--- /dev/null
+#ifndef BLOBS_RAND_GALOISLFSR_HPP_
+#define BLOBS_RAND_GALOISLFSR_HPP_
+
+#include <cassert>
+#include <cstdint>
+#include <limits>
+
+
+namespace blobs {
+namespace rand {
+
+class GaloisLFSR {
+
+public:
+ // seed should be non-zero
+ explicit GaloisLFSR(std::uint64_t seed) noexcept
+ : state(seed) {
+ if (state == 0) {
+ state = 1;
+ }
+ }
+
+ // get the next bit
+ bool operator ()() noexcept {
+ bool result = state & 1;
+ state >>= 1;
+ if (result) {
+ state |= 0x8000000000000000;
+ state ^= mask;
+ } else {
+ state &= 0x7FFFFFFFFFFFFFFF;
+ }
+ return result;
+ }
+
+ template<class T>
+ T operator ()(T &out) noexcept {
+ constexpr int num_bits =
+ std::numeric_limits<T>::digits +
+ std::numeric_limits<T>::is_signed;
+ for (int i = 0; i < num_bits; ++i) {
+ operator ()();
+ }
+ return out = static_cast<T>(state);
+ }
+
+ /// special case for randrom(boolean), since static_cast<bool>(0b10) == true
+ bool operator ()(bool &out) noexcept {
+ return out = operator ()();
+ }
+
+ template<class T>
+ T Next() noexcept {
+ T next;
+ return (*this)(next);
+ }
+
+ float SNorm() noexcept {
+ return float(Next<std::uint32_t>()) * (1.0f / 2147483647.5f) - 1.0f;
+ }
+
+ float UNorm() noexcept {
+ return float(Next<std::uint32_t>()) * (1.0f / 4294967295.0f);
+ }
+
+ template<class Container>
+ typename Container::reference From(Container &c) {
+ assert(c.size() > 0);
+ return c[Next<typename Container::size_type>() % c.size()];
+ }
+ template<class Container>
+ typename Container::const_reference From(const Container &c) {
+ assert(c.size() > 0);
+ return c[Next<typename Container::size_type>() % c.size()];
+ }
+
+private:
+ std::uint64_t state;
+ // bits 64, 63, 61, and 60 set to 1 (counting from 1 lo to hi)
+ static constexpr std::uint64_t mask = 0xD800000000000000;
+
+};
+
+}
+}
+
+#endif
--- /dev/null
+#ifndef BLOBS_RAND_OCTAVENOISE_HPP_
+#define BLOBS_RAND_OCTAVENOISE_HPP_
+
+#include "../graphics/glm.hpp"
+
+
+namespace blobs {
+namespace rand {
+
+template<class Noise>
+float OctaveNoise(
+ const Noise &noise,
+ const glm::vec3 &in,
+ int num,
+ float persistence,
+ float frequency = 1.0f,
+ float amplitude = 1.0f,
+ float growth = 2.0f
+) {
+ float total = 0.0f;
+ float max = 0.0f;
+ for (int i = 0; i < num; ++i) {
+ total += noise(in * frequency) * amplitude;
+ max += amplitude;
+ amplitude *= persistence;
+ frequency *= growth;
+ }
+
+ return total / max;
+}
+
+}
+}
+
+#endif
--- /dev/null
+#ifndef BLOBS_RAND_SIMPLEXNOISE_HPP_
+#define BLOBS_RAND_SIMPLEXNOISE_HPP_
+
+#include "../graphics/glm.hpp"
+
+#include <cstdint>
+
+
+namespace blobs {
+namespace rand {
+
+class SimplexNoise {
+
+public:
+ explicit SimplexNoise(std::uint64_t seed) noexcept;
+
+ float operator ()(const glm::vec3 &) const noexcept;
+
+private:
+ int Perm(int idx) const noexcept;
+ int Perm12(int idx) const noexcept;
+ const glm::vec3 &Grad(int idx) const noexcept;
+
+private:
+ int perm[512];
+ int perm12[512];
+ glm::vec3 grad[12];
+ glm::ivec3 second_ints[8];
+ glm::ivec3 third_ints[8];
+ glm::vec3 second_floats[8];
+ glm::vec3 third_floats[8];
+
+};
+
+}
+}
+
+#endif
--- /dev/null
+#ifndef BLOBS_RAND_WORLEYNOISE_HPP_
+#define BLOBS_RAND_WORLEYNOISE_HPP_
+
+#include "../graphics/glm.hpp"
+
+
+namespace blobs {
+namespace rand {
+
+/// implementation of Worley noise (aka Cell or Voroni noise)
+class WorleyNoise {
+
+public:
+ explicit WorleyNoise(unsigned int seed) noexcept;
