AlphaAnimation.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

// Based on code by omergilad.

#ifndef GUI_ANIMATION_ALPHA_ANIMATION_H
#define GUI_ANIMATION_ALPHA_ANIMATION_H

#include "gui/animation/Animation.h"

namespace GUI {

class AlphaAnimation: public Animation {
public:
    AlphaAnimation() {}
    virtual ~AlphaAnimation() {}
    float getEndAlpha() const { return _endAlpha; }
    void setEndAlpha(float endAlpha) { _endAlpha = endAlpha; }
    float getStartAlpha() const { return _startAlpha; }
    void setStartAlpha(float startAlpha) { _startAlpha = startAlpha; }

protected:
    virtual void updateInternal(Drawable* drawable, float interpolation) {
        // Calculate alpha value based on properties and interpolation
        drawable->setAlpha(_startAlpha * (1 - interpolation) + _endAlpha * interpolation);
    }

    float _startAlpha;
    float _endAlpha;
};

} // End of namespace GUI

#endif /* GUI_ANIMATION_ALPHA_ANIMATION_H */