/********************************************************************
 KWin - the KDE window manager
 This file is part of the KDE project.

 Copyright (C) 2009 Martin Gräßlin <kde@martin-graesslin.com>

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, see <http://www.gnu.org/licenses/>.
*********************************************************************/

#include "cubeslide.h"

#include <kwinconfig.h>
#include <kconfiggroup.h>

#include <math.h>

#include <GL/gl.h>

namespace KWin
{

KWIN_EFFECT( cubeslide, CubeSlideEffect )
KWIN_EFFECT_SUPPORTED( cubeslide, CubeSlideEffect::supported() )

CubeSlideEffect::CubeSlideEffect()
    {
    reconfigure( ReconfigureAll );
    }

CubeSlideEffect::~CubeSlideEffect()
    {
    }

bool CubeSlideEffect::supported()
    {
    return effects->compositingType() == OpenGLCompositing;
    }

void CubeSlideEffect::reconfigure( ReconfigureFlags )
    {
    KConfigGroup conf = effects->effectConfig( "CubeSlide" );
    rotationDuration = animationTime( conf, "RotationDuration", 500 );
    timeLine.setCurveShape( TimeLine::EaseInOutCurve );
    timeLine.setDuration( rotationDuration );
    dontSlidePanels = conf.readEntry( "DontSlidePanels", true );
    dontSlideStickyWindows = conf.readEntry( "DontSlideStickyWindows", false );
    usePagerLayout = conf.readEntry( "UsePagerLayout", true );
    }

void CubeSlideEffect::prePaintScreen( ScreenPrePaintData& data, int time)
    {
    if( !slideRotations.empty() )
        {
        data.mask |= PAINT_SCREEN_TRANSFORMED | Effect::PAINT_SCREEN_WITH_TRANSFORMED_WINDOWS | PAINT_SCREEN_BACKGROUND_FIRST;
        timeLine.addTime( time );
        if( dontSlidePanels )
            panels.clear();
        stickyWindows.clear();
        }
    effects->prePaintScreen( data, time );
    }

void CubeSlideEffect::paintScreen( int mask, QRegion region, ScreenPaintData& data)
    {
    if( !slideRotations.empty() )
        {
        glPushAttrib( GL_CURRENT_BIT | GL_ENABLE_BIT );
        glEnable( GL_CULL_FACE );
        glCullFace( GL_BACK );
        glPushMatrix();
        paintSlideCube( mask, region, data );
        glPopMatrix();
        glCullFace( GL_FRONT );
        glPushMatrix();
        paintSlideCube( mask, region, data );
        glPopMatrix();
        glDisable( GL_CULL_FACE );
        glPopAttrib();
        if( dontSlidePanels )
            {
            foreach( EffectWindow* w, panels )
                {
                WindowPaintData wData( w );
                effects->paintWindow( w, 0, QRegion( w->x(), w->y(), w->width(), w->height() ), wData );
                }
            }
        foreach( EffectWindow* w, stickyWindows )
            {
            WindowPaintData wData( w );
            effects->paintWindow( w, 0, QRegion( w->x(), w->y(), w->width(), w->height() ), wData );
            }
        }
    else
        effects->paintScreen( mask, region, data );
    }

void CubeSlideEffect::paintSlideCube(int mask, QRegion region, ScreenPaintData& data)
    {
    // slide cube only paints to desktops at a time
    // first the horizontal rotations followed by vertical rotations
    QRect rect = effects->clientArea( FullArea, effects->activeScreen(), effects->currentDesktop() );
    float point = rect.width()/2*tan(45.0f*M_PI/180.0f);
    cube_painting = true;
    painting_desktop = front_desktop;

