turbulence_texture.h

// Description: Turbulence texture
// Documentation: synthetic_textures.txt

#ifndef PASTELGFX_TURBULENCE_TEXTURE_H
#define PASTELGFX_TURBULENCE_TEXTURE_H

#include "pastel/gfx/texture/texture.h"
#include "pastel/gfx/noise.h"

namespace Pastel
{

    template <integer N = 2>
    class Turbulence_Texture
        : public Texture<real, N>
    {
    public:
        Turbulence_Texture()
            : noise_()
            , octaves_(5)
            , lacunarity_(2)
        {
        }

        virtual ~Turbulence_Texture()
        {
        }

        virtual real operator()(
            const Vector<real, N>& p,
            const Matrix<real>& m) const
        {
            real scale = 1;
            real value = 0;
            real amplitude = 1;

            for (integer i = 0;i < octaves_;++i)
            {
                value += noise_(p * scale, m) * amplitude;
                amplitude /= lacunarity_;
                scale *= 2.01423;
            }

            return value / 2;
        }

        void setOctaves(integer octaves)
        {
            ENSURE_OP(octaves, >=, 0);
            octaves_ = octaves;
        }

        integer octaves() const
        {
            return octaves_;
        }

        void setLacunarity(real lacunarity)
        {
            lacunarity_ = lacunarity;
        }

        real lacunarity() const
        {
            return lacunarity_;
        }

        virtual std::string name() const
        {
            return std::string("Turbulence");
        }

    private:
        Noise_Texture<N> noise_;
        integer octaves_;
        real lacunarity_;
    };

    template <integer N>
    Turbulence_Texture<N> turbulenceTexture()
    {
        return Turbulence_Texture<N>();
    }

}

#endif