nerdcruft/libcruft-util
1
0
Fork 0
Code Issues Releases Activity

noise/basis: parameterise basis functions

Browse Source
This commit is contained in:
Danny Robson 2015-05-18 17:16:04 +10:00
parent cacaee4c5d
commit 07513b078c
5 changed files with 171 additions and 121 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

220
noise/basis.cpp
View File

@ -34,93 +34,116 @@ using util::noise::cellular;
// Generate a type from [-UNIT..UNIT]
template <typename T>
T
generate (intmax_t x, intmax_t y, basis::seed_t);
//-----------------------------------------------------------------------------
template <>
double
generate (intmax_t x, intmax_t y, basis::seed_t seed) {
generate (intmax_t x, intmax_t y, uint64_t seed)
{
size_t idx = util::noise::permute (x, y, seed);
return util::noise::LUT[idx];
return T(util::noise::LUT[idx]);
}
//-----------------------------------------------------------------------------
template <>
util::vector2d
generate (intmax_t x, intmax_t y, basis::seed_t seed) {
generate (intmax_t x, intmax_t y, uint64_t seed)
{
auto u = util::noise::permute (x, y, seed);
auto v = util::noise::permute (u ^ seed);
return util::vector2d (util::noise::LUT[u], util::noise::LUT[v]);
return {
util::noise::LUT[u],
util::noise::LUT[v]
};
}
//-----------------------------------------------------------------------------
template <>
util::vector2f
generate (intmax_t x, intmax_t y, uint64_t seed)
{
auto u = util::noise::permute (x, y, seed);
auto v = util::noise::permute (u ^ seed);
return {
float (util::noise::LUT[u]),
float (util::noise::LUT[v])
};
}
///////////////////////////////////////////////////////////////////////////////
basis::basis (seed_t _seed):
template <typename T>
basis<T>::basis (seed_t _seed):
seed (_seed)
{ ; }
//-----------------------------------------------------------------------------
basis::basis ():
template <typename T>
basis<T>::basis ():
seed (util::random<seed_t> ())
{ ; }
//-----------------------------------------------------------------------------
basis::~basis ()
template <typename T>
basis<T>::~basis ()
{ ; }
//-----------------------------------------------------------------------------
double
basis::eval (double, double) const
template <typename T>
T
basis<T>::eval (T, T) const
{ unreachable (); }
//-----------------------------------------------------------------------------
namespace util { namespace noise {
template struct basis<float>;
template struct basis<double>;
} }
///////////////////////////////////////////////////////////////////////////////
template <util::noise::lerp_t<double> L>
value<L>::value (seed_t _seed):
basis (_seed)
template <typename T, util::noise::lerp_t<T> L>
value<T,L>::value (seed_t _seed):
basis<T> (_seed)
{ ; }
//-----------------------------------------------------------------------------
template <util::noise::lerp_t<double> L>
value<L>::value ()
template <typename T, util::noise::lerp_t<T> L>
value<T,L>::value ()
{ ; }
//-----------------------------------------------------------------------------
template <util::noise::lerp_t<double> L>
util::range<double>
value<L>::bounds (void) const
{ return { -1.0, 1.0 }; }
template <typename T, util::noise::lerp_t<T> L>
util::range<T>
value<T,L>::bounds (void) const
{ return { -1, 1 }; }
//-----------------------------------------------------------------------------
template <util::noise::lerp_t<double> L>
double
value<L>::eval (double x, double y) const {
template <typename T, util::noise::lerp_t<T> L>
T
value<T,L>::eval (T x, T y) const {
intmax_t x_int = static_cast<intmax_t> (x);
intmax_t y_int = static_cast<intmax_t> (y);
double x_fac = x - x_int;
double y_fac = y - y_int;
T x_fac = x - x_int;
T y_fac = y - y_int;
// Shift the coordinate system down a little to ensure we get unit weights
// for the lerp. It's better to do this than abs the fractional portion so
// we don't get reflections along the origin.
if (x < 0) { x_fac = 1.0 + x_fac; x_int -= 1; }
if (y < 0) { y_fac = 1.0 + y_fac; y_int -= 1; }
if (x < 0) { x_fac = 1 + x_fac; x_int -= 1; }
if (y < 0) { y_fac = 1 + y_fac; y_int -= 1; }
// Generate the four corner values
double p0 = generate<double> (x_int, y_int, this->seed);
double p1 = generate<double> (x_int + 1, y_int, this->seed);
double p2 = generate<double> (x_int, y_int + 1, this->seed);
double p3 = generate<double> (x_int + 1, y_int + 1, this->seed);
T p0 = generate<T> (x_int, y_int, this->seed);
T p1 = generate<T> (x_int + 1, y_int, this->seed);
T p2 = generate<T> (x_int, y_int + 1, this->seed);
T p3 = generate<T> (x_int + 1, y_int + 1, this->seed);
// Interpolate on one dimension, then the other.
return L (L (p0, p1, x_fac),
@ -130,62 +153,64 @@ value<L>::eval (double x, double y) const {
//-----------------------------------------------------------------------------
namespace util {
namespace noise {
template struct value<util::lerp::linear>;
template struct value<util::lerp::cubic>;
template struct value<util::lerp::quintic>;
}
}
namespace util { namespace noise {
template struct value<float, lerp::linear>;
template struct value<float, lerp::cubic>;
template struct value<float, lerp::quintic>;
template struct value<double, lerp::linear>;
template struct value<double, lerp::cubic>;
template struct value<double, lerp::quintic>;
} }
///////////////////////////////////////////////////////////////////////////////
template <util::noise::lerp_t<double> L>
gradient<L>::gradient (seed_t _seed):
basis (_seed)
template <typename T, util::noise::lerp_t<T> L>
gradient<T,L>::gradient (seed_t _seed):
basis<T> (_seed)
{ ; }
//-----------------------------------------------------------------------------
template <util::noise::lerp_t<double> L>
gradient<L>::gradient ()
template <typename T, util::noise::lerp_t<T> L>
