Add NOT-BUGS file with some common Vanilla gotchas.

Subversion-branch: /trunk/chocolate-doom
Subversion-revision: 2175

1 files changed, 112 insertions, 0 deletions

diff --git a/NOT-BUGS b/NOT-BUGS
new file mode 100644
index 00000000..8dbf7262
--- /dev/null
+++ b/NOT-BUGS
@@ -0,0 +1,112 @@
+
+The aim of Chocolate Doom is to behave as closely to Vanilla Doom as
+possible.  As a result, you may experience problems that you would
+also experience when using Vanilla Doom.  These are not "bugs" as
+Chocolate Doom is behaving as intended.
+
+This is not intended to be a comprehensive list of Vanilla Doom bugs.
+For more information, consult the "engine bugs" page of the Doom Wiki.
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+== Game exits after title screen with message about game version ==
+
+The game may exit after the title screen is shown, with a message like
+the following:
+
+    Demo is from a different game version!
+    (read 106, should be 109)
+
+    *** You may need to upgrade your version of Doom to v1.9. ***
+        See: http://doomworld.com/files/patches.shtml
+        This appears to be v1.6/v1.666.
+
+This usually indicates that your IWAD file that you are using to play
+the game (usually named doom.wad or doom2.wad) is out of date.
+Chocolate Doom only supports the v1.9 IWAD file.
+
+To fix the problem, you must upgrade to the v1.9 IWAD file.  The URL
+in the message has downloadable upgrade patches that you can use to
+upgrade.
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+== Game exits when accessing the options menu ==
+
+The game may exit with the message "Bad V_DrawPatch" when accessing
+the options menu, if you have your mouse sensitivity set high.
+
+The Doom options menu has a slider that allows the mouse sensitivity
+to be controlled; however, it has only a very limited range. It is
+common for experienced players to set a mouse sensitivity that is much
+higher than what can be set via the options menu. The setup program
+allows a larger range of values to be set.
+
+However, setting very high sensitivity values causes the game to exit
+when accessing the options menu under Vanilla Doom. Because Chocolate
+Doom aims to emulate Vanilla Doom as closely as possible, it does the
+same thing.
+
+One solution to the problem is to set a lower mouse sensitivity.
+Alternatively, all of the settings in the options menu can be
+controlled through Doom's key bindings anyway:
+
+    End game: F7
+    Messages on/off: F8
+    Graphic detail high/low: F5
+    Screen size smaller/larger: -/+
+    Sound volume menu: F4
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+== Game exits with "Savegame buffer overrun" when saving the game ==
+
+If you are playing on a particularly large level, it is possible that
+when you save the game, the game will quit with the message "Savegame
+buffer overrun".
+
+Vanilla Doom has a limited size memory bufferthat it uses for saving
+games.  If you are playing on a large level, the buffer may be too
+small for the entire savegame to fit.  Chocolate Doom allows the limit
+to be disabled: in the setup tool, go to the "compatibility" menu and
+disable the "Vanilla savegame limit" option.
+
+If this error happens to you, your game has not been lost!  A file
+named temp.dsg is saved; rename this to doomsav0.dsg to make it appear
+in the first slot in the "load game" menu.  (On Unix systems, you will
+need to look in the .chocolate-doom/savegames directory in your home
+directory)
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+== Game ends suddenly when recording a demo ==
+
+If you are recording a very long demo, the game may exit suddenly.
+Vanilla Doom has a limited size memory buffer that it uses to save the
+demo into.  When the buffer is full, the game exits.  You can tell if
+this happens, as the demo file will be around 131,072 bytes in size.
+
+You can work around this by using the -maxdemo command line parameter
+to specify a larger buffer size.  Alternatively, the limit can be
+disabled: in the setup tool, go to the compatibility menu and disable
+the "Vanilla demo limit" option.
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+== Game exits with a message about "visplanes" ==
+
+The game may exit with one of these messages:
+
+    R_FindPlane: no more visplanes
+    R_DrawPlanes: visplane overflow (129)
+
+This is known as the "visplane overflow" limit and is one of the most
+well-known Vanilla Doom engine limits.  You should only ever experience
+this when trying to play an add-on level.  The level you are trying to
+play is too complex; it was most likely designed to work with a limit
+removing source port.
+
+More information can be found here:
+
+    http://rome.ro/lee_killough/editing/visplane.shtml
+