;
						dx_ext1 = dx0 - 1 - 2 * SQUISH_CONSTANT_4D;
					}

					if ((c1 & 0x02) == 0) {
						ysv_ext0 = ysb;
						ysv_ext1 = ysb - 1;
						dy_ext0 = dy0 - 3 * SQUISH_CONSTANT_4D;
						dy_ext1 = dy0 + 1 - 2 * SQUISH_CONSTANT_4D;
					} else {
						ysv_ext0 = ysv_ext1 = ysb + 1;
						dy_ext0 = dy0 - 1 - 3 * SQUISH_CONSTANT_4D;
						dy_ext1 = dy0 - 1 - 2 * SQUISH_CONSTANT_4D;
					}

					if ((c1 & 0x04) == 0) {
						zsv_ext0 = zsb;
						zsv_ext1 = zsb - 1;
						dz_ext0 = dz0 - 3 * SQUISH_CONSTANT_4D;
						dz_ext1 = dz0 + 1 - 2 * SQUISH_CONSTANT_4D;
					} else {
						zsv_ext0 = zsv_ext1 = zsb + 1;
						dz_ext0 = dz0 - 1 - 3 * SQUISH_CONSTANT_4D;
						dz_ext1 = dz0 - 1 - 2 * SQUISH_CONSTANT_4D;
					}

					if ((c1 & 0x08) == 0) {
						wsv_ext0 = wsb;
						wsv_ext1 = wsb - 1;
						dw_ext0 = dw0 - 3 * SQUISH_CONSTANT_4D;
						dw_ext1 = dw0 + 1 - 2 * SQUISH_CONSTANT_4D;
					} else {
						wsv_ext0 = wsv_ext1 = wsb + 1;
						dw_ext0 = dw0 - 1 - 3 * SQUISH_CONSTANT_4D;
						dw_ext1 = dw0 - 1 - 2 * SQUISH_CONSTANT_4D;
					}

					//One combination is a permutation of (0,0,0,2) based on c2
					xsv_ext2 = xsb;
					ysv_ext2 = ysb;
					zsv_ext2 = zsb;
					wsv_ext2 = wsb;
					dx_ext2 = dx0 - 2 * SQUISH_CONSTANT_4D;
					dy_ext2 = dy0 - 2 * SQUISH_CONSTANT_4D;
					dz_ext2 = dz0 - 2 * SQUISH_CONSTANT_4D;
					dw_ext2 = dw0 - 2 * SQUISH_CONSTANT_4D;
					if ((c2 & 0x01) != 0) {
						xsv_ext2 += 2;
						dx_ext2 -= 2;
					} else if ((c2 & 0x02) != 0) {
						ysv_ext2 += 2;
						dy_ext2 -= 2;
					} else if ((c2 & 0x04) != 0) {
						zsv_ext2 += 2;
						dz_ext2 -= 2;
					} else {
						wsv_ext2 += 2;
						dw_ext2 -= 2;
					}

				} else { //Both closest points on the smaller side
					//One of the two extra points is (0,0,0,0)
					xsv_ext2 = xsb;
					ysv_ext2 = ysb;
					zsv_ext2 = zsb;
					wsv_ext2 = wsb;
					dx_ext2 = dx0;
					dy_ext2 = dy0;
					dz_ext2 = dz0;
					dw_ext2 = dw0;

					//Other two points are based on the omitted axes.
					byte c = cast(byte)(aPoint | bPoint);

					if ((c & 0x01) == 0) {
						xsv_ext0 = xsb - 1;
						xsv_ext1 = xsb;
						dx_ext0 = dx0 + 1 - SQUISH_CONSTANT_4D;
						dx_ext1 = dx0 - SQUISH_CONSTANT_4D;
					} else {
						xsv_ext0 = xsv_ext1 = xsb + 1;
						dx_ext0 = dx_ext1 = dx0 - 1 - SQUISH_CONSTANT_4D;
					}

					if ((c & 0x02) == 0) {
						ysv_ext0 = ysv_ext1 = ysb;
						dy_ext0 = dy_ext1 = dy0 - SQUISH_CONSTANT_4D;
						if ((c & 0x01) == 0x01)
						{
							ysv_ext0 -= 1;
							dy_ext0 += 1;
						} else {
							ysv_ext1 -= 1;
							dy_ext1 += 1;
						}
					} else {
						ysv_ext0 = ysv_ext1 = ysb + 1;
						dy_ext0 = dy_ext1 = dy0 - 1 - SQUISH_CONSTANT_4D;
					}

					if ((c & 0x04) == 0) {
						zsv_ext0 = zsv_ext1 = zsb;
						dz_ext0 = dz_ext1 = dz0 - SQUISH_CONSTANT_4D;
						if ((c & 0x03) == 0x03)
						{
							zsv_ext0 -= 1;
							dz_ext0 += 1;
						} else {
							zsv_ext1 -= 1;
							dz_ext1 += 1;
						}
					} else {
						zsv_ext0 = zsv_ext1 = zsb + 1;
						dz_ext0 = dz_ext1 = dz0 - 1 - SQUISH_CONSTANT_4D;
					}

					if ((c & 0x08) == 0)
					{
						wsv_ext0 = wsb;
						wsv_ext1 = wsb - 1;
						dw_ext0 = dw0 - SQUISH_CONSTANT_4D;
						dw_ext1 = dw0 + 1 - SQUISH_CONSTANT_4D;
					} else {
						wsv_ext0 = wsv_ext1 = wsb + 1;
						dw_ext0 = dw_ext1 = dw0 - 1 - SQUISH_CONSTANT_4D;
					}

