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/* |
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* OpenSimplex (Simplectic) Noise in Java |
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* Copyright 2014 Kurt Spencer |
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* |
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* Licensed under the Apache License, Version 2.0 (the "License"); |
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* you may not use this file except in compliance with the License. |
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* You may obtain a copy of the License at |
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* |
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* http://www.apache.org/licenses/LICENSE-2.0 |
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* |
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* Unless required by applicable law or agreed to in writing, software |
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* distributed under the License is distributed on an "AS IS" BASIS, |
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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* See the License for the specific language governing permissions and |
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* limitations under the License. |
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* |
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* (v0.0.1 with new gradient set and corresponding normalization factor, 9/19/14) |
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*/ |
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public class OpenSimplexNoise { |
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private static final double STRETCH_CONSTANT_3D = -1.0 / 6; |
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private static final double SQUISH_CONSTANT_3D = 1.0 / 3; |
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private short[] perm; |
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private short[] permGradIndex3D; |
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public OpenSimplexNoise() { |
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this(PERM_DEFAULT); |
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} |
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public OpenSimplexNoise(short[] perm) { |
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this.perm = perm; |
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permGradIndex3D = new short[256]; |
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for (int i = 0; i < 256; i++) { |
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permGradIndex3D[i] = (short)((perm[i] % (gradients3D.length / 3)) * 3); |
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} |
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} |
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//Initializes the class using a permutation array generated from a 64-bit seed. |
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//Generates a proper permutation (i.e. doesn't merely perform N successive pair swaps on a base array) |
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//Uses java.util.Random |
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public OpenSimplexNoise(long seed) { |
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perm = new short[256]; |
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permGradIndex3D = new short[256]; |
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short[] source = new short[256]; |
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for (short i = 0; i < 256; i++) |
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source[i] = i; |
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java.util.Random random = new java.util.Random(seed); |
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for (int i = 255; i >= 0; i--) { |
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int r = random.nextInt(i + 1); |
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perm[i] = source[r]; |
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permGradIndex3D[i] = (short)((perm[i] % (gradients3D.length / 3)) * 3); |
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source[r] = source[i]; |
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} |
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} |
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//3D OpenSimplex (Simplectic) Noise. |
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public double eval(double x, double y, double z) { |
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//Place input coordinates on simplectic lattice. |
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double stretchOffset = (x + y + z) * STRETCH_CONSTANT_3D; |
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double xs = x + stretchOffset; |
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double ys = y + stretchOffset; |
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double zs = z + stretchOffset; |
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//Floor to get simplectic lattice coordinates of rhombohedron (stretched cube) super-cell origin. |
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int xsb = fastFloor(xs); |
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int ysb = fastFloor(ys); |
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int zsb = fastFloor(zs); |
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//Skew out to get actual coordinates of rhombohedron origin. We'll need these later. |
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double squishOffset = (xsb + ysb + zsb) * SQUISH_CONSTANT_3D; |
