View source for DECALDEF

The '''DECALDEF''' lump allows the wad maker to redesign the [[decals]] that are left on walls by monsters or the player. [[Hitscan]] weapons and [[Projectile|projectiles]] can leave decals; {{flag|SHOOTABLE|shootable}} actors (normally, monsters) can also leave blood decals on walls next to them. 

You can also place decals on the map with a [[Classes:Decal|Decal thing]] (9200) or through [[ACS]] with [[SpawnDecal]]. Decals can be spawned in [[ZScript]]/[[DECORATE]] with [[A_SprayDecal]].

DECALDEF has the following definition types:
* '''Decal''' — definitions of the actual images to be used as decals, their colors, renderstyle, etc.
* '''Animator''' — animators can stretch, scale, fade out and perform other changes to decals after those have been created. Animators can be attached to decals.
* '''DecalGroup''' — allows grouping multiple decals together under one name, so a random decal will be picked from the list.
* '''Generator''' — generator is an instruction that allows attaching decals to an actor (like a [[puff]] or a [[projectile]]). Using this is optional; decals can instead be attached to a puff/projectile using its '''{{property|Decal}}''' property.


{{warning|All DECALDEF definitions are '''order-sensitive'''. This means that if one definition is referencing another (such as a DecalGroup referencing a Decal), the referenced definition must be placed ''earlier in the file''. As such, it's recommended to add definitions in the following order:
# All animators
# Animator combiners
# All decals
# All decal groups
# Generators (if used)}}

== Decal definition ==
The information of a decal begins with the decal itself followed by a generator to tell [[GZDoom]] which object will leave this decal. You can also specify a Decal ID in order to place decals directly on the map. The Decal ID must be a number between 1 and 65535 (inclusive). Several options can be used when defining a decal:

*{{c|pic <graphics name>}}
:This is the graphic ZDoom will paste on the wall.
*{{c|shade "rr gg bb"}}
:This allows you to recolor the picture using specific RGB values. The value is specified as a string containing 3 hexadecimal values.
*{{c|x-scale &lt;scale&gt;}}
:This scales the graphic on the x axis. 1.00 is default.
*{{c|y-scale &lt;scale&gt;}}
:This scales the graphic on the y axis. 1.00 is default.
*{{c|flipx}}
:This tells ZDoom to flip the graphic on the x axis when drawing it.
*{{c|flipy}}
:This tells ZDoom to flip the graphic on the y axis when drawing it.
*{{c|randomflipx}}
:This tells ZDoom to randomly flip the graphic on the x axis when drawing it.
*{{c|randomflipy}}
:This tells ZDoom to randomly flip the graphic on the y axis when drawing it.
*{{c|solid}}
:draws the decal non-translucent.
*{{c|opaqueblood}} {{deprecated}}
:As of {{git|5bcbe17}}, this flag is deprecated, use ''translatable'' instead!
*{{c|translatable}} {{git|5bcbe17}}
:Draws the decal non-shaded, i.e. the same way as sprites are drawn with the 'Normal' {{property|Renderstyle}}. This is useful when the decal is supposed to imitate the look of a sprite.
*{{c|translucent <alpha>}}
:Draws a translucent decal with the specified translucency. 0.0 means it's invisible, 1.0 means it's opaque
*{{c|add &lt;alpha&gt;}}
:Draws the decal with additive translucency. 0 means it's invisible, 1 means it's drawn in full intensity.
*{{c|fuzzy}}
:Draws the decal with a [[fuzz]] effect (like the {{class|spectre}} in ''[[Doom]]''.)
*{{c|fullbright}}
:Draws the decal full bright regardless of the current lighting in the sector.
*{{c|lowerdecal decalname}}
:Draws another decal below this one. The BFG lightning effect uses this for example
*{{c|colors "rr gg bb" "rr gg bb"}}
:Creates a translation table. <i>From a look at the implementation it doesn't look useful. If somebody has more information or some experience how to use it please post it here!</i>
*{{c|animator}}
:Sets a [[Decal animator]] for the current decal

Note that not all of these must be used for each decal. However, the following example shows each in use.

<syntaxhighlight lang="csharp">
decal MyDecal 4
{
    //The name of the graphic used by the decal:
    pic SCORCH1
    //The image will be shaded slightly green:
    shade "00 10 00" 
    //Scaled to 25% of the image's original size:
    x-scale 0.25
    y-scale 0.25
    //Will be randomly flipped along the X, or Y or both axes:
    randomflipx
    randomflipy
}
//Attaches this decal to the FrostMissile projectile class:
generator FrostMissile MyDecal
</syntaxhighlight>

In this example, the image "SCORCH1" is read, and shaded slightly green. It is then scaled to 25% its normal size, and randomly flipped on the two axes. To place this decal on a map with the decal thing, use an ID number of 4. The '''generator''' instruction attaches it to the Mage's {{class|FrostMissile}}.

