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authordscho <dscho>2002-12-06 16:03:50 +0000
committerdscho <dscho>2002-12-06 16:03:50 +0000
commit4d87189420b6225da7f38aa71aee840d816bd570 (patch)
tree2de78669b8dea0e6f8d6ae4e4d17ff825b5c6a88 /contrib/x11vnc.c
parentd60fda117b1d72d12984a07a4444d36a69da639e (diff)
downloadlibtdevnc-4d871894.tar.gz
libtdevnc-4d871894.zip
compiler warnings, contrib directory, new x11vnc from Karl Runge
Diffstat (limited to 'contrib/x11vnc.c')
-rw-r--r--contrib/x11vnc.c1352
1 files changed, 1352 insertions, 0 deletions
diff --git a/contrib/x11vnc.c b/contrib/x11vnc.c
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@@ -0,0 +1,1352 @@
+/*
+ * x0vnc.c: a VNC server for X displays.
+ *
+ * Copyright (c) 2002 Karl J. Runge <runge@karlrunge.com> 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.
+ *
+ *
+ * This program is based heavily on the following programs:
+ *
+ * x11vnc.c of the libvncserver project (Johannes E. Schindelin)
+ * krfb, the KDE desktopsharing project (Tim Jansen)
+ * x0rfbserver, the original native X vnc server (Jens Wagner)
+ *
+ * The primary goal of this program is to create a portable and simple
+ * command-line server utility that allows a VNC viewer to connect to an
+ * actual X display (as x11vnc, krfb, and x0rfbserver do). The only
+ * non-standard dependency of this program is the static library
+ * libvncserver.a (although in some environments libjpeg.so may not be
+ * readily available). To increase portability it is written in plain C.
+ *
+ * The next goal is to improve performance and interactive response.
+ * The algorithm currently used here to achieve this is that of krfb
+ * (based on x0rfbserver algorithm). Additional heuristics are also
+ * applied. Currently there are a bit too many of these...
+ *
+ * To build:
+ * Obtain the libvncserver package (http://libvncserver.sourceforge.net)
+ * and ensure that "make" and "make x11vnc" work correctly. Defining
+ * HAVE_PTHREADS in the Makefile is recommended. One then could move the
+ * x11vnc.c file aside, copy this file in its place into the source tree,
+ * and issue:
+ *
+ * make x11vnc
+ * mv x11vnc x0vnc
+ *
+ * to create the x0vnc binary. Otherwise, with x0vnc.c copied to
+ * libvncserver source directory, something like this should work:
+ *
+ * gcc -Wall -DALLOW24BPP -I. -DBACKCHANNEL -c x0vnc.c
+ * gcc -o x0vnc x0vnc.o -L. -lvncserver -L/usr/local/lib -lz -ljpeg \
+ * -L/usr/X11R6/lib -lX11 -lXext -lXtst
+ *
+ * include -DHAVE_PTHREADS ... -lpthread to use threads.
+ *
+ * On Solaris the 2nd command might look something like:
+ *
+ * gcc -o x0vnc x0vnc.o -L. -lvncserver -L/usr/local/lib -lz -ljpeg \
+ * -lsocket -lnsl -L/usr/X/lib -R/usr/X/lib -lX11 -lXext -lXtst
+ */
+
+#define KeySym RFBKeySym
+#include "rfb.h"
+
+#include <unistd.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <X11/extensions/XShm.h>
+#include <X11/extensions/XTest.h>
+#include <X11/keysym.h>
+
+Display *dpy = 0;
+int dpy_x, dpy_y;
+int bpp;
+int window;
+int button_mask = 0;
+
+XImage *tile;
+XImage *scanline;
+XImage *fullscreen;
+int fs_factor = 0;
+
+XShmSegmentInfo tile_shm;
+XShmSegmentInfo scanline_shm;
+XShmSegmentInfo fullscreen_shm;
+
+rfbScreenInfoPtr screen;
+rfbCursorPtr cursor;
+int bytes_per_line;
+
+/* size of the basic tile unit that is polled for changes: */
+int tile_x = 32;
+int tile_y = 32;
+int ntiles, ntiles_x, ntiles_y;
+
+/* arrays that indicate changed or checked tiles. */
+char *tile_has_diff, *tile_tried;
+
+typedef struct tile_change_region {
+ short first_line, last_line; /* start and end lines, along y, */
+ /* of the changed area inside a tile. */
+ short left_diff, right_diff; /* info about differences along edges. */
+ short top_diff, bot_diff;
+} region_t;
+
+/* array to hold the tiles region_t-s. */
+region_t *tile_region;
+
+typedef struct hint {
+ /* location x, y, height, and width of a change-rectangle */
+ /* (grows as adjacent horizontal tiles are glued together) */
+ int x, y, w, h;
+} hint_t;
+
+/* array to hold the hints: */
+hint_t *hint_list;
+
+int shared = 0; /* share vnc display. */
+int view_only = 0; /* client can only watch. */
+int connect_once = 1; /* allow only one client connection. */
+
+/*
+ * waitms is the msec to wait between screen polls. Not too old h/w shows
+ * poll times of 15-35ms, so maybe this value cuts the rest load by 2 or so.
