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salmonmoose/OpenSimplexNoise.java

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OpenSimplexNoise.java
/*
* OpenSimplex (Simplectic) Noise for 3D in Java
* (Preliminary Release)
*
* KdotJPG
*/
public class OpenSimplexNoise {
private static final double STRETCH_CONSTANT_3D = -1.0 / 6;
private static final double SQUISH_CONSTANT_3D = 1.0 / 3;
private short[] perm;
private short[] permGradIndex3D;
public OpenSimplexNoise() {
this(perm_default);
}
public OpenSimplexNoise(short[] perm) {
this.perm = perm;
permGradIndex3D = new short[256];
for (int i = 0; i < 256; i++) {
permGradIndex3D[i] = (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 java.util.Random
public OpenSimplexNoise(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;
java.util.Random random = new java.util.Random(seed);
for (int i = 255; i >= 0; i--) {
int r = random.nextInt(i + 1);
perm[i] = source[r];
permGradIndex3D[i] = (short)((perm[i] % (gradients3D.length / 3)) * 3);
source[r] = source[i];
}
}
//3D OpenSimplex (Simplectic) Noise.
public double eval(double x, double y, double z) {
//Place input coordinates on simplectic lattice.
double stretchOffset = (x + y + z) * STRETCH_CONSTANT_3D;
double xs = x + stretchOffset;
double ys = y + stretchOffset;
double zs = z + stretchOffset;
//Floor to get simplectic lattice 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.
double squishOffset = (xsb + ysb + zsb) * SQUISH_CONSTANT_3D;
double xb = xsb + squishOffset;
double yb = ysb + squishOffset;
double zb = zsb + squishOffset;
//Compute simplectic lattice coordinates relative to rhombohedral origin.
double xins = xs - xsb;
double yins = ys - ysb;
double zins = zs - zsb;
//Sum those together to get a value that determines which cell we're in.
double inSum = xins + yins + zins;
//Positions relative to origin point.
double dx0 = x - xb;
double dy0 = y - yb;
double dz0 = z - zb;
//We'll be defining these inside the next block and using them afterwards.
double dx_ext0, dy_ext0, dz_ext0;
double dx_ext1, dy_ext1, dz_ext1;
int xsv_ext0, ysv_ext0, zsv_ext0;
int xsv_ext1, ysv_ext1, zsv_ext1;
double 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;
double aScore = xins;
byte bPoint = 0x02;
double 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)
double 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 = (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)
double 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 (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);
}
} 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;
double aScore = xins;
byte bPoint = 0x05;
double 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)
double 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 = (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)
double dx3 = dx0 - 1 - 2 * SQUISH_CONSTANT_3D;
double dy3 = dy0 - 1 - 2 * SQUISH_CONSTANT_3D;
double dz3 = dz0 - 0 - 2 * SQUISH_CONSTANT_3D;
double 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)
double dx2 = dx3;
double dy2 = dy0 - 0 - 2 * SQUISH_CONSTANT_3D;
double dz2 = dz0 - 1 - 2 * SQUISH_CONSTANT_3D;
double 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)
double dx1 = dx0 - 0 - 2 * SQUISH_CONSTANT_3D;
double dy1 = dy3;
double dz1 = dz2;
double 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;
double 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.
double aScore;
byte aPoint;
boolean aIsFurtherSide;
double bScore;
byte bPoint;
boolean bIsFurtherSide;
//Decide between point (1,0,0) and (0,1,1) as closest
double 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
double 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 (0,0,1) and (1,1,0) will replace the furthest out of the two decided above, if closer.
double p3 = yins + zins;
if (p3 > 1) {
double 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 {
double 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 = (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 = (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)
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);
}
return value / 18;
}
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.
//I may release an updated version of this with a better set if I figure one out. This works though.
//Note: bytes in Java are signed. Keep this in mind if porting to another language.
private static byte[] gradients3D = new byte[] {
0,1,2, 0,2,1, 1,0,2, 2,0,1, 1,2,0, 2,1,0,
0,-1,2, 0,2,-1, -1,0,2, 2,0,-1, -1,2,0, 2,-1,0,
0,1,-2, 0,-2,1, 1,0,-2, -2,0,1, 1,-2,0, -2,1,0,
0,-1,-2, 0,-2,-1, -1,0,-2, -2,0,-1, -1,-2,0, -2,-1,0,
};
//The standardized permutation order as used in Ken Perlin's "Improved Noise" 2002,
//(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.
private static 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
};
}
/*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
* LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
Raw
OpenSimplexNoiseTest.java
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import java.io.*;
public class OpenSimplexNoiseTest
{
private static final int WIDTH = 512;
private static final int HEIGHT = 512;
private static final double FEATURE_SIZE = 24;
public static void main(String[] args)
throws IOException {
OpenSimplexNoise noise = new OpenSimplexNoise();
BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
for (int y = 0; y < HEIGHT; y++)
{
for (int x = 0; x < WIDTH; x++)
{
double value = noise.eval(x / FEATURE_SIZE, y / FEATURE_SIZE, 0.0);
int rgb = 0x010101 * (int)((value + 1) * 127.5);
image.setRGB(x, y, rgb);
}
}
ImageIO.write(image, "png", new File("noise.png"));
}
}
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