Introduction | Basics | Variables and Operators | Events | Weapons
Sector, Sprite and Wall Structures | Miscellaneous Commands

Many people are gonna find the information on the official Eduke site impenetrable. This guide is designed for you. It gives an explanation of the features with possible uses and examples. This section will be constantly updated.

Basics

First things first, all the old stuff from Duke Nukem Atomic has pretty much remained intact (although the properties of some primitives may change later). Thus, it would be a pretty good idea to know about the Duke Nukem Atomic CONs before you get started with EDuke. The article I'm writing on standard CON effects will not cover this: that's an article for experienced people who are looking to spice up their CONs. No, what you want is a CON FAQ written for beginners. You might find the one at MapFAQ Central a good start, I learnt all the commands pretty quickly using it.
Once you've absorbed the basics of the CON language and tried out some of the stuff in my other article you are ready to start here.

New stuff

The new stuff added so far:
-CON additions from WWII GI, including Events, Weapon Changes, Weapon Settings.
-Global variables and mathematical operators
-Texture detection for floors (not quite walls yet)
-System Variables
-Acess to the tags
-Acess to sector, sprite and wall structures

There are also a few other miscellaneous things like being able to change the MIDI track and such.

Variables and operators

Useage

Variables and operators open up a whole load of new possibilities for Eduke. With previous versions of Duke Nukem keeping track of variables for things like the score in a CTF game required the use of inventory items or other methods. Now we can simply define a variable for the score and do any operation with it we wish, quickly and easily.
Variables are numbers which vary. They are assigned tags so that you can keep track of their values. Operators are devices which alter the numbers stored by a variable. The end result of using variables and operators is to perform a mathematical function of some sort. How complex or how simple that is depends entirely on the programmer.

Syntax

gamevar <name> <value> <flag>
operatorvar <var1> <value>
operatorvarvar <var1> <var2>

Eh?

Gamevar tells Eduke to set up a new variable with a name and value you give it. The flag value tells it how to use the variable. It can either be a global variable, i.e. used everywhere, per-player, for multiplayer values etc, or per actor, for individual enemy settings etc...
Performing an operation either occurs with a variable and a value or another variable. They all take the form of the operator's name then var for a variable and number operation or varvar for variable and variable operation. See the appendix for information on these operators.

 

Examples

Here is the code to perform a 'bitstrip'. A bitstrip is a way of obtaining the values of the individual bits of a variable which is being used as a flag. That is to say, the value of the flag has no meaning in its decimal form, only the binary form gives us useful information. You'll need this code later on.

gamevar BIT 0 0

In the actor code...

getactor[THISACTOR].cstat FLAGVAR // Get the cstat flag for this actor
setvar BIT 1 // Set the first bit of the variable BIT
andvarvar BIT FLAGVAR // Check to see if bit 1 is set in FLAGVAR too
ifvare BIT 1 { ...rest of code, you know that bit one is set } else { ...do something else or... }
setvar BIT 2 // Set the second bit of the variable BIT
andvarvar BIT FLAGVAR // Check to see if bit 2 is set in FLAGVAR too
ifvare BIT 2 { ...bit 2 is set, do something } else { ...it's not set... }
setvar BIT 4 // Ser the third bit of the variable BIT
andvarvar BIT FLAGVAR // Check to see if bit 3 is set in FLAGVAR too

and so on... using values of 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768 to check all the bits of a 16 bit variable. You will not need to use all these values for cstat however, not all the bits contain usefull informaiton.
The code above works by performing an AND operator on the variable BIT that stores the value you want to check for. The AND function works by checking each of the bits in both variables and the result returned will only have the bits that are set in both. In the first line the BIT variable has bit 1 set by the decimal number 1. If the FLAGVAR variable also has bit 1 set then on performing an AND operation the value returned for BIT will be the same as it was before, otherwise it will be zero.