+ */
+int waitms = 30;
+int defer_update = 30; /* rfbDeferUpdateTime ms to wait before sends. */
+int use_threads = 1; /* but only if compiled with HAVE_PTHREADS */
+
+/* tile heuristics: */
+int use_hints = 1; /* use the krfb scheme of gluing tiles together. */
+int tile_fuzz = 2; /* tolerance for suspecting changed tiles touching */
+ /* a known changed tile. */
+int grow_fill = 3; /* do the grow islands heuristic with this width. */
+int gaps_fill = 4; /* do a final pass to try to fill gaps between tiles. */
+double fs_frac = 0.5; /* threshold tile fraction to do fullscreen updates. */
+
+#define NSCAN 32
+int scanlines[NSCAN] = { /* scan pattern jitter from x0rfbserver */
+ 0, 16, 8, 24, 4, 20, 12, 28,
+ 10, 26, 18, 2, 22, 6, 30, 14,
+ 1, 17, 9, 25, 7, 23, 15, 31,
+ 19, 3, 27, 11, 29, 13, 5, 21
+};
+
+int got_user_input;
+int count = 0;
+int shut_down = 0;
+
+/*
+ * Not sure why... but when threaded we have to mutex our X11 calls to
+ * avoid XIO crashes. This should not be too bad since keyboard and pointer
+ * updates are infrequent compared to the scanning. (note: these lines are
+ * noops unless HAVE_PTHREADS) XXX: what is going on?
+ */
+MUTEX(x11Mutex);
+#define X_LOCK LOCK(x11Mutex);
+#define X_UNLOCK UNLOCK(x11Mutex);
+
+void mark_hint(hint_t);
+
+void clean_up_exit (void) {
+
+ X_LOCK
+
+ XTestDiscard(dpy);
+
+ /* remove the shm areas: */
+
+ XShmDetach(dpy, &tile_shm);
+ XDestroyImage(tile);
+ shmdt(tile_shm.shmaddr);
+ shmctl(tile_shm.shmid, IPC_RMID, 0);
+
+ XShmDetach(dpy, &scanline_shm);
+ XDestroyImage(scanline);
+ shmdt(scanline_shm.shmaddr);
+ shmctl(scanline_shm.shmid, IPC_RMID, 0);
+
+ XShmDetach(dpy, &fullscreen_shm);
+ XDestroyImage(fullscreen);
+ shmdt(fullscreen_shm.shmaddr);
+ shmctl(fullscreen_shm.shmid, IPC_RMID, 0);
+
+ /* more cleanup? */
+
+ X_UNLOCK
+ exit(0);
+}
+
+void client_gone(rfbClientPtr client) {
+ if (connect_once) {
+ printf("only one connection allowed.\n");
+ clean_up_exit();
+ }
+}
+
+enum rfbNewClientAction new_client(rfbClientPtr client) {
+ if (connect_once) {
+ client->clientGoneHook = client_gone;
+ }
+ if (view_only) {
+ client->clientData = (void *) -1;
+ } else {
+ client->clientData = (void *) 0;
+ }
+ return(RFB_CLIENT_ACCEPT);
+}
+
+/* key event handler */
+static void keyboard(Bool down, KeySym keysym, rfbClientPtr client) {
+ KeyCode k;
+
+ if (view_only) {
+ return;
+ }
+
+ X_LOCK
+
+ k = XKeysymToKeycode(dpy, keysym);
+
+ if ( k != NoSymbol ) {
+ XTestFakeKeyEvent(dpy, k, down, CurrentTime);
+ XFlush(dpy);
+
+ got_user_input++;
+ }
+ X_UNLOCK
+}
+
+/* mouse event handler */
+static void pointer(int mask, int x, int y, rfbClientPtr client) {
+ int i;
+
+ if (view_only) {
+ return;
+ }
+
+ X_LOCK
+
+ XTestFakeMotionEvent(dpy, 0, x, y, CurrentTime);
+
+ got_user_input++;
+
+ for (i=0; i < 5; i++) {
+ if ( (button_mask & (1<<i)) != (mask & (1<<i)) ) {
+ XTestFakeButtonEvent(dpy, i+1,
+ (mask & (1<<i)) ? True : False, CurrentTime);
+ }
+ }
+ X_UNLOCK
+
+ /* remember the button state for next time: */
+ button_mask = mask;
+}
+
+/* simple fixed cursor */
+static char* cur_data =
+" "
+" "
+" x "
+" xx "
+" xxx "
+" xxxx "
+" xxxxx "
+" xxxxxx "
+" xxxxxxx "
+" xxxxxxxx "
+" xxxxx "
+" xx xx "
+" x xx "
+" xx "
+" xx "
+" xx "
+" "
+" ";
+
+static char* cur_mask =
+" "
+" xx "
+" xxx "
+" xxxx "
+" xxxxx "
+" xxxxxx "
+" xxxxxxx "
+" xxxxxxxx "
+" xxxxxxxxx "
+" xxxxxxxxxx "
+" xxxxxxxxxx "
+" xxxxxxx "
+" xxx xxxx "
+" xx xxxx "
+" xxxx "
+" xxxx "
+" xx "
+" ";
+int cursor_x = 18;
+int cursor_y = 18;
+
+void initialize_screen(int *argc, char **argv, XImage *fb) {
+
+ screen = rfbGetScreen(argc, argv, fb->width, fb->height,
+ fb->bits_per_pixel, 8, fb->bits_per_pixel/8);
+
+ screen->paddedWidthInBytes = fb->bytes_per_line;
+ screen->rfbServerFormat.bitsPerPixel = fb->bits_per_pixel;
+ screen->rfbServerFormat.depth = fb->depth;
+ screen->rfbServerFormat.trueColour = (CARD8) TRUE;
+
+ if ( screen->rfbServerFormat.bitsPerPixel == 8 ) {
+ /* 8 bpp */
+ screen->rfbServerFormat.redShift = 0;
+ screen->rfbServerFormat.greenShift = 2;
+ screen->rfbServerFormat.blueShift = 5;
+ screen->rfbServerFormat.redMax = 3;
+ screen->rfbServerFormat.greenMax = 7;
+ screen->rfbServerFormat.blueMax = 3;
+ } else {
+ /* general case ... */
+ screen->rfbServerFormat.redShift = 0;
+ if ( fb->red_mask ) {
+ while ( ! (fb->red_mask
