Add (possibly non-compatible) work-in-progress noise.{h,cpp} so that they...

Add (possibly non-compatible) work-in-progress noise.{h,cpp} so that they won't be accidentally lost. These are useful for upcoming mapgen updates.

src/noise.cpp.new

+/*
+Minetest-c55
+Copyright (C) 2010-2011 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+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 "noise.h"
+#include <iostream>
+#include "debug.h"
+
+#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
+};
+
+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
+			+ NOISE_MAGIC_SEED * seed) & 0x7fffffff;
+	n = (n>>13)^n;
+	n = (n * (n*n*60493+19990303) + 1376312589) & 0x7fffffff;
+	return 1.0 - (double)n/1073741824;
+}
+
+double noise3d(int x, int y, int z, int seed)
+{
+	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;
+}
+
+#if 0
+double noise2d_gradient(double x, double y, int seed)
+{
+	// 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)
+{
+	// 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;
+	// 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);
+	// Interpolate
+	return biLinearInterpolation(v00,v10,v01,v11,xl,yl);
+}
+#endif
+
+double noise3d_gradient(double x, double y, double z, int seed)
+{
+	// 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);
+	// Calculate the remaining part of the coordinates
+	double xl = x - (double)x0;
+	double yl = y - (double)y0;
+	double zl = z - (double)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);
+	// Interpolate
+	return triLinearInterpolation(v000,v100,v010,v110,v001,v101,v011,v111,xl,yl,zl);
+}
+
+double noise2d_perlin(double x, double y, int seed,
+		int octaves, double persistence)
+{
+	double a = 0;
+	double f = 1.0;
+	double g = 1.0;
+	for(int i=0; i<octaves; i++)
+	{
+		a += g * noise2d_gradient(x*f, y*f, seed+i);
+		f *= 2.0;
+		g *= persistence;
+	}
+	return a;
+}
+
+double noise2d_perlin_abs(double x, double y, int seed,
+		int octaves, double persistence)
+{
+	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));
+		f *= 2.0;
+		g *= persistence;
+	}
+	return a;
+}
+
+double noise3d_perlin(double x, double y, double z, int seed,
+		int octaves, double persistence)
+{
+	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);
+		f *= 2.0;
+		g *= persistence;
+	}
+	return a;
+}
+
+double noise3d_perlin_abs(double x, double y, double z, int seed,
+		int octaves, double persistence)
+{
+	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));
+		f *= 2.0;
+		g *= persistence;
+	}
+	return a;
+}
+
+// -1->0, 0->1, 1->0
+double contour(double v)
+{
+	v = fabs(v);
+	if(v >= 1.0)
+		return 0.0;
+	return (1.0-v);
+}
+
+double noise3d_param(const NoiseParams &param, double x, double y, double z)
+{
+	double s = param.pos_scale;
+	x /= s;
+	y /= s;
+	z /= s;
+
+	if(param.type == NOISE_PERLIN)
+	{
+		return param.noise_scale*noise3d_perlin(x,y,z, param.seed,
+				param.octaves,
+				param.persistence);
+	}
+	else if(param.type == NOISE_PERLIN_ABS)
+	{
+		return param.noise_scale*noise3d_perlin_abs(x,y,z, param.seed,
+				param.octaves,
+				param.persistence);
+	}
+	else if(param.type == NOISE_PERLIN_CONTOUR)
+	{
+		return contour(param.noise_scale*noise3d_perlin(x,y,z,
+				param.seed, param.octaves,
+				param.persistence));
+	}
+	else if(param.type == NOISE_PERLIN_CONTOUR_FLIP_YZ)
+	{
+		return contour(param.noise_scale*noise3d_perlin(x,z,y,
+				param.seed, param.octaves,
+				param.persistence));
+	}
+	else assert(0);
+}
+
+/*
+	NoiseBuffer
+*/
+
+NoiseBuffer::NoiseBuffer():
+	m_data(NULL)
+{
+}
+
+NoiseBuffer::~NoiseBuffer()
+{
+	clear();
+}
+