 

Appendix

Gamevar flags

0 - Global variable
1 - Perplayer variable
2 - Peractor variable

Operators

Note that the variable that is altered is always the first one written. The second variable for varvar operations is never altered. The arguement is either a variable or a value.
set - set the value of the variable with the arguement
add - add the value of the variable with the arguement
if...e - returns true if the arguement is equal
if...l - returns true if the variable is less than the arguement
if...g - returns true if the variable is greater than the arguement
mul - multiplies the value of the variable with the arguement
div - divides the value of the variable with the arguement
mod - gives the remainder of a division of the variable with the arguement
and - gives the result of an AND function of the variable with the arguement. An AND function checks the bits of each of the two values being compared and the bits in the result are set only if they were set in both of the values being operated on.
or - gives the result of an OR function of the variable with the arguement. An OR function checks the bits of each of the two values being compared and the bits in the result are set if they were set in either of the values being operated on.
rand - gives a random number from 0 to the arguement. Does not have a varvar yet, only numbers are valid arguements.

Addendum

Note on System Variables:
System variables are variables which you can alter like other variables above but are not defined by gamevar. They are used internally for several settings. The easiest way to explain is to tell you what they are and what they do.

RESPAWN_MONSTERS, RESPAWN_ITEMS, RESPAWN_INVENTORY, MONSTERS_OFF, COOP, MARKER and FFIRE are all variables associated with multiplay. They are the respawn times for monsters, items and inventory, monsters on or off, co-op play or not, respawn markers on or off and friendly fire on or off. You can change these dynamically in game. It's hard to see how some of them may be used but there you are...
LEVEL and VOLUME refer to the current map you are playing. They cannot be altered, only read.
TRIPBOMB_CONTROL changes the action of the tripbomb using 1 for a Trip wire (default), 2 for a timer and 3 for both (it's another flag system).

Events

Usage

Events are, well, events that happen in the game. Just read the stuff below to get an idea of what to use them for.

Syntax

onevent EVENT_NAME
{ ...do something... }
endevent

Eh?

Basically if the event with EVENT_NAME occurs the code in the curly brackets is executed. Many events have system variables associated with them that can alter their effects, maybe disable an effect or change its use. Look in the appendix for the full list.

 

Examples

Don't like using the current load tile?

onevent EVENT_GETLOADTILE // The entry tile for a level
setvar RETURN 1 // The entry tile will be set to tile 1
endevent // That's all folks...

 

