x11vnc: add -8to24 option for some multi-depth displays.

1 files changed, 38 insertions, 4 deletions

diff --git a/x11vnc/help.c b/x11vnc/help.c
index 0d6ddd5..f68b92b 100644
--- a/x11vnc/help.c
+++ b/x11vnc/help.c
@@ -147,6 +147,38 @@ void print_help(int mode) {
 "-overlay_nocursor      Sets -overlay, but does not try to draw the exact mouse\n"
 "                       cursor shape using the overlay mechanism.\n"
 "\n"
+"-8to24                 If -overlay is not supported on your OS, and you have a\n"
+"                       legacy 8bpp app that you want to view on a multi-depth\n"
+"                       display with default depth 24 (and is 32 bpp), try\n"
+"                       this option.  This option may not work on all X servers\n"
+"                       and hardware (tested on XFree86/Xorg mga driver).\n"
+"\n"
+"                       It enables a hack where x11vnc monitors windows within 3\n"
+"                       levels from the root window.  If it finds any that are\n"
+"                       8bpp it will apply a transformation for pixel data in\n"
+"                       these regions where it extracts the 8bpp index color\n"
+"                       value from bits 25-32 and maps them on to TrueColor\n"
+"                       values and inserts them into bits 1-24 (i.e. overwrites\n"
+"                       bits 1-24).  This method appears to work, but may still\n"
+"                       have bugs and note that it does hog resources.  If there\n"
+"                       are multiple 8bpp windows using different colormaps,\n"
+"                       one may have to iconify all but one for the colors to\n"
+"                       be correct.\n"
+"\n"
+"                       There may also be painting errors for clipping\n"
+"                       and switching between windows of depths 8 and 24.\n"
+"                       Heuristics are applied to try to minimize the painting\n"
+"                       errors.  One can also press 3 Alt_L's in a row to\n"
+"                       refresh the screen if the error does not repair itself.\n"
+"                       Also the option, say, -fixscreen V=3.0 may be use\n"
+"                       to periodically refresh the screen (at the cost of\n"
+"                       bandwidth).\n"
+"\n"
+"                       Note that -8to24 does not work on displays with 8bpp\n"
+"                       default visual with depth 24 applications.  The Xserver\n"
+"                       -cc option can be used to switch the default depth on\n"
+"                       multidepth setups.\n"
+"\n"
 "-scale fraction        Scale the framebuffer by factor \"fraction\".  Values\n"
 "                       less than 1 shrink the fb, larger ones expand it.  Note:\n"
 "                       image may not be sharp and response may be slower.\n"
@@ -1590,6 +1622,8 @@ void print_help(int mode) {
 "                       overlay_cursor  in -overlay mode, enable cursor drawing.\n"
 "                       overlay_nocursor disable cursor drawing. same as\n"
 "                                        nooverlay_cursor.\n"
+"                       8to24           enable  -8to24 mode (if applicable).\n"
+"                       no8to24         disable -8to24 mode.\n"
 "                       visual:vis      set -visual to \"vis\"\n"
 "                       scale:frac      set -scale to \"frac\"\n"
 "                       scale_cursor:f  set -scale_cursor to \"f\"\n"
@@ -1849,10 +1883,10 @@ void print_help(int mode) {
 "                       nowaitmapped clip flashcmap noflashcmap shiftcmap\n"
 "                       truecolor notruecolor overlay nooverlay overlay_cursor\n"
 "                       overlay_yescursor nooverlay_nocursor nooverlay_cursor\n"
-"                       nooverlay_yescursor overlay_nocursor visual scale\n"
-"                       scale_cursor viewonly noviewonly shared noshared\n"
-"                       forever noforever once timeout filexfer deny lock\n"
-"                       nodeny unlock connect allowonce allow localhost\n"
+"                       nooverlay_yescursor overlay_nocursor 8to24 no8to24\n"
+"                       visual scale scale_cursor viewonly noviewonly shared\n"
+"                       noshared forever noforever once timeout filexfer deny\n"
+"                       lock nodeny unlock connect allowonce allow localhost\n"
 "                       nolocalhost listen lookup nolookup accept afteraccept\n"
 "                       gone shm noshm flipbyteorder noflipbyteorder onetile\n"
 "                       noonetile solid_color solid nosolid blackout xinerama\n"