
Hexen II: Hammer of Thyrion 1.4.3
---------------------------------


1. Installation

  1.1 Getting Started
  1.2 Software Requirements
  1.3 Running the Game
  1.4 Sound and Midi
  1.5 Networking/Multiplayer
  1.6 Game Saves and Configuration files
  1.7 Fullscreen/Windowed modes and mouse

2. Known Problems

  2.1 Sound Problems
  2.2 Lines on Screen
  2.3 Fluxbox

3. General Info

  3.1 Mods
  3.2 Game Console
  3.3 Hardware Acceleration
  3.4 Links
  3.5 Thanks
  3.6 Contact

4. Appendix

----------------------------------------------------------------



1. INSTALLATION
---------------


1.1 Getting Started
-------------------

Hexen II source, and the Hammer of Thyrion source port, are free
but the game itself is not: You must have an original copy of the
game released by Raven Software and Activision. If you don't, then
download the demo version. The rest of this document assumes that
you own the retail version of the game.

Hexen II requires its game data to be updated to version 1.11 .
There are two ways to do this:

a. Using the installer:
   The installer will get the files from your original cdroms
   (the windows discs released by Raven and Activision back in
   1997), apply the latest patches, and install the binaries
   for you. The first option on the installer is mandatory and
   installs the original hexen2 game.

   The second option on the installer will allow you to install
   the Mission Pack "Portal of Praevus", should you have it.
   All you need to do is choosing the Praevus support check-box
   and readying your cdrom.

   Third option on the installer is HexenWorld Multiplayer
   support. No cdrom is necessary for this option.

   Here are the names of the binaries to be installed:

	hexen2	-  Hexen II (software rendering)
	glhexen2 - Hexen II (opengl rendering)
	h2ded	-  Hexen II Dedicated server
	hwcl	-  HexenWorld Client (software rendering)
	glhwcl	-  HexenWorld Client (opengl rendering)
	hwsv	-  HexenWorld Server
	hwmaster-  HexenWorld Master Server

b. Manual install/update of data files:
   Download the base binary tarball (e.g., hexen2-1.4.3.i586.tgz)
   and extract it. Copy the two files pak0.pak and pak1.pak from
   your cdrom into the "data1" directory in your own installation.
   Run the command " chmod 644 data1/pak* "  to fix their permis-
   sions. The pak filenames should be lower-cased, if not already.
   To patch the data files, type ./update_xdelta.sh (this update
   script and its requirements are included in the binary package).
   Confirm the result by checking with the following md5sums:

   c9675191e75dd25a3b9ed81ee7e05eff  data1/pak0.pak
   c2ac5b0640773eed9ebe1cda2eca2ad0  data1/pak1.pak

   As an alternative, the game launcher has the integrated ability
   of patching those pak files. Just press the button and it'll be
   done.

   If you have the mission pack (Portal of Praevus), copy the file
   pak3.pak from your cdrom into the "portals" directory in your
   own installation. Run the command " chmod 644 portals/pak* "
   to fix its permissions. No additional patching is necessary
   for the mission pack. Here is the md5sum of pak3.pak, just in
   case:

   77ae298dd0dcd16ab12f4a68067ff2c3  portals/pak3.pak

   If you want to install HexenWorld, download the HexenWorld
   binary package (e.g., hexenworld-1.4.3.i586.tgz) and extract
   it in the same directory you extracted the base HoT tarball.
   No additional patching is necessary for hexenworld.


1.2 Software Requirements
-------------------------

   SDL (min.: 1.2.4)	  : Simple DirectMedia Layer libraries.
			    1.2.7 and newer highly recommended.
			    If run on systems with SDL < 1.2.6,
			    anti-aliasing support will be auto-
			    matically disabled.

   SDL_mixer (min.: 1.2.4): Required for midi support (should
			    be compiled with timidity+ support)
			    1.2.5 and newer highly recommended.

   ALSA (min.: 0.9.8)	  : Advanced Linux Sound Architecture
			    libraries and kernel modules.
			    Necessary, if you use alsa-sound.
			    1.0.7 (or newer) recommended.

   GLIBC		  : If you compile your own binaries
			    any glibc >= 2.1 should be fine.
			    If you are using our linux binary
			    tarballs, you need glibc >= 2.3.
			    As for FreeBSD, version >= 5.3 is
			    required.