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double xb = xsb + squishOffset; |
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double yb = ysb + squishOffset; |
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double zb = zsb + squishOffset; |
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//Compute simplectic lattice coordinates relative to rhombohedral origin. |
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double xins = xs - xsb; |
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double yins = ys - ysb; |
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double zins = zs - zsb; |
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//Sum those together to get a value that determines which cell we're in. |
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double inSum = xins + yins + zins; |
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//Positions relative to origin point. |
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double dx0 = x - xb; |
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double dy0 = y - yb; |
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double dz0 = z - zb; |
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//We'll be defining these inside the next block and using them afterwards. |
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double dx_ext0, dy_ext0, dz_ext0; |
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double dx_ext1, dy_ext1, dz_ext1; |
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int xsv_ext0, ysv_ext0, zsv_ext0; |
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int xsv_ext1, ysv_ext1, zsv_ext1; |
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double value = 0; |
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if (inSum <= 1) { //We're inside the Tetrahedron (3-Simplex) at (0,0,0) |
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//Determine which two of (0,0,1), (0,1,0), (1,0,0) are closest. |
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byte aPoint = 0x01; |
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double aScore = xins; |
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byte bPoint = 0x02; |
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double bScore = yins; |
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if (aScore >= bScore && zins > bScore) { |
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bScore = zins; |
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bPoint = 0x04; |
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} else if (aScore < bScore && zins > aScore) { |
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aScore = zins; |
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aPoint = 0x04; |
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} |
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//Now we determine the two lattice points not part of the tetrahedron that may contribute. |
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//This depends on the closest two tetrahedral vertices, including (0,0,0) |
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double wins = 1 - inSum; |
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if (wins > aScore || wins > bScore) { //(0,0,0) is one of the closest two tetrahedral vertices. |
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byte c = (bScore > aScore ? bPoint : aPoint); //Our other closest vertex is the closest out of a and b. |
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if ((c & 0x01) == 0) { |
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xsv_ext0 = xsb - 1; |
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xsv_ext1 = xsb; |
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dx_ext0 = dx0 + 1; |
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dx_ext1 = dx0; |
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} else { |
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xsv_ext0 = xsv_ext1 = xsb + 1; |
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dx_ext0 = dx_ext1 = dx0 - 1; |
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} |
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if ((c & 0x02) == 0) { |
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ysv_ext0 = ysv_ext1 = ysb; |
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dy_ext0 = dy_ext1 = dy0; |
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if ((c & 0x01) == 0) { |
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ysv_ext1 -= 1; |
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dy_ext1 += 1; |
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} else { |
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ysv_ext0 -= 1; |
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dy_ext0 += 1; |
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} |
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} else { |
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ysv_ext0 = ysv_ext1 = ysb + 1; |
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dy_ext0 = dy_ext1 = dy0 - 1; |
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} |
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if ((c & 0x04) == 0) { |
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zsv_ext0 = zsb; |
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zsv_ext1 = zsb - 1; |
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dz_ext0 = dz0; |
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dz_ext1 = dz0 + 1; |
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} else { |
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zsv_ext0 = zsv_ext1 = zsb + 1; |
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dz_ext0 = dz_ext1 = dz0 - 1; |
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} |
