SPHKernels.hpp

Go to the documentation of this file.

// This code is based on Jet framework.
// Copyright (c) 2018 Doyub Kim
// CubbyFlow is voxel-based fluid simulation engine for computer games.
// Copyright (c) 2020 CubbyFlow Team
// Core Part: Chris Ohk, Junwoo Hwang, Jihong Sin, Seungwoo Yoo
// AI Part: Dongheon Cho, Minseo Kim
// We are making my contributions/submissions to this project solely in our
// personal capacity and are not conveying any rights to any intellectual
// property of any third parties.

// Adopted from the sample code of:
// Bart Adams and Martin Wicke,
// "Meshless Approximation Methods and Applications in Physics Based Modeling
// and Animation", Eurographics 2009 Tutorial

#ifndef CUBBYFLOW_SPH_KERNELS_HPP
#define CUBBYFLOW_SPH_KERNELS_HPP

#include <Core/Matrix/Matrix.hpp>

namespace CubbyFlow
{
template <size_t N>
struct SPHStdKernel
{
    // Do nothing
};

template <>
struct SPHStdKernel<2>
{
    SPHStdKernel();

    explicit SPHStdKernel(double kernelRadius);

    double operator()(double distance) const;

    [[nodiscard]] double FirstDerivative(double distance) const;

    [[nodiscard]] double SecondDerivative(double distance) const;

    [[nodiscard]] Vector2D Gradient(const Vector2D& point) const;

    [[nodiscard]] Vector2D Gradient(double distance,
                                    const Vector2D& direction) const;

    double h;

    double h2;

    double h3;

    double h4;
};

template <>
struct SPHStdKernel<3>
{
    SPHStdKernel();

    explicit SPHStdKernel(double kernelRadius);

    double operator()(double distance) const;

    [[nodiscard]] double FirstDerivative(double distance) const;

    [[nodiscard]] double SecondDerivative(double distance) const;

    [[nodiscard]] Vector3D Gradient(const Vector3D& point) const;

    [[nodiscard]] Vector3D Gradient(double distance,
                                    const Vector3D& direction) const;

    double h;

    double h2;

    double h3;

    double h5;
};

using SPHStdKernel2 = SPHStdKernel<2>;

using SPHStdKernel3 = SPHStdKernel<3>;

template <size_t N>
struct SPHSpikyKernel
{
    // Do nothing
};

template <>
struct SPHSpikyKernel<2>
{
    SPHSpikyKernel();

    explicit SPHSpikyKernel(double kernelRadius);

    double operator()(double distance) const;

    [[nodiscard]] double FirstDerivative(double distance) const;

    [[nodiscard]] double SecondDerivative(double distance) const;

    [[nodiscard]] Vector2D Gradient(const Vector2D& point) const;

    [[nodiscard]] Vector2D Gradient(double distance,
                                    const Vector2D& direction) const;

    double h;

    double h2;

    double h3;

    double h4;

    double h5;
};

template <>
struct SPHSpikyKernel<3>
{
    SPHSpikyKernel();

    explicit SPHSpikyKernel(double kernelRadius);

    double operator()(double distance) const;

    [[nodiscard]] double FirstDerivative(double distance) const;

    [[nodiscard]] double SecondDerivative(double distance) const;

    [[nodiscard]] Vector3D Gradient(const Vector3D& point) const;

    [[nodiscard]] Vector3D Gradient(double distance,
                                    const Vector3D& direction) const;

    double h;

    double h2;

    double h3;

    double h4;

    double h5;
};

using SPHSpikyKernel2 = SPHSpikyKernel<2>;

using SPHSpikyKernel3 = SPHSpikyKernel<3>;
}  // namespace CubbyFlow

#include <Core/Particle/SPHKernels-Impl.hpp>

#endif