/********************************************************************
 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 "resize.h"

#ifdef KWIN_HAVE_OPENGL_COMPOSITING
#include <kwinglutils.h>
#endif
#ifdef KWIN_HAVE_XRENDER_COMPOSITING
#include <X11/Xlib.h>
#include <X11/extensions/Xrender.h>
#endif

#include <KColorScheme>
#include <QVector2D>
#include <QVector4D>

namespace KWin
{

KWIN_EFFECT( resize, ResizeEffect )

ResizeEffect::ResizeEffect()
    : m_active( false )
    , m_resizeWindow( 0 )
    , m_useShader( false )
#ifdef KWIN_HAVE_OPENGL_COMPOSITING
    , m_vbo( 0 )
    , m_colorShader( 0 )
#endif
    {
    reconfigure( ReconfigureAll );
#ifdef KWIN_HAVE_OPENGL_COMPOSITING
    if (effects->compositingType() == OpenGLCompositing) {
        m_vbo = new GLVertexBuffer(GLVertexBuffer::Stream);
        m_vbo->setUseColor(true);
        // TODO: use GLPlatform
        if (GLShader::vertexShaderSupported() && GLShader::fragmentShaderSupported()) {
            m_colorShader = new GLShader(":/resources/scene-color-vertex.glsl", ":/resources/scene-color-fragment.glsl");
            if (m_colorShader->isValid()) {
                m_colorShader->bind();
                m_colorShader->setUniform("displaySize", QVector2D(displayWidth(), displayHeight()));
                m_colorShader->setUniform("geometry", QVector4D(0, 0, 0, 0));
                m_colorShader->unbind();
                m_vbo->setUseShader(true);
                m_useShader = true;
                kDebug(1212) << "Show Paint Shader is valid";
            } else {
                kDebug(1212) << "Show Paint Shader not valid";
            }
        }
    }
#endif
    }

ResizeEffect::~ResizeEffect()
    {
#ifdef KWIN_HAVE_OPENGL_COMPOSITING
    delete m_vbo;
    delete m_colorShader;
#endif
    }

void ResizeEffect::prePaintScreen( ScreenPrePaintData& data, int time )
    {
    if( m_active )
        {
        data.mask |= PAINT_SCREEN_WITH_TRANSFORMED_WINDOWS;
        }
    effects->prePaintScreen( data, time );
    }

void ResizeEffect::prePaintWindow( EffectWindow* w, WindowPrePaintData& data, int time )
    {
    if( m_active && w == m_resizeWindow )
        data.mask |= PAINT_WINDOW_TRANSFORMED;
    effects->prePaintWindow( w, data, time );
    }

void ResizeEffect::paintWindow( EffectWindow* w, int mask, QRegion region, WindowPaintData& data )
    {
    if( m_active && w == m_resizeWindow )
        {
        if( m_features & TextureScale )
            {
            data.xTranslate += m_currentGeometry.x() - m_originalGeometry.x();
            data.xScale *= m_currentGeometry.width();
            data.xScale /= m_originalGeometry.width();
            data.yTranslate += m_currentGeometry.y() - m_originalGeometry.y();
            data.yScale *= m_currentGeometry.height();
            data.yScale /= m_originalGeometry.height();
            }
        effects->paintWindow( w, mask, region, data );

        if( m_features & Outline )
        {
            QRegion intersection = m_originalGeometry.intersected( m_currentGeometry );
            QRegion paintRegion = QRegion(m_originalGeometry).united( m_currentGeometry ).subtracted( intersection );
            float alpha = 0.8f;
            QColor color = KColorScheme( QPalette::Normal, KColorScheme::Selection ).background().color();

#ifdef KWIN_HAVE_OPENGL_COMPOSITING
            if (effects->compositingType() == OpenGLCompositing) {
#ifndef KWIN_HAVE_OPENGLES
                glPushAttrib( GL_CURRENT_BIT | GL_ENABLE_BIT );
#endif
                if (m_useShader) {
                    m_colorShader->bind();
                }
                glEnable( GL_BLEND );
                glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
                color.setAlphaF(alpha);
                m_vbo->setColor(color);
                QVector<float> verts;
                verts.reserve(paintRegion.rects().count()*12);
                foreach( const QRect &r, paintRegion.rects() ) {
                    verts << r.x() + r.width() << r.y();
                    verts << r.x() << r.y();
                    verts << r.x() << r.y() + r.height();
                    verts << r.x() << r.y() + r.height();
                    verts << r.x() + r.width() << r.y() + r.height();
                    verts << r.x() + r.width() << r.y();
                }
                m_vbo->setData(verts.count()/2, 2, verts.data(), NULL);
                m_vbo->render(GL_TRIANGLES);
                if (m_useShader) {
                    m_colorShader->unbind();
                }
                glDisable(GL_BLEND);
#ifndef KWIN_HAVE_OPENGLES
                glPopAttrib();
#endif
            }
#endif

#ifdef KWIN_HAVE_XRENDER_COMPOSITING
            if( effects->compositingType() == XRenderCompositing)
                {
                XRenderColor col;
                col.alpha = int( alpha * 0xffff );
                col.red = int( alpha * 0xffff * color.red() / 255 );
                col.green = int( alpha * 0xffff * color.green() / 255 );
                col.blue= int( alpha * 0xffff * color.blue() / 255 );
                foreach( const QRect &r, paintRegion.rects() )
                    XRenderFillRectangle( display(), PictOpOver, effects->xrenderBufferPicture(),
                        &col, r.x(), r.y(), r.width(), r.height());
                }
#endif
            }
        }
        else
            effects->paintWindow( w, mask, region, data );
    }

void ResizeEffect::reconfigure( ReconfigureFlags )
    {
    KConfigGroup conf = effects->effectConfig("Resize");
    m_features = 0;
    if ( conf.readEntry( "TextureScale", true ) )
        m_features |= TextureScale;
    if ( conf.readEntry( "Outline", false ) )
        m_features |= Outline;
    }

void ResizeEffect::windowUserMovedResized( EffectWindow* w, bool first, bool last )
    {
    if( first && last )
        {
        // not interested in maximized
        return;
        }
    if( first && w->isUserResize() && !w->isUserMove() )
        {
        m_active = true;
        m_resizeWindow = w;
        m_originalGeometry = w->geometry();
        m_currentGeometry = w->geometry();
        w->addRepaintFull();
        }
    if( m_active && w == m_resizeWindow && last )
        {
        m_active = false;
        m_resizeWindow = NULL;
        effects->addRepaintFull();
        }
    }

void ResizeEffect::windowMoveResizeGeometryUpdate( EffectWindow* c, const QRect& geometry )
    {
    if( m_active && c == m_resizeWindow )
        {
        m_currentGeometry = geometry;
        effects->addRepaintFull();
        }
    }

} // namespace