				}
			} else { //One point on each "side"
				byte c1, c2;
				if (aIsBiggerSide) {
					c1 = aPoint;
					c2 = bPoint;
				} else {
					c1 = bPoint;
					c2 = aPoint;
				}

				//Two contributions are the bigger-sided point with each 0 replaced with -1.
				if ((c1 & 0x01) == 0) {
					xsv_ext0 = xsb - 1;
					xsv_ext1 = xsb;
					dx_ext0 = dx0 + 1 - SQUISH_CONSTANT_4D;
					dx_ext1 = dx0 - SQUISH_CONSTANT_4D;
				} else {
					xsv_ext0 = xsv_ext1 = xsb + 1;
					dx_ext0 = dx_ext1 = dx0 - 1 - SQUISH_CONSTANT_4D;
				}

				if ((c1 & 0x02) == 0) {
					ysv_ext0 = ysv_ext1 = ysb;
					dy_ext0 = dy_ext1 = dy0 - SQUISH_CONSTANT_4D;
					if ((c1 & 0x01) == 0x01) {
						ysv_ext0 -= 1;
						dy_ext0 += 1;
					} else {
						ysv_ext1 -= 1;
						dy_ext1 += 1;
					}
				} else {
					ysv_ext0 = ysv_ext1 = ysb + 1;
					dy_ext0 = dy_ext1 = dy0 - 1 - SQUISH_CONSTANT_4D;
				}

				if ((c1 & 0x04) == 0) {
					zsv_ext0 = zsv_ext1 = zsb;
					dz_ext0 = dz_ext1 = dz0 - SQUISH_CONSTANT_4D;
					if ((c1 & 0x03) == 0x03) {
						zsv_ext0 -= 1;
						dz_ext0 += 1;
					} else {
						zsv_ext1 -= 1;
						dz_ext1 += 1;
					}
				} else {
					zsv_ext0 = zsv_ext1 = zsb + 1;
					dz_ext0 = dz_ext1 = dz0 - 1 - SQUISH_CONSTANT_4D;
				}

				if ((c1 & 0x08) == 0) {
					wsv_ext0 = wsb;
					wsv_ext1 = wsb - 1;
					dw_ext0 = dw0 - SQUISH_CONSTANT_4D;
					dw_ext1 = dw0 + 1 - SQUISH_CONSTANT_4D;
				} else {
					wsv_ext0 = wsv_ext1 = wsb + 1;
					dw_ext0 = dw_ext1 = dw0 - 1 - SQUISH_CONSTANT_4D;
				}

				//One contribution is a permutation of (0,0,0,2) based on the smaller-sided point
				xsv_ext2 = xsb;
				ysv_ext2 = ysb;
				zsv_ext2 = zsb;
				wsv_ext2 = wsb;
				dx_ext2 = dx0 - 2 * SQUISH_CONSTANT_4D;
				dy_ext2 = dy0 - 2 * SQUISH_CONSTANT_4D;
				dz_ext2 = dz0 - 2 * SQUISH_CONSTANT_4D;
				dw_ext2 = dw0 - 2 * SQUISH_CONSTANT_4D;
				if ((c2 & 0x01) != 0) {
					xsv_ext2 += 2;
					dx_ext2 -= 2;
				} else if ((c2 & 0x02) != 0) {
					ysv_ext2 += 2;
					dy_ext2 -= 2;
				} else if ((c2 & 0x04) != 0) {
					zsv_ext2 += 2;
					dz_ext2 -= 2;
				} else {
					wsv_ext2 += 2;
					dw_ext2 -= 2;
				}
			}

			//Contribution (1,0,0,0)
			T dx1 = dx0 - 1 - SQUISH_CONSTANT_4D;
			T dy1 = dy0 - 0 - SQUISH_CONSTANT_4D;
			T dz1 = dz0 - 0 - SQUISH_CONSTANT_4D;
			T dw1 = dw0 - 0 - SQUISH_CONSTANT_4D;
			T attn1 = 2 - dx1 * dx1 - dy1 * dy1 - dz1 * dz1 - dw1 * dw1;
			if (attn1 > 0) {
				attn1 *= attn1;
				value += attn1 * attn1 * extrapolate(xsb + 1, ysb + 0, zsb + 0, wsb + 0, dx1, dy1, dz1, dw1);
			}