Appendix

Events

EVENT_INIT - called just when the game is initiated, only called once.
EVENT_ENTERLEVEL - called upon entering a level. The system variables LEVEL and VOLUME return the map being used.
EVENT_RESETWEAPONS - called when the player's weapons are reset when they enter a level or die.
EVENT_RESETINVENTORY - similar to RESETWEAPONS but for inventory instead.
EVENT_HOLSTER - the player has pressed the key for holster as defined in the setup file. Set the system variable RETURN to zero to allow default processing.
EVENT_LOOKLEFT - similar to HOLSTER but the player has pressed the look left key.
EVENT_LOOKRIGHT - similar to HOLSTER but the player has pressed the look right key.
EVENT_SOARUP - similar to HOLSTER but the player has pressed the jump key whilst using the jetpack.
EVENT_SOARDOWN - similar to HOLSTER but the player has pressed the crouch key whilst using the jetpack.
EVENT_CROUCH - similar to HOLSTER but the player has pressed the crouch key.
EVENT_JUMP - similar to HOLSTER but the player has pressed the jump key.
EVENT_RETURNTOCENTER - similar to HOLSTER but the player has pressed the center view key.
EVENT_LOOKUP - similar to HOLSTER but the player has pressed the look up key.
EVENT_LOOKDOWN - similar to HOLSTER but the player has pressed the look down key.
EVENT_AIMUP - similar to HOLSTER but the player has pressed the aim up key.
EVENT_AIMDOWN - similar to HOLSTER but the player has pressed the aim down key.
EVENT_FIRE - called when the player has pressed the fire key. The system variable WEAPON gives the weapon ID of the weapon being fired and the system variable WORKSLIKE is the weapon's works like setting. See the Weapons section. Set RETURN to zero to allow default processing.
EVENT_CHANGEWEAPON - called when the player is changing their weapon. The system variables WEAPON and WORKSLIKE give the same results as for the event FIRE. A value -1 means no weapon and there is no system variable RETURN.
EVENT_GETSHOTRANGE - called when the player is shooting. Again the system variables WEAPON and WORKSLIKE act the same as for the FIRE event. The system variables ANGRANGE and ZRANGE alter the spread of fire using polar co-ordinates. That is an angle and a distance from the center of the shot. A ZRANGE of 0 would always produce a shot on target. The numbers must be in powers of 2 however.
EVENT_GETAUTOAIMANGLE - called when weapon autoaim is being used. The system variable AUTOAIMANGLE sets the aim tracking, 0 would disable it, 48 is the default.
EVENT_GETLOADTILE - the tile to be used as the loading background. The value is set in the system variable RETURN.
EVENT_CHEATGETSTEROIDS - the player has used a cheat to get steroids. Set RETURN to the amount of steroids to give.
EVENT_CHEATGETHEAT - the player has used a cheat to get nightvision. Set RETURN to the amount of nightvision to give.
EVENT_CHEATGETBOOT - the player has used a cheat to get boots. Set RETURN to the amount of boots to give.
EVENT_CHEATGETSHEILD - the player has used a cheat to get armour. Set RETURN to the amount of armour to give.
EVENT_CHEATGETSCUBA - the player has used a cheat to get SCUBA gear. Set RETURN to the amount of SCUBA gear to give.

Weapons

Useage

The weapon controls for Eduke have been vastly improved and gives a lot more freedom over what you can do. I'm sure you don't need me to give you ideas about new weapons...

Syntax

gamevar WEAPONx_PROPERTY <value> 1

Eh?

Set the weapon property for weapon x with the value, x will be in the range 0-11, valid values are variable. See the appendix for the list of properties possible.

 

Examples

How many times has it been asked to change the pistol clip amount? Well now it's simple as:

gamedef WEAPON1_CLIP 30 0

 

Appendix

Properties

SHOOTS - what the weapon shoots, i.e., what tile number.
FIREDELAY - the number of animation frames before a shot actually takes place.
HOLDDELAY - the number of animation frames between shooting and reloading.
TOTALTIME - delay after firing before the weapon can be refired.
SPAWN - item to spawn, like bullet shells. If zero nothing is spawned.
SPAWNTIME - the number of frames before the item is spawned.
CLIP - the amount of ammo in the weapon's clip. 0 means there is no clip.
SHOTSPERBURST - number of shots per press of the fire button.
WORKSLIKE - how the weapon works, e.g. 9 would mean the weapon works like a trip bomb.
INITIALSOUND - the sound made initially. 0 means nothing is sounded.
FIRESOUND - sound made on the firing frame. 0 means nothing is sounded.
SOUND2TIME - as used in the shotgun for reloading sound. This is the time before it is heard.
SOUND2SOUND - sound made when SOUND2TIME is reached. 0 means nothing is sounded.
FLAGS - controls weapon operation using a flag system. From the list below add up all the values of the flags you want set to get the value to set FLAGS to.
1 - 'holstering' clears the current clip and gives you a fresh one.
2 - the weapon 'glows', like the shrinker and expander.
4 - automatic fire.
8 - during 'hold time' fire every frame.
16 - during 'hold time' fire every third frame.
32 - restart for automatic is 'randomized' by RND 3.
64 - uses ammo for each shot.
128 - weapon is the bomb trigger for the pipebomb.
256 - weapon use does not cause user to become 'visible'.
512 - weapon throws the shot item, like the pipebomb.
1024 - check weapon availability at 'reload' time.
2048 - player stops jumping.