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} else { //(0,0,0) is not one of the closest two tetrahedral vertices. |
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byte c = (byte)(aPoint | bPoint); //Our two extra vertices are determined by the closest two. |
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if ((c & 0x01) == 0) { |
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xsv_ext0 = xsb; |
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xsv_ext1 = xsb - 1; |
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dx_ext0 = dx0 - 2 * SQUISH_CONSTANT_3D; |
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dx_ext1 = dx0 + 1 - SQUISH_CONSTANT_3D; |
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} else { |
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xsv_ext0 = xsv_ext1 = xsb + 1; |
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dx_ext0 = dx0 - 1 - 2 * SQUISH_CONSTANT_3D; |
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dx_ext1 = dx0 - 1 - SQUISH_CONSTANT_3D; |
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} |
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if ((c & 0x02) == 0) { |
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ysv_ext0 = ysb; |
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ysv_ext1 = ysb - 1; |
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dy_ext0 = dy0 - 2 * SQUISH_CONSTANT_3D; |
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dy_ext1 = dy0 + 1 - SQUISH_CONSTANT_3D; |
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} else { |
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ysv_ext0 = ysv_ext1 = ysb + 1; |
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dy_ext0 = dy0 - 1 - 2 * SQUISH_CONSTANT_3D; |
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dy_ext1 = dy0 - 1 - SQUISH_CONSTANT_3D; |
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} |
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if ((c & 0x04) == 0) { |
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zsv_ext0 = zsb; |
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zsv_ext1 = zsb - 1; |
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dz_ext0 = dz0 - 2 * SQUISH_CONSTANT_3D; |
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dz_ext1 = dz0 + 1 - SQUISH_CONSTANT_3D; |
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} else { |
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zsv_ext0 = zsv_ext1 = zsb + 1; |
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dz_ext0 = dz0 - 1 - 2 * SQUISH_CONSTANT_3D; |
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dz_ext1 = dz0 - 1 - SQUISH_CONSTANT_3D; |
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} |
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} |
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//Contribution (0,0,0) |
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double attn0 = 2 - dx0 * dx0 - dy0 * dy0 - dz0 * dz0; |
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if (attn0 > 0) { |
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attn0 *= attn0; |
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value = attn0 * attn0 * extrapolate(xsb + 0, ysb + 0, zsb + 0, dx0, dy0, dz0); |
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} |
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//Contribution (0,0,1) |
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double dx1 = dx0 - 1 - SQUISH_CONSTANT_3D; |
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double dy1 = dy0 - 0 - SQUISH_CONSTANT_3D; |
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double dz1 = dz0 - 0 - SQUISH_CONSTANT_3D; |
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double attn1 = 2 - dx1 * dx1 - dy1 * dy1 - dz1 * dz1; |
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if (attn1 > 0) { |
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attn1 *= attn1; |
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value += attn1 * attn1 * extrapolate(xsb + 1, ysb + 0, zsb + 0, dx1, dy1, dz1); |
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} |
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//Contribution (0,1,0) |
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double dx2 = dx0 - 0 - SQUISH_CONSTANT_3D; |
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double dy2 = dy0 - 1 - SQUISH_CONSTANT_3D; |
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double dz2 = dz1; |
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double attn2 = 2 - dx2 * dx2 - dy2 * dy2 - dz2 * dz2; |
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if (attn2 > 0) { |
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attn2 *= attn2; |
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value += attn2 * attn2 * extrapolate(xsb + 0, ysb + 1, zsb + 0, dx2, dy2, dz2); |
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} |
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//Contribution (1,0,0) |
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double dx3 = dx2; |
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double dy3 = dy1; |
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double dz3 = dz0 - 1 - SQUISH_CONSTANT_3D; |
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double attn3 = 2 - dx3 * dx3 - dy3 * dy3 - dz3 * dz3; |
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if (attn3 > 0) { |
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attn3 *= attn3; |
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value += attn3 * attn3 * extrapolate(xsb + 0, ysb + 0, zsb + 1, dx3, dy3, dz3); |
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} |
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} else if (inSum >= 2) { //We're inside the Tetrahedron (3-Simplex) at (1,1,1) |
