DECORATE supports complex mathematical expressions as parameters for codepointers. (Unfortunately, expressions are not supported for the values of properties.) The expression may include standard operators (+, -, *, /, <<, >>, |, ? and : (ternary) etc.), math functions, and certain actor properties (occasionally called “keywords” in the forums) to compare values with. A_JumpIf, in particular, is meant to be used with expressions, but they can be used for any numeric (integer or floating point) parameter. For example, using velx, vely, and velz in A_SpawnItemEx to preserve velocity, or using args as arguments to a call of ACS_Execute.
- abs(x) — returns the absolute value of x.
- exp(x) - Returns the base-e exponential function of x, which is e raised to the power x: ex .(development version only)
- log(x) - Returns the natural logarithm of x -- the opposite of exp. (development version only)
- log10(x) - Returns the common (base-10) logarithm of x. (development version only)
- ceil(x) - Rounds x upward to the next closest integral value. Result is still floating point. (development version only)
- floor(x) - Rounds x down to the next closest integral value. Result is still floating point. (development version only)
- sqrt(x) — Returns the square root of x.
- min(float or int, ...) - Gets the smallest value of all values listed. Can take any amount of numbers, and can solve both ints and floats. (development version only)
- max(float or int, ...) - Gets the largest value of all values listed. Can take any amount of numbers, and can solve both ints and floats. (development version only)
- clamp(src, min, max) - Returns src within the range of min and max inclusively. All parameters can be ints or floats. (development version only)
- cos(x), sin(x), tan(x) — Returns cosine, sine, or tangent of angle x. x must be in degrees. Tan is (development version only)
- acos(x), asin(x), atan(x) — Returns the inverse cosine, sine, or tangent of x. Returns an angle in degrees. (development version only)
- cosh(x), sinh(x), tanh(x) — Returns the hyperbolic cosine, sine, or tangent of x. (development version only)
- atan2(y,x) - - Similar to atan, but used to get the quadrants the angles are in. Returns in degrees.(development version only)
- VectorAngle(x,y) - Like atan2, only with x first instead of y. Can be used to calculate an angle, for example, by passing coordinates to it. (development version only)
VectorAngle(user_x - user_x, user_y - user_y)
Random number functions
- random[identifier](min, max) — returns a random integer value between min and max
- random2[identifier](mask) — returns a random integer value between -mask and +mask. It is roughly equivalent to random(0, mask) - random(0, mask). If no mask is provided (random2()), the maximum value of 255 is used instead. Mask is used as a binary mask, e.g. if 9 is used, the random results can be [0, 1, 8, 9] - [0, 1, 8, 9], so it is advised to use as a mask values one less than a power of two, such as 1, 3, 7, 15, 31, 63, or 127.
- frandom[identifier](min, max) — returns a random floating point value between min and max
- randompick[identifier](int, ...) — picks a number from the numbers placed in it. This can take an unlimited amount of parameters, i.e. randompick(1, 4, 12, 16) will choose one of the four numbers.(New from )
- frandompick[identifier](float, ...) — similar to randompick but for float-point values. (New from )
identifier is optional. Calls to a random function with an identifier do not interfere with the RNG for calls with a different identifier, which can be used to make the outcome of some events unaffected by others.
- ACS_ExecuteWithResult — runs a script and uses its return value.
- ACS_NamedExecuteWithResult — runs a named script and uses its return value.
- CallACS — shorter alias for ACS_NamedExecuteWithResult.
These functions are not like regular DECORATE action functions. They can be used just like expressions (i.e. randompick) inside of action functions directly such as A_SetUserVar.
