
/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */

/*
    Rosegarden
    A MIDI and audio sequencer and musical notation editor.
    Copyright 2000-2023 the Rosegarden development team.

    Other copyrights also apply to some parts of this work.  Please
    see the AUTHORS file and individual file headers for details.

    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.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef RG_PIXMAPFUNCTIONS_H
#define RG_PIXMAPFUNCTIONS_H

#include <QBitmap>
#include <QPixmap>
#include <utility>


namespace Rosegarden
{



class PixmapFunctions
{
public:
    /**
     * Generate a heuristic mask for the given pixmap.  Unlike
     * QPixmap::createHeuristicMask, this removes from the mask all
     * pixels that are apparently "background" even if they appear in
     * holes in the middle of the image.  This is more usually what we
     * want than the default behaviour of createHeuristicMask.
     *
     * The rgb value specifies the colour to treat as background.
     *
     * This function is slow.
     */
    static QBitmap generateMask(const QPixmap &map, const QRgb &rgb);

    /**
     * Generate a heuristic mask for the given pixmap.  Unlike
     * QPixmap::createHeuristicMask, this removes from the mask all
     * pixels that are apparently "background" even if they appear in
     * holes in the middle of the image.  This is more usually what we
     * want than the default behaviour of createHeuristicMask.
     *
     * This function calculates its own estimated colour to match as
     * background.
     *
     * This function is slow.
     */
    static QBitmap generateMask(const QPixmap &map);

    /**
     * Colour a greyscale pixmap with the given hue.
     * minimum specifies the minimum value (in the HSV sense) that
     * will be used for any recoloured pixel.
     *
     * The original model using only hue and value is deeply entrenched and
     * tricky to change, but with only a hue and a value specified, and the
     * saturation calculated automatically as 255 - the minimum value, how do
     * you achieve a pure red?  By adding an extra saturation parameter was the
     * only thing I could think of, and here it is.
     */
    static QPixmap colourPixmap(const QPixmap &map, int hue, int minimum, int saturation = SaturationNotSpecified);

    /**
     * Make a pixmap grey, or otherwise reduce its intensity.
     */
    static QPixmap shadePixmap(const QPixmap &map);

    /// Return a QPixmap that is a mirror image of map (including mask)
    static QPixmap flipVertical(const QPixmap &map);

    /// Return a QPixmap that is a mirror image of map (including mask)
    static QPixmap flipHorizontal(const QPixmap &map);

    /// Return left and right parts of the QPixmap
    static std::pair<QPixmap, QPixmap> splitPixmap(const QPixmap &pixmap, int x);

    /**
     * Using QPainter::drawPixmap to draw one pixmap on another does
     * not appear to take the mask into account properly.  Background
     * pixels in the second pixmap erase foreground pixels in the
     * first one, regardless of whether they're masked or not.  This
     * function does what I expect.
     *
     * Note that the source pixmap _must_ have a mask.
     */
    static void drawPixmapMasked(QPixmap &dest, QBitmap &destMask,
                                 int x0, int y0,
                                 const QPixmap &src);

    static const int SaturationNotSpecified = -1;
};


}

#endif
