Added snoise (2d) implementation draft

This commit is contained in:
Christophe Riccio 2011-04-21 17:20:56 +01:00
parent a805b42f8b
commit 3bf665116d
5 changed files with 72 additions and 94 deletions

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@ -12,88 +12,7 @@ namespace glm
namespace core{
namespace function{
namespace noise{
namespace detail
{
template <typenane valType, typenane genType>
inline vecType permute
(
genType const & x0,
detail::tvec3<valType> const & p
)
{
genType x1 = mod(x0 * p.y, p.x);
return floor(mod((x1 + p.z) * x0, p.x));
}
template <typenane T>
inline T taylorInvSqrt(T const & r)
{
return T(0.83666002653408) + T(0.7) * T(0.85373472095314) - T(0.85373472095314) * r);
}
}//namespace detail
template <typename T>
T simplexNoise2(detail::tvec2<T> const & v)
{
static const detail::tvec4<T> pParam(17. * 17., 34., 1., 7.);
detail::tvec2<T> const C = detail::tvec2<T>(
0.211324865405187134, // (3.0-sqrt(3.0))/6.;
0.366025403784438597); // 0.5*(sqrt(3.0)-1.);
detail::tvec3<T> const D = detail::tvec3<T>(0., 0.5, 2.0) * T(3.14159265358979312);
// First corner
detail::tvec2<T> i = floor(v + dot(v, detail::tvec2<T>(C.y)));
detail::tvec2<T> x0 = v - i + dot(i, detail::tvec2<T>(C.x));
// Other corners
detail::tvec2<T> i1 = (x0.x > x0.y) ? detail::tvec2<T>(1, 0) : detail::tvec2<T>(0, 1) ;
// x0 = x0 - 0. + 0. * C
detail::tvec2<T> x1 = x0 - i1 + T(1) * detail::tvec2<T>(C.x);
detail::tvec2<T> x2 = x0 - T(1) + T(2) * detail::tvec2<T>(C.x);
// Permutations
i = mod(i, pParam.x);
detail::tvec3<T> p = permute(
permute(i.y + detail::tvec3<T>(T(0), i1.y, T(1)), detail::tvec3<T>(pParam))
+ i.x + detail::tvec3<T>(T(0), i1.x, T(1)), detail::tvec3<T>(pParam));
#ifndef USE_CIRCLE
// ( N points uniformly over a line, mapped onto a diamond.)
detail::tvec3<T> x = fract(p / pParam.w) ;
detail::tvec3<T> h = T(0.5) - abs(x) ;
detail::tvec3<T> sx = detail::tvec3<T>(lessThan(x, detail::tvec3<T>(D.x))) * T(2) - T(1);
detail::tvec3<T> sh = detail::tvec3<T>(lessThan(h, detail::tvec3<T>(D.x)));
detail::tvec3<T> a0 = x + sx * sh;
detail::tvec2<T> p0(a0.x, h.x);
detail::tvec2<T> p1(a0.y, h.y);
detail::tvec2<T> p2(a0.z, h.z);
# ifdef NORMALISE_GRADIENTS
p0 *= taylorInvSqrt(dot(p0, p0));
p1 *= taylorInvSqrt(dot(p1, p1));
p2 *= taylorInvSqrt(dot(p2, p2));
# endif
detail::tvec3<T> g = T(2) * detail::tvec3<T>(dot(p0, x0), dot(p1, x1), dot(p2, x2));
#else
// N points around a unit circle.
detail::tvec3<T> phi = D.z * mod(p, pParam.w) / pParam.w;
detail::tvec4<T> a0 = sin(phi.xxyy + D.xyxy);
detail::tvec2<T> a1 = sin(detail::tvec2<T>(phi.z) + D.xy);
detail::tvec3<T> g = detail::tvec3<T>(
dot(a0.xy, x0),
dot(detail::tvec2<T>(a0.z, a0.w), x1),
dot(detail::tvec2<T>(a1.x, a1.y), x2));
#endif
// mix
detail::tvec3<T> m = max(T(0.5) - detail::tvec3<T>(dot(x0,x0), dot(x1, x1), dot(x2, x2)), T(0));
m = m * m ;
return T(1.66666) * T(70) * dot(m * m, g);
}
}//namespace noise
}//namespace function

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@ -69,7 +69,6 @@
#include "./gtx/raw_data.hpp"
#include "./gtx/reciprocal.hpp"
#include "./gtx/rotate_vector.hpp"
#include "./gtx/simplex.hpp"
#include "./gtx/spline.hpp"
#include "./gtx/std_based_type.hpp"
#include "./gtx/string_cast.hpp"

