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

Copyright (C) 2007 Rivo Laks <rivolaks@hot.ee>
Copyright (C) 2008 Lucas Murray <lmurray@undefinedfire.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 "invert.h"

#include <kwinglutils.h>
#include <kactioncollection.h>
#include <kaction.h>
#include <klocale.h>
#include <kdebug.h>
#include <kwinshadereffect.h>
#include <KStandardDirs>

#include <QMatrix4x4>

namespace KWin
{

KWIN_EFFECT( invert, InvertEffect )
KWIN_EFFECT_SUPPORTED( invert, InvertEffect::supported() )

InvertEffect::InvertEffect()
    :   m_inited( false ),
        m_valid( true ),
        m_shader( NULL ),
        m_allWindows( false )
    {
    KActionCollection* actionCollection = new KActionCollection( this );

    KAction* a = (KAction*)actionCollection->addAction( "Invert" );
    a->setText( i18n( "Toggle Invert Effect" ));
    a->setGlobalShortcut( KShortcut( Qt::CTRL + Qt::META + Qt::Key_I ));
    connect(a, SIGNAL( triggered(bool) ), this, SLOT( toggle() ));

    KAction* b = (KAction*)actionCollection->addAction( "InvertWindow" );
    b->setText( i18n( "Toggle Invert Effect on Window" ));
    b->setGlobalShortcut( KShortcut( Qt::CTRL + Qt::META + Qt::Key_U ));
    connect(b, SIGNAL( triggered(bool) ), this, SLOT( toggleWindow() ));
    }

InvertEffect::~InvertEffect()
    {
    delete m_shader;
    }

bool InvertEffect::supported()
{
    return GLRenderTarget::supported() &&
            GLShader::fragmentShaderSupported() &&
            (effects->compositingType() == OpenGLCompositing);
}

bool InvertEffect::loadData()
{
    m_inited = true;
    if (!ShaderManager::instance()->isValid()) {
        return false;
    }

    const QString fragmentshader =  KGlobal::dirs()->findResource("data", "kwin/invert.frag");

    m_shader = ShaderManager::instance()->loadFragmentShader(ShaderManager::GenericShader, fragmentshader);
    if( !m_shader->isValid() )
        {
        kError(1212) << "The shader failed to load!" << endl;
        return false;
        }

    return true;
    }

void InvertEffect::prePaintScreen(ScreenPrePaintData &data, int time)
{
    if (m_valid && (m_allWindows || !m_windows.isEmpty())) {
        data.mask |= PAINT_SCREEN_WITH_TRANSFORMED_WINDOWS_WITHOUT_FULL_REPAINTS;
    }
    effects->prePaintScreen(data, time);
}

void InvertEffect::prePaintWindow(EffectWindow *w, WindowPrePaintData &data, int time)
{
    if (m_valid && ( m_allWindows != m_windows.contains( w ))) {
        data.mask |= PAINT_WINDOW_TRANSFORMED;
    }
    effects->prePaintWindow(w, data, time);
}

void InvertEffect::drawWindow( EffectWindow* w, int mask, QRegion region, WindowPaintData& data )
    {
    // Load if we haven't already
    if( m_valid && !m_inited )
        m_valid = loadData();

    bool useShader = m_valid && ( m_allWindows != m_windows.contains( w ));
    if (useShader) {
        ShaderManager *shaderManager = ShaderManager::instance();
        GLShader *genericShader = shaderManager->pushShader(ShaderManager::GenericShader);
        QMatrix4x4 screenTransformation = genericShader->getUniformMatrix4x4("screenTransformation");
        shaderManager->popShader();
        shaderManager->pushShader(m_shader);
        m_shader->setUniform("screenTransformation", screenTransformation);

        data.shader = m_shader;
    }

    effects->drawWindow( w, mask, region, data );

    if (useShader) {
        ShaderManager::instance()->popShader();
    }
    }

void InvertEffect::paintEffectFrame( KWin::EffectFrame* frame, QRegion region, double opacity, double frameOpacity )
    {
    if( m_valid && m_allWindows )
        {
        frame->setShader( m_shader );
        ShaderManager::instance()->pushShader(m_shader);
        m_shader->setUniform("screenTransformation", QMatrix4x4());
        m_shader->setUniform("windowTransformation", QMatrix4x4());
        effects->paintEffectFrame( frame, region, opacity, frameOpacity );
        ShaderManager::instance()->popShader();
        }
    else
        {
        effects->paintEffectFrame( frame, region, opacity, frameOpacity );
        }
    }

void InvertEffect::windowClosed( EffectWindow* w )
    {
    m_windows.removeOne( w );
    }

void InvertEffect::toggle()
    {
    m_allWindows = !m_allWindows;
    effects->addRepaintFull();
    }

void InvertEffect::toggleWindow()
    {
    if( !m_windows.contains( effects->activeWindow() ))
        m_windows.append( effects->activeWindow() );
    else
        m_windows.removeOne( effects->activeWindow() );
    effects->activeWindow()->addRepaintFull();
    }

} // namespace

#include "invert.moc"