/*
-Minetest-c55
-Copyright (C) 2010-2011 celeron55, Perttu Ahola <celeron55@gmail.com>
+ * Minetest
+ * Copyright (C) 2010-2014 celeron55, Perttu Ahola <celeron55@gmail.com>
+ * Copyright (C) 2010-2014 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ * 1. Redistributions of source code must retain the above copyright notice, this list of
+ * conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list
+ * of conditions and the following disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
-This program is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License along
-with this program; if not, write to the Free Software Foundation, Inc.,
-51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-*/
-
-#include <math.h>
+#include <cmath>
#include "noise.h"
#include <iostream>
+#include <cstring> // memset
+#include "debug.h"
+#include "util/numeric.h"
+#include "util/string.h"
+#include "exceptions.h"
-#define NOISE_MAGIC_X 1619
-#define NOISE_MAGIC_Y 31337
-#define NOISE_MAGIC_Z 52591
+#define NOISE_MAGIC_X 1619
+#define NOISE_MAGIC_Y 31337
+#define NOISE_MAGIC_Z 52591
#define NOISE_MAGIC_SEED 1013
-double cos_lookup[16] = {
- 1.0,0.9238,0.7071,0.3826,0,-0.3826,-0.7071,-0.9238,
- 1.0,-0.9238,-0.7071,-0.3826,0,0.3826,0.7071,0.9238
+typedef float (*Interp2dFxn)(
+ float v00, float v10, float v01, float v11,
+ float x, float y);
+
+typedef float (*Interp3dFxn)(
+ float v000, float v100, float v010, float v110,
+ float v001, float v101, float v011, float v111,
+ float x, float y, float z);
+
+float cos_lookup[16] = {
+ 1.0f, 0.9238f, 0.7071f, 0.3826f, .0f, -0.3826f, -0.7071f, -0.9238f,
+ 1.0f, -0.9238f, -0.7071f, -0.3826f, .0f, 0.3826f, 0.7071f, 0.9238f
+};
+
+FlagDesc flagdesc_noiseparams[] = {
+ {"defaults", NOISE_FLAG_DEFAULTS},
+ {"eased", NOISE_FLAG_EASED},
+ {"absvalue", NOISE_FLAG_ABSVALUE},
+ {"pointbuffer", NOISE_FLAG_POINTBUFFER},
+ {"simplex", NOISE_FLAG_SIMPLEX},
+ {NULL, 0}
};
-double dotProduct(double vx, double vy, double wx, double wy){
- return vx*wx+vy*wy;
-}
-
-double easeCurve(double t){
- return 6*pow(t,5)-15*pow(t,4)+10*pow(t,3);
-}
-
-double linearInterpolation(double x0, double x1, double t){
- return x0+(x1-x0)*t;
-}
-
-double biLinearInterpolation(double x0y0, double x1y0, double x0y1, double x1y1, double x, double y){
- double tx = easeCurve(x);
- double ty = easeCurve(y);
- /*double tx = x;
- double ty = y;*/
- double u = linearInterpolation(x0y0,x1y0,tx);
- double v = linearInterpolation(x0y1,x1y1,tx);
- return linearInterpolation(u,v,ty);
-}
-
-double triLinearInterpolation(
- double v000, double v100, double v010, double v110,
- double v001, double v101, double v011, double v111,
- double x, double y, double z)
-{
- /*double tx = easeCurve(x);
- double ty = easeCurve(y);
- double tz = easeCurve(z);*/
- double tx = x;
- double ty = y;
- double tz = z;
- return(
- v000*(1-tx)*(1-ty)*(1-tz) +
- v100*tx*(1-ty)*(1-tz) +
- v010*(1-tx)*ty*(1-tz) +
- v110*tx*ty*(1-tz) +
- v001*(1-tx)*(1-ty)*tz +
- v101*tx*(1-ty)*tz +
- v011*(1-tx)*ty*tz +
- v111*tx*ty*tz
- );
-}
-
-double noise2d(int x, int y, int seed)
-{
- int n = (NOISE_MAGIC_X * x + NOISE_MAGIC_Y * y
+///////////////////////////////////////////////////////////////////////////////
+
+PcgRandom::PcgRandom(u64 state, u64 seq)
+{
+ seed(state, seq);
+}
+
+void PcgRandom::seed(u64 state, u64 seq)
+{
+ m_state = 0U;
+ m_inc = (seq << 1u) | 1u;
+ next();
+ m_state += state;
+ next();
+}
+
+
+u32 PcgRandom::next()
+{
+ u64 oldstate = m_state;
+ m_state = oldstate * 6364136223846793005ULL + m_inc;
+
+ u32 xorshifted = ((oldstate >> 18u) ^ oldstate) >> 27u;
+ u32 rot = oldstate >> 59u;
+ return (xorshifted >> rot) | (xorshifted << ((-rot) & 31));
+}
+
+
+u32 PcgRandom::range(u32 bound)
+{
+ // If the bound is 0, we cover the whole RNG's range
+ if (bound == 0)
+ return next();
+
+ /*
+ This is an optimization of the expression:
+ 0x100000000ull % bound
+ since 64-bit modulo operations typically much slower than 32.