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//Determine which two tetrahedral vertices are the closest, out of (1,1,0), (1,0,1), (0,1,1) but not (1,1,1). |
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byte aPoint = 0x06; |
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double aScore = xins; |
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byte bPoint = 0x05; |
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double bScore = yins; |
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if (aScore <= bScore && zins < bScore) { |
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bScore = zins; |
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bPoint = 0x03; |
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} else if (aScore > bScore && zins < aScore) { |
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aScore = zins; |
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aPoint = 0x03; |
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} |
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//Now we determine the two lattice points not part of the tetrahedron that may contribute. |
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//This depends on the closest two tetrahedral vertices, including (1,1,1) |
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double wins = 3 - inSum; |
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if (wins < aScore || wins < bScore) { //(1,1,1) is one of the closest two tetrahedral vertices. |
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byte c = (bScore < aScore ? bPoint : aPoint); //Our other closest vertex is the closest out of a and b. |
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if ((c & 0x01) != 0) { |
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xsv_ext0 = xsb + 2; |
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xsv_ext1 = xsb + 1; |
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dx_ext0 = dx0 - 2 - 3 * SQUISH_CONSTANT_3D; |
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dx_ext1 = dx0 - 1 - 3 * SQUISH_CONSTANT_3D; |
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} else { |
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xsv_ext0 = xsv_ext1 = xsb; |
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dx_ext0 = dx_ext1 = dx0 - 3 * SQUISH_CONSTANT_3D; |
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} |
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if ((c & 0x02) != 0) { |
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ysv_ext0 = ysv_ext1 = ysb + 1; |
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dy_ext0 = dy_ext1 = dy0 - 1 - 3 * SQUISH_CONSTANT_3D; |
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if ((c & 0x01) != 0) { |
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ysv_ext1 += 1; |
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dy_ext1 -= 1; |
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} else { |
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ysv_ext0 += 1; |
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dy_ext0 -= 1; |
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} |
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} else { |
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ysv_ext0 = ysv_ext1 = ysb; |
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dy_ext0 = dy_ext1 = dy0 - 3 * SQUISH_CONSTANT_3D; |
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} |
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if ((c & 0x04) != 0) { |
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zsv_ext0 = zsb + 1; |
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zsv_ext1 = zsb + 2; |
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dz_ext0 = dz0 - 1 - 3 * SQUISH_CONSTANT_3D; |
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dz_ext1 = dz0 - 2 - 3 * SQUISH_CONSTANT_3D; |
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} else { |
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zsv_ext0 = zsv_ext1 = zsb; |
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dz_ext0 = dz_ext1 = dz0 - 3 * SQUISH_CONSTANT_3D; |
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} |
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} else { //(1,1,1) is not one of the closest two tetrahedral vertices. |
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byte c = (byte)(aPoint & bPoint); //Our two extra vertices are determined by the closest two. |
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if ((c & 0x01) != 0) { |
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xsv_ext0 = xsb + 1; |
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xsv_ext1 = xsb + 2; |
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dx_ext0 = dx0 - 1 - SQUISH_CONSTANT_3D; |
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dx_ext1 = dx0 - 2 - 2 * SQUISH_CONSTANT_3D; |
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} else { |
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xsv_ext0 = xsv_ext1 = xsb; |
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dx_ext0 = dx0 - SQUISH_CONSTANT_3D; |
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dx_ext1 = dx0 - 2 * SQUISH_CONSTANT_3D; |
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} |
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if ((c & 0x02) != 0) { |
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ysv_ext0 = ysb + 1; |
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ysv_ext1 = ysb + 2; |
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dy_ext0 = dy0 - 1 - SQUISH_CONSTANT_3D; |
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dy_ext1 = dy0 - 2 - 2 * SQUISH_CONSTANT_3D; |
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} else { |
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ysv_ext0 = ysv_ext1 = ysb; |
