/*************************************************************************
 * Copyright (C) 2014 by Hugo Pereira Da Costa <hugo.pereira@free.fr>    *
 *                                                                       *
 * 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 2 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, write to the                         *
 * Free Software Foundation, Inc.,                                       *
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA .        *
 *************************************************************************/

#include "tileset.h"

#include <QPainter>

//___________________________________________________________
inline bool bits(TileSet::Tiles flags, TileSet::Tiles testFlags)
{ return (flags & testFlags) == testFlags; }

//______________________________________________________________________________________
inline qreal devicePixelRatio( const QPixmap& pixmap )
{
    return pixmap.devicePixelRatio();
}

//______________________________________________________________________________________
inline void setDevicePixelRatio( QPixmap& pixmap, qreal value )
{
    return pixmap.setDevicePixelRatio( value );
}

//______________________________________________________________
void TileSet::initPixmap( PixmapList& pixmaps, const QPixmap &source, int width, int height, const QRect &rect)
{
    QSize size( width, height );
    if( !( size.isValid() && rect.isValid() ) )
    {
        pixmaps.append( QPixmap() );

    } else if( size != rect.size() ) {

        const qreal dpiRatio( devicePixelRatio( source ) );
        const QRect scaledRect( rect.topLeft()*dpiRatio, rect.size()*dpiRatio );
        const QSize scaledSize( size*dpiRatio );
        const QPixmap tile( source.copy(scaledRect) );
        QPixmap pixmap( scaledSize );

        pixmap.fill(Qt::transparent);
        QPainter painter(&pixmap);
        painter.drawTiledPixmap(0, 0, scaledSize.width(), scaledSize.height(), tile);
        setDevicePixelRatio( pixmap, dpiRatio );
        pixmaps.append( pixmap );

    } else {

        const qreal dpiRatio( devicePixelRatio( source ) );
        const QRect scaledRect( rect.topLeft()*dpiRatio, rect.size()*dpiRatio );
        QPixmap pixmap( source.copy( scaledRect ) );
        setDevicePixelRatio( pixmap, dpiRatio );
        pixmaps.append( pixmap );

    }

}

//______________________________________________________________
TileSet::TileSet():
    _w1(0),
    _h1(0),
    _w3(0),
    _h3(0)
{ _pixmaps.reserve(9); }

//______________________________________________________________
TileSet::TileSet(const QPixmap &source, int w1, int h1, int w2, int h2 ):
    _w1(w1),
    _h1(h1),
    _w3(0),
    _h3(0)
{
    _pixmaps.reserve(9);
    if( source.isNull() ) return;

    _w3 = source.width()/devicePixelRatio( source ) - (w1 + w2);
    _h3 = source.height()/devicePixelRatio( source ) - (h1 + h2);
    int w = w2;
    int h = h2;

    // initialise pixmap array
    initPixmap( _pixmaps, source, _w1, _h1, QRect(0, 0, _w1, _h1) );
    initPixmap( _pixmaps, source, w, _h1, QRect(_w1, 0, w2, _h1) );
    initPixmap( _pixmaps, source, _w3, _h1, QRect(_w1+w2, 0, _w3, _h1) );
    initPixmap( _pixmaps, source, _w1, h, QRect(0, _h1, _w1, h2) );
    initPixmap( _pixmaps, source, w, h, QRect(_w1, _h1, w2, h2) );
    initPixmap( _pixmaps, source, _w3, h, QRect(_w1+w2, _h1, _w3, h2) );
    initPixmap( _pixmaps, source, _w1, _h3, QRect(0, _h1+h2, _w1, _h3) );
    initPixmap( _pixmaps, source, w, _h3, QRect(_w1, _h1+h2, w2, _h3) );
    initPixmap( _pixmaps, source, _w3, _h3, QRect(_w1+w2, _h1+h2, _w3, _h3) );
}

//___________________________________________________________
void TileSet::render(const QRect &constRect, QPainter *painter, Tiles tiles) const
{

    const bool oldHint( painter->testRenderHint( QPainter::SmoothPixmapTransform ) );
    painter->setRenderHint( QPainter::SmoothPixmapTransform, true );

    // check initialization
    if( _pixmaps.size() < 9 ) return;

    // copy source rect
    QRect rect( constRect );

    // get rect dimensions
    int x0, y0, w, h;
    rect.getRect(&x0, &y0, &w, &h);

