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/* Copyright (C) 2002-2005 RealVNC Ltd. All Rights Reserved.
*
* This 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 software 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 software; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
#include <stdio.h>
#include <string.h>
#include <vector>
#include <rdr/types.h>
#include <rfb/Exception.h>
#include <rfb/ComparingUpdateTracker.h>
using namespace rfb;
ComparingUpdateTracker::ComparingUpdateTracker(PixelBuffer* buffer)
: fb(buffer), oldFb(fb->getPF(), 0, 0), firstCompare(true), enabled(true)
{
changed.assign_union(fb->getRect());
}
ComparingUpdateTracker::~ComparingUpdateTracker()
{
}
#define BLOCK_SIZE 64
bool ComparingUpdateTracker::compare()
{
std::vector<Rect> rects;
std::vector<Rect>::iterator i;
if (!enabled)
return false;
if (firstCompare) {
// NB: We leave the change region untouched on this iteration,
// since in effect the entire framebuffer has changed.
oldFb.setSize(fb->width(), fb->height());
for (int y=0; y<fb->height(); y+=BLOCK_SIZE) {
Rect pos(0, y, fb->width(), __rfbmin(fb->height(), y+BLOCK_SIZE));
int srcStride;
const rdr::U8* srcData = fb->getBuffer(pos, &srcStride);
oldFb.imageRect(pos, srcData, srcStride);
}
firstCompare = false;
return false;
}
copied.get_rects(&rects, copy_delta.x<=0, copy_delta.y<=0);
for (i = rects.begin(); i != rects.end(); i++)
oldFb.copyRect(*i, copy_delta);
changed.get_rects(&rects);
Region newChanged;
for (i = rects.begin(); i != rects.end(); i++)
compareRect(*i, &newChanged);
if (changed.equals(newChanged))
return false;
changed = newChanged;
return true;
}
void ComparingUpdateTracker::enable()
{
enabled = true;
}
void ComparingUpdateTracker::disable()
{
enabled = false;
// Make sure we update the framebuffer next time we get enabled
firstCompare = true;
}
void ComparingUpdateTracker::compareRect(const Rect& r, Region* newChanged)
{
if (!r.enclosed_by(fb->getRect())) {
Rect safe;
// Crop the rect and try again
safe = r.intersect(fb->getRect());
if (!safe.is_empty())
compareRect(safe, newChanged);
return;
}
int bytesPerPixel = fb->getPF().bpp/8;
int oldStride;
rdr::U8* oldData = oldFb.getBufferRW(r, &oldStride);
int oldStrideBytes = oldStride * bytesPerPixel;
std::vector<Rect> changedBlocks;
for (int blockTop = r.tl.y; blockTop < r.br.y; blockTop += BLOCK_SIZE)
{
// Get a strip of the source buffer
Rect pos(r.tl.x, blockTop, r.br.x, __rfbmin(r.br.y, blockTop+BLOCK_SIZE));
int fbStride;
const rdr::U8* newBlockPtr = fb->getBuffer(pos, &fbStride);
int newStrideBytes = fbStride * bytesPerPixel;
rdr::U8* oldBlockPtr = oldData;
int blockBottom = __rfbmin(blockTop+BLOCK_SIZE, r.br.y);
for (int blockLeft = r.tl.x; blockLeft < r.br.x; blockLeft += BLOCK_SIZE)
{
const rdr::U8* newPtr = newBlockPtr;
rdr::U8* oldPtr = oldBlockPtr;
int blockRight = __rfbmin(blockLeft+BLOCK_SIZE, r.br.x);
int blockWidthInBytes = (blockRight-blockLeft) * bytesPerPixel;
for (int y = blockTop; y < blockBottom; y++)
{
if (memcmp(oldPtr, newPtr, blockWidthInBytes) != 0)
{
// A block has changed - copy the remainder to the oldFb
changedBlocks.push_back(Rect(blockLeft, blockTop,
blockRight, blockBottom));
for (int y2 = y; y2 < blockBottom; y2++)
{
memcpy(oldPtr, newPtr, blockWidthInBytes);
newPtr += newStrideBytes;
oldPtr += oldStrideBytes;
}
break;
}
newPtr += newStrideBytes;
oldPtr += oldStrideBytes;
}
oldBlockPtr += blockWidthInBytes;
newBlockPtr += blockWidthInBytes;
}
oldData += oldStrideBytes * BLOCK_SIZE;
}
oldFb.commitBufferRW(r);
if (!changedBlocks.empty()) {
Region temp;
temp.setOrderedRects(changedBlocks);
newChanged->assign_union(temp);
}
}
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