- CheckClass — checks an actor's class name, returning true if it matches the passed parameter. (New from )
- CountInv - Gets the number of inventory items an actor is holding from a pointer and returns it to the expression. (development version only)
- CountProximity - Similar to A_CheckProximity but returns how many of the actors are found instead of jumping. (development version only)
- GetAngle - Gets the angle which an actor pointer can be found at. Can toggle the relative functionality (development version only)
- GetCvar - Gets a server cvar, internal or user. (development version only)
- GetCrouchFactor - Gets the current crouch factor of a player if the player is a pointer. (development version only)
- GetDistance - Gets the distance from the calling actor to a pointer. Can toggle the Z checking functionality. (development version only)
- GetGibHealth - Gets the gib health property of the calling actor. (development version only)
- GetPlayerInput Performs the same functionality as the ACS GetPlayerInput. (development version only)
- GetSpawnHealth - Gets the spawn health property of the calling actor. (development version only)
- GetSpriteAngle - Gets an Actor pointer's sprite angle. (development version only)
- GetSpriteRotation - Gets an Actor pointer's sprite rotation. (development version only)
- GetZAt - Gets the Z coordinate of a floor or ceiling at a specific set of coordinates. (development version only)
- IsPointerEqual — compares two actor pointers, returning true if they reference the same actor. (New from )
As of (development version only), assignment operators can be used directly on certain variables. This includes compound (+=, -=, etc.), direct (user_x = user_y = user_z) and incremental counting (user_test++, user_test--, --user_test, ++user_test, etc).
As of (development version only) it's also possible to directly modify some of the variables with the direct assignment operators. Those that are marked as read only (in italics, bold properties can be modified directly) must still rely upon the action function used to manipulate them. (i.e. A_Warp for x/y/z, A_ChangeVelocity for velx/vely/velz, etc.)
NOTE: Variable modifications will not be interpolated, or have any other effects performed upon them. If this is desired, use the action function directly associated with it instead (such as A_SetAngle for interpolating angle changes).
The following is dynamic data for use in DECORATE definitions and expressions:
- Actor position and movement
- x — The actor's X position in the world.
- y — Same, but for Y.
- z — Same, but for Z.
- angle — Actor's angle, in degrees
- ceilingz — See GetActorCeilingZ.
- floorz — See GetActorFloorZ.
- pitch — The actor's pitch in degrees.
- roll - The actor's roll. Currently, this only really affects players such as the rotation of view. (New from GZDoom only: not supported by ZDoom) ) (
- velx or momx — Actor's velocity along the absolute X axis. The "mom" names are (deprecated).
- vely or momy — Same, but for Y.
- velz or momz — Same, but for Z.
- Actor properties
- accuracy — The accuracy of the Actor.
- alpha — The Alpha value of the Actor.
- args — Arguments passed to the thing special; args through args are valid.
- damage — The actor's Damage.
- health — How much health the Actor has left.
- height — The actor's Height.
- mass — The actor's Mass.
- meleerange — The actor's MeleeRange.
- radius — The actor's Radius.
- reactiontime — The actor's ReactionTime.
- scaleX — The actor's horizontal scale. See A_SetScale.
- scaleY — The actor's vertical scale. See A_SetScale.
- score — The actor's score.
- special — ID of the special currently assigned to this actor.
- speed — The actor's Speed. (New from )
- stamina — The stamina of the Actor.
- tid — The actor's TID.
- tidtohate — TID of the current assigned target. (see Thing_Hate.)
- threshold — The actor's Threshold. (development version only)
- defthreshold — The actor's DefThreshold. (development version only)
- Constant Variables — Constant variables can be defined both inside and outside of an actor.
- User Variables — user variables are defined as "var int user_(name);" in actor properties.
- User Arrays — user arrays are defined as "var int user_(name)[(size)];" in actor properties.
- waterlevel — How "submerged" the actor is in a Transfer_Heights or 3D floor water pool:
- 0: Not submerged at all (e.g. standing on solid ground or on shallow TERRAIN-based water)
- 1: Less than half submerged ("ankle deep")
- 2: At least half submerged ("waist deep")
- 3: Entirely submerged (completely underwater)
See Projectile Trap