+ & (1 << screen->rfbServerFormat.redShift) ) ) {
+ screen->rfbServerFormat.redShift++;
+ }
+ }
+ screen->rfbServerFormat.greenShift = 0;
+ if ( fb->green_mask ) {
+ while ( ! (fb->green_mask
+ & (1 << screen->rfbServerFormat.greenShift) ) ) {
+ screen->rfbServerFormat.greenShift++;
+ }
+ }
+ screen->rfbServerFormat.blueShift = 0;
+ if ( fb->blue_mask ) {
+ while ( ! (fb->blue_mask
+ & (1 << screen->rfbServerFormat.blueShift) ) ) {
+ screen->rfbServerFormat.blueShift++;
+ }
+ }
+ screen->rfbServerFormat.redMax
+ = fb->red_mask >> screen->rfbServerFormat.redShift;
+ screen->rfbServerFormat.greenMax
+ = fb->green_mask >> screen->rfbServerFormat.greenShift;
+ screen->rfbServerFormat.blueMax
+ = fb->blue_mask >> screen->rfbServerFormat.blueShift;
+ }
+
+ screen->frameBuffer = fb->data;
+
+ /* XXX the following 3 settings are based on libvncserver defaults. */
+ if (screen->rfbPort == 5900) {
+ screen->autoPort = TRUE;
+ }
+ if (screen->rfbDeferUpdateTime == 5) {
+ screen->rfbDeferUpdateTime = defer_update;
+ }
+ if (shared && ! screen->rfbNeverShared) {
+ screen->rfbAlwaysShared = TRUE;
+ }
+
+ /* event callbacks: */
+ screen->newClientHook = new_client;
+ screen->kbdAddEvent = keyboard;
+ screen->ptrAddEvent = pointer;
+
+ cursor = rfbMakeXCursor(cursor_x, cursor_y, cur_data, cur_mask);
+ screen->cursor = cursor;
+
+ rfbInitServer(screen);
+
+ bytes_per_line = screen->paddedWidthInBytes;
+ bpp = screen->rfbServerFormat.bitsPerPixel;
+}
+
+/*
+ * setup tile numbers and allocate the tile and hint arrays:
+ */
+void initialize_tiles() {
+
+ ntiles_x = (dpy_x - 1)/tile_x + 1;
+ ntiles_y = (dpy_y - 1)/tile_y + 1;
+ ntiles = ntiles_x * ntiles_y;
+
+ tile_has_diff = (char *) malloc((size_t) (ntiles * sizeof(char)));
+ tile_tried = (char *) malloc((size_t) (ntiles * sizeof(char)));
+ tile_region = (region_t *) malloc((size_t) (ntiles * sizeof(region_t)));
+
+ /* there will never be more hints than tiles: */
+ hint_list = (hint_t *) malloc((size_t) (ntiles * sizeof(hint_t)));
+}
+
+/*
+ * silly function to factor dpy_y until fullscreen shm is not bigger than max.
+ * should always work unless dpy_y is a large prime or something... under
+ * failure fs_factor remains 0 and no fullscreen updates will be tried.
+ */
+void set_fs_factor(int max) {
+ int f, fac = 1, n = dpy_y;
+
+ if ( (bpp/8) * dpy_x * dpy_y <= max ) {
+ fs_factor = 1;
+ return;
+ }
+ for (f=2; f <= 101; f++) {
+ while (n % f == 0) {
+ n = n / f;
+ fac = fac * f;
+ if ( (bpp/8) * dpy_x * (dpy_y/fac) <= max ) {
+ fs_factor = fac;
+ return;
+ }
+ }
+ }
+}
+
+void initialize_shm() {
+
+ /* the tile (e.g. 32x32) shared memory area image: */
+
+ tile = XShmCreateImage(dpy, DefaultVisual(dpy, 0), bpp, ZPixmap,
+ NULL, &tile_shm, tile_x, tile_y);
+
+ tile_shm.shmid = shmget(IPC_PRIVATE,
+ tile->bytes_per_line * tile->height, IPC_CREAT | 0777);
+
+ tile_shm.shmaddr = tile->data = (char *) shmat(tile_shm.shmid, 0, 0);
+ tile_shm.readOnly = False;
+
+ XShmAttach(dpy, &tile_shm);
+
+
+ /* the scanline (e.g. 1280x1) shared memory area image: */
+
+ scanline = XShmCreateImage(dpy, DefaultVisual(dpy, 0), bpp, ZPixmap,
+ NULL, &scanline_shm, dpy_x, 1);
+
+ scanline_shm.shmid = shmget(IPC_PRIVATE,
+ scanline->bytes_per_line * scanline->height, IPC_CREAT | 0777);
+
+ scanline_shm.shmaddr = scanline->data
+ = (char *) shmat(scanline_shm.shmid, 0, 0);
+ scanline_shm.readOnly = False;
+
+ XShmAttach(dpy, &scanline_shm);
+
+ /*
+ * the fullscreen (e.g. 1280x1024/fs_factor) shared memory area image:
+ * (we cut down the size of the shm area to try avoid and shm segment
+ * limits, e.g. the default 1MB on Solaris)
+ */
+ set_fs_factor(1024 * 1024);
+ if (! fs_factor) {
+ printf("warning: fullscreen updates are disabled.\n");
+ return;
+ }
+
+ fullscreen = XShmCreateImage(dpy, DefaultVisual(dpy, 0), bpp, ZPixmap,
+ NULL, &fullscreen_shm, dpy_x, dpy_y/fs_factor);
+
+ fullscreen_shm.shmid = shmget(IPC_PRIVATE,
+ fullscreen->bytes_per_line * fullscreen->height, IPC_CREAT | 0777);
+
+ fullscreen_shm.shmaddr = fullscreen->data
+ = (char *) shmat(fullscreen_shm.shmid, 0, 0);
+ fullscreen_shm.readOnly = False;
+
+ XShmAttach(dpy, &fullscreen_shm);
+}
+
+/*
+ * A hint is a rectangular region built from 1 or more adjacent tiles
+ * glued together. Ultimately, this information in a single hint is sent
+ * to libvncserver rather than sending each tile separately.
