minetest/src/noise.h

233 lines
6.2 KiB
C++

/*
* 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.
*/
#pragma once
#include "irr_v3d.h"
#include "exceptions.h"
#include "util/string.h"
#if defined(RANDOM_MIN)
#undef RANDOM_MIN
#endif
#if defined(RANDOM_MAX)
#undef RANDOM_MAX
#endif
extern FlagDesc flagdesc_noiseparams[];
// Note: this class is not polymorphic so that its high level of
// optimizability may be preserved in the common use case
class PseudoRandom {
public:
const static u32 RANDOM_RANGE = 32767;
inline PseudoRandom(int seed=0):
m_next(seed)
{
}
inline void seed(int seed)
{
m_next = seed;
}
inline int next()
{
m_next = m_next * 1103515245 + 12345;
return (unsigned)(m_next / 65536) % (RANDOM_RANGE + 1);
}
inline int range(int min, int max)
{
if (max < min)
throw PrngException("Invalid range (max < min)");
/*
Here, we ensure the range is not too large relative to RANDOM_MAX,
as otherwise the effects of bias would become noticeable. Unlike
PcgRandom, we cannot modify this RNG's range as it would change the
output of this RNG for reverse compatibility.
*/
if ((u32)(max - min) > (RANDOM_RANGE + 1) / 10)
throw PrngException("Range too large");
return (next() % (max - min + 1)) + min;
}
private:
int m_next;
};
class PcgRandom {
public:
const static s32 RANDOM_MIN = -0x7fffffff - 1;
const static s32 RANDOM_MAX = 0x7fffffff;
const static u32 RANDOM_RANGE = 0xffffffff;
PcgRandom(u64 state=0x853c49e6748fea9bULL, u64 seq=0xda3e39cb94b95bdbULL);
void seed(u64 state, u64 seq=0xda3e39cb94b95bdbULL);
u32 next();
u32 range(u32 bound);
s32 range(s32 min, s32 max);
void bytes(void *out, size_t len);
s32 randNormalDist(s32 min, s32 max, int num_trials=6);
private:
u64 m_state;
u64 m_inc;
};
#define NOISE_FLAG_DEFAULTS 0x01
#define NOISE_FLAG_EASED 0x02
#define NOISE_FLAG_ABSVALUE 0x04
//// TODO(hmmmm): implement these!
#define NOISE_FLAG_POINTBUFFER 0x08
#define NOISE_FLAG_SIMPLEX 0x10
struct NoiseParams {
float offset = 0.0f;
float scale = 1.0f;
v3f spread = v3f(250, 250, 250);
s32 seed = 12345;
u16 octaves = 3;
float persist = 0.6f;
float lacunarity = 2.0f;
u32 flags = NOISE_FLAG_DEFAULTS;
NoiseParams() = default;
NoiseParams(float offset_, float scale_, const v3f &spread_, s32 seed_,
u16 octaves_, float persist_, float lacunarity_,
u32 flags_=NOISE_FLAG_DEFAULTS)
{
offset = offset_;
scale = scale_;
spread = spread_;
seed = seed_;
octaves = octaves_;
persist = persist_;
lacunarity = lacunarity_;
flags = flags_;
}
};
class Noise {
public:
NoiseParams np;
s32 seed;
u32 sx;
u32 sy;
u32 sz;
float *noise_buf = nullptr;
float *gradient_buf = nullptr;
float *persist_buf = nullptr;
float *result = nullptr;
Noise(const NoiseParams *np, s32 seed, u32 sx, u32 sy, u32 sz=1);
~Noise();
void setSize(u32 sx, u32 sy, u32 sz=1);
void setSpreadFactor(v3f spread);
void setOctaves(int octaves);
void gradientMap2D(
float x, float y,
float step_x, float step_y,
s32 seed);
void gradientMap3D(
float x, float y, float z,
float step_x, float step_y, float step_z,
s32 seed);
float *perlinMap2D(float x, float y, float *persistence_map=NULL);
float *perlinMap3D(float x, float y, float z, float *persistence_map=NULL);
inline float *perlinMap2D_PO(float x, float xoff, float y, float yoff,
float *persistence_map=NULL)
{
return perlinMap2D(
x + xoff * np.spread.X,
y + yoff * np.spread.Y,
persistence_map);
}
inline float *perlinMap3D_PO(float x, float xoff, float y, float yoff,
float z, float zoff, float *persistence_map=NULL)
{
return perlinMap3D(
x + xoff * np.spread.X,
y + yoff * np.spread.Y,
z + zoff * np.spread.Z,
persistence_map);
}
private:
void allocBuffers();
void resizeNoiseBuf(bool is3d);
void updateResults(float g, float *gmap, const float *persistence_map,
size_t bufsize);
};
float NoisePerlin2D(const NoiseParams *np, float x, float y, s32 seed);
float NoisePerlin3D(const NoiseParams *np, float x, float y, float z, s32 seed);
inline float NoisePerlin2D_PO(NoiseParams *np, float x, float xoff,
float y, float yoff, s32 seed)
{
return NoisePerlin2D(np,
x + xoff * np->spread.X,
y + yoff * np->spread.Y,
seed);
}
inline float NoisePerlin3D_PO(NoiseParams *np, float x, float xoff,
float y, float yoff, float z, float zoff, s32 seed)
{
return NoisePerlin3D(np,
x + xoff * np->spread.X,
y + yoff * np->spread.Y,
z + zoff * np->spread.Z,
seed);
}
// Return value: -1 ... 1
float noise2d(int x, int y, s32 seed);
float noise3d(int x, int y, int z, s32 seed);
float noise2d_gradient(float x, float y, s32 seed, bool eased=true);
float noise3d_gradient(float x, float y, float z, s32 seed, bool eased=false);
float noise2d_perlin(float x, float y, s32 seed,
int octaves, float persistence, bool eased=true);
inline float easeCurve(float t)
{
return t * t * t * (t * (6.f * t - 15.f) + 10.f);
}
float contour(float v);