			//Contribution (0,1,0,0)
			T dx2 = dx0 - 0 - SQUISH_CONSTANT_4D;
			T dy2 = dy0 - 1 - SQUISH_CONSTANT_4D;
			T dz2 = dz1;
			T dw2 = dw1;
			T attn2 = 2 - dx2 * dx2 - dy2 * dy2 - dz2 * dz2 - dw2 * dw2;
			if (attn2 > 0) {
				attn2 *= attn2;
				value += attn2 * attn2 * extrapolate(xsb + 0, ysb + 1, zsb + 0, wsb + 0, dx2, dy2, dz2, dw2);
			}

			//Contribution (0,0,1,0)
			T dx3 = dx2;
			T dy3 = dy1;
			T dz3 = dz0 - 1 - SQUISH_CONSTANT_4D;
			T dw3 = dw1;
			T attn3 = 2 - dx3 * dx3 - dy3 * dy3 - dz3 * dz3 - dw3 * dw3;
			if (attn3 > 0) {
				attn3 *= attn3;
				value += attn3 * attn3 * extrapolate(xsb + 0, ysb + 0, zsb + 1, wsb + 0, dx3, dy3, dz3, dw3);
			}

			//Contribution (0,0,0,1)
			T dx4 = dx2;
			T dy4 = dy1;
			T dz4 = dz1;
			T dw4 = dw0 - 1 - SQUISH_CONSTANT_4D;
			T attn4 = 2 - dx4 * dx4 - dy4 * dy4 - dz4 * dz4 - dw4 * dw4;
			if (attn4 > 0) {
				attn4 *= attn4;
				value += attn4 * attn4 * extrapolate(xsb + 0, ysb + 0, zsb + 0, wsb + 1, dx4, dy4, dz4, dw4);
			}

			//Contribution (1,1,0,0)
			T dx5 = dx0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dy5 = dy0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dz5 = dz0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dw5 = dw0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T attn5 = 2 - dx5 * dx5 - dy5 * dy5 - dz5 * dz5 - dw5 * dw5;
			if (attn5 > 0) {
				attn5 *= attn5;
				value += attn5 * attn5 * extrapolate(xsb + 1, ysb + 1, zsb + 0, wsb + 0, dx5, dy5, dz5, dw5);
			}

			//Contribution (1,0,1,0)
			T dx6 = dx0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dy6 = dy0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dz6 = dz0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dw6 = dw0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T attn6 = 2 - dx6 * dx6 - dy6 * dy6 - dz6 * dz6 - dw6 * dw6;
			if (attn6 > 0) {
				attn6 *= attn6;
				value += attn6 * attn6 * extrapolate(xsb + 1, ysb + 0, zsb + 1, wsb + 0, dx6, dy6, dz6, dw6);
			}

			//Contribution (1,0,0,1)
			T dx7 = dx0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dy7 = dy0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dz7 = dz0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dw7 = dw0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T attn7 = 2 - dx7 * dx7 - dy7 * dy7 - dz7 * dz7 - dw7 * dw7;
			if (attn7 > 0) {
				attn7 *= attn7;
				value += attn7 * attn7 * extrapolate(xsb + 1, ysb + 0, zsb + 0, wsb + 1, dx7, dy7, dz7, dw7);
			}

			//Contribution (0,1,1,0)
			T dx8 = dx0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dy8 = dy0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dz8 = dz0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dw8 = dw0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T attn8 = 2 - dx8 * dx8 - dy8 * dy8 - dz8 * dz8 - dw8 * dw8;
			if (attn8 > 0) {
				attn8 *= attn8;
				value += attn8 * attn8 * extrapolate(xsb + 0, ysb + 1, zsb + 1, wsb + 0, dx8, dy8, dz8, dw8);
			}

			//Contribution (0,1,0,1)
			T dx9 = dx0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dy9 = dy0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dz9 = dz0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dw9 = dw0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T attn9 = 2 - dx9 * dx9 - dy9 * dy9 - dz9 * dz9 - dw9 * dw9;
			if (attn9 > 0) {
				attn9 *= attn9;
				value += attn9 * attn9 * extrapolate(xsb + 0, ysb + 1, zsb + 0, wsb + 1, dx9, dy9, dz9, dw9);
			}

			//Contribution (0,0,1,1)
			T dx10 = dx0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dy10 = dy0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dz10 = dz0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dw10 = dw0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T attn10 = 2 - dx10 * dx10 - dy10 * dy10 - dz10 * dz10 - dw10 * dw10;
			if (attn10 > 0) {
				attn10 *= attn10;
				value += attn10 * attn10 * extrapolate(xsb + 0, ysb + 0, zsb + 1, wsb + 1, dx10, dy10, dz10, dw10);
			}
		} else { //We're inside the second dispentachoron (Rectified 4-Simplex)
			T aScore;
			byte aPoint;
			bool aIsBiggerSide = true;
			T bScore;
			byte bPoint;
			bool bIsBiggerSide = true;