+ */
+ u32 threshold = -bound % bound;
+ u32 r;
+
+ /*
+ If the bound is not a multiple of the RNG's range, it may cause bias,
+ e.g. a RNG has a range from 0 to 3 and we take want a number 0 to 2.
+ Using rand() % 3, the number 0 would be twice as likely to appear.
+ With a very large RNG range, the effect becomes less prevalent but
+ still present.
+
+ This can be solved by modifying the range of the RNG to become a
+ multiple of bound by dropping values above the a threshold.
+
+ In our example, threshold == 4 % 3 == 1, so reject values < 1
+ (that is, 0), thus making the range == 3 with no bias.
+
+ This loop may look dangerous, but will always terminate due to the
+ RNG's property of uniformity.
+ */
+ while ((r = next()) < threshold)
+ ;
+
+ return r % bound;
+}
+
+
+s32 PcgRandom::range(s32 min, s32 max)
+{
+ if (max < min)
+ throw PrngException("Invalid range (max < min)");
+
+ // We have to cast to s64 because otherwise this could overflow,
+ // and signed overflow is undefined behavior.
+ u32 bound = (s64)max - (s64)min + 1;
+ return range(bound) + min;
+}
+
+
+void PcgRandom::bytes(void *out, size_t len)
+{
+ u8 *outb = (u8 *)out;
+ int bytes_left = 0;
+ u32 r;
+
+ while (len--) {
+ if (bytes_left == 0) {
+ bytes_left = sizeof(u32);
+ r = next();
+ }
+
+ *outb = r & 0xFF;
+ outb++;
+ bytes_left--;
+ r >>= CHAR_BIT;
+ }
+}
+
+
+s32 PcgRandom::randNormalDist(s32 min, s32 max, int num_trials)
+{
+ s32 accum = 0;
+ for (int i = 0; i != num_trials; i++)
+ accum += range(min, max);
+ return myround((float)accum / num_trials);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+float noise2d(int x, int y, s32 seed)
+{
+ unsigned int n = (NOISE_MAGIC_X * x + NOISE_MAGIC_Y * y
+ NOISE_MAGIC_SEED * seed) & 0x7fffffff;
- n = (n>>13)^n;
- n = (n * (n*n*60493+19990303) + 1376312589) & 0x7fffffff;
- return 1.0 - (double)n/1073741824;
+ n = (n >> 13) ^ n;
+ n = (n * (n * n * 60493 + 19990303) + 1376312589) & 0x7fffffff;
+ return 1.f - (float)(int)n / 0x40000000;
}
-double noise3d(int x, int y, int z, int seed)
+
+float noise3d(int x, int y, int z, s32 seed)
{
- int n = (NOISE_MAGIC_X * x + NOISE_MAGIC_Y * y + NOISE_MAGIC_Z * z
+ unsigned int n = (NOISE_MAGIC_X * x + NOISE_MAGIC_Y * y + NOISE_MAGIC_Z * z
+ NOISE_MAGIC_SEED * seed) & 0x7fffffff;
- n = (n>>13)^n;
- n = (n * (n*n*60493+19990303) + 1376312589) & 0x7fffffff;
- return 1.0 - (double)n/1073741824;
+ n = (n >> 13) ^ n;
+ n = (n * (n * n * 60493 + 19990303) + 1376312589) & 0x7fffffff;
+ return 1.f - (float)(int)n / 0x40000000;
}
-#if 0
-double noise2d_gradient(double x, double y, int seed)
+
+inline float dotProduct(float vx, float vy, float wx, float wy)
{
- // Calculate the integer coordinates
- int x0 = (x > 0.0 ? (int)x : (int)x - 1);
- int y0 = (y > 0.0 ? (int)y : (int)y - 1);
- // Calculate the remaining part of the coordinates
- double xl = x - (double)x0;
- double yl = y - (double)y0;
- // Calculate random cosine lookup table indices for the integer corners.
