diff --git a/include/PerlinNoise.h b/include/PerlinNoise.h new file mode 100644 index 0000000..9ef109b --- /dev/null +++ b/include/PerlinNoise.h @@ -0,0 +1,28 @@ +#include + +// THIS CLASS IS A TRANSLATION TO C++11 FROM THE REFERENCE +// JAVA IMPLEMENTATION OF THE IMPROVED PERLIN FUNCTION (see http://mrl.nyu.edu/~perlin/noise/) +// THE ORIGINAL JAVA IMPLEMENTATION IS COPYRIGHT 2002 KEN PERLIN + +// I ADDED AN EXTRA METHOD THAT GENERATES A NEW PERMUTATION VECTOR (THIS IS NOT PRESENT IN THE ORIGINAL IMPLEMENTATION) + +#ifndef PERLINNOISE_H +#define PERLINNOISE_H + +class PerlinNoise { + // The permutation vector + std::vector p; +public: + // Initialize with the reference values for the permutation vector + PerlinNoise(); + // Generate a new permutation vector based on the value of seed + PerlinNoise(unsigned int seed); + // Get a noise value, for 2D images z can have any value + double noise(double x, double y, double z); +private: + double fade(double t); + double lerp(double t, double a, double b); + double grad(int hash, double x, double y, double z); +}; + +#endif diff --git a/include/ppm.h b/include/ppm.h new file mode 100644 index 0000000..f973c61 --- /dev/null +++ b/include/ppm.h @@ -0,0 +1,37 @@ +//Process a binary PPM file +#include +#include + +#ifndef PPM_H +#define PPM_H + +class ppm { + void init(); + //info about the PPM file (height and width) + unsigned int nr_lines; + unsigned int nr_columns; + +public: + //arrays for storing the R,G,B values + std::vector r; + std::vector g; + std::vector b; + // + unsigned int height; + unsigned int width; + unsigned int max_col_val; + //total number of elements (pixels) + unsigned int size; + + ppm(); + //create a PPM object and fill it with data stored in fname + ppm(const std::string &fname); + //create an "epmty" PPM image with a given width and height;the R,G,B arrays are filled with zeros + ppm(const unsigned int _width, const unsigned int _height); + //read the PPM image from fname + void read(const std::string &fname); + //write the PPM image in fname + void write(const std::string &fname); +}; + +#endif \ No newline at end of file diff --git a/source/PerlinNoise.cpp b/source/PerlinNoise.cpp new file mode 100644 index 0000000..f07795d --- /dev/null +++ b/source/PerlinNoise.cpp @@ -0,0 +1,93 @@ +#include "PerlinNoise.h" +#include +#include +#include + +// THIS IS A DIRECT TRANSLATION TO C++11 FROM THE REFERENCE +// JAVA IMPLEMENTATION OF THE IMPROVED PERLIN FUNCTION (see http://mrl.nyu.edu/~perlin/noise/) +// THE ORIGINAL JAVA IMPLEMENTATION IS COPYRIGHT 2002 KEN PERLIN + +// I ADDED AN EXTRA METHOD THAT GENERATES A NEW PERMUTATION VECTOR (THIS IS NOT PRESENT IN THE ORIGINAL IMPLEMENTATION) + +// Initialize with the reference values for the permutation vector +PerlinNoise::PerlinNoise() { + + // Initialize the permutation vector with the reference values + p = { + 151,160,137,91,90,15,131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142, + 8,99,37,240,21,10,23,190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117, + 35,11,32,57,177,33,88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71, + 134,139,48,27,166,77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41, + 55,46,245,40,244,102,143,54, 65,25,63,161,1,216,80,73,209,76,132,187,208, 89, + 18,169,200,196,135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226, + 250,124,123,5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182, + 189,28,42,223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, + 43,172,9,129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246, + 97,228,251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239, + 107,49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254, + 138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180 }; + // Duplicate the permutation vector + p.insert(p.end(), p.begin(), p.end()); +} + +// Generate a new permutation vector based on the value of seed +PerlinNoise::PerlinNoise(unsigned int seed) { + p.resize(256); + + // Fill p with values from 0 to 255 + std::iota(p.begin(), p.end(), 0); + + // Initialize a random engine with seed + std::default_random_engine engine(seed); + + // Suffle using the above random engine + std::shuffle(p.begin(), p.end(), engine); + + // Duplicate the permutation vector + p.insert(p.end(), p.begin(), p.end()); +} + +double PerlinNoise::noise(double x, double y, double z) { + // Find the unit cube that contains the point + int X = (int) floor(x) & 255; + int Y = (int) floor(y) & 255; + int Z = (int) floor(z) & 255; + + // Find relative x, y,z of point in cube + x -= floor(x); + y -= floor(y); + z -= floor(z); + + // Compute fade curves for each of x, y, z + double u = fade(x); + double v = fade(y); + double w = fade(z); + + // Hash coordinates of the 8 cube corners + int A = p[X] + Y; + int AA = p[A] + Z; + int AB = p[A + 1] + Z; + int B = p[X + 1] + Y; + int BA = p[B] + Z; + int BB = p[B + 1] + Z; + + // Add blended results from 8 corners of cube + double res = lerp(w, lerp(v, lerp(u, grad(p[AA], x, y, z), grad(p[BA], x-1, y, z)), lerp(u, grad(p[AB], x, y-1, z), grad(p[BB], x-1, y-1, z))), lerp(v, lerp(u, grad(p[AA+1], x, y, z-1), grad(p[BA+1], x-1, y, z-1)), lerp(u, grad(p[AB+1], x, y-1, z-1), grad(p[BB+1], x-1, y-1, z-1)))); + return (res + 1.0)/2.0; +} + +double PerlinNoise::fade(double t) { + return t * t * t * (t * (t * 6 - 15) + 10); +} + +double PerlinNoise::lerp(double t, double a, double b) { + return a + t * (b - a); +} + +double PerlinNoise::grad(int hash, double x, double y, double z) { + int h = hash & 15; + // Convert lower 4 bits of hash into 12 gradient directions + double u = h < 8 ? x : y, + v = h < 4 ? y : h == 12 || h == 14 ? x : z; + return ((h & 1) == 0 ? u : -u) + ((h & 2) == 0 ? v : -v); +} diff --git a/source/ppm.cpp b/source/ppm.cpp new file mode 100644 index 0000000..60ba6d8 --- /dev/null +++ b/source/ppm.cpp @@ -0,0 +1,127 @@ +#include +#include +#include +#include + +#include "ppm.h" + +//init with default values + +void ppm::init() { + width = 0; + height = 0; + max_col_val = 255; +} + +//create a PPM object + +ppm::ppm() { + init(); +} + +//create a PPM object and fill it with data stored in fname + +ppm::ppm(const std::string &fname) { + init(); + read(fname); +} + +//create an "epmty" PPM image with a given width and height;the R,G,B arrays are filled with zeros + +ppm::ppm(const unsigned int _width, const unsigned int _height) { + init(); + width = _width; + height = _height; + nr_lines = height; + nr_columns = width; + size = width*height; + + // fill r, g and b with 0 + r.resize(size); + g.resize(size); + b.resize(size); +} + +//read the PPM image from fname + +void ppm::read(const std::string &fname) { + std::ifstream inp(fname.c_str(), std::ios::in | std::ios::binary); + if (inp.is_open()) { + std::string line; + std::getline(inp, line); + if (line != "P6") { + std::cout << "Error. Unrecognized file format." << std::endl; + return; + } + std::getline(inp, line); + while (line[0] == '#') { + std::getline(inp, line); + } + std::stringstream dimensions(line); + + try { + dimensions >> width; + dimensions >> height; + nr_lines = height; + nr_columns = width; + } catch (std::exception &e) { + std::cout << "Header file format error. " << e.what() << std::endl; + return; + } + + std::getline(inp, line); + std::stringstream max_val(line); + try { + max_val >> max_col_val; + } catch (std::exception &e) { + std::cout << "Header file format error. " << e.what() << std::endl; + return; + } + + size = width*height; + + r.reserve(size); + g.reserve(size); + b.reserve(size); + + char aux; + for (unsigned int i = 0; i < size; ++i) { + inp.read(&aux, 1); + r[i] = (unsigned char) aux; + inp.read(&aux, 1); + g[i] = (unsigned char) aux; + inp.read(&aux, 1); + b[i] = (unsigned char) aux; + } + } else { + std::cout << "Error. Unable to open " << fname << std::endl; + } + inp.close(); +} + +//write the PPM image in fname + +void ppm::write(const std::string &fname) { + std::ofstream inp(fname.c_str(), std::ios::out | std::ios::binary); + if (inp.is_open()) { + + inp << "P6\n"; + inp << width; + inp << " "; + inp << height << "\n"; + inp << max_col_val << "\n"; + + char aux; + for (unsigned int i = 0; i < size; ++i) { + aux = (char) r[i]; + inp.write(&aux, 1); + aux = (char) g[i]; + inp.write(&aux, 1); + aux = (char) b[i]; + inp.write(&aux, 1); + } + } else { + std::cout << "Error. Unable to open " << fname << std::endl; + } + inp.close(); +}