   To compile your own binaries, you'll need a standard unix build
   environment. See the file COMPILE for details.


1.3 Running the Game:
----------------------

There are two ways to start Hammer of Thyrion. The simplest is
the game launcher, which can be accessed from your start
menu or by typing "hexen2" on the command line. Choose your
options and press "Launch Hexen2".

If you don't have the launcher installed, or are more
comfortable with a command line, you can run the game from an X
terminal window.  "cd" into the installation directory and run
any of the game binaries mentioned above. The game starts in
windowed mode by default and without mission pack support. Use the
"-f" switch to start in fullscreen and "-portals" or "-h2mp"
to run Portals of Praevus.

Important command-line switches:

 -portals | -h2mp	Activate the mission pack support: Necessary for
			playing the Portal of Praevus mission pack.
 -f | -fullscreen	Run the game fullscreen (can also be set from the menu)
 -w | -window		Run the game windowed (can also be set from the menu)
 -g | -gllibrary	Select 3D rendering library
 -width   N		Select screen size (can also be set from the menu)
 -height  N		Optional, Must be used with -width (can also be set
			from the menu)
 -bpp  N		Color depth for GL fullscreen mode
 -conwidth  N		Enables a bigger hud display and readable fonts
			at high resolutions. Valid conwidth values are
			values equal or less than the screen width above:
			Smaller the number, bigger the text. 640 is the
			sanest. Can also be adjusted from the menu.
 -nomouse		Disables mouse usage in game
 -heapsize  N		Heapsize (memory to allocate, in KB)
 -fsaa N		Enable N sample anti-aliasing (N: 0,2,4) (can also be
			set from the menu)
 -sync | -vsync		Enable syncing with monitor refresh (GL, Nvidia)
 -lm_4			Set lightmap format to GL_RGBA, which is actually
			the default format. RGBA lightmaps are required for
			colored lights. Can also be set from the menu.
 -lm_1			Set lightmap format to GL_LUMINANCE. (this was the
			old format that hexen2 originally used and it is
			a little faster than RGBA lightmaps). Can also be
			set from the menu.
 -paltex		Enable 8 bit (palettized) textures: saves video
			memory on old low-memory 3D accelerators if the
			proper opengl extension is supported. (can also be
			set from the menu)
 -nomtex		Disable multitexture detection/usage
 -3dfxgamma		Special gamma support for old Voodoo1/2/Rush
 -sndoss		Use OSS for audio (default)
 -sndalsa		Use ALSA for audio
 -sndsdl		Use SDL for audio
 -sndbsd		Use sunaudio (default for for openbsd and netbsd)
 -ossdev		OSS Audio device to use (default: /dev/dsp)
 -alsadev		ALSA Audio device to use (default: hw:0,0 )
 -sndspeed N		Sampling rate of sound playback (eg 22050,44100)
 -cddev			CD Audio device to use (default:
				/dev/cdrom for linux, /dev/acd0 for BSD)
 -nocdaudio		Disable cdrom music
 -nomidi		Disable MIDI music
 -s | -nosound		Run the game without sound
 -nolan			Disable networking (incompatible with -listen)
 -listen  N		Enable multiplayer with maximum N players
 -protocol N		Run the server using protocol version N, instead of
			the default. Valid values: 18 (old), 19 (default).
 -condebug | -debuglog	Logs the console output.
 -devlog		Enable full logging even when not in developer mode
 -v | -version		Display the game version
 -h | -help		Display short help message

If you wish to brighten the display, simply use the game's menu
entry. In the unlikely case that it doesn't work for you, you can
use the "xgamma" utility: Here is the script I use for xgamma:

    cd /usr/local/games/hexen2
    xgamma -q -gamma 1.3;       # brighten the display
    ./glhexen2 -width 800 -height 600 -f -heapsize 48000
	    			# default heapsize is 32768
    xgamma -q -gamma 1;         # restore old brightness

3dfx Voodoo1 and Voodoo2 users can employ the -3dfxgamma command line
switch to activate native 3dfx gamma controls.