- // They are looked up as unit vector gradients from the lookup table.
- int n00 = (int)((noise2d(x0, y0, seed)+1)*8);
- int n10 = (int)((noise2d(x0+1, y0, seed)+1)*8);
- int n01 = (int)((noise2d(x0, y0+1, seed)+1)*8);
- int n11 = (int)((noise2d(x0+1, y0+1, seed)+1)*8);
- // Make a dot product for the gradients and the positions, to get the values
- double s = dotProduct(cos_lookup[n00], cos_lookup[(n00+12)%16], xl, yl);
- double u = dotProduct(-cos_lookup[n10], cos_lookup[(n10+12)%16], 1.-xl, yl);
- double v = dotProduct(cos_lookup[n01], -cos_lookup[(n01+12)%16], xl, 1.-yl);
- double w = dotProduct(-cos_lookup[n11], -cos_lookup[(n11+12)%16], 1.-xl, 1.-yl);
- // Interpolate between the values
- return biLinearInterpolation(s,u,v,w,xl,yl);
-}
-#endif
-
-#if 1
-double noise2d_gradient(double x, double y, int seed)
+ return vx * wx + vy * wy;
+}
+
+
+inline float linearInterpolation(float v0, float v1, float t)
+{
+ return v0 + (v1 - v0) * t;
+}
+
+
+inline float biLinearInterpolation(
+ float v00, float v10,
+ float v01, float v11,
+ float x, float y)
+{
+ float tx = easeCurve(x);
+ float ty = easeCurve(y);
+ float u = linearInterpolation(v00, v10, tx);
+ float v = linearInterpolation(v01, v11, tx);
+ return linearInterpolation(u, v, ty);
+}
+
+
+inline float biLinearInterpolationNoEase(
+ float v00, float v10,
+ float v01, float v11,
+ float x, float y)
+{
+ float u = linearInterpolation(v00, v10, x);
+ float v = linearInterpolation(v01, v11, x);
+ return linearInterpolation(u, v, y);
+}
+
+
+float triLinearInterpolation(
+ float v000, float v100, float v010, float v110,
+ float v001, float v101, float v011, float v111,
+ float x, float y, float z)
+{
+ float tx = easeCurve(x);
+ float ty = easeCurve(y);
+ float tz = easeCurve(z);
+ float u = biLinearInterpolationNoEase(v000, v100, v010, v110, tx, ty);
+ float v = biLinearInterpolationNoEase(v001, v101, v011, v111, tx, ty);
+ return linearInterpolation(u, v, tz);
+}
+
+float triLinearInterpolationNoEase(
+ float v000, float v100, float v010, float v110,
+ float v001, float v101, float v011, float v111,
+ float x, float y, float z)
+{
+ float u = biLinearInterpolationNoEase(v000, v100, v010, v110, x, y);
+ float v = biLinearInterpolationNoEase(v001, v101, v011, v111, x, y);
+ return linearInterpolation(u, v, z);
+}
+
+float noise2d_gradient(float x, float y, s32 seed, bool eased)
{
// Calculate the integer coordinates
- int x0 = (x > 0.0 ? (int)x : (int)x - 1);
- int y0 = (y > 0.0 ? (int)y : (int)y - 1);
+ int x0 = myfloor(x);
+ int y0 = myfloor(y);
// Calculate the remaining part of the coordinates
- double xl = x - (double)x0;
- double yl = y - (double)y0;
- // Get values for corners of cube
- double v00 = noise2d(x0, y0, seed);
- double v10 = noise2d(x0+1, y0, seed);
- double v01 = noise2d(x0, y0+1, seed);
- double v11 = noise2d(x0+1, y0+1, seed);
+ float xl = x - (float)x0;
+ float yl = y - (float)y0;
+ // Get values for corners of square
+ float v00 = noise2d(x0, y0, seed);