+
+ float operator ()(const glm::vec3 &) const noexcept;
+
+private:
+ const unsigned int seed;
+ const int num_points;
+
+};
+
+}
+}
+
+#endif
--- /dev/null
+#include "GaloisLFSR.hpp"
+#include "SimplexNoise.hpp"
+#include "WorleyNoise.hpp"
+
+#include <cmath>
+#include <glm/gtx/norm.hpp>
+
+
+namespace {
+
+constexpr float one_third = 1.0f/3.0f;
+constexpr float one_sixth = 1.0f/6.0f;
+
+}
+
+namespace blobs {
+namespace rand {
+
+SimplexNoise::SimplexNoise(std::uint64_t 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 },
+})
+, second_ints({
+ // x>y x>z y>z
+ { 0, 0, 1 }, // 0 0 0 ZYX
+ { 0, 1, 0 }, // 0 0 1 YZX
+ { 0, 0, 1 }, // 0 1 0 illogical, but ZYX
+ { 0, 1, 0 }, // 0 1 1 YXZ
+ { 0, 0, 1 }, // 1 0 0 ZXY
+ { 1, 0, 0 }, // 1 0 1 illogical, but XYZ
+ { 1, 0, 0 }, // 1 1 0 XZY
+ { 1, 0, 0 }, // 1 1 1 XYZ
+})
+, third_ints({
+ // x>y x>z y>z
+ { 0, 1, 1 }, // 0 0 0 ZYX
+ { 0, 1, 1 }, // 0 0 1 YZX
+ { 0, 1, 1 }, // 0 1 0 illogical, but ZYX
+ { 1, 1, 0 }, // 0 1 1 YXZ
+ { 1, 0, 1 }, // 1 0 0 ZXY
+ { 1, 1, 0 }, // 1 0 1 illogical, but XYZ
+ { 1, 0, 1 }, // 1 1 0 XZY
+ { 1, 1, 0 }, // 1 1 1 XYZ
+})
+, second_floats({
+ // x>y x>z y>z
+ { 0.0f, 0.0f, 1.0f }, // 0 0 0 ZYX
+ { 0.0f, 1.0f, 0.0f }, // 0 0 1 YZX
+ { 0.0f, 0.0f, 1.0f }, // 0 1 0 illogical, but ZYX
+ { 0.0f, 1.0f, 0.0f }, // 0 1 1 YXZ
+ { 0.0f, 0.0f, 1.0f }, // 1 0 0 ZXY
+ { 1.0f, 0.0f, 0.0f }, // 1 0 1 illogical, but XYZ
+ { 1.0f, 0.0f, 0.0f }, // 1 1 0 XZY
+ { 1.0f, 0.0f, 0.0f }, // 1 1 1 XYZ
+})
+, third_floats({
+ // x>y x>z y>z
+ { 0.0f, 1.0f, 1.0f }, // 0 0 0 ZYX
+ { 0.0f, 1.0f, 1.0f }, // 0 0 1 YZX
+ { 0.0f, 1.0f, 1.0f }, // 0 1 0 illogical, but ZYX
+ { 1.0f, 1.0f, 0.0f }, // 0 1 1 YXZ
+ { 1.0f, 0.0f, 1.0f }, // 1 0 0 ZXY
+ { 1.0f, 1.0f, 0.0f }, // 1 0 1 illogical, but XYZ
+ { 1.0f, 0.0f, 1.0f }, // 1 1 0 XZY
+ { 1.0f, 1.0f, 0.0f }, // 1 1 1 XYZ
+}) {
+ 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);
+
+ bool x_ge_y = relative.x >= relative.y;
+ bool x_ge_z = relative.x >= relative.z;
+ bool y_ge_z = relative.y >= relative.z;
+ unsigned int st = (x_ge_y << 2) | (x_ge_z << 1) | y_ge_z;
+
+ glm::ivec3 second_int(second_ints[st]);
+ glm::ivec3 third_int(third_ints[st]);
+ glm::vec3 second_float(second_floats[st]);
+ glm::vec3 third_float(third_floats[st]);
+
+ glm::vec3 offset[4] = {
+ in - unskewed,
+ relative - second_float + one_sixth,
+ relative - third_float + one_third,
+ relative - 0.5f,
+ };
+
+ int index[3] = {
+ (int)(skewed.x) & 0xFF,
+ (int)(skewed.y) & 0xFF,
+ (int)(skewed.z) & 0xFF,
+ };
+
+ float n = 0.0f;
+
+ // I know 0.6 is wrong, but for some reason it looks better than 0.5
+
+ // 0
+ float t = glm::clamp(0.6f - glm::length2(offset[0]), 0.0f, 1.0f);
+ t *= t;
+ int corner = Perm12(index[0] + Perm(index[1] + Perm(index[2])));
+ n += t * t * glm::dot(Grad(corner), offset[0]);
+
+ // 1
+ t = glm::clamp(0.6f - glm::length2(offset[1]), 0.0f, 1.0f);
+ t *= t;
+ corner = Perm12(index[0] + second_int.x + Perm(index[1] + second_int.y + Perm(index[2] + second_int.z)));
+ n += t * t * glm::dot(Grad(corner), offset[1]);
+
+ // 2
+ t = glm::clamp(0.6f - glm::length2(offset[2]), 0.0f, 1.0f);
+ t *= t;
+ corner = Perm12(index[0] + third_int.x + Perm(index[1] + third_int.y + Perm(index[2] + third_int.z)));
+ n += t * t * glm::dot(Grad(corner), offset[2]);
+
+ // 3
+ t = glm::clamp(0.6f - glm::length2(offset[3]), 0.0f, 1.0f);
+ t *= t;