    // calculate pixmaps widths
    int wLeft(0);
    int wRight(0);
    if( _w1+_w3 > 0 )
    {
        qreal wRatio( qreal( _w1 )/qreal( _w1 + _w3 ) );
        wLeft = (tiles&Right) ? qMin( _w1, int(w*wRatio) ):_w1;
        wRight = (tiles&Left) ? qMin( _w3, int(w*(1.0-wRatio)) ):_w3;
    }

    // calculate pixmap heights
    int hTop(0);
    int hBottom(0);
    if( _h1+_h3 > 0 )
    {
        qreal hRatio( qreal( _h1 )/qreal( _h1 + _h3 ) );
        hTop = (tiles&Bottom) ? qMin( _h1, int(h*hRatio) ):_h1;
        hBottom = (tiles&Top) ? qMin( _h3, int(h*(1.0-hRatio)) ):_h3;
    }

    // calculate corner locations
    w -= wLeft + wRight;
    h -= hTop + hBottom;
    const int x1 = x0 + wLeft;
    const int x2 = x1 + w;
    const int y1 = y0 + hTop;
    const int y2 = y1 + h;

    const int w2 = _pixmaps.at(7).width()/devicePixelRatio( _pixmaps.at(7) );
    const int h2 = _pixmaps.at(5).height()/devicePixelRatio( _pixmaps.at(5) );

    // corner
    if( bits( tiles, Top|Left) )  painter->drawPixmap(x0, y0, _pixmaps.at(0), 0, 0, wLeft*devicePixelRatio( _pixmaps.at(0) ), hTop*devicePixelRatio( _pixmaps.at(0) ));
    if( bits( tiles, Top|Right) ) painter->drawPixmap(x2, y0, _pixmaps.at(2), (_w3-wRight)*devicePixelRatio( _pixmaps.at(2) ), 0, wRight*devicePixelRatio( _pixmaps.at(2) ), hTop*devicePixelRatio( _pixmaps.at(2) ) );
    if( bits( tiles, Bottom|Left) )  painter->drawPixmap(x0, y2, _pixmaps.at(6), 0, (_h3-hBottom)*devicePixelRatio( _pixmaps.at(6) ), wLeft*devicePixelRatio( _pixmaps.at(6) ),  hBottom*devicePixelRatio( _pixmaps.at(6) ));
    if( bits( tiles, Bottom|Right) ) painter->drawPixmap(x2, y2, _pixmaps.at(8), (_w3-wRight)*devicePixelRatio( _pixmaps.at(8) ), (_h3-hBottom)*devicePixelRatio( _pixmaps.at(8) ), wRight*devicePixelRatio( _pixmaps.at(8) ), hBottom*devicePixelRatio( _pixmaps.at(8) ) );

    // top and bottom
    if( w > 0 )
    {
        if( tiles&Top ) painter->drawPixmap(x1, y0, w, hTop, _pixmaps.at(1), 0, 0, w2*devicePixelRatio( _pixmaps.at(1) ), hTop*devicePixelRatio( _pixmaps.at(1) ) );
        if( tiles&Bottom ) painter->drawPixmap(x1, y2, w, hBottom, _pixmaps.at(7), 0, (_h3-hBottom)*devicePixelRatio( _pixmaps.at(7) ), w2*devicePixelRatio( _pixmaps.at(7) ), hBottom*devicePixelRatio( _pixmaps.at(7) ) );
    }

    // left and right
    if( h > 0 )
    {
        if( tiles&Left ) painter->drawPixmap(x0, y1, wLeft, h, _pixmaps.at(3), 0, 0, wLeft*devicePixelRatio( _pixmaps.at(3) ), h2*devicePixelRatio( _pixmaps.at(3) ) );
        if( tiles&Right ) painter->drawPixmap(x2, y1, wRight, h, _pixmaps.at(5), (_w3-wRight)*devicePixelRatio( _pixmaps.at(5) ), 0, wRight*devicePixelRatio( _pixmaps.at(5) ), h2*devicePixelRatio( _pixmaps.at(5) ) );
    }

    // center
    if( (tiles&Center) && h > 0 && w > 0 ) painter->drawPixmap(x1, y1, w, h, _pixmaps.at(4));

    // restore
    painter->setRenderHint( QPainter::SmoothPixmapTransform, oldHint );

}