1.4 Sound and Midi
------------------

Hexen II has some great sound effects, with the option of CD or
Midi background music. Unfortunately it didn't originally support
all sound cards. To fix this, it now includes a choice of three
sound drivers:

a. OSS sound code
-----------------
This is the default sound driver for Linux and FreeBSD. It uses OSS
(Open Sound System) kernel modules. It is compatible with most of
the Linux distributions but it is known not to work for a few people.
If you use the game launcher, select the OSS option from the sound
menu. If you use command line, "-sndoss" tells the game engine to use
OSS, but it isn't necessary (it is the default). If OSS doesn't work
for you, then please try the other options below.


b. ALSA sound code
------------------
This driver is for Linux and is based on the new ALSA (Advanced Linux
Sound Architecture) 1.0.x libraries. It can be used with new Linux
distributions such as Mandrake 10.x, Fedora Core 2/3, Debian-unstable
and the like. It works best with higher sampling rates. If you use the
game launcher, select the ALSA option from the sound menu. If you use
command line, then start the game with "-sndalsa" option. For example:

  ./glhexen2 -sndalsa -sndspeed 44100


c. SDL sound code
-----------------
This third option isolates you from many compatibility issues and
should be usable on most Linux distributions.  If you use the
launcher, select the SDL option from the sound menu.  If you use
command line, then start the game with "-sndsdl" argument.

  ./glhexen2 -sndsdl [other possible arguments]


d. BSD/SUN sound code
---------------------
The sunaudio driver is the default sound driver for our experimental
OpenBSD and NetBSD support. If you use the game launcher, select the
BSD option from the sound menu. If you use command line, "-sndbsd"
tells the game engine to use sunaudio, but it isn't necessary (it is
the default). If sunaudio doesn't work for you, then please try the
SDL driver.

If you can't get sound working, the "-nosound" option will disable
it. Send a bug report on the project page.


1.4.1 Midi support
------------------

On linux / unix, the midi background music requires 1.2.4 or a newer
version of SDL_mixer, preferably version 1.2.5 or later.  Currently,
it will not work in combination with the SDL sound option (-sndsdl).

If compiling SDL_mixer yourself, the default location for the timidity
data files (complete set of GUS patches) is "/usr/local/lib/timidity".
If you already have these files installed elsewhere, you will have
to symlink to this directory. For example:

    ln -s /usr/share/timidity /usr/local/lib/timidity

As an alternative, you can edit "SDL_mixer-1.2.x/timidity/config.h"
before compiling SDL_mixer, to point to your timidity data files.


1.5 Networking / Multiplayer
----------------------------

Since version 1.4.2 (engine version 1.19), Hammer of Thyrion binaries
are fully compatible Raven's Windows Hexen II-1.11 binaries.  When run
as a client, it can connect to Raven-1.11 servers and can play just
fine.  It can playback the demos created with 1.11 version, as well.
On the other hand, if a 1.11 client wants to connect to a H.o.T. server,
the server must be started with "-protocol 18" command line argument.
Remember that the original cdrom versions (1.03) are not supported at
all: Network compatibility is only valid with the updated 1.11 version.
Mission pack is, of course, fully network-compatible across platforms.
As for the other Hexen II ports such as UQE, Pa3PyX, NewHexen, JSHexen,
Hammer of Thyrion is compatible with them, too.


1.6 Game Saves and Configuration files
--------------------------------------

Your game saves and configuration files are stored in a folder
named  .hexen2 in your home folder:  ~/.hexen2   For the demo
version, it's ~/.hexen2demo instead.

Saves/configs for Hexen2 are stored under ~/.hexen2/data1
For the Mission Pack, they are stored under ~/.hexen2/portals


1.7 Fullscreen/Windowed modes and mouse
---------------------------------------

While playing the game, you can switch between fullscreen and
windowed modes by pressing ALT + Enter combination. Alternatively,
you can use the relevant menu option. The last setting will be
saved to the config and will be remembered by the game.

You can also change the resolution from the menu system. Again,
the last setting will be saved to the config and will be remembered
by the game.

The menu option "Use Mouse" enables/disables mouse usage on the
fly. While in windowed mode, disabling the mouse ungrabs the mouse
pointer, so that you can easily use your desktop. You can also
ungrab/regrab the mouse pointer by pressing the  CTRL + G  key
combination whenever you want.

----------------------------------------------------------------



2. KNOWN PROBLEMS
-----------------


2.1 Sound Problems
------------------

First, we recommend using high sampling rates. This can be done either
by a command line argument like "-sndspeed 44100" or "-sndspeed 48000",
or by using the game launcher. ALSA is the driver of choice - the OSS
driver may not work with all cards, and with SDL you have no midi.