+ corner = Perm12(index[0] + 1 + Perm(index[1] + 1 + Perm(index[2] + 1)));
+ n += t * t * glm::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 = glm::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;
+
+ float distance = glm::distance(in, point);
+ 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;
+}
+
+}
+}
--- /dev/null
+#include "GaloisLFSRTest.hpp"
+
+#include "rand/GaloisLFSR.hpp"
+
+#include <algorithm>
+#include <sstream>
+
+CPPUNIT_TEST_SUITE_REGISTRATION(blobs::rand::test::GaloisLFSRTest);
+
+using namespace std;
+
+
+namespace blobs {
+namespace rand {
+namespace test {
+
+void GaloisLFSRTest::setUp() {
+
+}
+
+void GaloisLFSRTest::tearDown() {
+
+}
+
+void GaloisLFSRTest::testFloatNorm() {
+ GaloisLFSR random(4);
+ for (int i = 0; i < 64; ++i) {
+ float value = random.SNorm();
+ AssertBetween(
+ "random signed normal float",
+ -1.0f, 1.0f, value);
+ }
+ for (int i = 0; i < 64; ++i) {
+ float value = random.UNorm();
+ AssertBetween(
+ "random unsigned normal float",
+ 0.0f, 1.0f, value);
+ }
+}
+
+void GaloisLFSRTest::testFromContainer() {
+ GaloisLFSR random(5);
+ const vector<int> container({ 1, 2, 3, 4, 5 });
+ for (int i = 0; i < 64; ++i) {
+ int element = random.From(container);
+ AssertContains(
+ "random element from container",
+ container, element);
+ }
+}
+
+void GaloisLFSRTest::AssertBetween(
+ string message,
+ float minimum,
+ float maximum,
+ float actual
+) {
+ stringstream msg;
+ msg << message << ": " << actual << " not in ["
+ << minimum << ',' << maximum << ']';
+ CPPUNIT_ASSERT_MESSAGE(
+ msg.str(),
+ minimum <= actual && actual <= maximum);
+
+}
+
+void GaloisLFSRTest::AssertContains(
+ string message,
+ const vector<int> &container,
+ int element
+) {
+ stringstream msg;
+ msg << message << ": " << element << " not in { ";
+ for (int i : container) {
+ msg << i << ' ';
+ }
+ msg << '}';
+ CPPUNIT_ASSERT_MESSAGE(
+ msg.str(),
+ find(container.begin(), container.end(), element) != container.end());
+
+}
+
+}
+}
+}
--- /dev/null
+#ifndef BLOBS_TEST_RAND_GALOISLFSRTEST_HPP
+#define BLOBS_TEST_RAND_GALOISLFSRTEST_HPP
+
+#include <cppunit/extensions/HelperMacros.h>
+
+#include <string>
+#include <vector>
+
+
+namespace blobs {
+namespace rand {
+namespace test {
+
+class GaloisLFSRTest
+: public CppUnit::TestFixture {
+
+CPPUNIT_TEST_SUITE(GaloisLFSRTest);
+
+CPPUNIT_TEST(testFloatNorm);
+CPPUNIT_TEST(testFromContainer);
+
+CPPUNIT_TEST_SUITE_END();
+
+public:
+ void setUp();
+ void tearDown();
+
+ void testFloatNorm();
+ void testFromContainer();
+
+ /// check if value is in range [minimum,maximum]
+ static void AssertBetween(
+ std::string message,
+ float minimum,
+ float maximum,
+ float actual);
+
+ static void AssertContains(
+ std::string message,
+ const std::vector<int> &container,
+ int element);
+
+};
+
+}
+}
+}
+
+#endif
--- /dev/null
+#include "StabilityTest.hpp"
+
+#include "rand/GaloisLFSR.hpp"
+#include "rand/SimplexNoise.hpp"
+#include "rand/WorleyNoise.hpp"
+
+#include <cstdint>
+#include <string>
+#include <sstream>
+#include <glm/gtx/io.hpp>
+
+CPPUNIT_TEST_SUITE_REGISTRATION(blobs::rand::test::StabilityTest);
+
+using namespace std;
+
+
+namespace blobs {
+namespace rand {
+namespace test {
+
+void StabilityTest::setUp() {
+
+}
+
+void StabilityTest::tearDown() {
+
+}
+
+
+void StabilityTest::testRNG() {
+ GaloisLFSR random(0);
+ uint16_t value;
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #1 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #2 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #3 from RNG",
+ uint16_t(0xB000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #4 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #5 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #6 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #7 from RNG",
+ uint16_t(0x4500), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #8 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #9 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #10 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #11 from RNG",
+ uint16_t(0x2E70), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #12 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #13 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #14 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #15 from RNG",
+ uint16_t(0x1011), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #16 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #17 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #18 from RNG",
+ uint16_t(0xB000), value
+ );
+ value = random.Next<uint16_t>();
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #19 from RNG (using Next())",
+ uint16_t(0x0B0B), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #20 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #21 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #22 from RNG",
+ uint16_t(0x1500), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #23 from RNG",
+ uint16_t(0x0454), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #24 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #25 from RNG",
+ uint16_t(0x0000), value
+ );
+ value = random.Next<uint16_t>();
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #26 from RNG (using Next())",
+ uint16_t(0xC970), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #27 from RNG",
+ uint16_t(0x02E5), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #28 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #29 from RNG",
+ uint16_t(0x0000), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #30 from RNG",
+ uint16_t(0x0101), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #31 from RNG",
+ uint16_t(0x0100), value
+ );
+ random(value);
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected value #32 from RNG",
+ uint16_t(0x0000), value
+ );
+
+ GaloisLFSR random1(1);
+ uint16_t value1;
+ for (int i = 0; i < 32; ++i) {
+ random1(value1);
+ }
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "RNG with seeds 0 and 1 differ",
+ value, value1
+ );
+
+ GaloisLFSR random_bool(0);
+ bool value_bool;
+ for (int i = 0; i < (16 * 32); ++i) {
+ random_bool(value_bool);
+ }
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected result for bool",
+ false, value_bool
+ );
+
+ GaloisLFSR random8(0);
+ uint8_t value8;
+ for (int i = 0; i < 31; ++i) {
+ random8(value8);
+ }
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected result for uint8",
+ uint8_t(0x10), value8
+ );
+
+ GaloisLFSR random32(0);
+ uint32_t value32;
+ for (int i = 0; i < 16; ++i) {
+ random32(value32);
+ }
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "unexpected result for uint32",
+ uint32_t(0xB0000000), value32
+ );
+}
+
+void StabilityTest::testSimplex() {
+ SimplexNoise noise(0);
+
+ Assert(noise, glm::vec3(0.0f, 0.0f, 0.0f), 0.0f);
+ Assert(noise, glm::vec3(0.0f, 0.0f, 1.0f), 0.652221322059631f);
+ Assert(noise, glm::vec3(0.0f, 1.0f, 0.0f), 0.867977976799011f);
+ Assert(noise, glm::vec3(0.0f, 1.0f, 1.0f), -0.107878111302853f);
+ Assert(noise, glm::vec3(1.0f, 0.0f, 0.0f), -0.107878260314465f);
+ Assert(noise, glm::vec3(1.0f, 0.0f, 1.0f), -6.31356940061778e-08f);
+ Assert(noise, glm::vec3(1.0f, 1.0f, 0.0f), -0.107878245413303f);
+ Assert(noise, glm::vec3(1.0f, 1.0f, 1.0f), 0.0f);
+
+ Assert(noise, glm::vec3( 0.0f, 0.0f, -1.0f), -0.107878483831882f);
+ Assert(noise, glm::vec3( 0.0f, -1.0f, 0.0f), -0.760099768638611f);
+ Assert(noise, glm::vec3( 0.0f, -1.0f, -1.0f), 0.0f);
+ Assert(noise, glm::vec3(-1.0f, 0.0f, 0.0f), 0.760099768638611f);
+ Assert(noise, glm::vec3(-1.0f, 0.0f, -1.0f), 0.0f);
+ Assert(noise, glm::vec3(-1.0f, -1.0f, 0.0f), -0.107878118753433f);
+ Assert(noise, glm::vec3(-1.0f, -1.0f, -1.0f), 0.0f);
+}
+
+void StabilityTest::testWorley() {
+ WorleyNoise noise(0);
+
+ Assert(noise, glm::vec3(0.0f, 0.0f, 0.0f), -0.117765009403229f);
+ Assert(noise, glm::vec3(0.0f, 0.0f, 1.0f), -0.209876894950867f);
+ Assert(noise, glm::vec3(0.0f, 1.0f, 0.0f), -0.290086328983307f);
+ Assert(noise, glm::vec3(0.0f, 1.0f, 1.0f), -0.332393705844879f);
+ Assert(noise, glm::vec3(1.0f, 0.0f, 0.0f), -0.621925830841064f);
+ Assert(noise, glm::vec3(1.0f, 0.0f, 1.0f), -0.338455379009247f);
+ Assert(noise, glm::vec3(1.0f, 1.0f, 0.0f), -0.386664032936096f);
+ Assert(noise, glm::vec3(1.0f, 1.0f, 1.0f), -0.533940434455872f);
+
+ Assert(noise, glm::vec3( 0.0f, 0.0f, -1.0f), -0.425480604171753f);
+ Assert(noise, glm::vec3( 0.0f, -1.0f, 0.0f), -0.189745843410492f);
+ Assert(noise, glm::vec3( 0.0f, -1.0f, -1.0f), -0.30408102273941f);
+ Assert(noise, glm::vec3(-1.0f, 0.0f, 0.0f), -0.618566155433655f);
+ Assert(noise, glm::vec3(-1.0f, 0.0f, -1.0f), -0.060045599937439f);
+ Assert(noise, glm::vec3(-1.0f, -1.0f, 0.0f), -0.366827547550201f);
+ Assert(noise, glm::vec3(-1.0f, -1.0f, -1.0f), -0.575981974601746f);
+}
+
+void StabilityTest::Assert(
+ const SimplexNoise &noise,
+ const glm::vec3 &position,
+ float expected
+) {
+ stringstream msg;
+ msg << "unexpected simplex noise value at " << position;
+ CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+ msg.str(),
+ expected, noise(position), numeric_limits<float>::epsilon()
+ );
+}
+
+void StabilityTest::Assert(
+ const WorleyNoise &noise,
+ const glm::vec3 &position,
+ float expected
+) {
+ stringstream msg;
+ msg << "unexpected worley noise value at " << position;
+ CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+ msg.str(),
+ expected, noise(position), numeric_limits<float>::epsilon()
+ );
+}
+
+}
+}
+}
--- /dev/null
+#ifndef BLOBS_TEST_RAND_STABILITYTEST_HPP
+#define BLOBS_TEST_RAND_STABILITYTEST_HPP
+
+#include "graphics/glm.hpp"
+
+#include <cppunit/extensions/HelperMacros.h>
+
+
+
+namespace blobs {
+namespace rand {
+
+class SimplexNoise;
+class WorleyNoise;
+
+namespace test {
+
+class StabilityTest
+: public CppUnit::TestFixture {
+
+CPPUNIT_TEST_SUITE(StabilityTest);
+
+CPPUNIT_TEST(testRNG);
+CPPUNIT_TEST(testSimplex);
+CPPUNIT_TEST(testWorley);
+
+CPPUNIT_TEST_SUITE_END();
+
+public:
+ void setUp();
+ void tearDown();
+
+ void testRNG();
+ void testSimplex();
+ void testWorley();
+
+ static void Assert(
+ const SimplexNoise &noise,
+ const glm::vec3 &position,
+ float expected);
+
+ static void Assert(
+ const WorleyNoise &noise,
+ const glm::vec3 &position,
+ float expected);
+
+};
+
+}
+}
+}
+
+#endif