+void NoiseBuffer::clear()
+{
+	if(m_data)
+		delete[] m_data;
+	m_data = NULL;
+	m_size_x = 0;
+	m_size_y = 0;
+	m_size_z = 0;
+}
+
+void NoiseBuffer::create(const NoiseParams &param,
+		double first_x, double first_y, double first_z,
+		double last_x, double last_y, double last_z,
+		double samplelength_x, double samplelength_y, double samplelength_z)
+{
+	clear();
+	
+	m_start_x = first_x - samplelength_x;
+	m_start_y = first_y - samplelength_y;
+	m_start_z = first_z - samplelength_z;
+	m_samplelength_x = samplelength_x;
+	m_samplelength_y = samplelength_y;
+	m_samplelength_z = samplelength_z;
+
+	m_size_x = (last_x - m_start_x)/samplelength_x + 2;
+	m_size_y = (last_y - m_start_y)/samplelength_y + 2;
+	m_size_z = (last_z - m_start_z)/samplelength_z + 2;
+
+	m_data = new double[m_size_x*m_size_y*m_size_z];
+
+	for(int x=0; x<m_size_x; x++)
+	for(int y=0; y<m_size_y; y++)
+	for(int z=0; z<m_size_z; z++)
+	{
+		double xd = (m_start_x + (double)x*m_samplelength_x);
+		double yd = (m_start_y + (double)y*m_samplelength_y);
+		double zd = (m_start_z + (double)z*m_samplelength_z);
+		double a = noise3d_param(param, xd,yd,zd);
+		intSet(x,y,z, a);
+	}
+}
+
+void NoiseBuffer::multiply(const NoiseParams &param)
+{
+	assert(m_data != NULL);
+
+	for(int x=0; x<m_size_x; x++)
+	for(int y=0; y<m_size_y; y++)
+	for(int z=0; z<m_size_z; z++)
+	{
+		double xd = (m_start_x + (double)x*m_samplelength_x);
+		double yd = (m_start_y + (double)y*m_samplelength_y);
+		double zd = (m_start_z + (double)z*m_samplelength_z);
+		double a = noise3d_param(param, xd,yd,zd);
+		intMultiply(x,y,z, a);
+	}
+}
+
+// Deprecated
+void NoiseBuffer::create(int seed, int octaves, double persistence,
+		bool abs,
+		double first_x, double first_y, double first_z,
+		double last_x, double last_y, double last_z,
+		double samplelength_x, double samplelength_y, double samplelength_z)
+{
+	NoiseParams param;
+	param.type = abs ? NOISE_PERLIN_ABS : NOISE_PERLIN;
+	param.seed = seed;
+	param.octaves = octaves;
+	param.persistence = persistence;
+
+	create(param, first_x, first_y, first_z,
+			last_x, last_y, last_z,
+			samplelength_x, samplelength_y, samplelength_z);
+}
+
+void NoiseBuffer::intSet(int x, int y, int z, double d)
+{
+	int i = m_size_x*m_size_y*z + m_size_x*y + x;
+	assert(i >= 0);
+	assert(i < m_size_x*m_size_y*m_size_z);
+	m_data[i] = d;
+}
+
+void NoiseBuffer::intMultiply(int x, int y, int z, double d)
+{
+	int i = m_size_x*m_size_y*z + m_size_x*y + x;
+	assert(i >= 0);
+	assert(i < m_size_x*m_size_y*m_size_z);
+	m_data[i] = m_data[i] * d;
+}
+
+double NoiseBuffer::intGet(int x, int y, int z)
+{
+	int i = m_size_x*m_size_y*z + m_size_x*y + x;
+	assert(i >= 0);
+	assert(i < m_size_x*m_size_y*m_size_z);
+	return m_data[i];
+}
+
+double NoiseBuffer::get(double x, double y, double z)
+{
+	x -= m_start_x;
+	y -= m_start_y;
+	z -= m_start_z;
+	x /= m_samplelength_x;
+	y /= m_samplelength_y;
+	z /= m_samplelength_z;
+	// 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);
+	// Calculate the remaining part of the coordinates
+	double xl = x - (double)x0;
+	double yl = y - (double)y0;
+	double zl = z - (double)z0;
+	// Get values for corners of cube
+	double v000 = intGet(x0,   y0,   z0);
+	double v100 = intGet(x0+1, y0,   z0);
+	double v010 = intGet(x0,   y0+1, z0);
+	double v110 = intGet(x0+1, y0+1, z0);
+	double v001 = intGet(x0,   y0,   z0+1);
+	double v101 = intGet(x0+1, y0,   z0+1);
+	double v011 = intGet(x0,   y0+1, z0+1);
+	double v111 = intGet(x0+1, y0+1, z0+1);
+	// Interpolate
+	return triLinearInterpolation(v000,v100,v010,v110,v001,v101,v011,v111,xl,yl,zl);
+}
+

