radial_texture.h

// Description: Distortion of a texture from cartesian to spherical space

#ifndef PASTELGFX_RADIAL_TEXTURE_H
#define PASTELGFX_RADIAL_TEXTURE_H

#include "pastel/gfx/texture/texture.h"
#include "pastel/gfx/color/colormixer.h"

#include "pastel/math/coordinate/coordinates.h"
#include "pastel/math/coordinate/coordinates_derivatives.h"

namespace Pastel
{

    template <typename Type, integer N = 2>
    class Radial_Texture
        : public Texture<Type, N>
    {
    public:
        Radial_Texture(
            const Texture<Type, N>& texture,
            const Vector<real, N>& center,
            const Vector<real, N>& sphericalStart,
            const Vector<real, N>& sphericalEnd)
            : texture_(texture)
            , center_(center)
            , sphericalStart_(sphericalStart)
            , sphericalEnd_(sphericalEnd)
        {
        }

        virtual ~Radial_Texture()
        {
        }

        virtual Type operator()(
            const Vector<real, N>& p,
            const Matrix<real>& m) const
        {
            Vector<real, N> spherical =
                sphericalStart_ + (sphericalEnd_ - sphericalStart_) * p;

            return texture_(
                center_ + sphericalToCartesian(spherical),
                sphericalToCartesianDerivative(spherical) * m);
        }

        virtual std::string name() const
        {
            return std::string("Radial(" + texture_.fullName() + ")");
        }

    private:
        const Texture<Type, N>& texture_;
        Vector<real, N> center_;
        Vector<real, N> sphericalStart_;
        Vector<real, N> sphericalEnd_;
    };

    template <typename Type, integer N>
    Radial_Texture<Type, N> radialTexture(
        const Texture<Type, N>& texture,
        const Vector<real, N>& center,
        const Vector<real, N>& sphericalStart,
        const Vector<real, N>& sphericalEnd)
    {
        return Radial_Texture<Type, N>(texture, center, sphericalStart, sphericalEnd);
    }

}

#endif