If you have problems making sound to work correctly, using the arts
sound server may help you:    artsd & ; artsdsp -m glhexen2 -sndoss
You may notice some lag in sound but if all fails this may be a good
enough workaround.

We have reports that some i8x0 sound chips not working correctly with
hexen2, and this is overcome either by using alsa driver of hexen2 at
48000 sampling rate, or by the arts workaround mentioned above.

The ALSA driver may complain about a non-power-of-two buffer size and
unsatisfactory sound may result.  The following was once reported for
an onboard VIA82xx audiocard:

	ALSA: Using device: default
	ALSA: 14867 bytes buffer with mmap interleaved access
	ALSA: WARNING: non-power of 2 buffer size. sound may be
	unsatisfactory. Recommend using either the plughw or hw
	devices or adjusting dmix to have a power of 2 buf size
	ALSA Audio initialized (16 bit, stereo, 44100 Hz)

You may resolve this by using a .asoundrc like the following,

	pcm.alsa_fixh2 {
		type dmix
		ipc_key 2048
		slave {
			pcm "hw:0"
			rate 48000
			period_time 0
			period_size 1024
			buffer_size 16384
			channels 4
		}
	}

and starting uhexen2 with (notice the -sndalsa -alsadev alsa_fixh2
parameters; tested and documented by Davide Cendron):

	$ glhexen2 -sndalsa -alsadev alsa_fixh2 -sndspeed 48000


2.2 Lines on Screen
-------------------

A common problem, especially with 3dfx cards, is flickering lines
across the screen caused by a GL tweak. To fix this, bring down
the console with the '~' key and enter 'gl_ztrick 0'.
With fresh installations of HoT-1.2.3 and later, this option is
disabled by default.


2.3 Fluxbox
-----------

Though it's a great window manager, older versions of fluxbox have
issues with some games in fullscreen mode. If this is the case,
hit "ALT + Enter" twice to switch into windowed mode and then back
into fullscreen mode.

----------------------------------------------------------------


3. GENERAL INFO
---------------


3.1 Mods
--------

Running a Hexen II mod is the same as running a Quake mod: You need
to specify its directory name after a -game argument on the command
line. For example, in order to run Fortress of Four Doors:

    ./glhexen2 -game fo4d

If you want to run your mod with mission pack support enabled, use
a command line with -portals argument included. For example:

    ./glhexen2 -portals -game fo4d

Fortress of Four Doors is one of the few large mods for Hexen II. It
has a confusing level near the middle, but is otherwise great. Look
around the web for the file fo4d.zip or fo4d.tgz .

Also, make sure to check out the botmatch mod "hcbots" available
at our project page.

And then, there is the somewhat incomplete Project Peanut: Developed
by Shanjaq, Project Peanut introduces RPG elements, such as a massive
array of spells, in a very interesting way. Its homepage is at:
http://www.geocities.com/shanjaq/index.html


3.2 Game Console
----------------

Games based on the Quake engine have an in game console - toggled by
the '~' key or by the Shift-Escape key combination - from which
variables can be changed.  Some of these affect performance, others
enable features. A brief list follows but for more info see:
http://www.planetquake.com/console/

variable	valid values
--------	------------

_snd_mixahead	0.1-0.9	: 0.1 = less latency,
			  0.9 = better performance

gl_multitexture	0 or 1	: Disable/enable multitexturing on the fly.
			  0 is default. Faster performance if the
			  hardware supports it. Also adjustable from
			  the menu.

gl_texturemode		: GL_NEAREST	(Point sample, least quality)
			  GL_LINEAR	(Bilinear, no mipmaps)
			  GL_NEAREST_MIPMAP_NEAREST
			  GL_NEAREST_MIPMAP_LINEAR
			  GL_LINEAR_MIPMAP_NEAREST (Bilinear: default)
			  GL_LINEAR_MIPMAP_LINEAR (Trilinear: best, slower)
			  Also adjustable from the menu. Bilinear is
			  recommended. If you don't have an ancient
			  graphics card, you should have no trouble
			  running with the trilinear filtering.

gl_constretch	0 or 1	: Disable/enable console background eye candy.

gl_ztrick	0 or 1	: 3% performance tweak (some cards unsupported)

gl_picmip	0, 1, 2	: 0 is default. 1 and 2 scale down the textures
			  (low quality), but the help screens and some
			  small fonts become unreadable and ugly. Keep
			  it as 0.

gl_playermip		: similar to gl_picmip, but for player skins.

snow_active	0 - 255	: 0 =  none,
			  1 =  normal
			  Amount designated by the map and higher acts as
			  a multiplier.