gradient<T,L>::gradient ()
{ ; }
//-----------------------------------------------------------------------------
template <util::noise::lerp_t<double> L>
util::range<double>
gradient<L>::bounds (void) const
{ return { -sqrt(2.0) / 2.0, sqrt (2.0) / 2.0 }; }
template <typename T, util::noise::lerp_t<T> L>
util::range<T>
gradient<T,L>::bounds (void) const
{ return { -std::sqrt(T{2}) / 2, std::sqrt (T{2}) / 2 }; }
//-----------------------------------------------------------------------------
template <util::noise::lerp_t<double> L>
double
gradient<L>::eval (double x, double y) const {
template <typename T, util::noise::lerp_t<T> L>
T
gradient<T,L>::eval (T x, T y) const {
intmax_t x_int = static_cast<intmax_t> (x);
intmax_t y_int = static_cast<intmax_t> (y);
double x_fac = x - x_int;
double y_fac = y - y_int;
T x_fac = x - x_int;
T y_fac = y - y_int;
// Shift the coordinate system down a little to ensure we get unit weights
// for the lerp. It's better to do this than abs the fractional portion so
// we don't get reflections along the origin.
if (x < 0) { x_fac = 1.0 + x_fac; x_int -= 1; }
if (y < 0) { y_fac = 1.0 + y_fac; y_int -= 1; }
if (x < 0) { x_fac = 1 + x_fac; x_int -= 1; }
if (y < 0) { y_fac = 1 + y_fac; y_int -= 1; }
// Generate the four corner values. It's not strictly necessary to
// normalise the values, but we get a more consistent and visually
// appealing range of outputs with normalised values.
vector2d p0 = generate<vector2d> (x_int, y_int, this->seed).normalise ();
vector2d p1 = generate<vector2d> (x_int + 1, y_int, this->seed).normalise ();
vector2d p2 = generate<vector2d> (x_int, y_int + 1, this->seed).normalise ();
vector2d p3 = generate<vector2d> (x_int + 1, y_int + 1, this->seed).normalise ();
auto p0 = generate<vector<2,T>> (x_int, y_int, this->seed).normalise ();
auto p1 = generate<vector<2,T>> (x_int + 1, y_int, this->seed).normalise ();
auto p2 = generate<vector<2,T>> (x_int, y_int + 1, this->seed).normalise ();
auto p3 = generate<vector<2,T>> (x_int + 1, y_int + 1, this->seed).normalise ();
double v0 = p0.x * x_fac + p0.y * y_fac;
double v1 = p1.x * (x_fac - 1.0) + p1.y * y_fac;
double v2 = p2.x * x_fac + p2.y * (y_fac - 1.0);
double v3 = p3.x * (x_fac - 1.0) + p3.y * (y_fac - 1.0);
T v0 = p0.x * x_fac + p0.y * y_fac;
T v1 = p1.x * (x_fac - 1) + p1.y * y_fac;
T v2 = p2.x * x_fac + p2.y * (y_fac - 1);
T v3 = p3.x * (x_fac - 1) + p3.y * (y_fac - 1);
return L (L (v0, v1, x_fac),
L (v2, v3, x_fac),
@ -196,45 +221,51 @@ gradient<L>::eval (double x, double y) const {
//-----------------------------------------------------------------------------
namespace util {
namespace noise {
template struct gradient<util::lerp::linear>;
template struct gradient<util::lerp::cubic>;
template struct gradient<util::lerp::quintic>;
template struct gradient<float, lerp::linear>;
template struct gradient<float, lerp::cubic>;
template struct gradient<float, lerp::quintic>;
template struct gradient<double, lerp::linear>;
template struct gradient<double, lerp::cubic>;
template struct gradient<double, lerp::quintic>;
}
}
///////////////////////////////////////////////////////////////////////////////
cellular::cellular (seed_t _seed):
basis (_seed)
template <typename T>
cellular<T>::cellular (seed_t _seed):
basis<T> (_seed)
{ ; }
//-----------------------------------------------------------------------------
cellular::cellular ()
template <typename T>
cellular<T>::cellular ()
{ ; }
//-----------------------------------------------------------------------------
util::range<double>
cellular::bounds (void) const
template <typename T>
util::range<T>
cellular<T>::bounds (void) const
{ return { 0.0, 1.5 }; }
//-----------------------------------------------------------------------------
double
cellular::eval (double x, double y) const {
using util::point2d;
template <typename T>
T
cellular<T>::eval (T x, T y) const {
intmax_t x_int = static_cast<intmax_t> (x);
intmax_t y_int = static_cast<intmax_t> (y);
double x_fac = x - x_int;
double y_fac = y - y_int;
T x_fac = x - x_int;
T y_fac = y - y_int;
// Generate the four corner values. It's not strictly necessary to
// normalise the values, but we get a more consistent and visually
// appealing range of outputs with normalised values.
if (x < 0) { x_fac = 1.0 + x_fac; x_int -= 1; }
if (y < 0) { y_fac = 1.0 + y_fac; y_int -= 1; }
if (x < 0) { x_fac = 1 + x_fac; x_int -= 1; }
if (y < 0) { y_fac = 1 + y_fac; y_int -= 1; }
// +---+---+---+
// | 0 | 1 | 2 |
@ -244,19 +275,19 @@ cellular::eval (double x, double y) const {
// | 6 | 7 | 8 |
// +---+---+---+
point2d centre = { x_fac, y_fac };
double distances[9] = { std::numeric_limits<double>::quiet_NaN () };
double *cursor = distances;
point<2,T> centre = { x_fac, y_fac };
T distances[9] = { std::numeric_limits<T>::quiet_NaN () };
T *cursor = distances;
for (signed y_off = -1; y_off <= 1 ; ++y_off)
for (signed x_off = -1; x_off <= 1; ++x_off) {
auto pos = point2d (double (x_off), double (y_off));
auto off = generate<vector2d> (x_int + x_off, y_int + y_off, this->seed);
off += 1.;
off /= 2.;
auto pos = point<2,T> (T (x_off), T (y_off));
auto off = generate<vector<2,T>> (x_int + x_off, y_int + y_off, this->seed);
off += T{1};
off /= T{2};
CHECK (off.x >= 0 && off.x <= 1.0);
CHECK (off.y >= 0 && off.y <= 1.0);
CHECK (off.x >= 0 && off.x <= 1);
CHECK (off.y >= 0 && off.y <= 1);
pos += off;
*cursor++ = pos.distance2 (centre);
@ -267,3 +298,10 @@ cellular::eval (double x, double y) const {
CHECK (bounds ().contains (distances[0]));
return distances[0];
}
//-----------------------------------------------------------------------------
namespace util { namespace noise {
template struct cellular<float>;
template struct cellular<double>;
} }

