private double GroundFunction(float s, float t)
{
// varying amplitude and frequency
float amplitude = 0.5f; // +a;
float frequency = 0.5f; // +f;
// define constants
int n = 7; // number of octaves
float alpha = 2.0f; // weight when sum is formed, approching 1 is noisier
float beta = 2.0f; // harmonic scaling/spacing
float scale = 5.0f * frequency;
double toReturn = Perlin.PerlinNoise2D(scale * s, scale * t, alpha, beta, n);
toReturn = amplitude * toReturn + amplitude * amplitude * toReturn + amplitude * amplitude * amplitude * toReturn + amplitude * amplitude * amplitude * amplitude * toReturn;
toReturn = Math.Sin(20 * 1 + s * toReturn) + Math.Sin(20 * 2 + s * toReturn) + Math.Sin(20 * 3 + s * toReturn) + Math.Sin(20 * 4 + s * toReturn);
// scale between 0 and 1
return(toReturn % 1.0f);
}
private double woodFunction(float s, float t, float r)
{
// variable amplitude and frequency
float amplitude = 6.0f; // +a;
float frequency = 2.0f; // +f;
// define toReturn variable
double toReturn = s * s + t * t; // f(s,t,r) = s^2 + t^2; // fixed r
// define perlin noise constants
int n = 2; // number of octaves
float alpha = 2.0f; // "division factor" (how much to damp subsequent octaves)
float beta = 2.0f; // factor that multiplies "jump" into noise
// perlin noise!!!
double perlin = Perlin.PerlinNoise2D(frequency * s, frequency * s, alpha, beta, n);
toReturn = toReturn + amplitude * perlin;
return(toReturn % 1.0f);
//double integerPart; // don't care about
//return modf(toReturn, &integerPart);
}