3.2.1 Software renderer options
-------------------------------

sbtrans		0, 1, 2	: HUD (status bar) transparency. 0: none (solid),
			  1: slightly transparent, 2: very transparent.
			  0 is default.

dmtrans		0, 1, 2	: Same as the sbtrans above, but used for the
			  small deathmatch overlay in multiplayer.


3.2.2 Other OpenGL options
-------------------------------

gl_coloredlight	 0, 1, 2: Static colored lights. 0 is the white light that
			  hexen2 traditionally uses. Mode 1 is colored
			  lighting. Mode 2 is experimental which combines
			  white and colored lighting (if available), and
			  sometimes can give better results then just
			  colored lighting, and is also slightly brighter.
			  0 is the default. Can also be adjusted from the
			  menu system. Changing this option requires the
			  level to be reloaded. Colored lighting requires
			  RGBA lightmaps which is also adjustable from the
			  menu system.

gl_colored_dynamic_lights 0 or 1:
			  Disable/enable colored dynamic lights. 0 is the
			  default. Also adjustable from the menu.

gl_extra_dynamic_lights   0 or 1:
			  Disable/enable extra dynamic lights. 0 is the
			  default. Also adjustable from the menu.

gl_stencilshadow  0 or 1: Disable/enable stencil buffered shadows on the
			  fly. Default is 0.  Adjustable from the menu.

gl_purge_maptex	  0 or 1: Purge opengl textures upon map change. Textures
			  won't keep accumulating from map to map but the
			  levels will load slower. Default is 1. Adjustable
			  from the menu.


3.2.3 Nvidia tweaks
-------------------------------

These are only valid for supported hardware (Geforce and better)
with Nvidia's proprietary video drivers installed.

The -sync or -vsync command line switch forces GL redraws to sync
with the monitor refresh for a more stable image. This is equivalent
to setting the environment variable __GL_SYNC_TO_VBLANK to 1.

You can also override our -fsaa switch if you set Nvidia specific
environment variable __GL_FSAA_MODE to an appropriate value.  The
details for this can usually be found in Nvidia's readme file
(/usr/share/doc/NVIDIA_GLX-1.0/README).  Briefly: Geforce 1 and 2
use mode 3 or 4, others 1, 2, 4 or 5.



3.3 Hardware Acceleration
-------------------------

Setting up hardware OpenGL acceleration under Linux used to be
a big deal in the past. Modern distros do this automatically
now.

Nvidia's drivers for all of their modern video cards are not
open source, and because of this many distributions do not
include them. If your Nvidia card is running slowly, this is
probably the cause, you should visit Nvidia.com to download the
linux installer. In my experience these drivers are great, but
not all versions work 100% with all cards. If you have a
misbehaving Nvidia video card, try a different driver version.

Linux kernel 2.6.8 / Nvidia driver version 6111 /TnT card and
possibly other cards and kernels have issues with the GL game.
Upgrade to NVIDIA-Linux-x86-1.0-7167 to fix these problems.
If you don't want to change your nvidia driver and the game seems
to halt, try using the alt-enter key combination to switch to
windowed mode and redraw the screen. This behavior is the same
for glquake.

3dfx Voodoo1, Voodoo2 and Voodoo Rush are no longer hardware
accelerated under XFree-4.x and X.org releases.  You need Glide,
and Mesa compiled against Glide.  For some more detailed info,
consult the document README.3dfx.


