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https://github.com/TigerVNC/tigervnc.git
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![Constantin Kaplinsky](/assets/img/avatar_default.png)
git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@2 3789f03b-4d11-0410-bbf8-ca57d06f2519
165 lines
4.0 KiB
C++
165 lines
4.0 KiB
C++
/* Copyright (C) 2002-2003 RealVNC Ltd. All Rights Reserved.
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*
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* This is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This software is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this software; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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* USA.
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*/
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//
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// RRE encoding function.
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//
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// This file is #included after having set the following macros:
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// BPP - 8, 16 or 32
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//
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// The data argument to RRE_ENCODE contains the pixel data, and it writes the
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// encoded version to the given OutStream. If the encoded version exceeds w*h
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// it aborts and returns -1, otherwise it returns the number of subrectangles.
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//
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#include <rdr/OutStream.h>
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namespace rfb {
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// CONCAT2E concatenates its arguments, expanding them if they are macros
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#ifndef CONCAT2E
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#define CONCAT2(a,b) a##b
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#define CONCAT2E(a,b) CONCAT2(a,b)
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#endif
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#define PIXEL_T rdr::CONCAT2E(U,BPP)
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#define WRITE_PIXEL CONCAT2E(writeOpaque,BPP)
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#define RRE_ENCODE CONCAT2E(rreEncode,BPP)
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int RRE_ENCODE (PIXEL_T* data, int w, int h, rdr::OutStream* os, PIXEL_T bg);
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int RRE_ENCODE (void* data, int w, int h, rdr::OutStream* os)
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{
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// Find the background colour - count occurrences of up to 4 different pixel
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// values, and choose the one which occurs most often.
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const int nCols = 4;
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PIXEL_T pix[nCols];
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int count[nCols] = { 0, };
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PIXEL_T* ptr = (PIXEL_T*)data;
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PIXEL_T* end = ptr + w*h;
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while (ptr < end) {
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int i;
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for (i = 0; i < nCols; i++) {
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if (count[i] == 0)
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pix[i] = *ptr;
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if (pix[i] == *ptr) {
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count[i]++;
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break;
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}
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}
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if (i == nCols) break;
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ptr++;
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}
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int bg = 0;
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for (int i = 1; i < nCols; i++)
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if (count[i] > count[bg]) bg = i;
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// Now call the function to do the encoding.
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return RRE_ENCODE ((PIXEL_T*)data, w, h, os, pix[bg]);
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}
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int RRE_ENCODE (PIXEL_T* data, int w, int h, rdr::OutStream* os, PIXEL_T bg)
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{
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int oldLen = os->length();
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os->WRITE_PIXEL(bg);
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int nSubrects = 0;
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for (int y = 0; y < h; y++)
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{
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int x = 0;
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while (x < w) {
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if (*data == bg) {
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x++;
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data++;
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continue;
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}
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// Find horizontal subrect first
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PIXEL_T* ptr = data+1;
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PIXEL_T* eol = data+w-x;
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while (ptr < eol && *ptr == *data) ptr++;
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int sw = ptr - data;
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ptr = data + w;
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int sh = 1;
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while (sh < h-y) {
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eol = ptr + sw;
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while (ptr < eol)
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if (*ptr++ != *data) goto endOfHorizSubrect;
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ptr += w - sw;
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sh++;
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}
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endOfHorizSubrect:
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// Find vertical subrect
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int vh;
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for (vh = sh; vh < h-y; vh++)
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if (data[vh*w] != *data) break;
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if (vh != sh) {
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ptr = data+1;
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int vw;
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for (vw = 1; vw < sw; vw++) {
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for (int i = 0; i < vh; i++)
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if (ptr[i*w] != *data) goto endOfVertSubrect;
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ptr++;
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}
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endOfVertSubrect:
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// If vertical subrect bigger than horizontal then use that.
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if (sw*sh < vw*vh) {
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sw = vw;
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sh = vh;
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}
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}
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nSubrects++;
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os->WRITE_PIXEL(*data);
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os->writeU16(x);
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os->writeU16(y);
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os->writeU16(sw);
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os->writeU16(sh);
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if (os->length() > oldLen + w*h) return -1;
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ptr = data+w;
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PIXEL_T* eor = data+w*sh;
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while (ptr < eor) {
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eol = ptr + sw;
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while (ptr < eol) *ptr++ = bg;
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ptr += w - sw;
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}
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x += sw;
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data += sw;
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}
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}
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return nSubrects;
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}
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#undef PIXEL_T
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#undef WRITE_PIXEL
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#undef RRE_ENCODE
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}
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