/*
    Scan Tailor - Interactive post-processing tool for scanned pages.
    Copyright (C)  Joseph Artsimovich <joseph.artsimovich@gmail.com>

    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 GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "DewarpingPointMapper.h"
#include "DistortionModel.h"
#include <QTransform>
#include <QSize>
#include <QRect>

namespace dewarping
{

DewarpingPointMapper::DewarpingPointMapper(
    DistortionModel const& distortion_model, double depth_perception,
    QTransform const& distortion_model_to_output, QRect const& output_content_rect)
    :   m_dewarper(
            CylindricalSurfaceDewarper(
                distortion_model.topCurve().polyline(),
                distortion_model.bottomCurve().polyline(),
                depth_perception
            )
        )
{
    // Model domain is a rectangle in output image coordinates that
    // will be mapped to our curved quadrilateral.
    QRect const model_domain(
        distortion_model.modelDomain(
            m_dewarper, distortion_model_to_output, output_content_rect
        ).toRect()
    );

    // Note: QRect::right() - QRect::left() will give you size() - 1 not size()!
    // That's intended.

    m_modelDomainLeft = model_domain.left();
    m_modelXScaleFromNormalized = model_domain.right() - model_domain.left();
    m_modelXScaleToNormalized = 1.0 / m_modelXScaleFromNormalized;

    m_modelDomainTop = model_domain.top();
    m_modelYScaleFromNormalized = model_domain.bottom() - model_domain.top();
    m_modelYScaleToNormalized = 1.0 / m_modelYScaleFromNormalized;
}

QPointF
DewarpingPointMapper::mapToDewarpedSpace(QPointF const& warped_pt) const
{
    QPointF const crv_pt(m_dewarper.mapToDewarpedSpace(warped_pt));
    double const dewarped_x = crv_pt.x() * m_modelXScaleFromNormalized + m_modelDomainLeft;
    double const dewarped_y = crv_pt.y() * m_modelYScaleFromNormalized + m_modelDomainTop;
    return QPointF(dewarped_x, dewarped_y);
}

QPointF
DewarpingPointMapper::mapToWarpedSpace(QPointF const& dewarped_pt) const
{
    double const crv_x = (dewarped_pt.x() - m_modelDomainLeft) * m_modelXScaleToNormalized;
    double const crv_y = (dewarped_pt.y() - m_modelDomainTop) * m_modelYScaleToNormalized;
    return m_dewarper.mapToWarpedSpace(QPointF(crv_x, crv_y));
}

} // namespace dewarping
