krfb/framebuffer.cpp

/* This file is part of the KDE project
   Copyright (C) 2007 Alessandro Praduroux <pradu@pradu.it>

   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; version 2
   of the License.
*/

#include "framebuffer.h"
#include "framebuffer.moc"

#include <QTimer>
#include <QRegion>
#include <QPixmap>
#include <QBitmap>

const int UPDATE_TIME = 500;

FrameBuffer::FrameBuffer(WId id, QObject *parent)
 : QObject(parent), win(id)
{
    //TODO: implement reference counting to avoid update the screen
    // while no client is connected.

    fbImage = QPixmap::grabWindow(win).toImage();
    fb = new char[fbImage.numBytes()];
    QTimer *t = new QTimer(this);
    connect(t, SIGNAL(timeout()), SLOT(updateFrameBuffer()));
    t->start(UPDATE_TIME);
}


FrameBuffer::~FrameBuffer()
{
    delete fb;
}

char * FrameBuffer::data()
{
    return fb;
}

void FrameBuffer::updateFrameBuffer()
{
    QImage img = QPixmap::grabWindow(win).toImage();
    QSize imgSize = img.size();


    // verify what part of the image need to be marked as changed
    // fbImage is the previous version of the image,
    // img is the current one

#if 0 // This is actually slower than updating the whole desktop...

    QImage map(imgSize, QImage::Format_Mono);
    map.fill(0);

    for (int x = 0; x < imgSize.width(); x++) {
        for (int y = 0; y < imgSize.height(); y++) {
            if (img.pixel(x,y) != fbImage.pixel(x,y)) {
                map.setPixel(x,y,1);
            }
        }
    }

    QRegion r(QBitmap::fromImage(map));
    tiles = tiles + r.rects();

#else
    tiles.append(img.rect());
#endif

    memcpy(fb, (const char*)img.bits(), img.numBytes());
    fbImage = img;

}

QVector< QRect > & FrameBuffer::modifiedTiles()
{
    return tiles;
}

int FrameBuffer::width()
{
    return fbImage.width();
}

int FrameBuffer::height()
{
    return fbImage.height();
}

void FrameBuffer::getServerFormat(rfbPixelFormat & format)
{
    format.bitsPerPixel = 32;
    format.depth = 32;
    format.trueColour = true;

    format.bigEndian = false;
    format.redShift = 16;
    format.greenShift = 8;
    format.blueShift = 0;
    format.redMax   = 0xff;
    format.greenMax = 0xff;
    format.blueMax  = 0xff;
}

int FrameBuffer::depth()
{
    return fbImage.depth();
}