Experimental support for setdesktopsize / extendeddesktopsize

configure.ac

@@ -285,6 +285,12 @@ elif test "$X_CFLAGS" != "-DX_DISPLAY_MISSING"; then
 			case `(uname -sr) 2>/dev/null` in
 			"SunOS 5"*) CPPFLAGS="$CPPFLAGS -I/usr/X11/include" ;;
 			esac
+
+			# support for setdesktopsize needs xrandr and libvncserver with setDesktopSizeHook
+			AC_CHECK_MEMBER([struct _rfbScreenInfo.setDesktopSizeHook],
+				[AC_DEFINE(HAVE_SETDESKTOPSIZE, 1, [libvncserver supports setDesktopSizeHook])],
+				[AC_MSG_WARN([Support for option -setdesktopsize disabled. Needs libvncserver 0.9.13])],
+				[[#include "rfb/rfb.h"]])
 		fi
 
 		X_LIBS="$X_LIBS $X_PRELIBS -lX11 $X_EXTRA_LIBS"

src/connections.c

@@ -838,7 +838,11 @@ void client_gone(rfbClientPtr client) {
 		}
 	}
 
-
+#if HAVE_SETDESKTOPSIZE
+	if (enable_setdesktopsize && xrandr && client_count == 0) {
+		xrandr_reset_scaling();
+	}
+#endif
 	if (no_autorepeat && client_count == 0) {
 		autorepeat(1, 0);
 	}

src/help.c

@@ -3058,6 +3058,14 @@ void print_help(int mode) {
 "                       prefix \"string\" with \"nc:\", e.g. \"nc:+90\",\n"
 "                       \"nc:xy\", etc.\n"
 "\n"
+#if HAVE_SETDESKTOPSIZE
+"-setdesktopsize        Allow client to change framebuffer resolution to fit\n"
+"                       size of client window. x11vnc will use xrandr commands\n"
+"                       to change the X framebuffer size. The mode of the physical\n"
+"                       screen will not be changed, but scaling will be used to\n"
+"                       display the new framebuffer size on the physical screen.\n"
+"\n"
+#endif
 "-padgeom WxH           Whenever a new vncviewer connects, the framebuffer is\n"
 "                       replaced with a fake, solid black one of geometry WxH.\n"
 "                       Shortly afterwards the framebuffer is replaced with the\n"

src/options.c

@@ -246,6 +246,7 @@ char *xrandr_mode = NULL;
 char *pad_geometry = NULL;
 time_t pad_geometry_time = 0;
 int use_snapfb = 0;
+int enable_setdesktopsize = 0;
 
 int use_xrecord = 0;
 int noxrecord = 0;

src/options.h

@@ -211,6 +211,7 @@ extern char *xrandr_mode;
 extern char *pad_geometry;
 extern time_t pad_geometry_time;
 extern int use_snapfb;
+extern int enable_setdesktopsize;
 
 extern int use_xrecord;
 extern int noxrecord;

src/screen.c

@@ -93,6 +93,9 @@ rfbBool vnc_reflect_send_cuttext(char *str, int len);
 static void debug_colormap(XImage *fb);
 static void set_visual(char *str);
 static void nofb_hook(rfbClientPtr cl);
+#if HAVE_SETDESKTOPSIZE
+static int set_desktop_size_hook(int width, int height, int numScreens, rfbExtDesktopScreen* extDesktopScreens, rfbClientPtr cl);
+#endif
 static void remove_fake_fb(void);
 static void install_fake_fb(int w, int h, int bpp);
 static void initialize_snap_fb(void);
@@ -819,6 +822,25 @@ void free_old_fb(void) {
 	}
 }
 
+#if HAVE_SETDESKTOPSIZE
+static int set_desktop_size_hook(int width, int height, int numScreens, rfbExtDesktopScreen* extDesktopScreens, rfbClientPtr cl)
+{
+    int i;
+
+    rfbLog("Received SetDesktopSize message from client requesting (%dx%d) framebuffer with screen configuration:\n", width, height);
+    for (i=0; i<numScreens; i++) {
+        rfbLog("- id: %d resolution: %dx%d x offset: %d y offset: %d flags: %d\n", extDesktopScreens[i].id, extDesktopScreens[i].width,
+               extDesktopScreens[i].height, extDesktopScreens[i].x, extDesktopScreens[i].y, extDesktopScreens[i].flags);
+    }
+    if (cl->viewOnly) {
+        rfbLog("Denying setDesktopSize request as client is view-only\n");
+        return rfbExtDesktopSize_ResizeProhibited;
+    }
+
+    return xrandr_set_scale_from(width, height) ? rfbExtDesktopSize_Success : rfbExtDesktopSize_InvalidScreenLayout;
+}
+#endif
+
 static char _lcs_tmp[128];
 static int _bytes0_size = 128, _bytes0[128];
 
