solid_noise.cc

// solid_noise.cc

#include "solid_noise.h"
#include "rng.h"

SolidNoise::SolidNoise() {
    RNG random;
    int i;

    grad[0]  = Vector3( 1, 1, 0);
    grad[1]  = Vector3(-1, 1, 0);
    grad[2]  = Vector3( 1,-1, 0);
    grad[3]  = Vector3(-1,-1, 0);

    grad[4]  = Vector3( 1, 0, 1);
    grad[5]  = Vector3(-1, 0, 1);
    grad[6]  = Vector3( 1, 0,-1);
    grad[7]  = Vector3(-1, 0,-1);

    grad[8]  = Vector3( 0, 1, 1);
    grad[9]  = Vector3( 0,-1, 1);
    grad[10] = Vector3( 0, 1,-1);
    grad[11] = Vector3( 0,-1,-1);

    grad[12] = Vector3( 1, 1, 0);
    grad[13] = Vector3(-1, 1, 0);
    grad[14] = Vector3( 0,-1, 1);
    grad[15] = Vector3( 0,-1,-1);

    for(i = 0; i < 16; i++)
        phi[i] = i;

    //shuffle phi
    for(i = 14; i >= 0; i--) {
        int target = int(random()*i);
        int temp = phi[i+1];
        phi[i+1] = phi[target];
        phi[target] = temp;
    }
}

float SolidNoise::turbulence(const Vector3& p, int depth) const {
    float sum = 0.0f;
    float weight = 1.0f;
    Vector3 ptemp(p);

    sum = fabs(noise(ptemp));

    for(int i = 1; i < depth; i++) {
        weight = weight * 2;
        ptemp.setX(p.x() * weight);
        ptemp.setY(p.y() * weight);
        ptemp.setZ(p.z() * weight);

        sum += fabs(noise(ptemp)) / weight;
    }
    return sum;
}

float SolidNoise::dturbulence(const Vector3& p, int depth, float d)
const {
    float sum = 0.0f;
    float weight = 1.0f;
    Vector3 ptemp(p);

    sum = fabs(noise(ptemp)) / d;

    for(int i = 1; i < depth; i++) {
        weight = weight * d;
        ptemp.setX(p.x() * weight);
        ptemp.setY(p.y() * weight);
        ptemp.setZ(p.z() * weight);

        sum += fabs(noise(ptemp)) / d;
    }
    return sum;
}

float SolidNoise::noise(const Vector3& p) const {
    int fi, fj, fk;
    float fu, fv, fw, sum;
    Vector3 v;

    fi = int(floor(p.x()));
    fj = int(floor(p.y()));
    fk = int(floor(p.z()));
    fu = p.x() - float(fi);
    fv = p.y() - float(fj);
    fw = p.z() - float(fk);
    sum = 0.0f;
    
    v = Vector3(fu, fv, fw);
    sum += knot(fi, fj, fk, v);

    v = Vector3(fu - 1, fv, fw);
    sum += knot(fi + 1, fj, fk, v);

    v = Vector3(fu, fv - 1, fw);
    sum += knot(fi, fj + 1, fk, v);

    v = Vector3(fu, fv, fw - 1);
    sum += knot(fi, fj, fk + 1, v);

    v = Vector3(fu - 1, fv - 1, fw);
    sum += knot(fi + 1, fj + 1, fk, v);

    v = Vector3(fu - 1, fv, fw - 1);
    sum += knot(fi + 1, fj, fk + 1, v);

    v = Vector3(fu, fv - 1, fw - 1);
    sum += knot(fi, fj + 1, fk + 1, v);

    v = Vector3(fu - 1, fv - 1, fw - 1);
    sum += knot(fi + 1, fj + 1, fk + 1, v);

    return sum;
}