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dragengine:modules:dragonscript:behavior_elements

Behavior Elements

Behavior Elements are build on top of the Scenery Elements and provide a composeable way to build game logic. This is the fastest way to build your game by befitting elements with reusable behavior while still retaining all the powerful coupling to other script classes.

Basics

Behavior elements are created by subclassing from BehaviorElementClass script class. This class extends the ElementClass script class with support to add Behavior Definitions. When a BehaviorElement instance is created these behavior definitions are used to befit the element with all the required functionality. All this can be done manually by using Scenery Elements but using Behavior Elements this boils down to just adding the behavior definitions you like to use.

Behavior definitions are created by subclassing from ECBehavior script class. This stands for Element Class Behavior. Behavior definitions typically contain Composeable Element Class or Element Class Property instances with appropriate parameters set. This has a few nice properties making life simpler.

Element class properties can be used with XML Subclassing. You can created a new element class just using an XML file (*.deeclass) and change the properties added by the behavior definition. This is especially useful for mappers to add variations of Game Objects without needing to touch script code for such a simple task.

Furthermore Element Stubs used to create Game Objects in your game world use the same names as the element class properties. This allows mappers to modify behaviors on a per Game Object basis if required.

You can query BehaviorElementClass if it contains behaviors of a specific type. Some behavior definitions can be used more than once on the same element class. In this case you can assign each instance a unique identifier. This identifier is used to distinguish between the behavior definition instances and acts also as prefix modified of the added element class properties.

Once a BehaviorElement instance is created each behavior definitions adds a subclass of ECBehaviorInstance. These provide the actual behavior to the BehaviorElement instance. Here too you can query the element if it contains instances of a specific behavior.

Behavior Compendium

Behaviors are split in two groups: Basic Behaviors and Complex Behaviors. Basic Behaviors add a small basic building block of game logic like for example a component showing the visual appearance of a game object. These are highly reusable. Complex Behaviors on the other hand typically expect one or more Basic Behaviors to be present in the element class to provide a complex behavior for example animating the visual appearance.

Many more complex behaviors can be created either just for this game project or to be shared with other projects. Behaviors can extend other behaviors by subclassing or by using other behaviors present in the behavior element class.

Examples

This is an example of an element class which which has a visual appearance, physical interaction, is animated, has two lights, has a speaker and moves along a rail. Basically this describes a kind of train running on a rail between two destinations.

Show Example

The above script code creates a working element class which adds instances of BehaviorElement to the game world set up with the defined behaviors. If you want to have a unique element instance for your class to work with you can modify the code like this:

Show Example

Using unique instances allows to add run-time features to your class on top of what BehaviorElement provides without creating an own behavior. In general it is recommended to work with behaviors only and creating your own ones. This way you can reuse game logic across different projects easily.

XML Element Classes

XML Element classes allow to create new element classes using an XML file (*.deeclass) instead of writing script code. XML element classes always subclass from an existing script class or XML element class. Using an XML element class you can change properties added by the behavior definitions.

Element class properties are typically in the form behavior.property or behavior(id).property. The identifier is omitted if it is empty string. For example the ECBehaviorComponent behavior uses the prefix component.. Hence component.model would set the _model_ property. The same for an ECBehaviorComponent with the identifier second. Here the name would be component(second).model.

Behaviors can be complex and nested. This allows behaviors to add other behaviors to achieve their goals. Such nested behaviors need to be differentiated from other behaviors of the same kind. The rule is to prefix the property names of the behaviors with their parent prefix to make them unique. For example if you have a fictional behavior MyBehavior with the prefix mybehavior. which adds one or more ECBehaviorComponent then the property names of those component behaviors would look like mybehavior.component.model or mybehavior.component(second).model. This nesting can go deeper depending on how complex of a behavior you are designing. In general it is favorable to keep the nesting as little as possible as this is easier to use for team members and modders.

Behavior Factories

Scripted element classes can be also assigned a list of Behavior Factories. This allows the user to add behaviors to XML element classes if they are in the list of allowed behavior factories. The DragonScript module provides the GenericBehaviorElementClass which contains the factories of all DragonScript module provided behavior factories. You can create your own behaviors and make them available to the generic behavior element class by extending BaseGameApp.createAndAddBehaviorFactories().

Adding behaviors is done using the behavior tag. Some behaviors require additional parameters during construction time. These parameters can be defined inside the behavior tag using the same tags as you use to define element properties. The behavior documentation list the supported parameters. After adding a behavior you can set the element properties outside the behavior tag as you usually would do.

To simplify the adding of behaviors properties of a just added behavior can be also defined by moving the property tags inside the behavior tag. If you do this you have to remove the behavior property prefix from the property names leaving being only the . as first character in the name. This way the DragonScript module prepends the behavior property prefix while setting the property values. This is easier to write, increases readability and has less possibility for errors. It is thus recommended to set properties of just added behaviors in this way.