+ float v10 = noise2d(x0+1, y0, seed);
+ float v01 = noise2d(x0, y0+1, seed);
+ float v11 = noise2d(x0+1, y0+1, seed);
// Interpolate
- return biLinearInterpolation(v00,v10,v01,v11,xl,yl);
+ if (eased)
+ return biLinearInterpolation(v00, v10, v01, v11, xl, yl);
+
+ return biLinearInterpolationNoEase(v00, v10, v01, v11, xl, yl);
}
-#endif
-double noise3d_gradient(double x, double y, double z, int seed)
+
+float noise3d_gradient(float x, float y, float z, s32 seed, bool eased)
{
// Calculate the integer coordinates
- int x0 = (x > 0.0 ? (int)x : (int)x - 1);
- int y0 = (y > 0.0 ? (int)y : (int)y - 1);
- int z0 = (z > 0.0 ? (int)z : (int)z - 1);
+ int x0 = myfloor(x);
+ int y0 = myfloor(y);
+ int z0 = myfloor(z);
// Calculate the remaining part of the coordinates
- double xl = x - (double)x0;
- double yl = y - (double)y0;
- double zl = z - (double)z0;
+ float xl = x - (float)x0;
+ float yl = y - (float)y0;
+ float zl = z - (float)z0;
// Get values for corners of cube
- double v000 = noise3d(x0, y0, z0, seed);
- double v100 = noise3d(x0+1, y0, z0, seed);
- double v010 = noise3d(x0, y0+1, z0, seed);
- double v110 = noise3d(x0+1, y0+1, z0, seed);
- double v001 = noise3d(x0, y0, z0+1, seed);
- double v101 = noise3d(x0+1, y0, z0+1, seed);
- double v011 = noise3d(x0, y0+1, z0+1, seed);
- double v111 = noise3d(x0+1, y0+1, z0+1, seed);
+ float v000 = noise3d(x0, y0, z0, seed);
+ float v100 = noise3d(x0 + 1, y0, z0, seed);
+ float v010 = noise3d(x0, y0 + 1, z0, seed);
+ float v110 = noise3d(x0 + 1, y0 + 1, z0, seed);
+ float v001 = noise3d(x0, y0, z0 + 1, seed);
+ float v101 = noise3d(x0 + 1, y0, z0 + 1, seed);
+ float v011 = noise3d(x0, y0 + 1, z0 + 1, seed);
+ float v111 = noise3d(x0 + 1, y0 + 1, z0 + 1, seed);
// Interpolate
- return triLinearInterpolation(v000,v100,v010,v110,v001,v101,v011,v111,xl,yl,zl);
+ if (eased) {
+ return triLinearInterpolation(
+ v000, v100, v010, v110,
+ v001, v101, v011, v111,
+ xl, yl, zl);
+ }
+
+ return triLinearInterpolationNoEase(
+ v000, v100, v010, v110,
+ v001, v101, v011, v111,
+ xl, yl, zl);
}
-double noise2d_perlin(double x, double y, int seed,
- int octaves, double persistence)
+
+float noise2d_perlin(float x, float y, s32 seed,
+ int octaves, float persistence, bool eased)
{
- double a = 0;
- double f = 1.0;
- double g = 1.0;
- for(int i=0; i<octaves; i++)
+ float a = 0;
+ float f = 1.0;
+ float g = 1.0;
+ for (int i = 0; i < octaves; i++)
{
- a += g * noise2d_gradient(x*f, y*f, seed+i);
+ a += g * noise2d_gradient(x * f, y * f, seed + i, eased);
f *= 2.0;
g *= persistence;
}
return a;
}
-double noise2d_perlin_abs(double x, double y, int seed,
- int octaves, double persistence)
+
+float noise2d_perlin_abs(float x, float y, s32 seed,
+ int octaves, float persistence, bool eased)
{
- double a = 0;
- double f = 1.0;
- double g = 1.0;
- for(int i=0; i<octaves; i++)
- {
- a += g * fabs(noise2d_gradient(x*f, y*f, seed+i));
+ float a = 0;
+ float f = 1.0;
+ float g = 1.0;
+ for (int i = 0; i < octaves; i++) {
