xfade_curve.h

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/*
 * Copyright (C) 2014-2015 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2014-2017 Robin Gareus <robin@gareus.org>
 *
 * 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.
 */
 
#ifndef __CANVAS_XFADECURVE_H__
#define __CANVAS_XFADECURVE_H__
 
#include "canvas/visibility.h"
#include "canvas/item.h"
#include "canvas/curve.h"
 
namespace ArdourCanvas {
 
class LIBCANVAS_API XFadeCurve : public Item, public InterpolatedCurve
{
public:
        enum XFadePosition {
                Start,
                End,
        };
 
        XFadeCurve (Canvas *);
        XFadeCurve (Canvas *, XFadePosition);
        XFadeCurve (Item*);
        XFadeCurve (Item*, XFadePosition);
 
        void set_fade_position (XFadePosition xfp) { _xfadeposition = xfp; }
        void set_show_background_fade (bool show) { show_background_fade = show; }
 
        void compute_bounding_box () const;
        void render (Rect const & area, Cairo::RefPtr<Cairo::Context>) const;
 
        void set_points_per_segment (uint32_t n);
        void set_inout (Points const & in, Points const & out);
 
        void set_outline_color (Gtkmm2ext::Color c) {
                begin_visual_change ();
                _outline_color = c;
                end_visual_change ();
        };
 
        void set_fill_color (Gtkmm2ext::Color c) {
                begin_visual_change ();
                _fill_color = c;
                end_visual_change ();
        }
 
private:
        struct CanvasCurve {
                CanvasCurve() : n_samples(0) { }
                Points points;
                Points samples;
                Points::size_type n_samples;
        };
 
        Cairo::Path * get_path(Rect const &, Cairo::RefPtr<Cairo::Context>, CanvasCurve const &) const;
        void close_path(Rect const &, Cairo::RefPtr<Cairo::Context>, CanvasCurve const &p, bool) const;
 
        uint32_t points_per_segment;
 
        CanvasCurve _in;
        CanvasCurve _out;
 
        XFadePosition    _xfadeposition;
        Gtkmm2ext::Color _outline_color;
        Gtkmm2ext::Color _fill_color;
 
        bool show_background_fade;
 
        void interpolate ();
};
 
}
 
#endif