			//Decide between (0,0,1,1) and (1,1,0,0)
			if (xins + yins < zins + wins) {
				aScore = xins + yins;
				aPoint = 0x0C;
			} else {
				aScore = zins + wins;
				aPoint = 0x03;
			}

			//Decide between (0,1,0,1) and (1,0,1,0)
			if (xins + zins < yins + wins) {
				bScore = xins + zins;
				bPoint = 0x0A;
			} else {
				bScore = yins + wins;
				bPoint = 0x05;
			}

			//Closer between (0,1,1,0) and (1,0,0,1) will replace the further of a and b, if closer.
			if (xins + wins < yins + zins) {
				T score = xins + wins;
				if (aScore <= bScore && score < bScore) {
					bScore = score;
					bPoint = 0x06;
				} else if (aScore > bScore && score < aScore) {
					aScore = score;
					aPoint = 0x06;
				}
			} else {
				T score = yins + zins;
				if (aScore <= bScore && score < bScore) {
					bScore = score;
					bPoint = 0x09;
				} else if (aScore > bScore && score < aScore) {
					aScore = score;
					aPoint = 0x09;
				}
			}

			//Decide if (0,1,1,1) is closer.
			T p1 = 3 - inSum + xins;
			if (aScore <= bScore && p1 < bScore) {
				bScore = p1;
				bPoint = 0x0E;
				bIsBiggerSide = false;
			} else if (aScore > bScore && p1 < aScore) {
				aScore = p1;
				aPoint = 0x0E;
				aIsBiggerSide = false;
			}

			//Decide if (1,0,1,1) is closer.
			T p2 = 3 - inSum + yins;
			if (aScore <= bScore && p2 < bScore) {
				bScore = p2;
				bPoint = 0x0D;
				bIsBiggerSide = false;
			} else if (aScore > bScore && p2 < aScore) {
				aScore = p2;
				aPoint = 0x0D;
				aIsBiggerSide = false;
			}

			//Decide if (1,1,0,1) is closer.
			T p3 = 3 - inSum + zins;
			if (aScore <= bScore && p3 < bScore) {
				bScore = p3;
				bPoint = 0x0B;
				bIsBiggerSide = false;
			} else if (aScore > bScore && p3 < aScore) {
				aScore = p3;
				aPoint = 0x0B;
				aIsBiggerSide = false;
			}

			//Decide if (1,1,1,0) is closer.
			T p4 = 3 - inSum + wins;
			if (aScore <= bScore && p4 < bScore) {
				bScore = p4;
				bPoint = 0x07;
				bIsBiggerSide = false;
			} else if (aScore > bScore && p4 < aScore) {
				aScore = p4;
				aPoint = 0x07;
				aIsBiggerSide = false;
			}

			//Where each of the two closest points are determines how the extra three vertices are calculated.
			if (aIsBiggerSide == bIsBiggerSide) {
				if (aIsBiggerSide) { //Both closest points on the bigger side
					byte c1 = cast(byte)(aPoint & bPoint);
					byte c2 = cast(byte)(aPoint | bPoint);

					//Two contributions are permutations of (0,0,0,1) and (0,0,0,2) based on c1
					xsv_ext0 = xsv_ext1 = xsb;
					ysv_ext0 = ysv_ext1 = ysb;
					zsv_ext0 = zsv_ext1 = zsb;
					wsv_ext0 = wsv_ext1 = wsb;
					dx_ext0 = dx0 - SQUISH_CONSTANT_4D;
					dy_ext0 = dy0 - SQUISH_CONSTANT_4D;
					dz_ext0 = dz0 - SQUISH_CONSTANT_4D;
					dw_ext0 = dw0 - SQUISH_CONSTANT_4D;
					dx_ext1 = dx0 - 2 * SQUISH_CONSTANT_4D;
					dy_ext1 = dy0 - 2 * SQUISH_CONSTANT_4D;
					dz_ext1 = dz0 - 2 * SQUISH_CONSTANT_4D;
					dw_ext1 = dw0 - 2 * SQUISH_CONSTANT_4D;
					if ((c1 & 0x01) != 0) {
						xsv_ext0 += 1;
						dx_ext0 -= 1;
						xsv_ext1 += 2;
						dx_ext1 -= 2;
					} else if ((c1 & 0x02) != 0) {
						ysv_ext0 += 1;
						dy_ext0 -= 1;
						ysv_ext1 += 2;
						dy_ext1 -= 2;
					} else if ((c1 & 0x04) != 0) {
						zsv_ext0 += 1;
						dz_ext0 -= 1;
						zsv_ext1 += 2;
						dz_ext1 -= 2;
					} else {
						wsv_ext0 += 1;
						dw_ext0 -= 1;
						wsv_ext1 += 2;
						dw_ext1 -= 2;
					}

