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Updated simplex noise 3D
This commit is contained in:
Christophe Riccio
parent
477382f798
commit
082d9151d8
@ -17,11 +17,17 @@
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namespace glm
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{
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template <typename T>
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inline detail::tvec3<T> permute(detail::tvec3<T> const & x)
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template <typename T, template<typename> class vecType>
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inline vecType<T> permute(vecType<T> const & x)
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{
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return mod(((x * T(34)) + T(1)) * x, T(289));
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}
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template <typename T, template<typename> class vecType>
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inline vecType<T> taylorInvSqrt(vecType<T> const & r)
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{
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return T(1.79284291400159) - T(0.85373472095314) * r;
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}
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namespace gtx{
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namespace noise
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@ -54,34 +60,123 @@ namespace noise
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detail::tvec3<T> p = permute(
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permute(i.y + detail::tvec3<T>(T(0), i1.y, T(1)))
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+ i.x + detail::tvec3<T>(T(0), i1.x, T(1)));
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/*
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detail::tvec3<T> m = max(T(0.5) - detail::tvec3<T>(
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dot(x0, x0),
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dot(detail::tvec2<T>(x12.x, x12.y), detail::tvec2<T>(x12.x, x12.y)),
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dot(detail::tvec2<T>(x12.z, x12.w), detail::tvec2<T>(x12.z, x12.w)), T(0.0));
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dot(detail::tvec2<T>(x12.z, x12.w), detail::tvec2<T>(x12.z, x12.w))), T(0));
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m = m * m ;
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m = m * m ;
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// Gradients: 41 points uniformly over a line, mapped onto a diamond.
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// The ring size 17*17 = 289 is close to a multiple of 41 (41*7 = 287)
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detail::tvec3<T> x = 2.0 * fract(p * C.w) - 1.0;
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detail::tvec3<T> h = abs(x) - 0.5;
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detail::tvec3<T> ox = floor(x + 0.5);
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detail::tvec3<T> x = T(2) * fract(p * C.w) - T(1);
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detail::tvec3<T> h = abs(x) - T(0.5);
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detail::tvec3<T> ox = floor(x + T(0.5));
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detail::tvec3<T> a0 = x - ox;
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// Normalise gradients implicitly by scaling m
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// Inlined for speed: m *= taylorInvSqrt( a0*a0 + h*h );
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m *= 1.79284291400159 - 0.85373472095314 * (a0 * a0 + h * h);
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m *= T(1.79284291400159) - T(0.85373472095314) * (a0 * a0 + h * h);
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// Compute final noise value at P
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detail::tvec3<T> g;
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g.x = a0.x * x0.x + h.x * x0.y;
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g.yz = a0.yz * x12.xz + h.yz * x12.yw;
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return 130.0 * dot(m, g);
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*/
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//g.yz = a0.yz * x12.xz + h.yz * x12.yw;
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g.y = a0.y * x12.x + h.y * x12.y;
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g.z = a0.z * x12.z + h.z * x12.w;
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return T(130) * dot(m, g);
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}
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template <typename T>
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inline T snoise(glm::detail::tvec3<T> const & v)
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{
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detail::tvec2<T> const C = detail::tvec2<T>(1.0 / 6.0, 1.0 / 3.0);
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detail::tvec4<T> const D = detail::tvec4<T>(0.0, 0.5, 1.0, 2.0);
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// First corner
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detail::tvec3<T> i = floor(v + dot(v, C.y));
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detail::tvec3<T> x0 = v - i + dot(i, C.x);
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// Other corners
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detail::tvec3<T> g = step(x0.yzx, x0.xyz);
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detail::tvec3<T> l = 1.0 - g;
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detail::tvec3<T> i1 = min( g.xyz, l.zxy );
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detail::tvec3<T> i2 = max( g.xyz, l.zxy );
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// x0 = x0 - 0.0 + 0.0 * C.xxx;
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// x1 = x0 - i1 + 1.0 * C.xxx;
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// x2 = x0 - i2 + 2.0 * C.xxx;
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// x3 = x0 - 1.0 + 3.0 * C.xxx;
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detail::tvec3<T> x1 = x0 - i1 + C.x;
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detail::tvec3<T> x2 = x0 - i2 + C.y; // 2.0*C.x = 1/3 = C.y
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detail::tvec3<T> x3 = x0 - D.y; // -1.0+3.0*C.x = -0.5 = -D.y
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// Permutations
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i = mod(i, T(289));
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detail::tvec4<T> p = permute(permute(permute(
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i.z + detail::tvec4<T>(0.0, i1.z, i2.z, 1.0)) +
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i.y + detail::tvec4<T>(0.0, i1.y, i2.y, 1.0)) +
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i.x + detail::tvec4<T>(0.0, i1.x, i2.x, 1.0));
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// Gradients: 7x7 points over a square, mapped onto an octahedron.
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// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
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T n_ = T(0.142857142857); // 1.0/7.0
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detail::tvec3<T> ns = n_ * D.wyz - D.xzx;
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detail::tvec4<T> j = p - T(49) * floor(p * ns.z * ns.z); // mod(p,7*7)
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detail::tvec4<T> x_ = floor(j * ns.z);
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detail::tvec4<T> y_ = floor(j - T(7) * x_ ); // mod(j,N)
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detail::tvec4<T> x = x_ * ns.x + ns;
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detail::tvec4<T> y = y_ * ns.x + ns;
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detail::tvec4<T> h = T(1) - abs(x) - abs(y);
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detail::tvec4<T> b0 = detail::tvec4<T>(x.xy, y.xy);
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detail::tvec4<T> b1 = detail::tvec4<T>(x.zw, y.zw);
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//vec4 s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0;
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//vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;
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detail::tvec4<T> s0 = floor(b0) * T(2) + T(1);
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detail::tvec4<T> s1 = floor(b1) * T(2) + T(1);
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detail::tvec4<T> sh = -step(h, detail::tvec4<T>(0));
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detail::tvec4<T> a0 = b0 + s0 * sh.xxyy;
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detail::tvec4<T> a1 = b1 + s1 * sh.zzww;
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detail::tvec3<T> p0 = vec3(a0.xy, h.x);
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detail::tvec3<T> p1 = vec3(a0.zw, h.y);
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detail::tvec3<T> p2 = vec3(a1.xy, h.z);
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detail::tvec3<T> p3 = vec3(a1.zw, h.w);
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//Normalise gradients
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detail::tvec4<T> norm = taylorInvSqrt(detail::tvec4<T>(
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dot(p0, p0),
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dot(p1, p1),
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dot(p2, p2),
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dot(p3, p3)));
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p0 *= norm.x;
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p1 *= norm.y;
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p2 *= norm.z;
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p3 *= norm.w;
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// Mix final noise value
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vec4 m = max(T(0.6) - detail::tvec4<T>(
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dot(x0, x0),
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dot(x1, x1),
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dot(x2, x2),
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dot(x3, x3)), T(0));
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m = m * m;
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return T(42) * dot(m * m, detail::tvec4<T>(
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dot(p0, x0),
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dot(p1, x1),
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dot(p2, x2),
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dot(p3, x3)));
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}
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}//namespace noise
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}//namespace gtx
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}//namespace glm
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