QPreview.h

/*
 *   Copyright 2011, 2012 Lukas Jirkovsky
 *
 *   This file is part of FotoSHOCK.
 *
 *   FotoSHOCK 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, version 3 of the License.
 *
 *   FotoSHOCK 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 FotoSHOCK.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef QPREVIEW_H
#define QPREVIEW_H

#include "MipMap.hpp"

#include <QGLWidget>

class QPreview : public QGLWidget {
Q_OBJECT
    public:
        QPreview(FotoSHOCKcore::MipMap* mipmap, QWidget* parent = 0, const QGLWidget* shareWidget = 0, Qt::WindowFlags f = 0);
        virtual ~QPreview();
        virtual QSize sizeHint() const;
    public slots:
        void changeZoom(int zoom);
        void zoomIn();
        void zoomOut();
        void fitWindow();
        void forceRedraw();
    signals:
        void zoomChanged(int zoom);
        void ROIchanged(unsigned int x, unsigned int y, unsigned int sizeX, unsigned int sizeY, const int mipmapLevel);
    protected:
        virtual void initializeGL();
        virtual void paintGL();
        virtual void resizeGL (int w, int h);

        virtual void mousePressEvent(QMouseEvent* event);
        virtual void mouseReleaseEvent(QMouseEvent* event);
        virtual void mouseMoveEvent(QMouseEvent* event);
    private:
        void updateUsedTiles(unsigned int width, unsigned int height);
        inline void updateViewportOffset(unsigned int width, unsigned int height);
        void loadTextures();

        // current scale in %, where 100% is the original size, 200% is two times bigger
        unsigned int m_zoom;
        // zoom relative to the current mipmap level
        float m_levelZoom;
        // mipmap associated with the preview
        FotoSHOCKcore::MipMap* m_mipmap;
        // mipmap level corresponding to the current zoom
        int m_mipmapLevel;
        // tile extent for the curent mipmap level
        unsigned int m_tileExtent;
        // tile extent scaled for the display
        unsigned int m_tileExtentScaled;
        unsigned int m_numOfTilesHoriz;

        // format and type of the data in the mipmap
        /*GLenum m_format;
        GLenum m_type;*/
        // all textures for the current mipmap level
        // only the visible ones + 1 one more is actually loaded
        // free them using glDeleteTextures
        GLuint* m_textures;
        size_t m_texturesSize;

        // true if the viewport is moved
        bool m_move;
        // position where the move started
        int startX;
        int startY;
        // current upper left corner of the viewport
        // absolute value
        int x;
        int y;
        // offset of a viewport, used to center the image on the widget
        int xViewportOffset;
        int yViewportOffset;

        unsigned int startTileVert;
        unsigned int endTileVert;
        unsigned int startTileHoriz;
        unsigned int endTileHoriz;
        // offset from the upper left corner
        unsigned int xOffset;
        unsigned int yOffset;
};

#endif