34
noise/basis.hpp
View File

@ -25,6 +25,7 @@ namespace util {
namespace noise {
template <typename T> using lerp_t = T (*)(T,T,T);
template <typename T>
struct basis {
typedef uint64_t seed_t;
@ -34,40 +35,47 @@ namespace util {
seed_t seed;
virtual range<double> bounds (void) const = 0;
virtual double eval (double x, double y) const = 0;
virtual range<T> bounds (void) const = 0;
virtual T eval (T x, T y) const = 0;
};
/// Perlin: single value per grid space
template <lerp_t<double>>
struct value : public basis {
template <typename T, lerp_t<T>>
struct value : public basis<T> {
using seed_t = typename basis<T>::seed_t;
value (seed_t);
value ();
virtual range<double> bounds (void) const;
virtual double eval (double x, double y) const;
virtual range<T> bounds (void) const override;
virtual T eval (T x, T y) const override;
};
/// Perlin: interpolated value across each grid space
template <lerp_t<double>L>
struct gradient : public basis {
template <typename T, lerp_t<T> L>
struct gradient : public basis<T> {
using seed_t = typename basis<T>::seed_t;
gradient (seed_t);
gradient ();
virtual range<double> bounds (void) const;
virtual double eval (double x, double y) const;
virtual range<T> bounds (void) const override;
virtual T eval (T x, T y) const override;
};
/// Cellular/Worley/Vornoi of order-1
struct cellular : public basis {
template <typename T>
struct cellular : public basis<T> {
using seed_t = typename basis<T>::seed_t;
cellular (seed_t);
cellular ();
virtual range<double> bounds (void) const;
virtual double eval (double x, double y) const;
virtual range<T> bounds (void) const override;
virtual T eval (T x, T y) const override;
};
}
}