(TODO: add video of behavior factories)

XML File Structure

elementClassbehaviorstring  stringfloat  floatinteger  intboolean  boolvector  vector3vector2  vector2point  point2point3  point3borderSize  borderSizerectArea  rectAreafloatRectArea  floatRectAreacolor  color4null  nulllistmapbehaviorstring  stringfloat  floatinteger  intboolean  boolvector  vector3vector2  vector2point  point2point3  point3borderSize  borderSizerectArea  rectAreafloatRectArea  floatRectAreacolor  color4null  nulllistmapliststring  stringfloat  floatinteger  intboolean  boolvector  vector3vector2  vector2point  point2point3  point3borderSize  borderSizerectArea  rectAreafloatRectArea  floatRectAreacolor  color4null  nulllistmapmapstring  stringfloat  floatinteger  intboolean  boolvector  vector3vector2  vector2point  point2point3  point3borderSize  borderSizerectArea  rectAreafloatRectArea  floatRectAreacolor  color4null  nulllistmap

Tags

elementClass

AttributeDescriptionRequiredDefault
nameUnique name of the element class to create.true-
className of the element class to subclass.true-
TagDescriptionOccuranceDefault
behaviorAdd behavior to element class.0..N-
string

Set named element property to string type value. Tag content is string value. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
0..Nempty string
float

Set named element property to float type value. Tag content is float value. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
0..N0
integer

Set named element property to integer type value. Tag content is integer value. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
0..N0
boolean

Set named element property to boolean type value. Tag content is boolean value where true, yes, 1 are true values and false, no, 0 are false values. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
0..Nfalse
vector

Set named element property to floating point vector type value. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
  • z: Z coordinate of vector. Optional. Defaults to 0.
0..N-
vector2

Set named element property to floating point vector2 type value. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
0..N-
point

Set named element property to integer point type value. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
0..N-
point3

Set named element property to integer point3 type value. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
  • z: Z coordinate of vector. Optional. Defaults to 0.
0..N-
borderSize

Set named element property to integer borderSize type value. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
  • left: Left value. Optional. Defaults to 0.
  • top: Top value. Optional. Defaults to 0.
  • right: Right value. Optional. Defaults to 0.
  • bottom: Bottom value. Optional. Defaults to 0.
  • all: Set left, top, right and bottom to the same value. Optional. Convenience attribute.
0..N-
rectArea

Set named element property to integer rectArea type value. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
  • x1: Left value. Optional. Defaults to 0.
  • y1: Top value. Optional. Defaults to 0.
  • x2: Right value. Optional. Defaults to 0.
  • y2: Bottom value. Optional. Defaults to 0.
0..N-
floatRectArea

Set named element property to floating point rectArea type value. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
  • x1: Left value. Optional. Defaults to 0.
  • y1: Top value. Optional. Defaults to 0.
  • x2: Right value. Optional. Defaults to 0.
  • y2: Bottom value. Optional. Defaults to 0.
0..N-
color

Set named element property to floating point color4 type value. Color can be defined either using hex, r/g/b/a or ir/ig/ib/ia. Mixing is not possible. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
  • r: Red value in the range 0..1 with values outside range allowed. Optional. Defaults to 0.
  • g: Green value in the range 0..1 with values outside range allowed. Optional. Defaults to 0.
  • b: Blue value in the range 0..1 with values outside range allowed. Optional. Defaults to 0.
  • a: Alpha value in the range 0..1 with values outside range allowed. Optional. Defaults to 1.
  • hex: Set color using hex notation. Value can be #rrggbb or #rrggbbaa with components in the range from 00 to ff. Both upper and lower case are valid. Optional. Convenience attribute.
  • ir: Red value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
  • ig: Green value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
  • ib: Blue value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
  • ia: Alpha value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
0..N-
null

Set named element property to null value. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
0..N-
list

Set named element property to Array value. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
0..N-
map

Set named element property to Dictionary value. Attributes:

  • name: Name of the property to set. Same name as used for stub properties in world editor. Required.
0..N-

behavior

AttributeDescriptionRequiredDefault
typeUnique name of the behavior to add to the element class. Only names matching behavior factories added to the super element class can be used.true-
idUnique identifier of behavior. Required to be used if multiple behaviors of the same type are added.falseempty string
TagDescriptionOccuranceDefault
string

Set named element property to string type value. Tag content is string value. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
0..Nempty string
float

Set named element property to float type value. Tag content is float value. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
0..N0
integer

Set named element property to integer type value. Tag content is integer value. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
0..N0
boolean

Set named element property to boolean type value. Tag content is boolean value where true, yes, 1 are true values and false, no, 0 are false values. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
0..Nfalse
vector

Set named element property to floating point vector type value. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
  • z: Z coordinate of vector. Optional. Defaults to 0.
0..N-
vector2

Set named element property to floating point vector2 type value. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
0..N-
point

Set named element property to integer point type value. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
0..N-
point3

Set named element property to integer point3 type value. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
  • z: Z coordinate of vector. Optional. Defaults to 0.
0..N-
borderSize