 

Addendum

Most weapons work exactly the same. The pipebomb and tripbomb being the major exceptions. The weapon display for the moment is still the same so the tile numbers and the way the tiles are used is still the same. Certain combinations of settings may cause the program to crash. The weapon system currently uses 'worklike' to control how the weapon works so there is not a major change from the old weapon system there. Not all settings are supported by all weapon 'modes'. For example, SOUND2TIME is only supported by the shotgun.

Sector, sprite and wall structures

Useage

With these commands you can alter a whole plethora of properties related to actors, walls and sectors. I can't possibly begin to list what can be done, instead I will write some example code for you to try with some of the ideas I have come up with. When the first version of Eduke is released I will have a level pack availible to show off these CONs.

Syntax

getthing[<var>].member <var2> setthing[<var>].member <var2>

Eh?

Get/set the property member for the thing with number var and place its value in var2. Note that many of the possible .members already have CON control, whereas a few certainly don't.

 

Examples

This example creates an actor for the first tile which will increase the floor height of the sector with number 0 by one every game cycle.

gamevar SECTOR 0 2 // Create a per actor variable called SECTOR (first value is amount to set second is a flag to set the variable as a per actor variable.)
gamevar PROPERTY 0 2 // Create a per actor variable called PROPERTY

useractor notenemy 0 0 // Create the useractor
getsector[SECTOR].floorz PROPERTY // Get the floor height of the sector with number set in SECTOR and place the value in PROPERTY
addvar PROPERTY 1 // Increase the value of PROPERTY by 1, experiment with this bit to get different effects for the sectors rate of rise. A negative fall will make it fall, multiplying the value causes an exponential increase.
setsector[SECTOR].floorz PROPERTY // Set the floor height of the sector with number set in SECTOR with PROPERTY
enda

Why cycle through only two colours?

gamevar SECTOR 0 2
gamevar PAL 1 2
define TIME 30
useractor notenemy 0 0
setsector[THISACTOR].ceilingpal PAL
setsector[THISACTOR].floorpal PAL
ifcount TIME { addvar PAL 1 } // Set the speed of colour change to TIME
ifvarg PAL 8 { setvar PAL 1 } // If the palette is green set back to blue
ifvarg PAL 2 { setvar PAL 8 } // Palette goes from blue-red-green
enda

More examples to come as I think of them... possible ones to thing about include Doom style falling pillars that drop underwater...

 

Appendix

There are a few gaps here, some of the .members I could not work out their functions. If you know what any of these missing .members do then e-mail me.

getactor/setactor .member values.

x - the x position of the actor
y - the y position of the actor
z - the z position of the actor
cstat - the properties of the actor, the same for the cstat CON command.
picnum - the actor's texture
shade - the shade of the actor
pal - the palette of the actor
clipdist - the clipping distance of the actor
filler - un-used bytes used to pad the next member variable out to an even alignment - Matteus.
xrepeat - the x size of the actor
yrepeat - the y size of the actor
xoffset - the x orientation of the actor texture
yoffset - the y orientation of the actor texture
sectnum - the number of the sector the actor is in
statnum - internal list that the actor is on (active, inactive, etc). - Matteus
ang - the direction the sprite faces
owner - 'owner' for actor is used to determine who shot something. This is used to give proper credit when a pipebomb blows somebody up, for instance. - Matteus.
xvel - the x velocity of the actor
yvel - the y velocity of the actor
zvel - the z velocity of the actor
lotag - the actor's lotag
hitag - the actor's hitag
extra - extra is used for actors to point to the offset in the compiled code for the start of the 'actor' or 'useractor'. - Matteus.

getsector/setsector .member values.

