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

Copyright (C) 2008 Lubos Lunak <l.lunak@kde.org>

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 "kwinxrenderutils.h"

#ifdef KWIN_HAVE_XRENDER_COMPOSITING

#include <QVector>
#include <QPixmap>
#include <QPainter>
#include <kdebug.h>

namespace KWin
{

// Convert QRegion to XserverRegion. All code uses XserverRegion
// only when really necessary as the shared implementation uses
// QRegion.
XserverRegion toXserverRegion( QRegion region )
    {
    QVector< QRect > rects = region.rects();
    XRectangle* xr = new XRectangle[ rects.count() ];
    for( int i = 0;
         i < rects.count();
         ++i )
        {
        xr[ i ].x = rects[ i ].x();
        xr[ i ].y = rects[ i ].y();
        xr[ i ].width = rects[ i ].width();
        xr[ i ].height = rects[ i ].height();
        }
    XserverRegion ret = XFixesCreateRegion( display(), xr, rects.count());
    delete[] xr;
    return ret;
    }

// adapted from Qt, because this really sucks ;)
XRenderColor preMultiply(const QColor &c, float opacity)
{
    XRenderColor color;
    const uint A = c.alpha() * opacity,
               R = c.red(),
               G = c.green(),
               B = c.blue();
    color.alpha = (A | A << 8);
    color.red   = (R | R << 8) * color.alpha / 0x10000;
    color.green = (G | G << 8) * color.alpha / 0x10000;
    color.blue  = (B | B << 8) * color.alpha / 0x10000;
    return color;
}

XRenderPicture xRenderFill( const XRenderColor *xc )
    {
    Pixmap pixmap = XCreatePixmap( display(), rootWindow(), 1, 1, 32 );
    XRenderPictureAttributes pa; pa.repeat = True;
    XRenderPicture fill( pixmap, 32 );
    XFreePixmap( display(), pixmap );
    XRenderChangePicture (display(), fill, CPRepeat, &pa);
    XRenderFillRectangle( display(), PictOpSrc, fill, xc, 0, 0, 1, 1 );
    return fill;
    }

XRenderPicture xRenderFill( const QColor &c )
    {
    XRenderColor xc = preMultiply(c);
    return xRenderFill( &xc );
    }

static XRenderPicture _blendPicture = X::None;
static XRenderColor _blendColor;
XRenderPicture xRenderBlendPicture(double opacity)
    {
    _blendColor.alpha = ushort(opacity * 0xffff);
    if (_blendPicture == X::None)
        _blendPicture = xRenderFill(&_blendColor);
    else
        XRenderFillRectangle(display(), PictOpSrc, _blendPicture, &_blendColor, 0, 0, 1, 1);
    return _blendPicture;
    }


static XRenderPicture *_circle[4] = {NULL, NULL, NULL, NULL};

#define DUMP_CNR(_SECT_, _W_, _H_, _XOFF_, _YOFF_)\
    dump = QPixmap(_W_, _H_);\
    dump.fill(Qt::transparent);\
    p.begin(&dump);\
    p.drawPixmap( 0, 0, tmp, _XOFF_, _YOFF_, _W_, _H_ );\
    p.end();\
    _circle[_SECT_] = new XRenderPicture(dump);

#define CS 8
    
static XRenderPicture *circle(int i)
    {
    if (!_circle[0])
        {
        QPixmap tmp(2*CS, 2*CS);
        tmp.fill(Qt::transparent);
        QPainter p(&tmp);
        p.setRenderHint(QPainter::Antialiasing);
        p.setPen(Qt::NoPen); p.setBrush(Qt::black);
        p.drawEllipse(tmp.rect());
        p.end();
        QPixmap dump;
        DUMP_CNR(0, CS, CS, 0, 0);
        DUMP_CNR(1, CS, CS, CS, 0);
        DUMP_CNR(2, CS, CS, CS, CS);
        DUMP_CNR(3, CS, CS, 0, CS);
        }
    return _circle[i];
    }

void xRenderRoundBox( Picture pict, const QRect &rect, int , const QColor &c )
    {
    XRenderPicture fill = xRenderFill(c);
    int op = c.alpha() == 255 ? PictOpSrc : PictOpOver;
    // TODO: implement second paramenter "roundness"
    // so rather use ?? XRenderCompositeTriFan (dpy, op, src, dst, maskFormat, xSrc, ySrc,
                                                    //XPointFixed *points, npoint);
    // this will require "points on a circle" calculation, however...
    
    int s = qMin(CS, qMin(rect.height()/2, rect.width()/2));
    int x,y,b,r;
    rect.getCoords(&x,&y,&r,&b);
    r -= (s - 1);
    b -= (s - 1);
    XRenderComposite( display(), PictOpOver, fill, *circle(0), pict, 0, 0, 0, 0, x, y, CS, CS );
    XRenderComposite( display(), PictOpOver, fill, *circle(1), pict, 0, 0, CS-s, 0, r, y, s, s );
    XRenderComposite( display(), PictOpOver, fill, *circle(2), pict, 0, 0, CS-s, CS-s, r, b, s, s );
    XRenderComposite( display(), PictOpOver, fill, *circle(3), pict, 0, 0, 0, CS-s, x, b, s, s );
    XRenderComposite( display(), op, fill, 0, pict, 0, 0, 0, 0, x+s, y, rect.width()-2*s, s);
    XRenderComposite( display(), op, fill, 0, pict, 0, 0, 0, 0, x, y+s, rect.width(), rect.height()-2*s);
    XRenderComposite( display(), op, fill, 0, pict, 0, 0, 0, 0, x+s, b, rect.width()-2*s, s);
    }

#undef CS
#undef DUMP_CNR

// XRenderFind(Standard)Format() is a roundtrip, so cache the results
static XRenderPictFormat* renderformats[ 33 ];

static Picture createPicture( Pixmap pix, int depth )
    {
    if( pix == None )
        return None;
    if( renderformats[ depth ] == NULL )
        {
        switch( depth)
            {
            case 1:
                renderformats[ 1 ] = XRenderFindStandardFormat( display(), PictStandardA1 );
              break;
            case 8:
                renderformats[ 8 ] = XRenderFindStandardFormat( display(), PictStandardA8 );
              break;
            case 24:
                renderformats[ 24 ] = XRenderFindStandardFormat( display(), PictStandardRGB24 );
              break;
            case 32:
                renderformats[ 32 ] = XRenderFindStandardFormat( display(), PictStandardARGB32 );
              break;
            default:
                {
                XRenderPictFormat req;
                long mask = PictFormatType | PictFormatDepth;
                req.type = PictTypeDirect;
                req.depth = depth;
                renderformats[ depth ] = XRenderFindFormat( display(), mask, &req, 0 );
              break;
                }
            }
        if( renderformats[ depth ] == NULL )
            {
            kWarning( 1212 ) << "Could not find XRender format for depth" << depth;
            return None;
            }
        }
    return XRenderCreatePicture( display(), pix, renderformats[ depth ], 0, NULL );
    }

XRenderPicture::XRenderPicture( QPixmap pix )
    : d( new XRenderPictureData( createPicture( pix.handle(), pix.depth())))
    {
    }

XRenderPicture::XRenderPicture( Pixmap pix, int depth )
    : d( new XRenderPictureData( createPicture( pix, depth )))
    {
    }

} // namespace

#endif