tdebase/kicker/libkicker/kshadowengine.h

/* This file is proposed to be part of the KDE libraries.
 * Copyright (C) 2003 Laur Ivan <laurivan@eircom.net>
 *
 * Many thanks to:
 *  - Bernardo Hung <deciare@gta.igs.net> for the enhanced shadow
 *    algorithm (currently used)
 *  - Tim Jansen <tim@tjansen.de> for the API updates and fixes.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License version 2 as published by the Free Software Foundation.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#ifndef __FX_SHADOW
#define __FX_SHADOW

#include <tqpixmap.h>
#include <tqimage.h>
#include <tqcolor.h>

#include <kdemacros.h>

class KShadowSettings;

/**
 * This class implements the shadow algorithm(s). It uses a FxData
 * object for its parameters. Note that the shadow algorithm is using the
 * luminosity of the original pixmap for the shadow one.
 * @see KShadowSettings
 * @author laur.ivan@corvil.com
 * @since 3.2
 */
class KDE_EXPORT KShadowEngine
{
public:
    /// Creates a new shadow engine.
    KShadowEngine();

    ~KShadowEngine();

    /**
    * Creates a new shadow engine.
    * @param fx the shadow settings object with the configuration. The Shadow
    *        Engine will own this object and also delete it. Must
    *        be heap-allocated
    */
    KShadowEngine(KShadowSettings *fx);

    /**
    * Set the KShadowSettings object.
    * @param fx the shadow settings object with the configuration. The Shadow
    *        Engine will own this object and also delete it. Must
    *        be heap-allocated.
    */
    void setShadowSettings(KShadowSettings *fx);

    /**
    * Get the current KShadowSettings.
    * @param the current shadow settings
    */
    KShadowSettings *shadowSettings();

    /**
    * Make shadow!
    *
    * textPixmap is the original pixmap where a (white) text is drawn.
    * bgColor is the color used for the shadow.
    * @param textPixmap the pixmap of the text
    * @param bgColor the background color
    * @return the resulting image
    */
    TQImage makeShadow(const TQPixmap& textPixmap, const TQColor &bgColor);

private:
    // No static objects in libs, and no static deleters in kdefx...
    //static KShadowSettings s_defaultShadowSettings;

    KShadowSettings *m_shadowSettings;

    /*
    * a simple algorithm with 3 pixels thickness
    */
    double defaultDecay(TQImage& source, int x, int y);

    /*
    * a slower algorithm where the influence of a pixel
    * is  tqGray(px)/(abs(dx) + abs(dy) +1).
    */
    double doubleLinearDecay(TQImage& source, int x, int y);

    /*
    * a very slow algorithm where the influence of a pixel
    * is  tqGray(px)/(sqrt(sqr(dx) + sqr(dy)) +1).
    */
    double radialDecay(TQImage& source, int x, int y);

    /*
    * a nice/fast algorithm proposed by Bernardo Hung
    */
    double noDecay(TQImage& source, int x, int y);

    void *d;
};

class KDE_EXPORT KTextShadowEngine : public KShadowEngine
{
public:
    KTextShadowEngine();
    
    void drawText(TQPainter &p, const TQRect &tr, int tf, const TQString &str, const TQSize &size);
};

#endif