					//One contribution is a permutation of (1,1,1,-1) based on c2
					xsv_ext2 = xsb + 1;
					ysv_ext2 = ysb + 1;
					zsv_ext2 = zsb + 1;
					wsv_ext2 = wsb + 1;
					dx_ext2 = dx0 - 1 - 2 * SQUISH_CONSTANT_4D;
					dy_ext2 = dy0 - 1 - 2 * SQUISH_CONSTANT_4D;
					dz_ext2 = dz0 - 1 - 2 * SQUISH_CONSTANT_4D;
					dw_ext2 = dw0 - 1 - 2 * SQUISH_CONSTANT_4D;
					if ((c2 & 0x01) == 0) {
						xsv_ext2 -= 2;
						dx_ext2 += 2;
					} else if ((c2 & 0x02) == 0) {
						ysv_ext2 -= 2;
						dy_ext2 += 2;
					} else if ((c2 & 0x04) == 0) {
						zsv_ext2 -= 2;
						dz_ext2 += 2;
					} else {
						wsv_ext2 -= 2;
						dw_ext2 += 2;
					}
				} else { //Both closest points on the smaller side
					//One of the two extra points is (1,1,1,1)
					xsv_ext2 = xsb + 1;
					ysv_ext2 = ysb + 1;
					zsv_ext2 = zsb + 1;
					wsv_ext2 = wsb + 1;
					dx_ext2 = dx0 - 1 - 4 * SQUISH_CONSTANT_4D;
					dy_ext2 = dy0 - 1 - 4 * SQUISH_CONSTANT_4D;
					dz_ext2 = dz0 - 1 - 4 * SQUISH_CONSTANT_4D;
					dw_ext2 = dw0 - 1 - 4 * SQUISH_CONSTANT_4D;

					//Other two points are based on the shared axes.
					byte c = cast(byte)(aPoint & bPoint);

					if ((c & 0x01) != 0) {
						xsv_ext0 = xsb + 2;
						xsv_ext1 = xsb + 1;
						dx_ext0 = dx0 - 2 - 3 * SQUISH_CONSTANT_4D;
						dx_ext1 = dx0 - 1 - 3 * SQUISH_CONSTANT_4D;
					} else {
						xsv_ext0 = xsv_ext1 = xsb;
						dx_ext0 = dx_ext1 = dx0 - 3 * SQUISH_CONSTANT_4D;
					}

					if ((c & 0x02) != 0) {
						ysv_ext0 = ysv_ext1 = ysb + 1;
						dy_ext0 = dy_ext1 = dy0 - 1 - 3 * SQUISH_CONSTANT_4D;
						if ((c & 0x01) == 0)
						{
							ysv_ext0 += 1;
							dy_ext0 -= 1;
						} else {
							ysv_ext1 += 1;
							dy_ext1 -= 1;
						}
					} else {
						ysv_ext0 = ysv_ext1 = ysb;
						dy_ext0 = dy_ext1 = dy0 - 3 * SQUISH_CONSTANT_4D;
					}

					if ((c & 0x04) != 0) {
						zsv_ext0 = zsv_ext1 = zsb + 1;
						dz_ext0 = dz_ext1 = dz0 - 1 - 3 * SQUISH_CONSTANT_4D;
						if ((c & 0x03) == 0)
						{
							zsv_ext0 += 1;
							dz_ext0 -= 1;
						} else {
							zsv_ext1 += 1;
							dz_ext1 -= 1;
						}
					} else {
						zsv_ext0 = zsv_ext1 = zsb;
						dz_ext0 = dz_ext1 = dz0 - 3 * SQUISH_CONSTANT_4D;
					}

					if ((c & 0x08) != 0)
					{
						wsv_ext0 = wsb + 1;
						wsv_ext1 = wsb + 2;
						dw_ext0 = dw0 - 1 - 3 * SQUISH_CONSTANT_4D;
						dw_ext1 = dw0 - 2 - 3 * SQUISH_CONSTANT_4D;
					} else {
						wsv_ext0 = wsv_ext1 = wsb;
						dw_ext0 = dw_ext1 = dw0 - 3 * SQUISH_CONSTANT_4D;
					}
				}
			} else { //One point on each "side"
				byte c1, c2;
				if (aIsBiggerSide) {
					c1 = aPoint;
					c2 = bPoint;
				} else {
					c1 = bPoint;
					c2 = aPoint;
				}

