Transform.h

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// -*- lsst-c++ -*-
/*
 * LSST Data Management System
 * Copyright 2008-2017 LSST Corporation.
 *
 * This product includes software developed by the
 * LSST Project (http://www.lsst.org/).
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the LSST License Statement and
 * the GNU General Public License along with this program.  If not,
 * see <http://www.lsstcorp.org/LegalNotices/>.
 */

#ifndef LSST_AFW_GEOM_TRANSFORM_H
#define LSST_AFW_GEOM_TRANSFORM_H

#include <memory>
#include <vector>

#include "astshim.h"
#include "Eigen/Core"
#include "ndarray.h"

#include "lsst/afw/geom/Endpoint.h"
#include "lsst/afw/table/io/Persistable.h"

namespace lsst {
namespace afw {
namespace geom {

class SkyWcs;

template <class FromEndpoint, class ToEndpoint>
class Transform final :
    public table::io::PersistableFacade<Transform<FromEndpoint,ToEndpoint>>,
    public table::io::Persistable
{
    // SkyWcs is a friend so it can call a protected Transform constructor
    friend class SkyWcs;

public:
    using FromArray = typename FromEndpoint::Array;
    using FromPoint = typename FromEndpoint::Point;
    using ToArray = typename ToEndpoint::Array;
    using ToPoint = typename ToEndpoint::Point;

    Transform(Transform const &) = default;
    Transform(Transform &&) = default;
    Transform &operator=(Transform const &) = delete;
    Transform &operator=(Transform &&) = delete;
    ~Transform() = default;

    explicit Transform(ast::Mapping const &mapping, bool simplify = true);

    explicit Transform(ast::FrameSet const &frameSet, bool simplify = true);

    bool hasForward() const { return _mapping->hasForward(); }

    bool hasInverse() const { return _mapping->hasInverse(); }

    FromEndpoint getFromEndpoint() const { return _fromEndpoint; }

    std::shared_ptr<const ast::Mapping> getMapping() const { return _mapping; }

    ToEndpoint getToEndpoint() const { return _toEndpoint; }

    ToPoint applyForward(FromPoint const &point) const;

    ToArray applyForward(FromArray const &array) const;

    FromPoint applyInverse(ToPoint const &point) const;

    FromArray applyInverse(ToArray const &array) const;

    std::shared_ptr<Transform<ToEndpoint, FromEndpoint>> getInverse() const;

    Eigen::MatrixXd getJacobian(FromPoint const &x) const;

    template <class NextToEndpoint>
    std::shared_ptr<Transform<FromEndpoint, NextToEndpoint>> then(
            Transform<ToEndpoint, NextToEndpoint> const &next, bool simplify = true) const;

    static std::string getShortClassName();

    static std::shared_ptr<Transform<FromEndpoint, ToEndpoint>> readStream(std::istream &is);

    static std::shared_ptr<Transform<FromEndpoint, ToEndpoint>> readString(std::string &str);

    void writeStream(std::ostream &os) const;

    std::string writeString() const;

    bool isPersistable() const override { return true; }

protected:
    explicit Transform(std::shared_ptr<ast::Mapping> mapping);

    // implement afw::table::io::Persistable interface
    std::string getPersistenceName() const override { return getShortClassName(); }

    // implement afw::table::io::Persistable interface
    std::string getPythonModule() const override { return "lsst.afw.geom"; }

    // implement afw::table::io::Persistable interface
    void write(OutputArchiveHandle &handle) const override;

private:
    FromEndpoint _fromEndpoint;
    std::shared_ptr<const ast::Mapping> _mapping;
    ToEndpoint _toEndpoint;
};

template <class FromEndpoint, class ToEndpoint>
std::ostream &operator<<(std::ostream &os, Transform<FromEndpoint, ToEndpoint> const &transform);

// typedefs for the most common transforms; names match Python names

using TransformPoint2ToPoint2 = Transform<Point2Endpoint, Point2Endpoint>;
using TransformPoint2ToGeneric = Transform<Point2Endpoint, GenericEndpoint>;
using TransformPoint2ToSpherePoint = Transform<Point2Endpoint, SpherePointEndpoint>;

}  // namespace geom
}  // namespace afw
}  // namespace lsst

#endif