src/noise.h.new

+/*
+Minetest-c55
+Copyright (C) 2010-2011 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+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.
+*/
+
+#ifndef NOISE_HEADER
+#define NOISE_HEADER
+
+double easeCurve(double t);
+ 
+// Return value: -1 ... 1
+double noise2d(int x, int y, int seed);
+double noise3d(int x, int y, int z, int seed);
+
+double noise2d_gradient(double x, double y, int seed);
+double noise3d_gradient(double x, double y, double z, int seed);
+
+double noise2d_perlin(double x, double y, int seed,
+		int octaves, double persistence);
+
+double noise2d_perlin_abs(double x, double y, int seed,
+		int octaves, double persistence);
+
+double noise3d_perlin(double x, double y, double z, int seed,
+		int octaves, double persistence);
+
+double noise3d_perlin_abs(double x, double y, double z, int seed,
+		int octaves, double persistence);
+
+enum NoiseType
+{
+	NOISE_PERLIN,
+	NOISE_PERLIN_ABS,
+	NOISE_PERLIN_CONTOUR,
+	NOISE_PERLIN_CONTOUR_FLIP_YZ
+};
+
+struct NoiseParams
+{
+	NoiseType type;
+	int seed;
+	int octaves;
+	double persistence;
+	double pos_scale;
+	double noise_scale; // Useful for contour noises
+	
+	NoiseParams(NoiseType type_=NOISE_PERLIN, int seed_=0,
+			int octaves_=3, double persistence_=0.5,
+			double pos_scale_=100.0, double noise_scale_=1.0):
+		type(type_),
+		seed(seed_),
+		octaves(octaves_),
+		persistence(persistence_),
+		pos_scale(pos_scale_),
+		noise_scale(noise_scale_)
+	{
+	}
+};
+
+double noise3d_param(const NoiseParams &param, double x, double y, double z);
+
+class NoiseBuffer
+{
+public:
+	NoiseBuffer();
+	~NoiseBuffer();
+	
+	void clear();
+	void create(const NoiseParams &param,
+			double first_x, double first_y, double first_z,
+			double last_x, double last_y, double last_z,
+			double samplelength_x, double samplelength_y, double samplelength_z);
+	void multiply(const NoiseParams &param);
+	// Deprecated
+	void create(int seed, int octaves, double persistence,
+			bool abs,
+			double first_x, double first_y, double first_z,
+			double last_x, double last_y, double last_z,
+			double samplelength_x, double samplelength_y, double samplelength_z);
+
+	void intSet(int x, int y, int z, double d);
+	void intMultiply(int x, int y, int z, double d);
+	double intGet(int x, int y, int z);
+	double get(double x, double y, double z);
+
+private:
+	double *m_data;
+	double m_start_x, m_start_y, m_start_z;
+	double m_samplelength_x, m_samplelength_y, m_samplelength_z;
+	int m_size_x, m_size_y, m_size_z;
+};
+
+#endif
+