3.4 Links
---------

    Hammer of Thyrion
	Home page		: http://uhexen2.sourceforge.net/
	Project page		: http://sourceforge.net/projects/uhexen2/
	Work-in-progress	: http://uhexen2.sourceforge.net/devel/
	CVS Repository		: http://uhexen2.cvs.sourceforge.net/uhexen2/
	MorphOS port		: http://www.binaryriot.org/users/kiero/
				  http://aminet.net/package/game/shoot/GLHexen2
	GP2X port		: http://www.gp32x.com/board/index.php?showtopic=40562
				  http://www.dcemu.co.uk/vbulletin/showthread.php?p=2148019592
	PalmOS port		: http://www.metaviewsoft.de/

    Hammer of Thyrion Packages / builds
	FreshPorts for FreeBSD	:
		main package	: http://www.freshports.org/games/uhexen2/
		extra package	: http://www.freshports.org/games/uhexen2-extras/
	SuSE RPM packages	: http://packman.links2linux.de/package/hexen2/
	Arch Linux packages	: http://aur.archlinux.org/packages.php?do_Details=1&ID=12618
	Gentoo ebuilds		:
		the main ebuild	: http://bugs.gentoo.org/show_bug.cgi?id=105780
		for demo data	: http://bugs.gentoo.org/show_bug.cgi?id=139262
		for extra data	: http://bugs.gentoo.org/show_bug.cgi?id=139278
		the cvs version	: http://bugs.gentoo.org/show_bug.cgi?id=181824
	Gentoo Sunrise overlay	: http://overlays.gentoo.org/svn/proj/sunrise/reviewed/games-fps/
	Nokia N770/800/810 build: http://www.internettablettalk.com/forums/showthread.php?p=134552

    Other Hexen II ports
	Hexen II PSP port	: http://jurajstyk.host.sk/
	Korax's UQE Hexen II	: http://www.quake-engine.com/

    Older, currently inactive Hexen II ports
	Anvil of Thyrion	: http://aot.linuxgames.com/
	Hexen II Mac port	: http://macglquake.sourceforge.net/
	Hexen II Dreamcast	: http://dcquake.sourceforge.net/
	JSHexen II		: http://jurajstyk.host.sk/
	Pa3PyX's Hexen II	: http://pa3pyx.dnsalias.org/
	NewHexen		: http://newhexen.raven-games.com/

    Other web links
	Official Hexen II FAQ	: http://www.raven-games.com/hex2faq/
	Hexen2-Linux Game Tome	: http://happypenguin.org/show?Hammer%20of%20Thyrion
	Hexen2-Linux Gamer Guide: http://linux.strangegamer.com/index.php?title=HeXen_II
	Linux Quake How-To	: http://tldp.org/HOWTO/Quake-HOWTO.html
	id Software		: http://www.idsoftware.com/
	Raven Software		: http://www.ravensoft.com/
	SDL homepage		: http://www.libsdl.org/
	ALSA homepage		: http://www.alsa-project.org/
	Lowercase Utility	: http://filerenameutils.sourceforge.net/


3.5 Thanks
----------

Thanks to ID Software, Raven Games and Activision for a great
game and for supporting open source software. Also thanks to
Dan Olson and Clément Bourdarias for the initial Linux port
(AoT) and to Sourceforge.net for hosting HoT.
Mega thanks to all the unheralded Doom/Quake/Hexen modders.


3.6 Contact
-----------

Ozkan Sezer      <sezero@users.sourceforge.net>
Steven Atkinson  <stevenaaus@users.sourceforge.net>
Levent Yavas     <leventy@users.sourceforge.net>



---------------------------------
APPENDIX  A.  Some Legacy Options
---------------------------------

If, while running around, the screen occasionally twitches up
and down, then you must disable lookspring by typing
"lookspring 0" in the game console, or by editing your
config.cfg file in $HOME/.hexen2/data1/config.cfg.

Lookspring, lookstrafe and keyboard look (+klook) are legacy
options for systems without a mouse which we actually didn't
kill for historical reasons. They are pretty much of no use
today, and we recommend disabling them if they are not already.

These options and key bindings are removed from the menu system
as of Hammer of Thyrion 1.3.0.  For reference, here are what
they are meant to do, as written in the old manuals:

  lookspring:	0 or 1. Returns your view immediately to straight
		ahead when you release the look up / down key.
		Otherwise, you must move forward for a step or
		two before your view snaps back.
  lookstrafe:	0 or 1. If you are using the look up / down key,
		then this option causes you to sidestep instead
		of turn when you try to move left or right.
  keyboard look: If +klook is bound to a key, press that key to
		use your movement keys to look up or down.
  mouse look:	If +mlook is bound to a key, press that key to
		allow your mouse to look up or down (by sliding
		it forward and back), and to remain looking up
		or down even if you move forward.