    ScreenPaintData firstFaceData = data;
    ScreenPaintData secondFaceData = data;
    RotationData firstFaceRot = RotationData();
    RotationData secondFaceRot = RotationData();
    RotationDirection direction = slideRotations.head();
    int secondDesktop;
    switch ( direction )
        {
        case Left:
            firstFaceRot.axis = RotationData::YAxis;
            secondFaceRot.axis = RotationData::YAxis;
            if( usePagerLayout )
                secondDesktop = effects->desktopToLeft( front_desktop, true );
            else
                {
                secondDesktop = front_desktop - 1;
                if( secondDesktop == 0 )
                    secondDesktop = effects->numberOfDesktops();
                }
            firstFaceRot.angle = 90.0f*timeLine.value();
            secondFaceRot.angle = -90.0f*(1.0f - timeLine.value());
            break;
        case Right:
            firstFaceRot.axis = RotationData::YAxis;
            secondFaceRot.axis = RotationData::YAxis;
            if( usePagerLayout )
                secondDesktop = effects->desktopToRight( front_desktop, true );
            else
                {
                secondDesktop = front_desktop + 1;
                if( secondDesktop > effects->numberOfDesktops() )
                    secondDesktop = 1;
                }
            firstFaceRot.angle = -90.0f*timeLine.value();
            secondFaceRot.angle = 90.0f*(1.0f - timeLine.value());
            break;
        case Upwards:
            firstFaceRot.axis = RotationData::XAxis;
            secondFaceRot.axis = RotationData::XAxis;
            secondDesktop = effects->desktopAbove( front_desktop, true);
            firstFaceRot.angle = -90.0f*timeLine.value();
            secondFaceRot.angle = 90.0f*(1.0f - timeLine.value());
            point = rect.height()/2*tan(45.0f*M_PI/180.0f);
            break;
        case Downwards:
            firstFaceRot.axis = RotationData::XAxis;
            secondFaceRot.axis = RotationData::XAxis;
            secondDesktop = effects->desktopBelow( front_desktop, true );
            firstFaceRot.angle = 90.0f*timeLine.value();
            secondFaceRot.angle = -90.0f*(1.0f - timeLine.value());
            point = rect.height()/2*tan(45.0f*M_PI/180.0f);
            break;
        default:
            // totally impossible
            return;
        }
    // front desktop
    firstFaceRot.xRotationPoint = rect.width()/2;
    firstFaceRot.yRotationPoint = rect.height()/2;
    firstFaceRot.zRotationPoint = -point;
    firstFaceData.rotation = &firstFaceRot;
    other_desktop = secondDesktop;
    firstDesktop = true;
    effects->paintScreen( mask, region, firstFaceData );
    // second desktop
    other_desktop = painting_desktop;
    painting_desktop = secondDesktop;
    firstDesktop = false;
    secondFaceRot.xRotationPoint = rect.width()/2;
    secondFaceRot.yRotationPoint = rect.height()/2;
    secondFaceRot.zRotationPoint = -point;
    secondFaceData.rotation = &secondFaceRot;
    effects->paintScreen( mask, region, secondFaceData );
    cube_painting = false;
    painting_desktop = effects->currentDesktop();
    }

void CubeSlideEffect::prePaintWindow( EffectWindow* w,  WindowPrePaintData& data, int time)
    {
    if( !slideRotations.empty() && cube_painting )
        {
        QRect rect = effects->clientArea( FullArea, effects->activeScreen(), painting_desktop );
        if( dontSlidePanels && w->isDock())
            {
            panels.insert( w );
            }
        if( !w->isManaged() )
            {
            stickyWindows.insert( w );
            }
        else if( dontSlideStickyWindows && !w->isDock() &&
            !w->isDesktop() && w->isOnAllDesktops())
            {
            stickyWindows.insert( w );
            }
        if( w->isOnDesktop( painting_desktop ) )
            {
            if( w->x() < rect.x() )
                {
                data.quads = data.quads.splitAtX( -w->x() );
                }
            if( w->x() + w->width() > rect.x() + rect.width() )
                {
                data.quads = data.quads.splitAtX( rect.width() - w->x() );
                }
            if( w->y() < rect.y() )
                {
                data.quads = data.quads.splitAtY( -w->y() );
                }
            if( w->y() + w->height() > rect.y() + rect.height() )
                {
                data.quads = data.quads.splitAtY( rect.height() - w->y() );
                }
            w->enablePainting( EffectWindow::PAINT_DISABLED_BY_DESKTOP );
            }
        else if( w->isOnDesktop( other_desktop ) )
            {
            RotationDirection direction = slideRotations.head();
            bool enable = false;
            if( w->x() < rect.x() &&
                ( direction == Left || direction == Right ) )
                {
                data.quads = data.quads.splitAtX( -w->x() );
                enable = true;
                }
            if( w->x() + w->width() > rect.x() + rect.width() &&
                ( direction == Left || direction == Right ) )
                {
                data.quads = data.quads.splitAtX( rect.width() - w->x() );
                enable = true;
                }
            if( w->y() < rect.y() &&
                ( direction == Upwards || direction == Downwards ) )
                {
                data.quads = data.quads.splitAtY( -w->y() );
                enable = true;
                }
            if( w->y() + w->height() > rect.y() + rect.height() &&
                ( direction == Upwards || direction == Downwards ) )
                {
                data.quads = data.quads.splitAtY( rect.height() - w->y() );
                enable = true;
                }
            if( enable )
                {
                data.setTransformed();
                data.setTranslucent();
                w->enablePainting( EffectWindow::PAINT_DISABLED_BY_DESKTOP );
                }
            else
                w->disablePainting( EffectWindow::PAINT_DISABLED_BY_DESKTOP );
            }
        else
            w->disablePainting( EffectWindow::PAINT_DISABLED_BY_DESKTOP );
        }
    effects->prePaintWindow( w, data, time );
    }

void CubeSlideEffect::paintWindow( EffectWindow* w, int mask, QRegion region, WindowPaintData& data)
    {
    if( !slideRotations.empty() && cube_painting )
        {
        if( dontSlidePanels && w->isDock() )
            return;
        if( stickyWindows.contains( w ) )
            return;