24
noise/fractal.cpp
View File

@ -55,7 +55,7 @@ template <typename B>
util::noise::fbm<B>::fbm (unsigned _octaves,
double _frequency,
double _lacunarity,
basis::seed_t _seed):
seed_t _seed):
fractal (_octaves, _frequency, _lacunarity),
basis (_seed)
{ ; }
@ -90,11 +90,11 @@ util::noise::fbm<B>::eval (double x, double y) const {
//-----------------------------------------------------------------------------
template struct util::noise::fbm<util::noise::cellular>;
template struct util::noise::fbm<util::noise::gradient<util::lerp::linear>>;
template struct util::noise::fbm<util::noise::gradient<util::lerp::quintic>>;
template struct util::noise::fbm<util::noise::value<util::lerp::linear>>;
template struct util::noise::fbm<util::noise::value<util::lerp::quintic>>;
template struct util::noise::fbm<util::noise::cellular<double>>;
template struct util::noise::fbm<util::noise::gradient<double,util::lerp::linear>>;
template struct util::noise::fbm<util::noise::gradient<double,util::lerp::quintic>>;
template struct util::noise::fbm<util::noise::value<double,util::lerp::linear>>;
template struct util::noise::fbm<util::noise::value<double,util::lerp::quintic>>;
///////////////////////////////////////////////////////////////////////////////
@ -102,7 +102,7 @@ template <typename B>
util::noise::musgrave<B>::musgrave (unsigned _octaves,
double _frequency,
double _lacunarity,
basis::seed_t _seed):
seed_t _seed):
fractal (_octaves, _frequency, _lacunarity),
basis (_seed)
{ ; }
@ -156,9 +156,9 @@ util::noise::musgrave<B>::eval (double x, double y) const {
//-----------------------------------------------------------------------------
template struct util::noise::musgrave<util::noise::cellular>;
template struct util::noise::musgrave<util::noise::gradient<util::lerp::linear>>;
template struct util::noise::musgrave<util::noise::gradient<util::lerp::quintic>>;
template struct util::noise::musgrave<util::noise::value<util::lerp::linear>>;
template struct util::noise::musgrave<util::noise::value<util::lerp::quintic>>;
template struct util::noise::musgrave<util::noise::cellular<double>>;
template struct util::noise::musgrave<util::noise::gradient<double,util::lerp::linear>>;
template struct util::noise::musgrave<util::noise::gradient<double,util::lerp::quintic>>;
template struct util::noise::musgrave<util::noise::value<double,util::lerp::linear>>;
template struct util::noise::musgrave<util::noise::value<double,util::lerp::quintic>>;

8
noise/fractal.hpp
View File

@ -41,10 +41,12 @@ namespace util {
/// Fractal Brownian Motion summation.
template <typename B>
struct fbm : public fractal {
using seed_t = typename basis<double>::seed_t;
fbm (unsigned octaves,
double frequency,
double lacunarity,
basis::seed_t seed);
seed_t seed);
fbm ();
B basis;
@ -55,10 +57,12 @@ namespace util {
/// Rigid Multifractal noise summation.
template <typename B>
struct musgrave : public fractal {
using seed_t = typename basis<double>::seed_t;
musgrave (unsigned octaves,
double frequency,
double lacunarity,
basis::seed_t seed);
seed_t seed);
musgrave ();
B basis;

6
tools/noise.cpp
View File

@ -11,9 +11,9 @@ main (void)
//using basis_t = util::noise::gradient<lerp_t>;
//using noise_t = util::noise::fbm<basis_t>;
//using noise_t = util::noise::fbm<util::noise::gradient<util::lerp::quintic>>;
//using noise_t = util::noise::musgrave<util::noise::gradient<util::lerp::quintic>>;
using noise_t = util::noise::fbm<util::noise::cellular>;
using noise_t = util::noise::fbm<util::noise::gradient<double,util::lerp::quintic>>;
//using noise_t = util::noise::musgrave<util::noise::gradient<double,util::lerp::quintic>>;
//using noise_t = util::noise::fbm<util::noise::cellular<double>>;
util::noise::fill (img, noise_t {});