+++ /dev/null
-#include "noise.hpp"
-
-#include <cmath>
-
-
-namespace {
-
-constexpr float one_third = 1.0f/3.0f;
-constexpr float one_sixth = 1.0f/6.0f;
-
-}
-
-namespace blank {
-
-GaloisLFSR::GaloisLFSR(std::uint64_t seed) noexcept
-: state(seed) {
-
-}
-
-bool GaloisLFSR::operator ()() noexcept {
- bool result = state & 1;
- state >>= 1;
- if (result) {
- state |= 0x8000000000000000;
- state ^= mask;
- } else {
- state &= 0x7FFFFFFFFFFFFFFF;
- }
- return result;
-}
-
-
-SimplexNoise::SimplexNoise(unsigned int seed) noexcept
-: grad({
- { 1.0f, 1.0f, 0.0f },
- { -1.0f, 1.0f, 0.0f },
- { 1.0f, -1.0f, 0.0f },
- { -1.0f, -1.0f, 0.0f },
- { 1.0f, 0.0f, 1.0f },
- { -1.0f, 0.0f, 1.0f },
- { 1.0f, 0.0f, -1.0f },
- { -1.0f, 0.0f, -1.0f },
- { 0.0f, 1.0f, 1.0f },
- { 0.0f, -1.0f, 1.0f },
- { 0.0f, 1.0f, -1.0f },
- { 0.0f, -1.0f, -1.0f },
-}) {
- GaloisLFSR random(seed ^ 0x0123456789ACBDEF);
- unsigned char value;
- for (size_t i = 0; i < 256; ++i) {
- perm[i] = random(value);
- perm[i] &= 0xFF;
- perm[i + 256] = perm[i];
- perm12[i] = perm[i] % 12;
- perm12[i + 256] = perm12[i];
- }
-}
-
-
-float SimplexNoise::operator ()(const glm::vec3 &in) const noexcept {
- float skew = (in.x + in.y + in.z) * one_third;
-
- glm::vec3 skewed(glm::floor(in + skew));
- float tr = (skewed.x + skewed.y + skewed.z) * one_sixth;
-
- glm::vec3 unskewed(skewed - tr);
- glm::vec3 relative(in - unskewed);
-
- glm::vec3 second, third;
-
- if (relative.x >= relative.y) {
- if (relative.y >= relative.z) {
- second = { 1, 0, 0 };
- third = { 1, 1, 0 };
- } else if (relative.x >= relative.z) {
- second = { 1, 0, 0 };
- third = { 1, 0, 1 };
- } else {
- second = { 0, 0, 1 };
- third = { 1, 0, 1 };
- }
- } else if (relative.y < relative.z) {
- second = { 0, 0, 1 };
- third = { 0, 1, 1 };
- } else if (relative.x < relative.z) {
- second = { 0, 1, 0 };
- third = { 0, 1, 1 };
- } else {
- second = { 0, 1, 0 };
- third = { 1, 1, 0 };
- }
-
- glm::vec3 offset[4] = {
- in - unskewed,
- relative - second + one_sixth,
- relative - third + one_third,
- relative - 0.5f,
- };
-
- int index[3] = {
- (int)(skewed.x) & 0xFF,
- (int)(skewed.y) & 0xFF,
- (int)(skewed.z) & 0xFF,
- };
-
- float n = 0.0f;
-
- // 0
- float t = 0.6f - dot(offset[0], offset[0]);
- if (t > 0.0f) {
- t *= t;
- int corner = Perm12(index[0] + Perm(index[1] + Perm(index[2])));
- n += t * t * dot(Grad(corner), offset[0]);
- }
-
- // 1
- t = 0.6f - dot(offset[1], offset[1]);
- if (t > 0.0f) {
- t *= t;
- int corner = Perm12(index[0] + int(second.x) + Perm(index[1] + int(second.y) + Perm(index[2] + int(second.z))));
- n += t * t * dot(Grad(corner), offset[1]);
- }
-
- // 2
- t = 0.6f - dot(offset[2], offset[2]);
- if (t > 0.0f) {
- t *= t;
- int corner = Perm12(index[0] + int(third.x) + Perm(index[1] + int(third.y) + Perm(index[2] + int(third.z))));
- n += t * t * dot(Grad(corner), offset[2]);
- }
-
- // 3
- t = 0.6f - dot(offset[3], offset[3]);
- if (t > 0.0f) {
- t *= t;
- int corner = Perm12(index[0] + 1 + Perm(index[1] + 1 + Perm(index[2] + 1)));
- n += t * t * dot(Grad(corner), offset[3]);
- }
-
- return 32.0f * n;
-}
-
-
-int SimplexNoise::Perm(int idx) const noexcept {
- return perm[idx];
-}
-
-int SimplexNoise::Perm12(int idx) const noexcept {
- return perm12[idx];
-}
-
-const glm::vec3 &SimplexNoise::Grad(int idx) const noexcept {
- return grad[idx];
-}
-
-
-WorleyNoise::WorleyNoise(unsigned int seed) noexcept
-: seed(seed)
-, num_points(8) {
-
-}
-
-float WorleyNoise::operator ()(const glm::vec3 &in) const noexcept {
- glm::vec3 center = floor(in);
-
- float closest = 1.0f; // cannot be farther away than 1.0
-
- for (int z = -1; z <= 1; ++z) {
- for (int y = -1; y <= 1; ++y) {
- for (int x = -1; x <= 1; ++x) {
- glm::vec3 cube(center.x + x, center.y + y, center.z + z);
- unsigned int cube_rand =
- (unsigned(cube.x) * 130223) ^
- (unsigned(cube.y) * 159899) ^
- (unsigned(cube.z) * 190717) ^
- seed;
-
- for (int i = 0; i < num_points; ++i) {
- glm::vec3 point(cube);
- cube_rand = 190667 * cube_rand + 109807;
- point.x += float(cube_rand % 262144) / 262144.0f;
- cube_rand = 135899 * cube_rand + 189169;
- point.y += float(cube_rand % 262144) / 262144.0f;
- cube_rand = 159739 * cube_rand + 112139;
- point.z += float(cube_rand % 262144) / 262144.0f;
-
- glm::vec3 diff(in - point);
- float distance = sqrt(dot(diff, diff));
- if (distance < closest) {
- closest = distance;
- }
- }
- }
- }
- }
-
- // closest ranges (0, 1), so normalizing to (-1,1) is trivial
- // though heavily biased towards lower numbers
- return 2.0f * closest - 1.0f;
-}
-
-}
projects / blank.git / blobdiff