        // filter out quads overlapping the edges
        QRect rect = effects->clientArea( FullArea, effects->activeScreen(), painting_desktop );
        if( w->isOnDesktop( painting_desktop ) )
            {
            if( w->x() < rect.x() )
                {
                WindowQuadList new_quads;
                foreach( const WindowQuad &quad, data.quads )
                    {
                    if( quad.right() > -w->x() )
                        {
                        new_quads.append( quad );
                        }
                    }
                data.quads = new_quads;
                }
            if( w->x() + w->width() > rect.x() + rect.width() )
                {
                WindowQuadList new_quads;
                foreach( const WindowQuad &quad, data.quads )
                    {
                    if( quad.right() <= rect.width() - w->x() )
                        {
                        new_quads.append( quad );
                        }
                    }
                data.quads = new_quads;
                }
            if( w->y() < rect.y() )
                {
                WindowQuadList new_quads;
                foreach( const WindowQuad &quad, data.quads )
                    {
                    if( quad.bottom() > -w->y() )
                        {
                        new_quads.append( quad );
                        }
                    }
                data.quads = new_quads;
                }
            if( w->y() + w->height() > rect.y() + rect.height() )
                {
                WindowQuadList new_quads;
                foreach( const WindowQuad &quad, data.quads )
                    {
                    if( quad.bottom() <= rect.height() - w->y() )
                        {
                        new_quads.append( quad );
                        }
                    }
                data.quads = new_quads;
                }
            }
        // paint windows overlapping edges from other desktop
        if( w->isOnDesktop( other_desktop ) && ( mask & PAINT_WINDOW_TRANSFORMED ) )
            {
            RotationDirection direction = slideRotations.head();
            if( w->x() < rect.x() &&
            ( direction == Left || direction == Right ) )
                {
                WindowQuadList new_quads;
                data.xTranslate = rect.width();
                foreach( const WindowQuad &quad, data.quads )
                    {
                    if( quad.right() <= -w->x() )
                        {
                        new_quads.append( quad );
                        }
                    }
                data.quads = new_quads;
                }
            if( w->x() + w->width() > rect.x() + rect.width() &&
                ( direction == Left || direction == Right ) )
                {
                WindowQuadList new_quads;
                data.xTranslate = -rect.width();
                foreach( const WindowQuad &quad, data.quads )
                    {
                    if( quad.right() > rect.width() - w->x() )
                        {
                        new_quads.append( quad );
                        }
                    }
                data.quads = new_quads;
                }
            if( w->y() < rect.y() &&
                ( direction == Upwards || direction == Downwards ) )
                {
                WindowQuadList new_quads;
                data.yTranslate = rect.height();
                foreach( const WindowQuad &quad, data.quads )
                    {
                    if( quad.bottom() <= -w->y() )
                        {
                        new_quads.append( quad );
                        }
                    }
                data.quads = new_quads;
                }
            if( w->y() + w->height() > rect.y() + rect.height() &&
                ( direction == Upwards || direction == Downwards ) )
                {
                WindowQuadList new_quads;
                data.yTranslate = -rect.height();
                foreach( const WindowQuad &quad, data.quads )
                    {
                    if( quad.bottom() > rect.height() - w->y() )
                        {
                        new_quads.append( quad );
                        }
                    }
                data.quads = new_quads;
                }
            if( firstDesktop )
                data.opacity *= timeLine.value();
            else
                data.opacity *= ( 1.0 - timeLine.value() );
            }
        }
    effects->paintWindow( w, mask, region, data );
    }