+ a += g * std::fabs(noise2d_gradient(x * f, y * f, seed + i, eased));
f *= 2.0;
g *= persistence;
}
return a;
}
-double noise3d_perlin(double x, double y, double z, int seed,
- int octaves, double persistence)
+
+float noise3d_perlin(float x, float y, float z, s32 seed,
+ int octaves, float persistence, bool eased)
{
- double a = 0;
- double f = 1.0;
- double g = 1.0;
- for(int i=0; i<octaves; i++)
- {
- a += g * noise3d_gradient(x*f, y*f, z*f, seed+i);
+ float a = 0;
+ float f = 1.0;
+ float g = 1.0;
+ for (int i = 0; i < octaves; i++) {
+ a += g * noise3d_gradient(x * f, y * f, z * f, seed + i, eased);
f *= 2.0;
g *= persistence;
}
return a;
}
-double noise3d_perlin_abs(double x, double y, double z, int seed,
- int octaves, double persistence)
+
+float noise3d_perlin_abs(float x, float y, float z, s32 seed,
+ int octaves, float persistence, bool eased)
{
- double a = 0;
- double f = 1.0;
- double g = 1.0;
- for(int i=0; i<octaves; i++)
- {
- a += g * fabs(noise3d_gradient(x*f, y*f, z*f, seed+i));
+ float a = 0;
+ float f = 1.0;
+ float g = 1.0;
+ for (int i = 0; i < octaves; i++) {
+ a += g * std::fabs(noise3d_gradient(x * f, y * f, z * f, seed + i, eased));
f *= 2.0;
g *= persistence;
}
return a;
}
+
+float contour(float v)
+{
+ v = std::fabs(v);
+ if (v >= 1.0)
+ return 0.0;
+ return (1.0 - v);
+}
+
+
+///////////////////////// [ New noise ] ////////////////////////////
+
+
+float NoisePerlin2D(NoiseParams *np, float x, float y, s32 seed)
+{
+ float a = 0;
+ float f = 1.0;
+ float g = 1.0;
+
+ x /= np->spread.X;
+ y /= np->spread.Y;
+ seed += np->seed;
+
+ for (size_t i = 0; i < np->octaves; i++) {
+ float noiseval = noise2d_gradient(x * f, y * f, seed + i,
+ np->flags & (NOISE_FLAG_DEFAULTS | NOISE_FLAG_EASED));
+
+ if (np->flags & NOISE_FLAG_ABSVALUE)
+ noiseval = std::fabs(noiseval);
+
+ a += g * noiseval;
+ f *= np->lacunarity;
+ g *= np->persist;
+ }
+
+ return np->offset + a * np->scale;
+}
+
+
+float NoisePerlin3D(NoiseParams *np, float x, float y, float z, s32 seed)
+{
+ float a = 0;
+ float f = 1.0;
+ float g = 1.0;
+
+ x /= np->spread.X;
+ y /= np->spread.Y;
+ z /= np->spread.Z;
+ seed += np->seed;
+
+ for (size_t i = 0; i < np->octaves; i++) {
+ float noiseval = noise3d_gradient(x * f, y * f, z * f, seed + i,
+ np->flags & NOISE_FLAG_EASED);
+
+ if (np->flags & NOISE_FLAG_ABSVALUE)
+ noiseval = std::fabs(noiseval);
+
+ a += g * noiseval;
+ f *= np->lacunarity;
+ g *= np->persist;
+ }
+
+ return np->offset + a * np->scale;
+}
+
+
+Noise::Noise(NoiseParams *np_, s32 seed, u32 sx, u32 sy, u32 sz)
+{
+ memcpy(&np, np_, sizeof(np));
+ this->seed = seed;
+ this->sx = sx;
+ this->sy = sy;
+ this->sz = sz;
+
+ allocBuffers();
+}
+
+
+Noise::~Noise()
+{
+ delete[] gradient_buf;
+ delete[] persist_buf;
+ delete[] noise_buf;
+ delete[] result;
+}
+
+
+void Noise::allocBuffers()
+{
+ if (sx < 1)
+ sx = 1;
+ if (sy < 1)
+ sy = 1;
+ if (sz < 1)
+ sz = 1;
+
+ this->noise_buf = NULL;
+ resizeNoiseBuf(sz > 1);
+
+ delete[] gradient_buf;