+ */
+void create_tile_hint(int x, int y, int th, hint_t *hint) {
+ int w = dpy_x - x;
+ int h = dpy_y - y;
+
+ if (w > tile_x) {
+ w = tile_x;
+ }
+ if (h > th) {
+ h = th;
+ }
+
+ hint->x = x;
+ hint->y = y;
+ hint->w = w;
+ hint->h = h;
+}
+
+void extend_tile_hint(int x, int y, int th, hint_t *hint) {
+ int w = dpy_x - x;
+ int h = dpy_y - y;
+
+ if (w > tile_x) {
+ w = tile_x;
+ }
+ if (h > th) {
+ h = th;
+ }
+
+ if (hint->x > x) { /* extend to the left */
+ hint->w += hint->x - x;
+ hint->x = x;
+ }
+ if (hint->y > y) { /* extend upward */
+ hint->h += hint->y - y;
+ hint->y = y;
+ }
+
+ if (hint->x + hint->w < x + w) { /* extend to the right */
+ hint->w = x + w - hint->x;
+ }
+ if (hint->y + hint->h < y + h) { /* extend downward */
+ hint->h = y + h - hint->y;
+ }
+}
+
+void save_hint(hint_t hint, int loc) {
+ /* copy it to the global array: */
+
+ hint_list[loc].x = hint.x;
+ hint_list[loc].y = hint.y;
+ hint_list[loc].w = hint.w;
+ hint_list[loc].h = hint.h;
+}
+
+
+/*
+ * Glue together horizontal "runs" of adjacent changed tiles into one big
+ * rectangle change "hint" to be passed to the vnc machinery.
+ */
+void hint_updates() {
+ hint_t hint;
+ int x, y, i, n, ty, th;
+ int hint_count = 0, in_run = 0;
+
+ for (y=0; y < ntiles_y; y++) {
+ for (x=0; x < ntiles_x; x++) {
+ n = x + y * ntiles_x;
+
+ if (tile_has_diff[n]) {
+ ty = tile_region[n].first_line;
+ th = tile_region[n].last_line - ty + 1;
+ if (! in_run) {
+ create_tile_hint( x * tile_x,
+ y * tile_y + ty, th, &hint);
+ in_run = 1;
+ } else {
+ extend_tile_hint( x * tile_x,
+ y * tile_y + ty, th, &hint);
+ }
+ } else {
+ if (in_run) {
+ /* end of a row run of altered tiles: */
+ save_hint(hint, hint_count++);
+ in_run = 0;
+ }
+ }
+ }
+ if (in_run) { /* save the last row run */
+ save_hint(hint, hint_count++);
+ in_run = 0;
+ }
+ }
+
+ for (i=0; i < hint_count; i++) {
+ /* pass update info to vnc: */
+ mark_hint(hint_list[i]);
+ }
+}
+
+/*
+ * Notifies libvncserver of a changed hint rectangle.
+ */
+void mark_hint(hint_t hint) {
+ int x = hint.x;
+ int y = hint.y;
+ int w = hint.w;
+ int h = hint.h;
+
+ rfbMarkRectAsModified(screen, x, y, x + w, y + h);
+}
+
+/*
+ * Notifies libvncserver of a changed tile rectangle.
+ */
+void mark_tile(int x, int y, int height) {
+ int w = dpy_x - x;
+ int h = dpy_y - y;
+
+ if (w > tile_x) {
+ w = tile_x;
+ }
+
+ /* height is the height of the changed portion of the tile */
+ if (h > height) {
+ h = height;
+ }
+
+ rfbMarkRectAsModified(screen, x, y, x + w, y + h);
+}
+
+/*
+ * Simply send each modified tile separately to the vnc machinery:
+ * (i.e. no hints)
+ */
+void tile_updates() {
+ int x, y, n, ty, th;
+
+ for (y=0; y < ntiles_y; y++) {
+ for (x=0; x < ntiles_x; x++) {
+ n = x + y * ntiles_x;
+
+ if (tile_has_diff[n]) {
+ ty = tile_region[n].first_line;
+ th = tile_region[n].last_line - ty + 1;
+
+ mark_tile(x * tile_x, y * tile_y + ty, th);
+ }
+ }
+ }
+}
+
+/*
+ * copy_tile() is called on a tile with a known change (from a scanline
+ * diff) or a suspected change (from our various heuristics).
+ *
+ * Examine the whole tile for the y-range of difference, copy that
+ * image difference to the vnc framebuffer, and do bookkeepping wrt
+ * the y-range and edge differences.
+ *
+ * This call is somewhat costly, maybe 1-2 ms. Primarily the XShmGetImage
+ * and then the memcpy/memcmp.
