/***************************************************************************
 *   Copyright (c) 2005 Imetric 3D GmbH                                    *
 *                                                                         *
 *   This file is part of the FreeCAD CAx development system.              *
 *                                                                         *
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU Library General Public           *
 *   License as published by the Free Software Foundation; either          *
 *   version 2 of the License, or (at your option) any later version.      *
 *                                                                         *
 *   This library  is distributed in the hope that it will be useful,      *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU Library General Public License for more details.                  *
 *                                                                         *
 *   You should have received a copy of the GNU Library General Public     *
 *   License along with this library; see the file COPYING.LIB. If not,    *
 *   write to the Free Software Foundation, Inc., 59 Temple Place,         *
 *   Suite 330, Boston, MA  02111-1307, USA                                *
 *                                                                         *
 ***************************************************************************/


#ifndef BASE_VIEWPROJ_H
#define BASE_VIEWPROJ_H

#include "Vector3D.h"
#include "Matrix.h"


namespace Base
{

/**
 * Abstract base class for all project methods.
 */
class BaseExport ViewProjMethod
{
public:
    ViewProjMethod(const ViewProjMethod&) = default;
    ViewProjMethod(ViewProjMethod&&) = default;
    ViewProjMethod& operator=(const ViewProjMethod&) = default;
    ViewProjMethod& operator=(ViewProjMethod&&) = default;
    virtual ~ViewProjMethod() = default;

    virtual bool isValid() const;
    /** Convert 3D point to 2D projection plane */
    virtual Vector3f operator()(const Vector3f& rclPt) const = 0;
    /** Convert 3D point to 2D projection plane */
    virtual Vector3d operator()(const Vector3d& rclPt) const = 0;
    /** Convert a 2D point on the projection plane in 3D space */
    virtual Vector3f inverse(const Vector3f& rclPt) const = 0;
    /** Convert a 2D point on the projection plane in 3D space */
    virtual Vector3d inverse(const Vector3d& rclPt) const = 0;
    /** Calculate the projection (+ mapping) matrix */
    virtual Matrix4D getProjectionMatrix() const = 0;
    /** Calculate the composed projection matrix */
    Matrix4D getComposedProjectionMatrix() const;
    /** Apply an additional transformation to the input points */
    void setTransform(const Base::Matrix4D&);
    const Base::Matrix4D& getTransform() const
    {
        return transform;
    }

protected:
    ViewProjMethod();
    void transformInput(const Base::Vector3f&, Base::Vector3f&) const;
    void transformInput(const Base::Vector3d&, Base::Vector3d&) const;

private:
    bool hasTransform {false};
    Base::Matrix4D transform;
};

/**
 * The ViewProjMatrix class returns the result of the multiplication
 * of the 3D vector and the view transformation matrix.
 */
class BaseExport ViewProjMatrix: public ViewProjMethod
{
public:
    explicit ViewProjMatrix(const Matrix4D& rclMtx);

    Vector3f operator()(const Vector3f& inp) const override;
    Vector3d operator()(const Vector3d& inp) const override;
    Vector3f inverse(const Vector3f& src) const override;
    Vector3d inverse(const Vector3d& src) const override;

    Matrix4D getProjectionMatrix() const override;

private:
    bool isOrthographic;
    Matrix4D _clMtx, _clMtxInv;
};

/**
 * The ViewOrthoProjMatrix class returns the result of the multiplication
 * of the 3D vector and the transformation matrix.
 * Unlike ViewProjMatrix this class is not supposed to project points onto
 * a viewport but project points onto a plane in 3D.
 */
class BaseExport ViewOrthoProjMatrix: public ViewProjMethod
{
public:
    explicit ViewOrthoProjMatrix(const Matrix4D& rclMtx);

    Vector3f operator()(const Vector3f& rclPt) const override;
    Vector3d operator()(const Vector3d& rclPt) const override;
    Vector3f inverse(const Vector3f& rclPt) const override;
    Vector3d inverse(const Vector3d& rclPt) const override;

    Matrix4D getProjectionMatrix() const override;

private:
    Matrix4D _clMtx, _clMtxInv;
};

}  // namespace Base

#endif  // BASE_VIEWPROJ_H