+ delete[] persist_buf;
+ delete[] result;
+
+ try {
+ size_t bufsize = sx * sy * sz;
+ this->persist_buf = NULL;
+ this->gradient_buf = new float[bufsize];
+ this->result = new float[bufsize];
+ } catch (std::bad_alloc &e) {
+ throw InvalidNoiseParamsException();
+ }
+}
+
+
+void Noise::setSize(u32 sx, u32 sy, u32 sz)
+{
+ this->sx = sx;
+ this->sy = sy;
+ this->sz = sz;
+
+ allocBuffers();
+}
+
+
+void Noise::setSpreadFactor(v3f spread)
+{
+ this->np.spread = spread;
+
+ resizeNoiseBuf(sz > 1);
+}
+
+
+void Noise::setOctaves(int octaves)
+{
+ this->np.octaves = octaves;
+
+ resizeNoiseBuf(sz > 1);
+}
+
+
+void Noise::resizeNoiseBuf(bool is3d)
+{
+ // Maximum possible spread value factor
+ float ofactor = (np.lacunarity > 1.0) ?
+ pow(np.lacunarity, np.octaves - 1) :
+ np.lacunarity;
+
+ // Noise lattice point count
+ // (int)(sz * spread * ofactor) is # of lattice points crossed due to length
+ float num_noise_points_x = sx * ofactor / np.spread.X;
+ float num_noise_points_y = sy * ofactor / np.spread.Y;
+ float num_noise_points_z = sz * ofactor / np.spread.Z;
+
+ // Protect against obviously invalid parameters
+ if (num_noise_points_x > 1000000000.f ||
+ num_noise_points_y > 1000000000.f ||
+ num_noise_points_z > 1000000000.f)
+ throw InvalidNoiseParamsException();
+
+ // Protect against an octave having a spread < 1, causing broken noise values
+ if (np.spread.X / ofactor < 1.0f ||
+ np.spread.Y / ofactor < 1.0f ||
+ np.spread.Z / ofactor < 1.0f) {
+ errorstream << "A noise parameter has too many octaves: "
+ << np.octaves << " octaves" << std::endl;
+ throw InvalidNoiseParamsException("A noise parameter has too many octaves");
+ }
+
+ // + 2 for the two initial endpoints
+ // + 1 for potentially crossing a boundary due to offset
+ size_t nlx = (size_t)std::ceil(num_noise_points_x) + 3;
+ size_t nly = (size_t)std::ceil(num_noise_points_y) + 3;
+ size_t nlz = is3d ? (size_t)std::ceil(num_noise_points_z) + 3 : 1;
+
+ delete[] noise_buf;
+ try {
+ noise_buf = new float[nlx * nly * nlz];
+ } catch (std::bad_alloc &e) {
+ throw InvalidNoiseParamsException();
+ }
+}
+
+
+/*
+ * NB: This algorithm is not optimal in terms of space complexity. The entire
+ * integer lattice of noise points could be done as 2 lines instead, and for 3D,
+ * 2 lines + 2 planes.
+ * However, this would require the noise calls to be interposed with the
+ * interpolation loops, which may trash the icache, leading to lower overall
+ * performance.
+ * Another optimization that could save half as many noise calls is to carry over
+ * values from the previous noise lattice as midpoints in the new lattice for the
+ * next octave.
+ */
+#define idx(x, y) ((y) * nlx + (x))
+void Noise::gradientMap2D(
+ float x, float y,
+ float step_x, float step_y,
+ s32 seed)
+{
+ float v00, v01, v10, v11, u, v, orig_u;
+ u32 index, i, j, noisex, noisey;
+ u32 nlx, nly;
+ s32 x0, y0;
+
+ bool eased = np.flags & (NOISE_FLAG_DEFAULTS | NOISE_FLAG_EASED);
+ Interp2dFxn interpolate = eased ?