@@ -3651,6 +3673,11 @@ void initialize_screen(int *argc, char **argv, XImage *fb) {
 	screen->ptrAddEvent = pointer_event;
 	screen->setXCutText = xcut_receive;
 	screen->setTranslateFunction = set_xlate_wrapper;
+#if HAVE_SETDESKTOPSIZE
+	if (enable_setdesktopsize) {
+		screen->setDesktopSizeHook = set_desktop_size_hook;
+	}
+#endif
 
 	screen->kbdReleaseAllKeys = kbd_release_all_keys; 
 	screen->setSingleWindow = set_single_window; 

src/x11vnc.c

@@ -3888,6 +3888,12 @@ int main(int argc, char* argv[]) {
 			grab_buster = 0;
 			continue;
 		}
+#if HAVE_SETDESKTOPSIZE
+		if (!strcmp(arg, "-setdesktopsize")) {
+			enable_setdesktopsize = 1;
+			continue;
+		}
+#endif
 		if (!strcmp(arg, "-snapfb")) {
 			use_snapfb = 1;
 			continue;

src/xrandr.c

@@ -304,4 +304,154 @@ int known_xrandr_mode(char *s) {
 	}
 }
 
+#if HAVE_SETDESKTOPSIZE
+/* Set framebuffer size to w x h
+ * Does not alter physical resolution but scales desired framebuffer to physical display resolution */
+rfbBool xrandr_set_scale_from(int w, int h)
+{
+    XTransform transform;
+    XRRScreenResources *screens;
+    XRRCrtcInfo *crtcInfo;
+    XRROutputInfo *outputInfo;
+    RRCrtc xrandr_crtc;
+    RROutput xrandr_output;
+    XRRModeInfo *modeInfo = NULL;
+    int i;
+
+    double sx, sy;
+    int	major, minor, minWidth, minHeight, maxWidth, maxHeight;
+    char *filter;
+
+    if (!xrandr_present)
+        return FALSE;
+
+    X_LOCK;
+    XRRQueryVersion(dpy, &major, &minor);
+    if (major < 1 || (major == 1 && minor < 3)) {
+        rfbLog("Need at least RANDR 1.3 to support scaling, only %d.%d available\n", major, minor);
+        X_UNLOCK;
+        return FALSE;
+    }
+
+    if (w != -1 && XRRGetScreenSizeRange(dpy, rootwin, &minWidth, &minHeight, &maxWidth, &maxHeight)) {
+        if (w > maxWidth || h > maxHeight) {
+            w = nmin(w, maxWidth);
+            h = nmin(h, maxHeight);
+            rfbLog("Requested size exceeds maximum size of (%dx%d), reduced to (%dx%d)\n", maxWidth, maxHeight, w, h);
+        }
+        if (w < minWidth || h < minHeight) {
+            w = nmax(w, minWidth);
+            h = nmax(h, minHeight);
+            rfbLog("Requested size is smaller than minimum size of (%dx%d), enlarged to (%dx%d)\n", minWidth, minHeight, w, h);
+        }
+    }
+
+    screens = XRRGetScreenResourcesCurrent(dpy, rootwin);
+    if (!screens->ncrtc || !screens->noutput) {
+        rfbLog("RANDR Error: XRRGetScreenResourcesCurrent() did not return any crtcs and/or outputs\n");
+        XRRFreeScreenResources(screens);
+        X_UNLOCK;
+        return FALSE;
+    }
+
+    /* We only support using using one screen for now */
+    xrandr_output = XRRGetOutputPrimary(dpy, rootwin);
+    if (!xrandr_output)
+        xrandr_output = screens->outputs[0];
+
+    xrandr = 1;
+    outputInfo = XRRGetOutputInfo(dpy, screens, xrandr_output);
+    xrandr_crtc = outputInfo->crtc;
+
+    if (!xrandr_crtc) {
+        if (w != -1) {
+            rfbLog("RANDR: running headless without screen. Setting fb size without scaling.\n");
+            XRRSetScreenSize(dpy, rootwin, w, h, w / 2.8, h / 2.8);
+        }
+        XRRFreeOutputInfo(outputInfo);
+        XRRFreeScreenResources(screens);
+        X_UNLOCK;
+        return TRUE;
+    }
+    crtcInfo = XRRGetCrtcInfo(dpy, screens, xrandr_crtc);