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dy_ext0 = dy0 - SQUISH_CONSTANT_3D; |
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dy_ext1 = dy0 - 2 * SQUISH_CONSTANT_3D; |
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} |
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if ((c & 0x04) != 0) { |
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zsv_ext0 = zsb + 1; |
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zsv_ext1 = zsb + 2; |
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dz_ext0 = dz0 - 1 - SQUISH_CONSTANT_3D; |
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dz_ext1 = dz0 - 2 - 2 * SQUISH_CONSTANT_3D; |
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} else { |
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zsv_ext0 = zsv_ext1 = zsb; |
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dz_ext0 = dz0 - SQUISH_CONSTANT_3D; |
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dz_ext1 = dz0 - 2 * SQUISH_CONSTANT_3D; |
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} |
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} |
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//Contribution (1,1,0) |
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double dx3 = dx0 - 1 - 2 * SQUISH_CONSTANT_3D; |
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double dy3 = dy0 - 1 - 2 * SQUISH_CONSTANT_3D; |
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double dz3 = dz0 - 0 - 2 * SQUISH_CONSTANT_3D; |
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double attn3 = 2 - dx3 * dx3 - dy3 * dy3 - dz3 * dz3; |
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if (attn3 > 0) { |
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attn3 *= attn3; |
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value = attn3 * attn3 * extrapolate(xsb + 1, ysb + 1, zsb + 0, dx3, dy3, dz3); |
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} |
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//Contribution (1,0,1) |
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double dx2 = dx3; |
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double dy2 = dy0 - 0 - 2 * SQUISH_CONSTANT_3D; |
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double dz2 = dz0 - 1 - 2 * SQUISH_CONSTANT_3D; |
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double attn2 = 2 - dx2 * dx2 - dy2 * dy2 - dz2 * dz2; |
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if (attn2 > 0) { |
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attn2 *= attn2; |
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value += attn2 * attn2 * extrapolate(xsb + 1, ysb + 0, zsb + 1, dx2, dy2, dz2); |
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} |
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//Contribution (0,1,1) |
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double dx1 = dx0 - 0 - 2 * SQUISH_CONSTANT_3D; |
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double dy1 = dy3; |
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double dz1 = dz2; |
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double attn1 = 2 - dx1 * dx1 - dy1 * dy1 - dz1 * dz1; |
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if (attn1 > 0) { |
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attn1 *= attn1; |
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value += attn1 * attn1 * extrapolate(xsb + 0, ysb + 1, zsb + 1, dx1, dy1, dz1); |
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} |
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//Contribution (1,1,1) |
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dx0 = dx0 - 1 - 3 * SQUISH_CONSTANT_3D; |
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dy0 = dy0 - 1 - 3 * SQUISH_CONSTANT_3D; |
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dz0 = dz0 - 1 - 3 * SQUISH_CONSTANT_3D; |
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double attn0 = 2 - dx0 * dx0 - dy0 * dy0 - dz0 * dz0; |
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if (attn0 > 0) { |
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attn0 *= attn0; |
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value += attn0 * attn0 * extrapolate(xsb + 1, ysb + 1, zsb + 1, dx0, dy0, dz0); |
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} |
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} else { //We're inside the Octahedron (Rectified 3-Simplex) in between. |
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double aScore; |
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byte aPoint; |
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boolean aIsFurtherSide; |
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double bScore; |
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byte bPoint; |
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boolean bIsFurtherSide; |
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//Decide between point (1,0,0) and (0,1,1) as closest |
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double p1 = xins + yins; |
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if (p1 > 1) { |
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aScore = p1 - 1; |
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aPoint = 0x03; |
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aIsFurtherSide = true; |
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} else { |
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aScore = 1 - p1; |
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aPoint = 0x04; |
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aIsFurtherSide = false; |
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} |
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//Decide between point (0,1,0) and (1,0,1) as closest |