Set named element property to integer borderSize type value. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
  • left: Left value. Optional. Defaults to 0.
  • top: Top value. Optional. Defaults to 0.
  • right: Right value. Optional. Defaults to 0.
  • bottom: Bottom value. Optional. Defaults to 0.
  • all: Set left, top, right and bottom to the same value. Optional. Convenience attribute.
0..N-
rectArea

Set named element property to integer rectArea type value. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
  • x1: Left value. Optional. Defaults to 0.
  • y1: Top value. Optional. Defaults to 0.
  • x2: Right value. Optional. Defaults to 0.
  • y2: Bottom value. Optional. Defaults to 0.
0..N-
floatRectArea

Set named element property to floating point rectArea type value. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
  • x1: Left value. Optional. Defaults to 0.
  • y1: Top value. Optional. Defaults to 0.
  • x2: Right value. Optional. Defaults to 0.
  • y2: Bottom value. Optional. Defaults to 0.
0..N-
color

Set named element property to floating point color4 type value. Color can be defined either using hex, r/g/b/a or ir/ig/ib/ia. Mixing is not possible. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
  • r: Red value in the range 0..1 with values outside range allowed. Optional. Defaults to 0.
  • g: Green value in the range 0..1 with values outside range allowed. Optional. Defaults to 0.
  • b: Blue value in the range 0..1 with values outside range allowed. Optional. Defaults to 0.
  • a: Alpha value in the range 0..1 with values outside range allowed. Optional. Defaults to 1.
  • hex: Set color using hex notation. Value can be #rrggbb or #rrggbbaa with components in the range from 00 to ff. Both upper and lower case are valid. Optional. Convenience attribute.
  • ir: Red value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
  • ig: Green value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
  • ib: Blue value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
  • ia: Alpha value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
0..N-
null

Set named element property to null value. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
0..N-
list

Set named element property to Array value. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
0..N-
map

Set named element property to Dictionary value. Attributes:

  • name: Name of the parameter/property to set. If the name begins with with . the element property is set using name with behavior property prefix prepended. Otherwise construction parameter is set with the given name. Required.
0..N-

list

TagDescriptionOccuranceDefault
stringString type value. Tag content is string value.0..Nempty string
floatFloat type value. Tag content is float value.0..N0
integerInteger type value. Tag content is integer value.0..N0
booleanBoolean type value. Tag content is boolean value where true, yes, 1 are true values and false, no, 0 are false values.0..Nfalse
vector

Floating point vector type value. Attributes:

  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
  • z: Z coordinate of vector. Optional. Defaults to 0.
0..N-
vector2

Floating point vector2 type value. Attributes:

  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
0..N-
point

Integer point type value. Attributes:

  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
0..N-
point3

Integer point3 type value. Attributes:

  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
  • z: Z coordinate of vector. Optional. Defaults to 0.
0..N-
borderSize

Integer borderSize type value. Attributes:

  • left: Left value. Optional. Defaults to 0.
  • top: Top value. Optional. Defaults to 0.
  • right: Right value. Optional. Defaults to 0.
  • bottom: Bottom value. Optional. Defaults to 0.
  • all: Set left, top, right and bottom to the same value. Optional. Convenience attribute.
0..N-
rectArea

Integer rectArea type value. Attributes:

  • x1: Left value. Optional. Defaults to 0.
  • y1: Top value. Optional. Defaults to 0.
  • x2: Right value. Optional. Defaults to 0.
  • y2: Bottom value. Optional. Defaults to 0.
0..N-
floatRectArea

Floating point rectArea type value. Attributes:

  • x1: Left value. Optional. Defaults to 0.
  • y1: Top value. Optional. Defaults to 0.
  • x2: Right value. Optional. Defaults to 0.
  • y2: Bottom value. Optional. Defaults to 0.
0..N-
color

Floating point color4 type value. Color can be defined either using hex, r/g/b/a or ir/ig/ib/ia. Mixing is not possible. Attributes:

  • r: Red value in the range 0..1 with values outside range allowed. Optional. Defaults to 0.
  • g: Green value in the range 0..1 with values outside range allowed. Optional. Defaults to 0.
  • b: Blue value in the range 0..1 with values outside range allowed. Optional. Defaults to 0.
  • a: Alpha value in the range 0..1 with values outside range allowed. Optional. Defaults to 1.
  • hex: Set color using hex notation. Value can be #rrggbb or #rrggbbaa with components in the range from 00 to ff. Both upper and lower case are valid. Optional. Convenience attribute.
  • ir: Red value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
  • ig: Green value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
  • ib: Blue value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
  • ia: Alpha value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
0..N-
nullNull value.0..N-
listArray value.0..N-
mapDictionary value.0..N-

map

TagDescriptionOccuranceDefault
string

Set string value. Attributes:

  • key: Key to assign value to. Required.
0..Nempty string
float

Set float type value. Tag content is float value. Attributes:

  • key: Key to assign value to. Required.
0..N0
integer

Set integer type value. Tag content is integer value. Attributes:

  • key: Key to assign value to. