bunch of noise stuff

This commit is contained in:
Yggdrasil75
2025-11-07 13:27:05 -05:00
parent 82c0e2527f
commit 90a34cd433
3 changed files with 475 additions and 60 deletions

View File

@@ -32,14 +32,14 @@ private:
Vec4 waterColor; Vec4 waterColor;
public: public:
Sim2(int width = 512, int height = 512, uint32_t seed = 12345) Sim2(int width = 512, int height = 512, uint32_t seed = 42)
: gridWidth(width), gridHeight(height), scale(4.0f), octaves(4), : gridWidth(width), gridHeight(height), scale(4.0f), octaves(4),
persistence(0.5f), lacunarity(2.0f), seed(seed), offset(0, 0), persistence(0.5f), lacunarity(2.0f), seed(seed), offset(0, 0),
elevationMultiplier(1.0f), waterLevel(0.3f), elevationMultiplier(1.0f), waterLevel(0.3f),
landColor(0.2f, 0.8f, 0.2f, 1.0f), // Green landColor(0.2f, 0.8f, 0.2f, 1.0f), // Green
waterColor(0.2f, 0.3f, 0.8f, 1.0f) // Blue waterColor(0.2f, 0.3f, 0.8f, 1.0f) // Blue
{ {
noiseGenerator = std::make_unique<Noise2>(seed); noiseGenerator = std::make_unique<Noise2>(seed,Noise2::WORLEY,Noise2::PRECOMPUTED);
generateTerrain(); generateTerrain();
} }

View File

@@ -13,6 +13,22 @@ class Sim2 {
private: private:
Noise2 noise; Noise2 noise;
Grid2 terrainGrid; Grid2 terrainGrid;
} int width;
int height;
float scale;
int octaves;
float lacunarity;
int seed;
float elevationMult;
float waterLevel;
Vec4 landColor;
Vec4 waterColor;
float erosion;
public:
Sim2(int width = 512, int height = 512, int seed = 42, float scale = 4) :
width(width), height(height), scale(scale), octaves(4), seed(seed)
{ }
};
#endif #endif

View File

@@ -6,20 +6,122 @@
#include <random> #include <random>
#include <functional> #include <functional>
#include <algorithm> #include <algorithm>
#include <array>
#include <vector>
#include <unordered_map>
struct Grad { float x, y; }; struct Grad { float x, y; };
std::array<Grad, 256> gradients;
class Noise2 { class Noise2 {
public:
enum NoiseType {
PERLIN,
SIMPLEX,
VALUE,
WORLEY,
GABOR,
POISSON_DISK,
FRACTAL,
WAVELET,
GAUSSIAN,
CELLULAR
};
enum GradientType {
HASH_BASED,
SIN_BASED,
DOT_BASED,
PRECOMPUTED
};
private: private:
std::mt19937 rng; std::mt19937 rng;
std::uniform_real_distribution<float> dist; std::uniform_real_distribution<float> dist;
public:
Noise2(uint32_t seed = 0) : rng(seed), dist(0.0f, 1.0f) {}
// Set random seed // Precomputed gradient directions for 8 directions
static constexpr std::array<Grad, 8> grads = {
Grad{1.0f, 0.0f},
Grad{0.707f, 0.707f},
Grad{0.0f, 1.0f},
Grad{-0.707f, 0.707f},
Grad{-1.0f, 0.0f},
Grad{-0.707f, -0.707f},
Grad{0.0f, -1.0f},
Grad{0.707f, -0.707f}
};
NoiseType currentType;
GradientType gradType;
uint32_t currentSeed;
// Permutation table for Simplex noise
std::array<int, 512> perm;
// For Worley noise
std::vector<Vec2> featurePoints;
// For Gabor noise
float gaborFrequency;
float gaborBandwidth;
// For wavelet noise
std::vector<float> waveletCoefficients;
public:
Noise2(uint32_t seed = 0, NoiseType type = PERLIN, GradientType gradType = PRECOMPUTED) :
rng(seed), dist(0.0f, 1.0f), currentType(type), gradType(gradType),
currentSeed(seed), gaborFrequency(4.0f), gaborBandwidth(0.5f)
{
initializePermutationTable(seed);
initializeFeaturePoints(64, seed); // Default 64 feature points
initializeWaveletCoefficients(32, seed); // 32x32 wavelet coefficients
}
// Set random seed and reinitialize dependent structures
void setSeed(uint32_t seed) { void setSeed(uint32_t seed) {
currentSeed = seed;
rng.seed(seed); rng.seed(seed);
initializePermutationTable(seed);
initializeFeaturePoints(featurePoints.size(), seed);
initializeWaveletCoefficients(static_cast<int>(std::sqrt(waveletCoefficients.size())), seed);
}
// Set noise type
void setNoiseType(NoiseType type) {
currentType = type;
}
// Set gradient type
void setGradientType(GradientType type) {
gradType = type;
}
// Main noise function that routes to the selected algorithm
float noise(float x, float y, int octaves = 1, float persistence = 0.5f, float lacunarity = 2.0f) {
switch (currentType) {
case PERLIN:
return perlinNoise(x, y, octaves, persistence, lacunarity);
case SIMPLEX:
return simplexNoise(x, y, octaves, persistence, lacunarity);
case VALUE:
return valueNoise(x, y, octaves, persistence, lacunarity);
case WORLEY:
return worleyNoise(x, y);
case GABOR:
return gaborNoise(x, y);
case POISSON_DISK:
return poissonDiskNoise(x, y);
case FRACTAL:
return fractalNoise(x, y, octaves, persistence, lacunarity);
case WAVELET:
return waveletNoise(x, y);
case GAUSSIAN:
return gaussianNoise(x, y);
case CELLULAR:
return cellularNoise(x, y);
default:
return perlinNoise(x, y, octaves, persistence, lacunarity);
}
} }
// Generate simple value noise // Generate simple value noise
@@ -56,7 +158,141 @@ public:
return (total / maxValue + 1.0f) * 0.5f; // Normalize to [0,1] return (total / maxValue + 1.0f) * 0.5f; // Normalize to [0,1]
} }
// Generate a grayscale noise grid float simplexNoise(float x, float y, int octaves = 1, float persistence = 0.5f, float lacunarity = 2.0f) {
float total = 0.0f;
float frequency = 1.0f;
float amplitude = 1.0f;
float maxValue = 0.0f;
for (int i = 0; i < octaves; i++) {
total += rawSimplexNoise(x * frequency, y * frequency) * amplitude;
maxValue += amplitude;
amplitude *= persistence;
frequency *= lacunarity;
}
return (total / maxValue + 1.0f) * 0.5f;
}
// Worley (cellular) noise
float worleyNoise(float x, float y) {
if (featurePoints.empty()) return 0.0f;
// Find the closest and second closest feature points
float minDist1 = std::numeric_limits<float>::max();
float minDist2 = std::numeric_limits<float>::max();
for (const auto& point : featurePoints) {
float dx = x - point.x;
float dy = y - point.y;
float dist = dx * dx + dy * dy; // Squared distance for performance
if (dist < minDist1) {
minDist2 = minDist1;
minDist1 = dist;
} else if (dist < minDist2) {
minDist2 = dist;
}
}
// Return distance to closest feature point (normalized)
return std::sqrt(minDist1);
}
// Cellular noise variation
float cellularNoise(float x, float y) {
if (featurePoints.empty()) return 0.0f;
float minDist1 = std::numeric_limits<float>::max();
float minDist2 = std::numeric_limits<float>::max();
for (const auto& point : featurePoints) {
float dx = x - point.x;
float dy = y - point.y;
float dist = dx * dx + dy * dy;
if (dist < minDist1) {
minDist2 = minDist1;
minDist1 = dist;
} else if (dist < minDist2) {
minDist2 = dist;
}
}
// Cellular pattern: second closest minus closest
return std::sqrt(minDist2) - std::sqrt(minDist1);
}
// Gabor noise
float gaborNoise(float x, float y) {
// Simplified Gabor noise - in practice this would be more complex
float gaussian = std::exp(-(x*x + y*y) / (2.0f * gaborBandwidth * gaborBandwidth));
float cosine = std::cos(2.0f * M_PI * gaborFrequency * (x + y));
return gaussian * cosine;
}
// Poisson disk noise
float poissonDiskNoise(float x, float y) {
// Sample Poisson disk distribution
// This is a simplified version - full implementation would use more sophisticated sampling
float minDist = std::numeric_limits<float>::max();
for (const auto& point : featurePoints) {
float dx = x - point.x;
float dy = y - point.y;
float dist = std::sqrt(dx * dx + dy * dy);
minDist = std::min(minDist, dist);
}
return 1.0f - std::min(minDist * 10.0f, 1.0f); // Invert and scale
}
// Fractal noise (fractional Brownian motion)
float fractalNoise(float x, float y, int octaves = 8, float persistence = 0.5f, float lacunarity = 2.0f) {
float total = 0.0f;
float frequency = 1.0f;
float amplitude = 1.0f;
float maxValue = 0.0f;
for (int i = 0; i < octaves; i++) {
total += improvedNoise(x * frequency, y * frequency) * amplitude;
maxValue += amplitude;
amplitude *= persistence;
frequency *= lacunarity;
}
// Fractal noise often has wider range, so we don't normalize as strictly
return total;
}
// Wavelet noise
float waveletNoise(float x, float y) {
// Simplified wavelet noise using precomputed coefficients
int ix = static_cast<int>(std::floor(x * 4)) % 32;
int iy = static_cast<int>(std::floor(y * 4)) % 32;
if (ix < 0) ix += 32;
if (iy < 0) iy += 32;
return waveletCoefficients[iy * 32 + ix];
}
// Gaussian noise
float gaussianNoise(float x, float y) {
// Use coordinates to seed RNG for deterministic results
rng.seed(static_cast<uint32_t>(x * 1000 + y * 1000 + currentSeed));
// Box-Muller transform for Gaussian distribution
float u1 = dist(rng);
float u2 = dist(rng);
float z0 = std::sqrt(-2.0f * std::log(u1)) * std::cos(2.0f * M_PI * u2);
// Normalize to [0,1] range
return (z0 + 3.0f) / 6.0f; // Assuming 3 sigma covers most of the distribution
}
// Generate a grayscale noise grid using current noise type
Grid2 generateGrayNoise(int width, int height, Grid2 generateGrayNoise(int width, int height,
float scale = 1.0f, float scale = 1.0f,
int octaves = 1, int octaves = 1,
@@ -72,7 +308,7 @@ public:
float nx = (x + offset.x) / width * scale; float nx = (x + offset.x) / width * scale;
float ny = (y + offset.y) / height * scale; float ny = (y + offset.y) / height * scale;
float noiseValue = perlinNoise(nx, ny, octaves, persistence); float noiseValue = noise(nx, ny, octaves, persistence);
// Convert to position and grayscale color // Convert to position and grayscale color
Vec2 position(x, y); Vec2 position(x, y);
@@ -126,15 +362,15 @@ public:
float nx = (x + offset.x) / width; float nx = (x + offset.x) / width;
float ny = (y + offset.y) / height; float ny = (y + offset.y) / height;
// Generate separate noise for each channel // Generate separate noise for each channel using current noise type
float r = perlinNoise(nx * scale.x, ny * scale.x, float r = noise(nx * scale.x, ny * scale.x,
static_cast<int>(octaves.x), persistence.x); static_cast<int>(octaves.x), persistence.x);
float g = perlinNoise(nx * scale.y, ny * scale.y, float g = noise(nx * scale.y, ny * scale.y,
static_cast<int>(octaves.y), persistence.y); static_cast<int>(octaves.y), persistence.y);
float b = perlinNoise(nx * scale.z, ny * scale.z, float b = noise(nx * scale.z, ny * scale.z,
static_cast<int>(octaves.z), persistence.z); static_cast<int>(octaves.z), persistence.z);
float a = perlinNoise(nx * scale.w, ny * scale.w, float a = noise(nx * scale.w, ny * scale.w,
static_cast<int>(octaves.w), persistence.w); static_cast<int>(octaves.w), persistence.w);
Vec2 position(x, y); Vec2 position(x, y);
Vec4 color(r, g, b, a); Vec4 color(r, g, b, a);
@@ -164,7 +400,7 @@ public:
float ny = (y + offset.y) / height * scale; float ny = (y + offset.y) / height * scale;
// Use multiple octaves for more natural terrain // Use multiple octaves for more natural terrain
float heightValue = perlinNoise(nx, ny, octaves, persistence); float heightValue = noise(nx, ny, octaves, persistence);
// Apply some curve to make it more terrain-like // Apply some curve to make it more terrain-like
heightValue = std::pow(heightValue, 1.5f); heightValue = std::pow(heightValue, 1.5f);
@@ -203,7 +439,138 @@ public:
return grid; return grid;
} }
// Generate specific noise type directly
Grid2 generateSpecificNoise(NoiseType type, int width, int height,
float scale = 1.0f, int octaves = 1,
float persistence = 0.5f, uint32_t seed = 0) {
NoiseType oldType = currentType;
currentType = type;
auto grid = generateGrayNoise(width, height, scale, octaves, persistence, seed);
currentType = oldType;
return grid;
}
private: private:
// Initialize permutation table for Simplex noise
void initializePermutationTable(uint32_t seed) {
std::mt19937 localRng(seed);
std::uniform_int_distribution<int> intDist(0, 255);
// Create initial permutation
std::array<int, 256> p;
for (int i = 0; i < 256; i++) {
p[i] = i;
}
// Shuffle using Fisher-Yates
for (int i = 255; i > 0; i--) {
int j = intDist(localRng) % (i + 1);
std::swap(p[i], p[j]);
}
// Duplicate for overflow
for (int i = 0; i < 512; i++) {
perm[i] = p[i & 255];
}
}
// Initialize feature points for Worley/Poisson noise
void initializeFeaturePoints(int numPoints, uint32_t seed) {
std::mt19937 localRng(seed);
std::uniform_real_distribution<float> localDist(0.0f, 1.0f);
featurePoints.clear();
featurePoints.reserve(numPoints);
for (int i = 0; i < numPoints; i++) {
featurePoints.emplace_back(localDist(localRng), localDist(localRng));
}
}
// Initialize wavelet coefficients
void initializeWaveletCoefficients(int size, uint32_t seed) {
std::mt19937 localRng(seed);
std::uniform_real_distribution<float> localDist(-1.0f, 1.0f);
waveletCoefficients.resize(size * size);
for (int i = 0; i < size * size; i++) {
waveletCoefficients[i] = (localDist(localRng) + 1.0f) * 0.5f; // Normalize to [0,1]
}
}
// Raw Simplex noise implementation
float rawSimplexNoise(float x, float y) {
// Skewing factors for 2D
const float F2 = 0.5f * (std::sqrt(3.0f) - 1.0f);
const float G2 = (3.0f - std::sqrt(3.0f)) / 6.0f;
// Skew the input space
float s = (x + y) * F2;
int i = fastFloor(x + s);
int j = fastFloor(y + s);
float t = (i + j) * G2;
float X0 = i - t;
float Y0 = j - t;
float x0 = x - X0;
float y0 = y - Y0;
// Determine which simplex we're in
int i1, j1;
if (x0 > y0) {
i1 = 1; j1 = 0;
} else {
i1 = 0; j1 = 1;
}
// Calculate other corners
float x1 = x0 - i1 + G2;
float y1 = y0 - j1 + G2;
float x2 = x0 - 1.0f + 2.0f * G2;
float y2 = y0 - 1.0f + 2.0f * G2;
// Calculate contributions from each corner
float n0, n1, n2;
float t0 = 0.5f - x0*x0 - y0*y0;
if (t0 < 0) n0 = 0.0f;
else {
t0 *= t0;
n0 = t0 * t0 * grad(perm[i + perm[j]], x0, y0);
}
float t1 = 0.5f - x1*x1 - y1*y1;
if (t1 < 0) n1 = 0.0f;
else {
t1 *= t1;
n1 = t1 * t1 * grad(perm[i + i1 + perm[j + j1]], x1, y1);
}
float t2 = 0.5f - x2*x2 - y2*y2;
if (t2 < 0) n2 = 0.0f;
else {
t2 *= t2;
n2 = t2 * t2 * grad(perm[i + 1 + perm[j + 1]], x2, y2);
}
return 70.0f * (n0 + n1 + n2);
}
// Fast floor function
int fastFloor(float x) {
int xi = static_cast<int>(x);
return x < xi ? xi - 1 : xi;
}
// Gradient function for Simplex noise
float grad(int hash, float x, float y) {
int h = hash & 7;
float u = h < 4 ? x : y;
float v = h < 4 ? y : x;
return ((h & 1) ? -u : u) + ((h & 2) ? -2.0f * v : 2.0f * v);
}
// Raw noise function (simple hash-based) // Raw noise function (simple hash-based)
float rawNoise(float x, float y) { float rawNoise(float x, float y) {
// Simple hash function for deterministic noise // Simple hash function for deterministic noise
@@ -211,11 +578,11 @@ private:
int yi = static_cast<int>(std::floor(y)); int yi = static_cast<int>(std::floor(y));
// Use the RNG to generate consistent noise based on grid position // Use the RNG to generate consistent noise based on grid position
rng.seed(xi * 1619 + yi * 31337); rng.seed(xi * 1619 + yi * 31337 + currentSeed);
return dist(rng); return dist(rng);
} }
// Improved noise function (Perlin-like) // Improved noise function (Perlin-like) using selected gradient type
float improvedNoise(float x, float y) { float improvedNoise(float x, float y) {
// Integer part // Integer part
int xi = static_cast<int>(std::floor(x)); int xi = static_cast<int>(std::floor(x));
@@ -229,7 +596,7 @@ private:
float u = fade(xf); float u = fade(xf);
float v = fade(yf); float v = fade(yf);
// Gradient noise from corners // Gradient noise from corners using selected gradient calculation
float n00 = gradNoise(xi, yi, xf, yf); float n00 = gradNoise(xi, yi, xf, yf);
float n01 = gradNoise(xi, yi + 1, xf, yf - 1); float n01 = gradNoise(xi, yi + 1, xf, yf - 1);
float n10 = gradNoise(xi + 1, yi, xf - 1, yf); float n10 = gradNoise(xi + 1, yi, xf - 1, yf);
@@ -241,6 +608,76 @@ private:
return lerp(x1, x2, v); return lerp(x1, x2, v);
} }
// Gradient noise function using selected gradient type
float gradNoise(int xi, int yi, float xf, float yf) {
switch (gradType) {
case HASH_BASED:
return hashGradNoise(xi, yi, xf, yf);
case SIN_BASED:
return sinGradNoise(xi, yi, xf, yf);
case DOT_BASED:
return dotGradNoise(xi, yi, xf, yf);
case PRECOMPUTED:
default:
return precomputedGradNoise(xi, yi, xf, yf);
}
}
// Fast gradient noise function using precomputed gradient directions
float precomputedGradNoise(int xi, int yi, float xf, float yf) {
// Generate deterministic hash from integer coordinates
int hash = (xi * 1619 + yi * 31337 + currentSeed);
// Use hash to select from 8 precomputed gradient directions
int gradIndex = hash & 7; // 8 directions (0-7)
// Dot product between distance vector and gradient
return xf * grads[gradIndex].x + yf * grads[gradIndex].y;
}
// Hash-based gradient noise
float hashGradNoise(int xi, int yi, float xf, float yf) {
// Generate hash from coordinates
uint32_t hash = (xi * 1619 + yi * 31337 + currentSeed);
// Use hash to generate gradient angle
hash = (hash << 13) ^ hash;
hash = (hash * (hash * hash * 15731 + 789221) + 1376312589);
float angle = (hash & 0xFFFF) / 65535.0f * 2.0f * M_PI;
// Gradient vector
float gx = std::cos(angle);
float gy = std::sin(angle);
// Dot product
return xf * gx + yf * gy;
}
// Sine-based gradient noise
float sinGradNoise(int xi, int yi, float xf, float yf) {
// Use sine of coordinates to generate gradient
float angle = std::sin(xi * 12.9898f + yi * 78.233f + currentSeed) * 43758.5453f;
angle = angle - std::floor(angle); // Fractional part
angle *= 2.0f * M_PI;
float gx = std::cos(angle);
float gy = std::sin(angle);
return xf * gx + yf * gy;
}
// Dot product based gradient noise
float dotGradNoise(int xi, int yi, float xf, float yf) {
// Simple dot product with random vector based on coordinates
float random = std::sin(xi * 127.1f + yi * 311.7f) * 43758.5453123f;
random = random - std::floor(random);
Vec2 grad(std::cos(random * 2.0f * M_PI), std::sin(random * 2.0f * M_PI));
Vec2 dist(xf, yf);
return grad.dot(dist);
}
// Fade function for smooth interpolation // Fade function for smooth interpolation
float fade(float t) { float fade(float t) {
return t * t * t * (t * (t * 6 - 15) + 10); return t * t * t * (t * (t * 6 - 15) + 10);
@@ -257,44 +694,6 @@ private:
if (x > upperlimit) return upperlimit; if (x > upperlimit) return upperlimit;
return x; return x;
} }
// float grad(const int& hash, const float& b, const float& c, const float& d) {
// TIME_FUNCTION;
// int h = hash & 15;
// float u = (h < 8) ? c : b;
// float v = (h < 4) ? b : ((h == 12 || h == 14) ? c : d);
// return (((h & 1) == 0) ? u : -u) + (((h & 2) == 0) ? v : -v);
// }
float gradNoise(int xi, int yi, float xf, float yf) {
// Generate deterministic "random" unit vector using hash
int hash = (xi * 1619 + yi * 31337);
// Use hash to generate angle in fixed steps (faster than trig)
float angle = (hash & 255) * (2.0f * 3.14159265f / 256.0f);
// Or even faster: use gradient table with 8 or 16 precomputed directions
int gradIndex = hash & 7; // 8 directions
static constexpr std::array<Grad, 8> grads = {
{1,0}, {0.707f,0.707f}, {0,1}, {-0.707f,0.707f},
{-1,0}, {-0.707f,-0.707f}, {0,-1}, {0.707f,-0.707f}
};
return xf * grads[gradIndex].x + yf * grads[gradIndex].y;
}
// Gradient noise function
float slowGradNoise(int xi, int yi, float xf, float yf) {
// Generate consistent random gradient from integer coordinates
rng.seed(xi * 1619 + yi * 31337);
float angle = dist(rng) * 2.0f * 3.14159265f;
// Gradient vector
float gx = std::cos(angle);
float gy = std::sin(angle);
// Dot product
return xf * gx + yf * gy;
}
}; };
#endif #endif