=== Blood decals ===
The engine is hardcoded to use either the decalgroup '''BloodSplat''' or the decalgroup '''BloodSmear''' for blood splattered on walls. This depends on the damage inflicted:
*Less than 15: one BloodSplat decal (about 60% chance of no decal at all if damage is less than 11);
*Less than 25: two BloodSplat decals;
*25 or more: either three BloodSplat decals (nearly 91% chance) or one BloodSmear decal (about 9% chance).
These decals are then projected on nearby walls, if possible, according to the direction of the attack, slightly altered by random noise.

[[TraceBleed]] and [[TraceBleedAngle]] are [[ZScript]] functions that can manually place blood decals (without changing their internal names).

== Decal generator ==
{{note|Using '''generator''' is not required: decals can be attached to projectiles/puffs with the '''{{property|Decal}}''' actor property in [[ZScript]]/[[DECORATE]].}}
The '''generator''' keyword allows attaching a decal to a [[projectile]] or [[puff]]:
<syntaxhighlight lang="csharp">
generator FrostMissile MyDecal
</syntaxhighlight>

Using {{c|None}} instead of an actual decal name, clears the decal that was previously assigned to the generator.

An {{c|optional}} keyword can be added after {{c|generator}} to exempt a generator definition from being error-reported by the engine if the referenced actor or decal definitions do not exist.

== Decal groups ==
The following example shows a decal which randomly selects between two different decals to paste. The decals are set up as usual, and a "decalgroup" header is added, with the names of the two (or more) decals to use. The generator then references the decalgroup.
<syntaxhighlight lang="csharp">
decal MyDecal1
{
	pic PLASMA1
	shade "08 08 08"
	randomflipx
	randomflipy
}
decal MyDecal2
{
	pic PLASMA2
	shade "08 08 08"
	randomflipx
	randomflipy
}
decalgroup MyDecal
{
	MyDecal1        1
	MyDecal2        1
}</syntaxhighlight>

== Decal animators ==
Decal animators describe how a decal is changed after it has been created. Animators are defined as follows:

 animatortype AnimatorName
 {
   <properties>
   ...
 }

Any decal animator defined this way can be specified in a decal definition by using the <code>Animator</code> keyword. 

Animator types are listed below.

===Fader===
Fader is an animator that fades a decal out by reducing its opacity. The syntax is:

 fader FaderName
 {
    DecayStart <seconds>
    DecayTime <seconds>
 }

*{{c|DecayStart}}
:The time in seconds the decal remains unchanged until the fading process starts.
*{{c|DecayTime}}
:The time in seconds it takes for the decal to completely fade out and disappear.

===Stretcher===
Stretcher is an animator that stretches the decal to a defined size. The syntax is:

 stretcher StretcherName
 {
    GoalX <size>
    GoalY <size>
    StretchStart <seconds>
    StretchTime <seconds>
 }

*{{c|GoalX}}
:The final horizontal scaling factor of the decal
*{{c|GoalY}}
:The final vertical scaling factor of the decal
*{{c|StretchStart}}
:The time in seconds the decal remains unchanged until the stretching process starts 
*{{c|StretchTime}}
:The time in seconds how long the stretching process will take.

===Slider===
Slider is an animator that slides the decal along the wall. The syntax is: 

 slider SliderName
 {
    DistX <size>
    DistY <size>
    SlideStart <seconds>
    SlideTime <seconds>
 }

*{{c|DistX}}
:The distance the decal moves in X-direction
*{{c|DistY}}
:The distance the decal moves in Y-direction
*{{c|SlideStart}}
:The time in seconds the decal remains unchanged until the sliding process starts 
*{{c|SlideTime}}
:The time in seconds how long the sliding process will take.

===ColorChanger===
ColorChanger gradually alters the color of a decal. The syntax is: 

 colorchanger ChangerName
 {
    Color "rr gg bb"
    FadeStart <seconds>
    FadeTime <seconds>
 }

*{{c|Color}}
:The color the decal should change into.
*{{c|FadeStart}}
:The time in seconds the decal remains unchanged until the changing process starts 
*{{c|FadeTime}}
:The time in seconds how long the changing process will take.

===Combiner===
Combiner is a method to group multiple animators (since decals themselves can't have more than one animator attached). The syntax is:

 Combiner CombinerName
 {
    AnimatorName
    AnimatorName
    ...
 }

Each AnimatorName must specify a previously defined animator.

== See also ==
* [[Puff]]
* [[Projectile]]

[[category:ZDoom special lumps]]
[[category:Graphics lumps]]