libcruft-util/tools/noise.cpp

42 lines
1.4 KiB
C++

#include "image.hpp"
#include "noise.hpp"
#include "noise/lerp.hpp"
#include "extent.hpp"
int
main (void)
{
// setup the output buffer
util::extent2u size (1920, 1080);
util::image::buffer<float> img (size);
// setup the noise generator
//util::noise::fbm<float, util::noise::cellular<float>> b;
//util::noise::rmf<float, util::noise::cellular<float>> b;
//util::noise::hmf<float, util::noise::gradient<float,util::lerp::quintic>> b;
util::noise::hetero<float, util::noise::gradient<float,util::lerp::quintic>> b;
//b.octaves = 3;
b.frequency = 10.f / size.w;
b.lacunarity = 2;
b.basis.seed = time (NULL);
// generate the values. offset positions slightly to avoid simple axis issues with perlin basis
for (size_t y = 0; y < size.h; ++y)
for (size_t x = 0; x < size.w; ++x) {
auto v = b ({float(x + 20), float(y + 20)});
img.data ()[y * size.w + x] = v;
}
// rescale into the range [0, 1]
auto range = std::minmax_element (img.begin (), img.end ());
auto offset = *range.first;
auto div = *range.second - *range.first;
std::cerr << "range: [" << *range.first << ", " << *range.second << "]\n";
std::transform (img.begin (), img.end (), img.begin (), [offset,div] (auto i) { return (i - offset) / div; });
// write the image to disk
auto grey = img.clone<uint8_t> ();
util::pgm::write (grey, "noise.ppm");
}