int main() {
float scale = 400.f;
float offset_x = 5.9f;
float offset_y = 5.1f;
float offset_z = 0.05f;
float lacunarity = 1.99f;
float persistance = 0.5f;
Img img;
while (!img.is_closed()) {
Measure measure;
measure.start();
const SimplexNoise simplex(0.1f/scale, 0.5f, lacunarity, persistance); // Amplitude of 0.5 for the 1st octave : sum ~1.0f
const int octaves = static_cast<int>(5 + std::log(scale)); // Estimate number of octaves needed for the current scale
std::ostringstream title;
title << "2D Simplex Perlin noise (" << octaves << " octaves)";
img.set_title(title.str().c_str());
for (int row = 0; row < img.height(); ++row) {
const float y = static_cast<float>(row - img.height()/2 + offset_y*scale);
for (int col = 0; col < img.width(); ++col) {
const float x = static_cast<float>(col - img.width()/2 + offset_x*scale);
// TODO(SRombauts): Add 'erosion' with simple smoothing like exponential, and other 'modifiers' like in libnoise
// Generate "biomes", ie smooth geographic variation in frequency & amplitude,
// and add smaller details, summing the noise values for the coordinate
const float noise = simplex.fractal(octaves, x, y) + offset_z;
const color3f color = ramp(noise); // convert to color
img.draw_point(col, row, (float*)&color);
}
}
img.display();
const double diff_ms = measure.get();
std::cout << std::fixed << diff_ms << "ms\n";
img.user(scale, offset_x, offset_y, offset_z, lacunarity, persistance);
}
return 0;
}