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double p2 = xins + zins; |
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if (p2 > 1) { |
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bScore = p2 - 1; |
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bPoint = 0x05; |
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bIsFurtherSide = true; |
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} else { |
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bScore = 1 - p2; |
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bPoint = 0x02; |
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bIsFurtherSide = false; |
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} |
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//The closest out of the two (0,0,1) and (1,1,0) will replace the furthest out of the two decided above, if closer. |
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double p3 = yins + zins; |
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if (p3 > 1) { |
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double score = p3 - 1; |
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if (aScore <= bScore && aScore < score) { |
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aScore = score; |
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aPoint = 0x06; |
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aIsFurtherSide = true; |
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} else if (aScore > bScore && bScore < score) { |
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bScore = score; |
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bPoint = 0x06; |
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bIsFurtherSide = true; |
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} |
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} else { |
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double score = 1 - p3; |
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if (aScore <= bScore && aScore < score) { |
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aScore = score; |
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aPoint = 0x01; |
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aIsFurtherSide = false; |
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} else if (aScore > bScore && bScore < score) { |
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bScore = score; |
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bPoint = 0x01; |
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bIsFurtherSide = false; |
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} |
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} |
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//Where each of the two closest points are determines how the extra two vertices are calculated. |
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if (aIsFurtherSide == bIsFurtherSide) { |
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if (aIsFurtherSide) { //Both closest points on (1,1,1) side |
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//One of the two extra points is (1,1,1) |
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dx_ext0 = dx0 - 1 - 3 * SQUISH_CONSTANT_3D; |
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dy_ext0 = dy0 - 1 - 3 * SQUISH_CONSTANT_3D; |
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dz_ext0 = dz0 - 1 - 3 * SQUISH_CONSTANT_3D; |
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xsv_ext0 = xsb + 1; |
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ysv_ext0 = ysb + 1; |
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zsv_ext0 = zsb + 1; |
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//Other extra point is based on the shared axis. |
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byte c = (byte)(aPoint & bPoint); |
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if ((c & 0x01) != 0) { |
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dx_ext1 = dx0 - 2 - 2 * SQUISH_CONSTANT_3D; |
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dy_ext1 = dy0 - 2 * SQUISH_CONSTANT_3D; |
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dz_ext1 = dz0 - 2 * SQUISH_CONSTANT_3D; |
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xsv_ext1 = xsb + 2; |
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ysv_ext1 = ysb; |
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zsv_ext1 = zsb; |
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} else if ((c & 0x02) != 0) { |
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dx_ext1 = dx0 - 2 * SQUISH_CONSTANT_3D; |
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dy_ext1 = dy0 - 2 - 2 * SQUISH_CONSTANT_3D; |
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dz_ext1 = dz0 - 2 * SQUISH_CONSTANT_3D; |
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xsv_ext1 = xsb; |
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ysv_ext1 = ysb + 2; |
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zsv_ext1 = zsb; |
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} else { |
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dx_ext1 = dx0 - 2 * SQUISH_CONSTANT_3D; |
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dy_ext1 = dy0 - 2 * SQUISH_CONSTANT_3D; |
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dz_ext1 = dz0 - 2 - 2 * SQUISH_CONSTANT_3D; |
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xsv_ext1 = xsb; |
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ysv_ext1 = ysb; |
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zsv_ext1 = zsb + 2; |
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} |
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} else {//Both closest points on (0,0,0) side |