+ biLinearInterpolation : biLinearInterpolationNoEase;
+
+ x0 = std::floor(x);
+ y0 = std::floor(y);
+ u = x - (float)x0;
+ v = y - (float)y0;
+ orig_u = u;
+
+ //calculate noise point lattice
+ nlx = (u32)(u + sx * step_x) + 2;
+ nly = (u32)(v + sy * step_y) + 2;
+ index = 0;
+ for (j = 0; j != nly; j++)
+ for (i = 0; i != nlx; i++)
+ noise_buf[index++] = noise2d(x0 + i, y0 + j, seed);
+
+ //calculate interpolations
+ index = 0;
+ noisey = 0;
+ for (j = 0; j != sy; j++) {
+ v00 = noise_buf[idx(0, noisey)];
+ v10 = noise_buf[idx(1, noisey)];
+ v01 = noise_buf[idx(0, noisey + 1)];
+ v11 = noise_buf[idx(1, noisey + 1)];
+
+ u = orig_u;
+ noisex = 0;
+ for (i = 0; i != sx; i++) {
+ gradient_buf[index++] = interpolate(v00, v10, v01, v11, u, v);
+
+ u += step_x;
+ if (u >= 1.0) {
+ u -= 1.0;
+ noisex++;
+ v00 = v10;
+ v01 = v11;
+ v10 = noise_buf[idx(noisex + 1, noisey)];
+ v11 = noise_buf[idx(noisex + 1, noisey + 1)];
+ }
+ }
+
+ v += step_y;
+ if (v >= 1.0) {
+ v -= 1.0;
+ noisey++;
+ }
+ }
+}
+#undef idx
+
+
+#define idx(x, y, z) ((z) * nly * nlx + (y) * nlx + (x))
+void Noise::gradientMap3D(
+ float x, float y, float z,
+ float step_x, float step_y, float step_z,
+ s32 seed)
+{
+ float v000, v010, v100, v110;
+ float v001, v011, v101, v111;
+ float u, v, w, orig_u, orig_v;
+ u32 index, i, j, k, noisex, noisey, noisez;
+ u32 nlx, nly, nlz;
+ s32 x0, y0, z0;
+
+ Interp3dFxn interpolate = (np.flags & NOISE_FLAG_EASED) ?
+ triLinearInterpolation : triLinearInterpolationNoEase;
+
+ x0 = std::floor(x);
+ y0 = std::floor(y);
+ z0 = std::floor(z);
+ u = x - (float)x0;
+ v = y - (float)y0;
+ w = z - (float)z0;
+ orig_u = u;
+ orig_v = v;
+
+ //calculate noise point lattice
+ nlx = (u32)(u + sx * step_x) + 2;
+ nly = (u32)(v + sy * step_y) + 2;
+ nlz = (u32)(w + sz * step_z) + 2;
+ index = 0;
+ for (k = 0; k != nlz; k++)
+ for (j = 0; j != nly; j++)
+ for (i = 0; i != nlx; i++)
+ noise_buf[index++] = noise3d(x0 + i, y0 + j, z0 + k, seed);
+
+ //calculate interpolations
+ index = 0;
+ noisey = 0;
+ noisez = 0;
+ for (k = 0; k != sz; k++) {
+ v = orig_v;
+ noisey = 0;
+ for (j = 0; j != sy; j++) {
+ v000 = noise_buf[idx(0, noisey, noisez)];
+ v100 = noise_buf[idx(1, noisey, noisez)];
+ v010 = noise_buf[idx(0, noisey + 1, noisez)];
+ v110 = noise_buf[idx(1, noisey + 1, noisez)];
+ v001 = noise_buf[idx(0, noisey, noisez + 1)];
+ v101 = noise_buf[idx(1, noisey, noisez + 1)];
+ v011 = noise_buf[idx(0, noisey + 1, noisez + 1)];
+ v111 = noise_buf[idx(1, noisey + 1, noisez + 1)];
+
+ u = orig_u;
+ noisex = 0;
+ for (i = 0; i != sx; i++) {
+ gradient_buf[index++] = interpolate(
+ v000, v100, v010, v110,
+ v001, v101, v011, v111,
+ u, v, w);
+
+ u += step_x;
+ if (u >= 1.0) {
+ u -= 1.0;
+ noisex++;
+ v000 = v100;
+ v010 = v110;
+ v100 = noise_buf[idx(noisex + 1, noisey, noisez)];
