/***************************************************************************
 *   Copyright (c) 2010 Werner Mayer <wmayer[at]users.sourceforge.net>     *
 *                                                                         *
 *   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                                *
 *                                                                         *
 ***************************************************************************/


#include <Inventor/SbTesselator.h>
#include <QAbstractItemModel>
#include <QAbstractItemView>
#include <QItemSelection>
#include <QItemSelectionModel>


#include <App/DocumentObject.h>

#include "Utilities.h"


using namespace Gui;


ViewVolumeProjection::ViewVolumeProjection(const SbViewVolume& vv)
    : viewVolume(vv)
{
    matrix = viewVolume.getMatrix();
    invert = matrix.inverse();
}

Base::Vector3f ViewVolumeProjection::operator()(const Base::Vector3f& pt) const
{
    Base::Vector3f src;
    transformInput(pt, src);

    SbVec3f pt3d(src.x, src.y, src.z);

    // See SbViewVolume::projectToScreen
    matrix.multVecMatrix(pt3d, pt3d);

    return Base::Vector3f(0.5 * pt3d[0] + 0.5, 0.5 * pt3d[1] + 0.5, 0.5 * pt3d[2] + 0.5);
}

Base::Vector3d ViewVolumeProjection::operator()(const Base::Vector3d& pt) const
{
    auto ptf = Base::convertTo<Base::Vector3f>(pt);
    ptf = operator()(ptf);
    return Base::convertTo<Base::Vector3d>(ptf);
}

Base::Vector3f ViewVolumeProjection::inverse(const Base::Vector3f& pt) const
{
    SbVec3f pt3d(2.0f * pt.x - 1.0f, 2.0f * pt.y - 1.0f, 2.0f * pt.z - 1.0f);
    invert.multVecMatrix(pt3d, pt3d);
    return Base::Vector3f(pt3d[0], pt3d[1], pt3d[2]);
}

Base::Vector3d ViewVolumeProjection::inverse(const Base::Vector3d& pt) const
{
    auto ptf = Base::convertTo<Base::Vector3f>(pt);
    ptf = inverse(ptf);
    return Base::convertTo<Base::Vector3d>(ptf);
}

Base::Matrix4D ViewVolumeProjection::getProjectionMatrix() const
{
    // Inventor stores the transposed matrix
    Base::Matrix4D mat;

    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 4; j++) {
            mat[i][j] = matrix[j][i];
        }
    }

    return mat;
}

// ----------------------------------------------------------------------------

void Tessellator::tessCB(void* v0, void* v1, void* v2, void* cbdata)
{
    int* vtx0 = (int*)v0;
    int* vtx1 = (int*)v1;
    int* vtx2 = (int*)v2;

    auto array = (std::vector<int>*)cbdata;
    array->push_back(*vtx0);
    array->push_back(*vtx1);
    array->push_back(*vtx2);
    array->push_back(-1);
}

Tessellator::Tessellator(const std::vector<SbVec2f>& poly)
    : polygon(poly)
{}

std::vector<int> Tessellator::tessellate() const
{
    std::vector<int> indices(polygon.size());
    std::vector<int> face_indices;

    SbTesselator tessellator(tessCB, &face_indices);
    tessellator.beginPolygon();

    int index = 0;
    for (std::vector<SbVec2f>::const_iterator it = polygon.begin(); it != polygon.end();
         ++it, index++) {
        indices[index] = index;
        tessellator.addVertex(SbVec3f((*it)[0], (*it)[1], 0.0f), &(indices[index]));
    }

    // run the triangulation now
    tessellator.endPolygon();
    return face_indices;
}

// ----------------------------------------------------------------------------

class ItemViewSelection::MatchName
{
public:
    explicit MatchName(const QString& n)
        : name(n)
    {}
    bool operator()(const App::DocumentObject* obj)
    {
        return name == QLatin1String(obj->getNameInDocument());
    }

private:
    QString name;
};

ItemViewSelection::ItemViewSelection(QAbstractItemView* view)
    : view(view)
{}

void ItemViewSelection::applyFrom(const std::vector<App::DocumentObject*> objs)
{
    QAbstractItemModel* model = view->model();
    QItemSelection range;
    for (int i = 0; i < model->rowCount(); i++) {
        QModelIndex item = model->index(i, 0);
        if (item.isValid()) {
            QVariant name = model->data(item, Qt::UserRole);
            std::vector<App::DocumentObject*>::const_iterator it;
            it = std::find_if(objs.begin(), objs.end(), MatchName(name.toString()));
            if (it != objs.end()) {
                range.select(item, item);
            }
        }
    }

    view->selectionModel()->select(range, QItemSelectionModel::Select);
}