void CubeSlideEffect::postPaintScreen()
    {
    effects->postPaintScreen();
    if( !slideRotations.empty() )
        {
        if( timeLine.value() == 1.0 )
            {
            RotationDirection direction = slideRotations.dequeue();
            switch (direction)
                {
                case Left:
                    if( usePagerLayout )
                        front_desktop = effects->desktopToLeft( front_desktop, true );
                    else
                        {
                        front_desktop--;
                        if( front_desktop == 0 )
                            front_desktop = effects->numberOfDesktops();
                        }
                    break;
                case Right:
                    if( usePagerLayout )
                        front_desktop = effects->desktopToRight( front_desktop, true );
                    else
                        {
                        front_desktop++;
                        if( front_desktop > effects->numberOfDesktops() )
                            front_desktop = 1;
                        }
                    break;
                case Upwards:
                    front_desktop = effects->desktopAbove( front_desktop, true );
                    break;
                case Downwards:
                    front_desktop = effects->desktopBelow( front_desktop, true );
                    break;
                }
            timeLine.setProgress( 0.0 );
            if( slideRotations.count() == 1 )
                timeLine.setCurveShape( TimeLine::EaseOutCurve );
            else
                timeLine.setCurveShape( TimeLine::LinearCurve );
            if( slideRotations.empty() )
                {
                effects->setActiveFullScreenEffect( 0 );
                }
            }
        effects->addRepaintFull();
        }
    }

void CubeSlideEffect::desktopChanged( int old )
    {
    if( effects->activeFullScreenEffect() && effects->activeFullScreenEffect() != this )
        return;
    if( old > effects->numberOfDesktops() )
        {
        // number of desktops has been reduced -> no animation
        return;
        }
    bool activate = true;
    if( !slideRotations.empty() )
        {
        // last slide still in progress
        activate = false;
        RotationDirection direction = slideRotations.dequeue();
        slideRotations.clear();
        slideRotations.enqueue( direction );
        switch (direction)
            {
            case Left:
                if( usePagerLayout )
                    old = effects->desktopToLeft( front_desktop, true );
                else
                    {
                    old = front_desktop - 1;
                    if( old == 0 )
                        old = effects->numberOfDesktops();
                    }
                break;
            case Right:
                if( usePagerLayout )
                    old = effects->desktopToRight( front_desktop, true );
                else
                    {
                    old = front_desktop + 1;
                    if( old > effects->numberOfDesktops() )
                        old = 1;
                    }
                break;
            case Upwards:
                old = effects->desktopAbove( front_desktop, true );
                break;
            case Downwards:
                old = effects->desktopBelow( front_desktop, true );
                break;
            }
        }
    if( usePagerLayout )
        {
        // calculate distance in respect to pager
        QPoint diff = effects->desktopGridCoords( effects->currentDesktop() ) - effects->desktopGridCoords( old );
        if( qAbs( diff.x() ) > effects->desktopGridWidth()/2 )
            {
            int sign = -1 * (diff.x()/qAbs( diff.x() ));
            diff.setX( sign * ( effects->desktopGridWidth() - qAbs( diff.x() )));
            }
        if( diff.x() > 0 )
            {
            for( int i=0; i<diff.x(); i++ )
                {
                slideRotations.enqueue( Right );
                }
            }
        else if( diff.x() < 0 )
            {
            diff.setX( -diff.x() );
            for( int i=0; i<diff.x(); i++ )
                {
                slideRotations.enqueue( Left );
                }
            }
        if( qAbs( diff.y() ) > effects->desktopGridHeight()/2 )
            {
            int sign = -1 * (diff.y()/qAbs( diff.y() ));
            diff.setY( sign * ( effects->desktopGridHeight() - qAbs( diff.y() )));
            }
        if( diff.y() > 0 )
            {
            for( int i=0; i<diff.y(); i++ )
                {
                slideRotations.enqueue( Downwards );
                }
            }
        if( diff.y() < 0 )
            {
            diff.setY( -diff.y() );
            for( int i=0; i<diff.y(); i++ )
                {
                slideRotations.enqueue( Upwards );
                }
            }
        }
    else
        {
        // ignore pager layout
        int left = old - effects->currentDesktop();
        if( left < 0 )
            left = effects->numberOfDesktops() + left;
        int right = effects->currentDesktop() - old;
        if( right < 0 )
            right = effects->numberOfDesktops() + right;
        if( left < right )
            {
            for( int i=0; i<left; i++ )
                {
                slideRotations.enqueue( Left );
                }
            }
        else
            {
            for( int i=0; i<right; i++ )
                {
                slideRotations.enqueue( Right );
                }
            }
        }
    timeLine.setDuration( (float)rotationDuration / (float)slideRotations.count() );
    if( activate )
        {
        if( slideRotations.count() == 1 )
            timeLine.setCurveShape( TimeLine::EaseInOutCurve );
        else
            timeLine.setCurveShape( TimeLine::EaseInCurve );
        effects->setActiveFullScreenEffect( this );
        timeLine.setProgress( 0.0 );
        front_desktop = old;
        effects->addRepaintFull();
        }
    }

} // namespace