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@ -40,22 +40,22 @@ namespace glm
//! Classic perlin noise.
//! From GLM_GTX_noise extension.
template <typename vecType>
typename vecType::value_type cnoise(
vecType const & p);
template <typename T, template<typename> class vecType>
typename T cnoise(
vecType<T> const & p);
//! Periodic perlin noise.
//! From GLM_GTX_noise extension.
template <typename vecType>
typename vecType::value_type pnoise(
vecType const & p,
vecType const & rep);
template <typename T, template<typename> class vecType>
typename T pnoise(
vecType<T> const & p,
vecType<T> const & rep);
//! Simplex noise.
//! From GLM_GTX_noise extension.
template <typename vecType>
typename vecType::value_type snoise(
vecType const & p);
template <typename T, template<typename> class vecType>
typename T snoise(
vecType<T> const & p);
///@}

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@ -15,12 +15,72 @@
// - GLM core
///////////////////////////////////////////////////////////////////////////////////////////////////
namespace glm{
namespace glm
{
template <typename T>
inline detail::tvec3<T> permute(detail::tvec3<T> const & x)
{
return mod(((x * T(34)) + T(1)) * x, T(289));
}
namespace gtx{
namespace noise
{
template <typename T>
inline T snoise(glm::detail::tvec2<T> const & v)
{
detail::tvec4<T> const C = detail::tvec4<T>(
T( 0.211324865405187), // (3.0 - sqrt(3.0)) / 6.0
T( 0.366025403784439), // 0.5 * (sqrt(3.0) - 1.0)
T(-0.577350269189626), // -1.0 + 2.0 * C.x
T( 0.024390243902439)); // 1.0 / 41.0
// First corner
detail::tvec2<T> i = floor(v + dot(v, detail::tvec2<T>(C[1])));
detail::tvec2<T> x0 = v - i + dot(i, detail::tvec2<T>(C[0]));
// Other corners
//i1.x = step( x0.y, x0.x ); // x0.x > x0.y ? 1.0 : 0.0
//i1.y = 1.0 - i1.x;
detail::tvec2<T> i1 = (x0.x > x0.y) ? detail::tvec2<T>(1, 0) : detail::tvec2<T>(0, 1);
// x0 = x0 - 0.0 + 0.0 * C.xx ;
// x1 = x0 - i1 + 1.0 * C.xx ;
// x2 = x0 - 1.0 + 2.0 * C.xx ;
detail::tvec4<T> x12 = detail::tvec4<T>(x0.x, x0.y, x0.x, x0.y) + detail::tvec4<T>(C.x, C.x, C.z, C.z);
x12 = detail::tvec4<T>(detail::tvec2<T>(x12) - i1, x12.z, x12.w);
// Permutations
i = mod(i, T(289)); // Avoid truncation effects in permutation
detail::tvec3<T> p = permute(
permute(i.y + detail::tvec3<T>(T(0), i1.y, T(1)))
+ i.x + detail::tvec3<T>(T(0), i1.x, T(1)));
/*
detail::tvec3<T> m = max(T(0.5) - detail::tvec3<T>(
dot(x0, x0),
dot(detail::tvec2<T>(x12.x, x12.y), detail::tvec2<T>(x12.x, x12.y)),
dot(detail::tvec2<T>(x12.z, x12.w), detail::tvec2<T>(x12.z, x12.w)), T(0.0));
m = m * m ;
m = m * m ;
// Gradients: 41 points uniformly over a line, mapped onto a diamond.
// The ring size 17*17 = 289 is close to a multiple of 41 (41*7 = 287)
detail::tvec3<T> x = 2.0 * fract(p * C.w) - 1.0;
detail::tvec3<T> h = abs(x) - 0.5;
detail::tvec3<T> ox = floor(x + 0.5);
detail::tvec3<T> a0 = x - ox;
// Normalise gradients implicitly by scaling m
// Inlined for speed: m *= taylorInvSqrt( a0*a0 + h*h );
m *= 1.79284291400159 - 0.85373472095314 * (a0 * a0 + h * h);
// Compute final noise value at P
detail::tvec3<T> g;
g.x = a0.x * x0.x + h.x * x0.y;
g.yz = a0.yz * x12.xz + h.yz * x12.yw;
return 130.0 * dot(m, g);
*/
}
}//namespace noise
}//namespace gtx

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@ -13,5 +13,5 @@
int main()
{
float ValueSNoise2D = glm::snoise(glm::vec2(0.5f));
}