+ v110 = noise_buf[idx(noisex + 1, noisey + 1, noisez)];
+ v001 = v101;
+ v011 = v111;
+ v101 = noise_buf[idx(noisex + 1, noisey, noisez + 1)];
+ v111 = noise_buf[idx(noisex + 1, noisey + 1, noisez + 1)];
+ }
+ }
+
+ v += step_y;
+ if (v >= 1.0) {
+ v -= 1.0;
+ noisey++;
+ }
+ }
+
+ w += step_z;
+ if (w >= 1.0) {
+ w -= 1.0;
+ noisez++;
+ }
+ }
+}
+#undef idx
+
+
+float *Noise::perlinMap2D(float x, float y, float *persistence_map)
+{
+ float f = 1.0, g = 1.0;
+ size_t bufsize = sx * sy;
+
+ x /= np.spread.X;
+ y /= np.spread.Y;
+
+ memset(result, 0, sizeof(float) * bufsize);
+
+ if (persistence_map) {
+ if (!persist_buf)
+ persist_buf = new float[bufsize];
+ for (size_t i = 0; i != bufsize; i++)
+ persist_buf[i] = 1.0;
+ }
+
+ for (size_t oct = 0; oct < np.octaves; oct++) {
+ gradientMap2D(x * f, y * f,
+ f / np.spread.X, f / np.spread.Y,
+ seed + np.seed + oct);
+
+ updateResults(g, persist_buf, persistence_map, bufsize);
+
+ f *= np.lacunarity;
+ g *= np.persist;
+ }
+
+ if (std::fabs(np.offset - 0.f) > 0.00001 || std::fabs(np.scale - 1.f) > 0.00001) {
+ for (size_t i = 0; i != bufsize; i++)
+ result[i] = result[i] * np.scale + np.offset;
+ }
+
+ return result;
+}
+
+
+float *Noise::perlinMap3D(float x, float y, float z, float *persistence_map)
+{
+ float f = 1.0, g = 1.0;
+ size_t bufsize = sx * sy * sz;
+
+ x /= np.spread.X;
+ y /= np.spread.Y;
+ z /= np.spread.Z;
+
+ memset(result, 0, sizeof(float) * bufsize);
+
+ if (persistence_map) {
+ if (!persist_buf)
+ persist_buf = new float[bufsize];
+ for (size_t i = 0; i != bufsize; i++)
+ persist_buf[i] = 1.0;
+ }
+
+ for (size_t oct = 0; oct < np.octaves; oct++) {
+ gradientMap3D(x * f, y * f, z * f,
+ f / np.spread.X, f / np.spread.Y, f / np.spread.Z,
+ seed + np.seed + oct);
+
+ updateResults(g, persist_buf, persistence_map, bufsize);
+
+ f *= np.lacunarity;
+ g *= np.persist;
+ }
+
+ if (std::fabs(np.offset - 0.f) > 0.00001 || std::fabs(np.scale - 1.f) > 0.00001) {
+ for (size_t i = 0; i != bufsize; i++)
+ result[i] = result[i] * np.scale + np.offset;
+ }
+
+ return result;
+}
+
+
+void Noise::updateResults(float g, float *gmap,
+ const float *persistence_map, size_t bufsize)
+{
+ // This looks very ugly, but it is 50-70% faster than having
+ // conditional statements inside the loop
+ if (np.flags & NOISE_FLAG_ABSVALUE) {
+ if (persistence_map) {
+ for (size_t i = 0; i != bufsize; i++) {
+ result[i] += gmap[i] * std::fabs(gradient_buf[i]);
+ gmap[i] *= persistence_map[i];
+ }
+ } else {
+ for (size_t i = 0; i != bufsize; i++)
+ result[i] += g * std::fabs(gradient_buf[i]);
+ }
+ } else {
+ if (persistence_map) {
+ for (size_t i = 0; i != bufsize; i++) {
+ result[i] += gmap[i] * gradient_buf[i];
+ gmap[i] *= persistence_map[i];
+ }
+ } else {
+ for (size_t i = 0; i != bufsize; i++)
+ result[i] += g * gradient_buf[i];
+ }
+ }
+}