+ */
+void copy_tile(int tx, int ty) {
+ int x, y, line, first_line, last_line;
+ int size_x, size_y, n, dw, dx;
+ int pixelsize = bpp >> 3;
+ short l_diff = 0, r_diff = 0;
+
+ char *src, *dst, *s_src, *s_dst, *m_src, *m_dst;
+ char *h_src, *h_dst;
+
+ x = tx * tile_x;
+ y = ty * tile_y;
+
+ size_x = dpy_x - x;
+ if ( size_x > tile_x ) {
+ size_x = tile_x;
+ }
+ size_y = dpy_y - y;
+ if ( size_y > tile_y ) {
+ size_y = tile_y;
+ }
+ n = tx + ty * ntiles_x; /* number of the tile */
+
+ X_LOCK
+ if ( size_x == tile_x && size_y == tile_y ) {
+ /* general case: */
+ XShmGetImage(dpy, window, tile, x, y, AllPlanes);
+ } else {
+ /*
+ * near bottom or rhs edge case:
+ * (but only if tile size does not divide screen size)
+ */
+ XGetSubImage(dpy, window, x, y, size_x, size_y, AllPlanes,
+ ZPixmap, tile, 0, 0);
+ }
+ X_UNLOCK
+
+ src = (unsigned char*) tile->data;
+ dst = screen->frameBuffer + y * bytes_per_line + x * pixelsize;
+
+ s_src = src;
+ s_dst = dst;
+
+ first_line = -1;
+
+ /* find the first line with difference: */
+ for (line = 0; line < size_y; line++) {
+ if ( memcmp(s_dst, s_src, size_x * pixelsize) ) {
+ first_line = line;
+ break;
+ }
+ s_src += tile->bytes_per_line;
+ s_dst += bytes_per_line;
+ }
+
+ tile_tried[n] = 1;
+ if (first_line == -1) {
+ /* tile has no difference, note it and get out: */
+ tile_has_diff[n] = 0;
+ return;
+ } else {
+ /*
+ * make sure it is recorded (e.g. sometimes we guess tiles
+ * and they came in with tile_has_diff 0)
+ */
+ tile_has_diff[n] = 1;
+ }
+
+ m_src = src + (tile->bytes_per_line * size_y);
+ m_dst = dst + (bytes_per_line * size_y);
+ last_line = first_line;
+
+ /* find the last line with difference: */
+ for (line = size_y - 1; line > first_line; line--) {
+ m_src -= tile->bytes_per_line;
+ m_dst -= bytes_per_line;
+ if ( memcmp(m_dst, m_src, size_x * pixelsize) ) {
+ last_line = line;
+ break;
+ }
+ }
+
+ /* look for differences on left and right hand edges: */
+ dx = (size_x - tile_fuzz) * pixelsize;
+ dw = tile_fuzz * pixelsize;
+
+ h_src = src;
+ h_dst = dst;
+ for (line = 0; line < size_y; line++) {
+ if (! l_diff && memcmp(h_dst, h_src, dw) ) {
+ l_diff = 1;
+ }
+ if (! r_diff && memcmp(h_dst + dx, h_src + dx, dw) ) {
+ r_diff = 1;
+ }
+ if (l_diff && r_diff) {
+ break;
+ }
+ h_src += tile->bytes_per_line;
+ h_dst += bytes_per_line;
+ }
+
+ /* now copy the difference to the vnc framebuffer: */
+ for (line = first_line; line <= last_line; line++) {
+ memcpy(s_dst, s_src, size_x * pixelsize);
+ s_src += tile->bytes_per_line;
+ s_dst += bytes_per_line;
+ }
+
+ /* record all the info in the region array for this tile: */
+ tile_region[n].first_line = first_line;
+ tile_region[n].last_line = last_line;
+ tile_region[n].left_diff = l_diff;
+ tile_region[n].right_diff = r_diff;
+
+ tile_region[n].top_diff = 0;
+ tile_region[n].bot_diff = 0;
+ if ( first_line < tile_fuzz ) {
+ tile_region[n].top_diff = 1;
+ }
+ if ( last_line > (size_y - 1) - tile_fuzz ) {
+ tile_region[n].bot_diff = 1;
+ }
+}
+
+/*
+ * The copy_tile() call in the loop below copies the changed tile into
+ * the vnc framebuffer. Note that copy_tile() sets the tile_region
+ * struct to have info about the y-range of the changed region and also
+ * whether the tile edges contain diffs (within distance tile_fuzz).
+ *
+ * We use this tile_region info to try to guess if the downward and right
+ * tiles will have diffs. These tiles will be checked later in the loop
+ * (since y+1 > y and x+1 > x).
+ *
+ * See copy_tiles_backward_pass() for analogous checking upward and
+ * left tiles.
+ */
+void copy_all_tiles() {
+ int x, y, n, m;
+
+ for (y=0; y < ntiles_y; y++) {
+ for (x=0; x < ntiles_x; x++) {
+ n = x + y * ntiles_x;
+
+ if (tile_has_diff[n]) {
+ copy_tile(x, y);
+ }
+ if (! tile_has_diff[n]) {
+ /*
+ * n.b. copy_tile() may have detected
+ * no change and reset tile_has_diff to 0.
+ */
+ continue;
+ }
+
+ /* neighboring tile downward: */
+ if ( (y+1) < ntiles_y && tile_region[n].bot_diff) {
+ m = x + (y+1) * ntiles_x;
+ if (! tile_has_diff[m]) {
+ tile_has_diff[m] = 1;
+ }
+ }
+ /* neighboring tile to right: */
+ if ( (x+1) < ntiles_x && tile_region[n].right_diff) {
+ m = (x+1) + y * ntiles_x;
+ if (! tile_has_diff[m]) {
+ tile_has_diff[m] = 1;
+ }
+ }
+ }
+ }
+}
+
+/*
+ * Here starts a bunch of heuristics to guess/detect changed tiles.
+ * They are:
+ * copy_tiles_backward_pass, fill_tile_gaps/gap_try, grow_islands/island_try
+ * They are of varying utility... and perhaps some should be dropped.