+
+    for (i=0; i<screens->nmode; i++)
+    {
+        if (screens->modes[i].id == crtcInfo->mode)
+        {
+            modeInfo = &screens->modes[i];
+            break;
+        }
+    }
+
+    if (!modeInfo) {
+        rfbLog("RANDR Error: cannot find current mode\n");
+        XRRFreeCrtcInfo(crtcInfo);
+        XRRFreeOutputInfo(outputInfo);
+        XRRFreeScreenResources(screens);
+        X_UNLOCK;
+        return FALSE;
+    }
+
+    if (w == -1) {
+        w = modeInfo->width;
+        h = modeInfo->height;
+    }
+    if (!outputInfo->mm_width) {
+        /* Just assume 72 dpi, which is about 2.8 dpmm */
+        outputInfo->mm_width = modeInfo->width / 2.8;
+        outputInfo->mm_height = modeInfo->height / 2.8;
+    }
+
+    sx = (double) w / modeInfo->width;
+    sy = (double) h / modeInfo->height;
+
+    memset(&transform, 0, sizeof(transform));
+    transform.matrix[0][0] = XDoubleToFixed(sx);
+    transform.matrix[1][1] = XDoubleToFixed(sy);
+    transform.matrix[2][2] = XDoubleToFixed(1.0);
+
+    if (sx != 1 || sy != 1)
+        filter = "bilinear";
+    else
+        filter = "nearest";
+
+    XGrabServer(dpy);
+
+    /* Disable all crtc */
+    for (i=0; i<screens->ncrtc; i++)
+    {
+        XRRSetCrtcConfig(dpy, screens, screens->crtcs[i], CurrentTime,
+                          0, 0, None, RR_Rotate_0, NULL, 0);
+    }
+
+    /* Set framebuffer size */
+    XRRSetScreenSize(dpy, rootwin, w, h, outputInfo->mm_width, outputInfo->mm_height);
+    /* Set transform */
+    XRRSetCrtcTransform(dpy, xrandr_crtc, &transform, filter, NULL, 0);
+    /* Enable first crtc again */
+    XRRSetCrtcConfig(dpy, screens, xrandr_crtc, CurrentTime,
+        0, 0, crtcInfo->mode, crtcInfo->rotation, crtcInfo->outputs, crtcInfo->noutput);
+
+    XUngrabServer(dpy);
+    XRRFreeOutputInfo(outputInfo);
+    XRRFreeCrtcInfo(crtcInfo);
+    XRRFreeScreenResources(screens);
+    X_UNLOCK;
+
+    /* Leave creating the new frame buffer up to the xrandr event monitoring
+       code. (If we already create it here, we risk it is going
+       to be resized back to the old size, because multiple randr events
+       are enroute due to our changes, and the first may still mention
+       the old size.) */
+
+    return TRUE;
+}
+
+/* Restore scaling to original size */
+void xrandr_reset_scaling()
+{
+    xrandr_set_scale_from(-1, -1);
+}
+#endif
 

src/xrandr.h

@@ -49,6 +49,8 @@ extern Time xrandr_cfg_time;
 extern void initialize_xrandr(void);
 extern int check_xrandr_event(char *msg);
 extern int known_xrandr_mode(char *s);
+extern rfbBool xrandr_set_scale_from(int w, int h);
+extern void xrandr_reset_scaling();
 
 #define XRANDR_SET_TRAP_RET(x,y)  \
 	if (subwin || xrandr) { \

x11vnc.1

@@ -3365,6 +3365,14 @@ If you do not want the cursor shape to be rotated
 prefix \fIstring\fR with "nc:", e.g. "nc:+90",
 "nc:xy", etc.
 .PP
+\fB-setdesktopsize\fR
+.IP
+Allow client to change framebuffer resolution to fit
+size of client window. x11vnc will use xrandr commands
+to change the X framebuffer size. The mode of the physical
+screen will not be changed, but scaling will be used to
+display the new framebuffer size on the physical screen.
+.PP
 \fB-padgeom\fR \fIWxH\fR
 .IP
 Whenever a new vncviewer connects, the framebuffer is