				//Two contributions are the bigger-sided point with each 1 replaced with 2.
				if ((c1 & 0x01) != 0) {
					xsv_ext0 = xsb + 2;
					xsv_ext1 = xsb + 1;
					dx_ext0 = dx0 - 2 - 3 * SQUISH_CONSTANT_4D;
					dx_ext1 = dx0 - 1 - 3 * SQUISH_CONSTANT_4D;
				} else {
					xsv_ext0 = xsv_ext1 = xsb;
					dx_ext0 = dx_ext1 = dx0 - 3 * SQUISH_CONSTANT_4D;
				}

				if ((c1 & 0x02) != 0) {
					ysv_ext0 = ysv_ext1 = ysb + 1;
					dy_ext0 = dy_ext1 = dy0 - 1 - 3 * SQUISH_CONSTANT_4D;
					if ((c1 & 0x01) == 0) {
						ysv_ext0 += 1;
						dy_ext0 -= 1;
					} else {
						ysv_ext1 += 1;
						dy_ext1 -= 1;
					}
				} else {
					ysv_ext0 = ysv_ext1 = ysb;
					dy_ext0 = dy_ext1 = dy0 - 3 * SQUISH_CONSTANT_4D;
				}

				if ((c1 & 0x04) != 0) {
					zsv_ext0 = zsv_ext1 = zsb + 1;
					dz_ext0 = dz_ext1 = dz0 - 1 - 3 * SQUISH_CONSTANT_4D;
					if ((c1 & 0x03) == 0) {
						zsv_ext0 += 1;
						dz_ext0 -= 1;
					} else {
						zsv_ext1 += 1;
						dz_ext1 -= 1;
					}
				} else {
					zsv_ext0 = zsv_ext1 = zsb;
					dz_ext0 = dz_ext1 = dz0 - 3 * SQUISH_CONSTANT_4D;
				}

				if ((c1 & 0x08) != 0) {
					wsv_ext0 = wsb + 1;
					wsv_ext1 = wsb + 2;
					dw_ext0 = dw0 - 1 - 3 * SQUISH_CONSTANT_4D;
					dw_ext1 = dw0 - 2 - 3 * SQUISH_CONSTANT_4D;
				} else {
					wsv_ext0 = wsv_ext1 = wsb;
					dw_ext0 = dw_ext1 = dw0 - 3 * SQUISH_CONSTANT_4D;
				}

				//One contribution is a permutation of (1,1,1,-1) based on the smaller-sided point
				xsv_ext2 = xsb + 1;
				ysv_ext2 = ysb + 1;
				zsv_ext2 = zsb + 1;
				wsv_ext2 = wsb + 1;
				dx_ext2 = dx0 - 1 - 2 * SQUISH_CONSTANT_4D;
				dy_ext2 = dy0 - 1 - 2 * SQUISH_CONSTANT_4D;
				dz_ext2 = dz0 - 1 - 2 * SQUISH_CONSTANT_4D;
				dw_ext2 = dw0 - 1 - 2 * SQUISH_CONSTANT_4D;
				if ((c2 & 0x01) == 0) {
					xsv_ext2 -= 2;
					dx_ext2 += 2;
				} else if ((c2 & 0x02) == 0) {
					ysv_ext2 -= 2;
					dy_ext2 += 2;
				} else if ((c2 & 0x04) == 0) {
					zsv_ext2 -= 2;
					dz_ext2 += 2;
				} else {
					wsv_ext2 -= 2;
					dw_ext2 += 2;
				}
			}

			//Contribution (1,1,1,0)
			T dx4 = dx0 - 1 - 3 * SQUISH_CONSTANT_4D;
			T dy4 = dy0 - 1 - 3 * SQUISH_CONSTANT_4D;
			T dz4 = dz0 - 1 - 3 * SQUISH_CONSTANT_4D;
			T dw4 = dw0 - 3 * SQUISH_CONSTANT_4D;
			T attn4 = 2 - dx4 * dx4 - dy4 * dy4 - dz4 * dz4 - dw4 * dw4;
			if (attn4 > 0) {
				attn4 *= attn4;
				value += attn4 * attn4 * extrapolate(xsb + 1, ysb + 1, zsb + 1, wsb + 0, dx4, dy4, dz4, dw4);
			}

			//Contribution (1,1,0,1)
			T dx3 = dx4;
			T dy3 = dy4;
			T dz3 = dz0 - 3 * SQUISH_CONSTANT_4D;
			T dw3 = dw0 - 1 - 3 * SQUISH_CONSTANT_4D;
			T attn3 = 2 - dx3 * dx3 - dy3 * dy3 - dz3 * dz3 - dw3 * dw3;
			if (attn3 > 0) {
				attn3 *= attn3;
				value += attn3 * attn3 * extrapolate(xsb + 1, ysb + 1, zsb + 0, wsb + 1, dx3, dy3, dz3, dw3);
			}

			//Contribution (1,0,1,1)
			T dx2 = dx4;
			T dy2 = dy0 - 3 * SQUISH_CONSTANT_4D;
			T dz2 = dz4;
			T dw2 = dw3;
			T attn2 = 2 - dx2 * dx2 - dy2 * dy2 - dz2 * dz2 - dw2 * dw2;
			if (attn2 > 0) {
				attn2 *= attn2;
				value += attn2 * attn2 * extrapolate(xsb + 1, ysb + 0, zsb + 1, wsb + 1, dx2, dy2, dz2, dw2);
			}