wallptr - the number for the first wall, i.e. the one used for slopes
wallnum - the number of walls in the sector
ceilingz - the height of the ceiling
floorz - the height of the floor
ceilingstat - miscellaneous information on the sector see addendum after this section
floorstat - miscellaneous information on the sector see addendum after this section
ceilingpicnum - the texture for the ceiling
ceilingheinum - the slope of the ceiling
ceilingshade - the shade for the ceiling
ceilingpal - the pallete for the ceiling
ceilingxpanning - the x panning for the ceiling texture
ceilingypanning - the y panning for the ceiling texture
floorpicnum - the texture for the floor
floorheinum - the slope for the floor
floorshade - the shade for the floor
floorpal - the pallete for the floor
floorxpanning - the x panning for the floor texture
floorypanning - the y panning for the floor texture
visibility - the sector visibility
filler - un-used bytes used to pad the next member variable out to an even alignment - Matteus.
lotag - the sector lotag
hitag - the sector hitag
extra - something Silverman left open to the game programmer, according to TerminX

getwall/setwall .member values.

x - the x co-ord of the first point of the wall
y - the y co-orf of the first point of the wall
point2 - the wall number that gives the second point's co-ords in it's x and y members
nextwall - for double sided walls, the wall number assigned to the other side, else -1
nextsector - for double sided walls, the sector number assigned to the other side, else -1
cstat - the propeties for the wall, as with the cstat for sprites. Note that some have no effect unless the wall is a red line wall.
picnum - the texture used for the normal wall
overpicnum - the texture used for the top wall
shade - the wall shade
pal - the wall palette
xrepeat - the x size of the texture
yrepeat - the y size of the texture
xpanning - the x panning of the texture
ypanning - the y panning of the texture
lotag - the wall lotag
hitag - the wall hitag
extra - something Silverman left open to the game programmer, according to TerminX

 

Addendum

Note on [THISACTOR]:
A very useful little flag, this will get the .member value for the current actor or the sector which the actor is in.
It's use is very simple, getactor[THISACTOR].x XPOS, will get the current actor's X position. getsector[THISACTOR].floorz FLOOR is a faster way of writing:

getactor[THISACTOR].sectnum SECTOR
getsector[SECTOR].floorz FLOORZ

Which would have the same effect.

Note on floorstat/ceilingstat:
bit 0: 1 = parallaxing, 0 = not
bit 1: 1 = sloped, 0 = not
bit 2: 1 = swap x&y, 0 = not
bit 3: 1 = double smooshiness, i.e. change the size of the floor textures
bit 4: 1 = x-flip
bit 5: 1 = y-flip
bit 6: 1 = Align texture to first wall of sector
bits 7-15: reserved
Thus the numbers stored in the stat's are binary flags. To read them you'll need to do a 'bitstrip', which is mentioned in the variables section.

Miscellaneous commands

Audio commands:
ifsound <sound> - returns true if the current sound with number given by <sound> is playing.
starttrack <value> - start the midi track with the number value defined sequentially by the music command.

Texture commands:
gettexturefloor - get the current sector's floor texture in the variable TEXTURE
gettextureceiling - get the current sector's ceiling texture in the variable TEXTURE
gettexturewall - not yet implemented
Note :- these commands are achievable using member structures.

lowtag/httag commands:
spgetlotag - get the current actor's lotag in the variable LOTAG
spgethitag - get the current actor's hitag in the variable HITAG
sectgetlotag - get the current sector's lotag in the variable LOTAG
sectgethitag - get the current sector's hitag in the variable HITAG
Note :- these commands are achievable using member structures.

Movement commands:
getplayerangle <var> - get the player's current angle in the variable var
setplayerangle <var> - set the player's current angle with the variable var
lockplayer <var> - lock the player's movement for a count of var.
getangletotarget <var> - get the angle to face the nearest or current player in the variable var
setactorangle <var> - set the actor's angle with the variable var
getactorangle <var> - get the actor's angle in the variable var