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//One of the two extra points is (0,0,0) |
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dx_ext0 = dx0; |
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dy_ext0 = dy0; |
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dz_ext0 = dz0; |
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xsv_ext0 = xsb; |
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ysv_ext0 = ysb; |
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zsv_ext0 = zsb; |
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//Other extra point is based on the omitted axis. |
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byte c = (byte)(aPoint | bPoint); |
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if ((c & 0x01) == 0) { |
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dx_ext1 = dx0 + 1 - SQUISH_CONSTANT_3D; |
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dy_ext1 = dy0 - 1 - SQUISH_CONSTANT_3D; |
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dz_ext1 = dz0 - 1 - SQUISH_CONSTANT_3D; |
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xsv_ext1 = xsb - 1; |
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ysv_ext1 = ysb + 1; |
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zsv_ext1 = zsb + 1; |
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} else if ((c & 0x02) == 0) { |
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dx_ext1 = dx0 - 1 - SQUISH_CONSTANT_3D; |
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dy_ext1 = dy0 + 1 - SQUISH_CONSTANT_3D; |
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dz_ext1 = dz0 - 1 - SQUISH_CONSTANT_3D; |
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xsv_ext1 = xsb + 1; |
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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) |
|
if ((c2 & 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 ((c2 & 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; |
|
} |
|
} |
|
|
|
//Contribution (0,0,1) |
|
double dx1 = dx0 - 1 - SQUISH_CONSTANT_3D; |
|
double dy1 = dy0 - 0 - SQUISH_CONSTANT_3D; |
|
double dz1 = dz0 - 0 - SQUISH_CONSTANT_3D; |
|
double 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) |
|
double dx2 = dx0 - 0 - SQUISH_CONSTANT_3D; |
|
double dy2 = dy0 - 1 - SQUISH_CONSTANT_3D; |
|
double dz2 = dz1; |
|
double 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 (1,0,0) |
|
double dx3 = dx2; |
|
double dy3 = dy1; |
|
double dz3 = dz0 - 1 - SQUISH_CONSTANT_3D; |
|
double 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) |
|
double dx4 = dx0 - 1 - 2 * SQUISH_CONSTANT_3D; |
|
double dy4 = dy0 - 1 - 2 * SQUISH_CONSTANT_3D; |
|
double dz4 = dz0 - 0 - 2 * SQUISH_CONSTANT_3D; |
|
double 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) |
|
double dx5 = dx4; |
|
double dy5 = dy0 - 0 - 2 * SQUISH_CONSTANT_3D; |
|
double dz5 = dz0 - 1 - 2 * SQUISH_CONSTANT_3D; |
|
double 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) |
|
double dx6 = dx0 - 0 - 2 * SQUISH_CONSTANT_3D; |
|
double dy6 = dy4; |
|
double dz6 = dz5; |
|
double 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 |
|
double 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 |
|
double 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); |
|
} |
|
|
|
//Normalization constant tested using over 4 billion evaluations to bound range within [-1,1]. |
|
//This is a safe upper bound. Actual min/max values found over the course of the 4 billion |
|
//evaluations were -28.12974224468639 (min) and 28.134269887817773 (max). |
|
return value / 28.25; |
|
} |
|
|
|
private double extrapolate(int xsb, int ysb, int zsb, double dx, double dy, double dz) |
|
{ |
|
short index = permGradIndex3D[(perm[(perm[xsb & 0xFF] + ysb) & 0xFF] + zsb) & 0xFF]; |
|
return gradients3D[index] * dx |
|
+ gradients3D[index + 1] * dy |
|
+ gradients3D[index + 2] * dz; |
|
} |
|
|
|
private static int fastFloor(double x) { |
|
int xi = (int)x; |
|
return x < xi ? xi - 1 : xi; |
|
} |
|
|
|
//Array of gradient values for 3D. |
|
//(New gradient set 9/19/14) |
|
private static byte[] gradients3D = new byte[] { |
|
0, 3, 2, 0, 2, 3, 3, 0, 2, 2, 0, 3, 3, 2, 0, 2, 3, 0, |
|
0,-3, 2, 0, 2,-3, -3, 0, 2, 2, 0,-3, -3, 2, 0, 2,-3, 0, |
|
0, 3,-2, 0,-2, 3, 3, 0,-2, -2, 0, 3, 3,-2, 0, -2, 3, 0, |
|
0,-3,-2, 0,-2,-3, -3, 0,-2, -2, 0,-3, -3,-2, 0, -2,-3, 0, |
|
}; |
|
|
|
//The standardized permutation order as used in Ken Perlin's "Improved Noise" |
|
//(and basically every noise implementation on the Internet). |
|
//Also note that there's no reason this can't be a byte array other than that this is Java. |
|
public static final short[] PERM_DEFAULT = new short[] { |
|
151,160,137, 91, 90, 15,131, 13,201, 95, 96, 53,194,233, 7,225, |
|
140, 36,103, 30, 69,142, 8, 99, 37,240, 21, 10, 23,190, 6,148, |
|
247,120,234, 75, 0, 26,197, 62, 94,252,219,203,117, 35, 11, 32, |
|
57,177, 33, 88,237,149, 56, 87,174, 20,125,136,171,168, 68,175, |
|
74,165, 71,134,139, 48, 27,166, 77,146,158,231, 83,111,229,122, |
|
60,211,133,230,220,105, 92, 41, 55, 46,245, 40,244,102,143, 54, |
|
65, 25, 63,161, 1,216, 80, 73,209, 76,132,187,208, 89, 18,169, |
|
200,196,135,130,116,188,159, 86,164,100,109,198,173,186, 3, 64, |
|
52,217,226,250,124,123, 5,202, 38,147,118,126,255, 82, 85,212, |
|
207,206, 59,227, 47, 16, 58, 17,182,189, 28, 42,223,183,170,213, |
|
119,248,152, 2, 44,154,163, 70,221,153,101,155,167, 43,172, 9, |
|
129, 22, 39,253, 19, 98,108,110, 79,113,224,232,178,185,112,104, |
|
218,246, 97,228,251, 34,242,193,238,210,144, 12,191,179,162,241, |
|
81, 51,145,235,249, 14,239,107, 49,192,214, 31,181,199,106,157, |
|
184, 84,204,176,115,121, 50, 45,127, 4,150,254,138,236,205, 93, |
|
222,114, 67, 29, 24, 72,243,141,128,195, 78, 66,215, 61,156,180 |
|
}; |
|
} |