			//Contribution (0,1,1,1)
			T dx1 = dx0 - 3 * SQUISH_CONSTANT_4D;
			T dz1 = dz4;
			T dy1 = dy4;
			T dw1 = dw3;
			T attn1 = 2 - dx1 * dx1 - dy1 * dy1 - dz1 * dz1 - dw1 * dw1;
			if (attn1 > 0) {
				attn1 *= attn1;
				value += attn1 * attn1 * extrapolate(xsb + 0, ysb + 1, zsb + 1, wsb + 1, dx1, dy1, dz1, dw1);
			}

			//Contribution (1,1,0,0)
			T dx5 = dx0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dy5 = dy0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dz5 = dz0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dw5 = dw0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T attn5 = 2 - dx5 * dx5 - dy5 * dy5 - dz5 * dz5 - dw5 * dw5;
			if (attn5 > 0) {
				attn5 *= attn5;
				value += attn5 * attn5 * extrapolate(xsb + 1, ysb + 1, zsb + 0, wsb + 0, dx5, dy5, dz5, dw5);
			}

			//Contribution (1,0,1,0)
			T dx6 = dx0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dy6 = dy0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dz6 = dz0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dw6 = dw0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T attn6 = 2 - dx6 * dx6 - dy6 * dy6 - dz6 * dz6 - dw6 * dw6;
			if (attn6 > 0) {
				attn6 *= attn6;
				value += attn6 * attn6 * extrapolate(xsb + 1, ysb + 0, zsb + 1, wsb + 0, dx6, dy6, dz6, dw6);
			}

			//Contribution (1,0,0,1)
			T dx7 = dx0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dy7 = dy0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dz7 = dz0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dw7 = dw0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T attn7 = 2 - dx7 * dx7 - dy7 * dy7 - dz7 * dz7 - dw7 * dw7;
			if (attn7 > 0) {
				attn7 *= attn7;
				value += attn7 * attn7 * extrapolate(xsb + 1, ysb + 0, zsb + 0, wsb + 1, dx7, dy7, dz7, dw7);
			}

			//Contribution (0,1,1,0)
			T dx8 = dx0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dy8 = dy0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dz8 = dz0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dw8 = dw0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T attn8 = 2 - dx8 * dx8 - dy8 * dy8 - dz8 * dz8 - dw8 * dw8;
			if (attn8 > 0) {
				attn8 *= attn8;
				value += attn8 * attn8 * extrapolate(xsb + 0, ysb + 1, zsb + 1, wsb + 0, dx8, dy8, dz8, dw8);
			}

			//Contribution (0,1,0,1)
			T dx9 = dx0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dy9 = dy0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dz9 = dz0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dw9 = dw0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T attn9 = 2 - dx9 * dx9 - dy9 * dy9 - dz9 * dz9 - dw9 * dw9;
			if (attn9 > 0) {
				attn9 *= attn9;
				value += attn9 * attn9 * extrapolate(xsb + 0, ysb + 1, zsb + 0, wsb + 1, dx9, dy9, dz9, dw9);
			}

			//Contribution (0,0,1,1)
			T dx10 = dx0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dy10 = dy0 - 0 - 2 * SQUISH_CONSTANT_4D;
			T dz10 = dz0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T dw10 = dw0 - 1 - 2 * SQUISH_CONSTANT_4D;
			T attn10 = 2 - dx10 * dx10 - dy10 * dy10 - dz10 * dz10 - dw10 * dw10;
			if (attn10 > 0) {
				attn10 *= attn10;
				value += attn10 * attn10 * extrapolate(xsb + 0, ysb + 0, zsb + 1, wsb + 1, dx10, dy10, dz10, dw10);
			}
		}

		//First extra vertex
		T attn_ext0 = 2 - dx_ext0 * dx_ext0 - dy_ext0 * dy_ext0 - dz_ext0 * dz_ext0 - dw_ext0 * dw_ext0;
		if (attn_ext0 > 0)
		{
			attn_ext0 *= attn_ext0;
			value += attn_ext0 * attn_ext0 * extrapolate(xsv_ext0, ysv_ext0, zsv_ext0, wsv_ext0, dx_ext0, dy_ext0, dz_ext0, dw_ext0);
		}

		//Second extra vertex
		T attn_ext1 = 2 - dx_ext1 * dx_ext1 - dy_ext1 * dy_ext1 - dz_ext1 * dz_ext1 - dw_ext1 * dw_ext1;
		if (attn_ext1 > 0)
		{
			attn_ext1 *= attn_ext1;
			value += attn_ext1 * attn_ext1 * extrapolate(xsv_ext1, ysv_ext1, zsv_ext1, wsv_ext1, dx_ext1, dy_ext1, dz_ext1, dw_ext1);
		}