+ */
+
+/*
+ * Try to predict whether the upward and/or leftward tile has been modified.
+ * copy_all_tiles() has already done downward and rightward tiles.
+ */
+void copy_tiles_backward_pass() {
+ int x, y, n, m;
+
+ for (y = ntiles_y - 1; y >= 0; y--) {
+ for (x = ntiles_x - 1; x >= 0; x--) {
+ n = x + y * ntiles_x; /* number of this tile */
+
+ if (! tile_has_diff[n]) {
+ continue;
+ }
+
+ m = x + (y-1) * ntiles_x; /* neighboring tile upward */
+
+ if (y >= 1 && ! tile_has_diff[m] && tile_region[n].top_diff) {
+ if (! tile_tried[m]) {
+ copy_tile(x, y-1);
+ }
+ }
+
+ m = (x-1) + y * ntiles_x; /* neighboring tile to left */
+
+ if (x >= 1 && ! tile_has_diff[m] && tile_region[n].left_diff) {
+ if (! tile_tried[m]) {
+ copy_tile(x-1, y);
+ }
+ }
+ }
+ }
+}
+
+void gap_try(int x, int y, int *run, int *saw, int along_x) {
+ int n, m, i, xt, yt;
+
+ n = x + y * ntiles_x;
+
+ if (! tile_has_diff[n]) {
+ if (*saw) {
+ (*run)++; /* extend the gap run. */
+ }
+ return;
+ }
+ if (! *saw || *run == 0 || *run > gaps_fill) {
+ *run = 0; /* unacceptable run. */
+ *saw = 1;
+ return;
+ }
+
+ for (i=1; i <= *run; i++) { /* iterate thru the run. */
+ if (along_x) {
+ xt = x - i;
+ yt = y;
+ } else {
+ xt = x;
+ yt = y - i;
+ }
+
+ m = xt + yt * ntiles_x;
+ if (tile_tried[m]) { /* do not repeat tiles */
+ continue;
+ }
+
+ copy_tile(xt, yt);
+ }
+ *run = 0;
+ *saw = 1;
+}
+
+/*
+ * Look for small gaps of unchanged tiles that may actually contain changes.
+ * E.g. when paging up and down in a web broswer or terminal there can
+ * be a distracting delayed filling in of such gaps. gaps_fill is the
+ * tweak parameter that sets the width of the gaps that are checked.
+ *
+ * btw, grow_islands() is actually pretty successful at doing this too.
+ */
+void fill_tile_gaps() {
+ int x, y, run, saw;
+
+ /* horizontal: */
+ for (y=0; y < ntiles_y; y++) {
+ run = 0;
+ saw = 0;
+ for (x=0; x < ntiles_x; x++) {
+ gap_try(x, y, &run, &saw, 1);
+ }
+ }
+
+ /* vertical: */
+ for (x=0; x < ntiles_x; x++) {
+ run = 0;
+ saw = 0;
+ for (y=0; y < ntiles_y; y++) {
+ gap_try(x, y, &run, &saw, 0);
+ }
+ }
+}
+
+void island_try(int x, int y, int u, int v, int *run) {
+ int n, m;
+
+ n = x + y * ntiles_x;
+ m = u + v * ntiles_x;
+
+ if (tile_has_diff[n]) {
+ (*run)++;
+ } else {
+ *run = 0;
+ }
+
+ if (tile_has_diff[n] && ! tile_has_diff[m]) {
+ /* found discontinuity */
+
+ if (tile_tried[m]) {
+ return;
+ } else if (*run < grow_fill) {
+ return;
+ }
+
+ copy_tile(u, v);
+ }
+}
+
+/*
+ * Scan looking for discontinuities in tile_has_diff[]. Try to extend
+ * the boundary of the discontinuity (i.e. make the island larger).
+ * Vertical scans are skipped since they do not seem to yield much...
+ */
+void grow_islands() {
+ int x, y, run;
+
+ /*
+ * n.b. the way we scan here should keep an extension going,
+ * and so also fill in gaps effectively...
+ */
+
+ /* left to right: */
+ for (y=0; y < ntiles_y; y++) {
+ run = 0;
+ for (x=0; x <= ntiles_x - 2; x++) {
+ island_try(x, y, x+1, y, &run);
+ }
+ }
+ /* right to left: */
+ for (y=0; y < ntiles_y; y++) {
+ run = 0;
+ for (x = ntiles_x - 1; x >= 1; x--) {
+ island_try(x, y, x-1, y, &run);
+ }
+ }
+}
+
+/*
+ * copy the whole X screen to the vnc framebuffer. For a large enough
+ * number of changed tiles, this is faster than tiles scheme at retrieving
+ * the info from the X server. Bandwidth to client is another issue...
+ * use -fs 1.0 to disable.
+ */
+void copy_screen() {
+ int pixelsize = bpp >> 3;
+ char *vnc_fb;
+ int i, y, block_size, xi;
+
+ block_size = (dpy_x * (dpy_y/fs_factor) * pixelsize);
+
+ vnc_fb = screen->frameBuffer;
+ y = 0;
+
+ for (i=0; i < fs_factor; i++) {
+ xi = XShmGetImage(dpy, window, fullscreen, 0, y, AllPlanes);
+ memcpy(vnc_fb, fullscreen->data, (size_t) block_size);
+
+ y += dpy_y / fs_factor;
+ vnc_fb += block_size;
+ }
+
+ rfbMarkRectAsModified(screen, 0, 0, dpy_x, dpy_y);
+}
+
+/*
+ * Loop over 1-pixel tall horizontal scanlines looking for changes.
+ * Record the changes in tile_has_diff[]. Scanlines in the loop are
+ * equally spaced along y by NSCAN pixels, but have a slightly random
+ * starting offset ystart ( < NSCAN ) from scanlines[].
+ */
+int scan_display(int ystart, int rescan) {
+ int x, y, w, n;
+ int tile_count = 0;
+ int pixelsize = bpp >> 3;
+ char *src, *dst;
+
+ y = ystart;
+
+ while (y < dpy_y) {
+
+ /* grab the horizontal scanline from the display: */
+ X_LOCK
+ XShmGetImage(dpy, window, scanline, 0, y, AllPlanes);
+ X_UNLOCK
+
+ x = 0;
+ while (x < dpy_x) {
+ n = (x/tile_x) + (y/tile_y) * ntiles_x;
+
+ if (rescan && tile_has_diff[n]) {
+ tile_count++;
+ x += NSCAN;
+ continue;
+ }
+
+ /* set ptrs to correspond to the x offset: */
+ src = (unsigned char*) scanline->data + x * pixelsize;
+ dst = screen->frameBuffer + y * bytes_per_line
+ + x * pixelsize;
+
+ /* compute the width of data to be compared: */
+ if ( x + NSCAN > dpy_x ) {
+ w = dpy_x - x;
+ } else {
+ w = NSCAN;
+ }
+
+ if (memcmp(dst, src, w * pixelsize) ) {
+ /* found a difference, record it: */
+ tile_has_diff[n] = 1;
+ tile_count++;
+ }
+ x += NSCAN;
+ }
+ y += NSCAN;
+ }
+ return tile_count;
+}
+
+/*
+ * toplevel for the scanning, rescanning, and applying the heuristics.
+ */
+void scan_for_updates() {
+ int i, tile_count;
+ double frac1 = 0.1; /* tweak parameter to try a 2nd scan_display() */
+
+ for (i=0; i < ntiles; i++) {
+ tile_has_diff[i] = 0;
+ tile_tried[i] = 0;
+ }
+
+ /*
+ * n.b. this program has only been tested so far with
+ * tile_x = tile_y = NSCAN = 32!
+ */
+
+ count++;
+ count %= NSCAN;
+
+ /* scan with the initial y to the jitter value from scanlines: */
+ tile_count = scan_display( scanlines[count], 0 );
+
+ if (fs_factor && frac1 >= fs_frac) {
+ /* make frac1 < fs_frac if fullscreen updates are enabled */
+ frac1 = fs_frac/2.0;
+ }
+
+ if ( tile_count > frac1 * ntiles) {
+ /*
+ * many tiles have changed, so try a rescan (since it should
+ * be short compared to the many upcoming copy_tile() calls)
+ */
+
+ /* this check is done to skip the extra scan_display() call */
+ if (! fs_factor || tile_count <= fs_frac * ntiles) {
+ int cp;
+
+ /* choose a different y shift for the 2nd scan: */
+ cp = (NSCAN - count) % NSCAN;
+
+ tile_count = scan_display( scanlines[cp], 1 );
+ }
+
+ /*
+ * At some number of changed tiles it is better to just
+ * copy the full screen at once. I.e. time = c1 + m * r1
+ * where m is number of tiles and c1 is the scan_display()
+ * time: for some m it crosses the full screen update time.
+ *
+ * We try to predict that crossover with the fs_frac fudge
+ * factor... seems to be about 1/2 the total number
+ * of tiles. n.b. this ignores network bandwidth, etc.
+ * use -fs 1.0 to disable on slow links.
+ */
+ if (fs_factor && tile_count > fs_frac * ntiles) {
+ copy_screen();
+ return;
+ }
+ }
+
+ /* copy all tiles with differences from display to vnc framebuffer: */
+ copy_all_tiles();
+
+ /*
+ * This backward pass for upward and left tiles complements what
+ * was done in copy_all_tiles() for downward and right tiles.
+ */
+ copy_tiles_backward_pass();
+
+ if (grow_fill) {
+ grow_islands();
+ }
+
+ if (gaps_fill) {
+ fill_tile_gaps();
+ }
+
+ if (use_hints) {
+ hint_updates(); /* use krfb/x0rfbserver hints algorithm */
+ } else {
+ tile_updates(); /* send each tile change individually */
+ }
+}
+
+void watch_loop(void) {
+ int cnt = 0;
+
+#if !defined(HAVE_PTHREADS)
+ use_threads = 0;
+#endif
+
+ if (use_threads) {
+ rfbRunEventLoop(screen, -1, TRUE);
+ }
+
+ while (1) {
+ got_user_input = 0;
+
+ if (! use_threads) {
+ rfbProcessEvents(screen, -1);
+
+ if (got_user_input && cnt % 10 != 0) {
+ /* every 10-th drops thru to code below... */
+ XFlush(dpy);
+ continue;
+ }
+ }
+
+ if (shut_down) {
+ clean_up_exit();
+ }
+
+ if (! screen->rfbClientHead) { /* waiting for a client */
+ usleep(200 * 1000);
+ continue;
+ }
+
+ rfbUndrawCursor(screen);
+ scan_for_updates();
+
+ usleep(waitms * 1000);
+
+ cnt++;
+ }
+}
+
+void print_help() {
+ char help[] = "
+x0vnc options:
+
+-defer time time in ms to wait for updates before sending to
+ client [rfbDeferUpdateTime] (default %d)
+-wait time time in ms to pause between screen polls. used
+ to cut down on load (default %d)
+
+-gaps n heuristic to fill in gaps in rows or cols of n or less
+ tiles. used to improve text paging (default %d).
+-grow n heuristic to grow islands of changed tiles n or wider
+ by checking the tile near the boundary (default %d).
+-fs f if the fraction of changed tiles in a poll is greater
+ than f, the whole screen is updated (default %.2f)
+-fuzz n tolerance in pixels to mark a tiles edges as changed.
+ (default %d).
+-hints use krfb/x0rfbserver hints (glue changed adjacent
+ horizontal tiles into one big rectangle) (default %s).
+-nohints do not use hints; send each tile separately.
+
+-threads use threaded algorithm [rfbRunEventLoop] if compiled
+ with threads (default %s).
+-nothreads do not use [rfbRunEventLoop].
+-viewonly clients can only watch (default %s).
+-shared VNC display is shared (default %s)
+
+These options are passed to libvncserver:
+
+";
+ fprintf(stderr, help, defer_update, waitms, gaps_fill, grow_fill,
+ fs_frac, tile_fuzz,
+ use_hints ? "on":"off", use_threads ? "on":"off",
+ view_only ? "on":"off", shared ? "on":"off");
+ rfbUsage();
+ exit(1);
+}
+
+int main(int argc, char** argv) {
+
+ XImage *fb;
+ int i, scr, ev, er, maj, min;
+ char *use_dpy = NULL;
+
+
+ /* used to pass args we do not know about to rfbGetScreen(): */
+ int argc2 = 1; char *argv2[100];
+ argv2[0] = argv[0];
+
+ for (i=1; i < argc; i++) {
+ if (!strcmp(argv[i], "-display")) {
+ use_dpy = argv[++i];
+ } else if (!strcmp(argv[i], "-defer")) {
+ defer_update = atoi(argv[++i]);
+ } else if (!strcmp(argv[i], "-wait")) {
+ waitms = atoi(argv[++i]);
+ } else if (!strcmp(argv[i], "-gaps")) {
+ gaps_fill = atoi(argv[++i]);
+ } else if (!strcmp(argv[i], "-grow")) {
+ grow_fill = atoi(argv[++i]);
+ } else if (!strcmp(argv[i], "-fs")) {
+ fs_frac = atof(argv[++i]);
+ } else if (!strcmp(argv[i], "-fuzz")) {
+ tile_fuzz = atoi(argv[++i]);
+ } else if (!strcmp(argv[i], "-hints")) {
+ use_hints = 1;
+ } else if (!strcmp(argv[i], "-nohints")) {
+ use_hints = 0;
+ } else if (!strcmp(argv[i], "-threads")) {
+ use_threads = 1;
+ } else if (!strcmp(argv[i], "-nothreads")) {
+ use_threads = 0;
+ } else if (!strcmp(argv[i], "-viewonly")) {
+ view_only = 1;
+ } else if (!strcmp(argv[i], "-shared")) {
+ shared = 1;
+ } else if (!strcmp(argv[i], "-h")
+ || !strcmp(argv[i], "-help")) {
+ print_help();
+ } else {
+ /* otherwise copy it for use below. */
+ printf("passing arg to libvncserver: %s\n", argv[i]);
+ if (argc2 < 100) {
+ argv2[argc2++] = argv[i];
+ }
+ }
+ }
+ if (tile_fuzz < 1) {
+ tile_fuzz = 1;
+ }
+ if (waitms < 0) {
+ waitms = 0;
+ }
+ printf("defer: %d\n", defer_update);
+ printf("waitms: %d\n", waitms);
+ printf("tile_fuzz: %d\n", tile_fuzz);
+ printf("gaps_fill: %d\n", gaps_fill);
+ printf("grow_fill: %d\n", grow_fill);
+ printf("fs_frac: %.2f\n", fs_frac);
+ printf("use_hints: %d\n", use_hints);
+ printf("viewonly: %d\n", view_only);
+ printf("shared: %d\n", shared);
+
+ if (use_dpy) {
+ dpy = XOpenDisplay(use_dpy);
+ } else if ( (use_dpy = getenv("DISPLAY")) ) {
+ dpy = XOpenDisplay(use_dpy);
+ } else {
+ dpy = XOpenDisplay("");
+ }
+ if (! dpy) {
+ printf("XOpenDisplay failed (%s)\n", use_dpy);
+ exit(1);
+ } else if (use_dpy) {
+ printf("Using display %s\n", use_dpy);
+ } else {
+ printf("Using default display.\n");
+ }
+
+ if (! XTestQueryExtension(dpy, &ev, &er, &maj, &min)) {
+ printf("Display does not support the XTest extension.\n");
+ exit(1);
+ }
+ if (! XShmQueryExtension(dpy)) {
+ printf("Display does not support XShm extension"
+ " (must be local).\n");
+ exit(1);
+ }
+
+ /*
+ * Window managers will often grab the display during resize, etc.
+ * To avoid deadlock (our user resize input is not processed)
+ * we tell the server to process our requests during all grabs:
+ */
+ XTestGrabControl(dpy, True);
+
+ scr = DefaultScreen(dpy);
+ window = RootWindow(dpy, scr);
+
+ dpy_x = DisplayWidth(dpy, scr);
+ dpy_y = DisplayHeight(dpy, scr);
+
+ fb = XGetImage(dpy, window, 0, 0, dpy_x, dpy_y, AllPlanes, ZPixmap);
+ printf("Read initial data from display into framebuffer.\n");
+
+ if (fb->bits_per_pixel == 24) {
+ printf("warning: 24 bpp may have poor performance.\n");
+ }
+
+ /*
+ * n.b. we do not have to X_LOCK X11 calls until watch_loop()
+ * is called since we are single-threaded until then.
+ */
+
+ initialize_screen(&argc2, argv2, fb);
+
+ initialize_tiles();
+
+ initialize_shm();
+
+ printf("screen setup finished.\n");
+
+ watch_loop();
+
+ return(0);
+}