		//Third extra vertex
		T attn_ext2 = 2 - dx_ext2 * dx_ext2 - dy_ext2 * dy_ext2 - dz_ext2 * dz_ext2 - dw_ext2 * dw_ext2;
		if (attn_ext2 > 0)
		{
			attn_ext2 *= attn_ext2;
			value += attn_ext2 * attn_ext2 * extrapolate(xsv_ext2, ysv_ext2, zsv_ext2, wsv_ext2, dx_ext2, dy_ext2, dz_ext2, dw_ext2);
		}

		return value / NORM_CONSTANT_4D;
	}

	private T extrapolate(int xsb, int ysb, T dx, T dy)
	{
		int index = perm[(perm[xsb & 0xFF] + ysb) & 0xFF] & 0x0E;
		return gradients2D[index] * dx
			+ gradients2D[index + 1] * dy;
	}

	private T extrapolate(int xsb, int ysb, int zsb, T dx, T dy, T dz)
	{
		int index = permGradIndex3D[(perm[(perm[xsb & 0xFF] + ysb) & 0xFF] + zsb) & 0xFF];
		return gradients3D[index] * dx
			+ gradients3D[index + 1] * dy
			+ gradients3D[index + 2] * dz;
	}

	private T extrapolate(int xsb, int ysb, int zsb, int wsb, T dx, T dy, T dz, T dw)
	{
		int index = perm[(perm[(perm[(perm[xsb & 0xFF] + ysb) & 0xFF] + zsb) & 0xFF] + wsb) & 0xFF] & 0xFC;
		return gradients4D[index] * dx
			+ gradients4D[index + 1] * dy
			+ gradients4D[index + 2] * dz
			+ gradients4D[index + 3] * dw;
	}

	private static int fastFloor(T x) {
		int xi = cast(int)x;
		return x < xi ? xi - 1 : xi;
	}

	//Gradients for 2D. They approximate the directions to the
	//vertices of an octagon from the center.
	private static immutable byte[] gradients2D = [
		 5,  2,    2,  5,
		-5,  2,   -2,  5,
		 5, -2,    2, -5,
		-5, -2,   -2, -5,
	];

	//Gradients for 3D. They approximate the directions to the
	//vertices of a rhombicuboctahedron from the center, skewed so
	//that the triangular and square facets can be inscribed inside
	//circles of the same radius.
	private static immutable byte[] gradients3D = [
		-11,  4,  4,     -4,  11,  4,    -4,  4,  11,
		 11,  4,  4,      4,  11,  4,     4,  4,  11,
		-11, -4,  4,     -4, -11,  4,    -4, -4,  11,
		 11, -4,  4,      4, -11,  4,     4, -4,  11,
		-11,  4, -4,     -4,  11, -4,    -4,  4, -11,
		 11,  4, -4,      4,  11, -4,     4,  4, -11,
		-11, -4, -4,     -4, -11, -4,    -4, -4, -11,
		 11, -4, -4,      4, -11, -4,     4, -4, -11,
	];

	//Gradients for 4D. They approximate the directions to the
	//vertices of a disprismatotesseractihexadecachoron from the center,
	//skewed so that the tetrahedral and cubic facets can be inscribed inside
	//spheres of the same radius.
	private static immutable byte[] gradients4D = [
	     3,  1,  1,  1,      1,  3,  1,  1,      1,  1,  3,  1,      1,  1,  1,  3,
	    -3,  1,  1,  1,     -1,  3,  1,  1,     -1,  1,  3,  1,     -1,  1,  1,  3,
	     3, -1,  1,  1,      1, -3,  1,  1,      1, -1,  3,  1,      1, -1,  1,  3,
	    -3, -1,  1,  1,     -1, -3,  1,  1,     -1, -1,  3,  1,     -1, -1,  1,  3,
	     3,  1, -1,  1,      1,  3, -1,  1,      1,  1, -3,  1,      1,  1, -1,  3,
	    -3,  1, -1,  1,     -1,  3, -1,  1,     -1,  1, -3,  1,     -1,  1, -1,  3,
	     3, -1, -1,  1,      1, -3, -1,  1,      1, -1, -3,  1,      1, -1, -1,  3,
	    -3, -1, -1,  1,     -1, -3, -1,  1,     -1, -1, -3,  1,     -1, -1, -1,  3,
	     3,  1,  1, -1,      1,  3,  1, -1,      1,  1,  3, -1,      1,  1,  1, -3,
	    -3,  1,  1, -1,     -1,  3,  1, -1,     -1,  1,  3, -1,     -1,  1,  1, -3,
	     3, -1,  1, -1,      1, -3,  1, -1,      1, -1,  3, -1,      1, -1,  1, -3,
	    -3, -1,  1, -1,     -1, -3,  1, -1,     -1, -1,  3, -1,     -1, -1,  1, -3,
	     3,  1, -1, -1,      1,  3, -1, -1,      1,  1, -3, -1,      1,  1, -1, -3,
	    -3,  1, -1, -1,     -1,  3, -1, -1,     -1,  1, -3, -1,     -1,  1, -1, -3,
	     3, -1, -1, -1,      1, -3, -1, -1,      1, -1, -3, -1,      1, -1, -1, -3,
	    -3, -1, -1, -1,     -1, -3, -1, -1,     -1, -1, -3, -1,     -1, -1, -1, -3,
	];
}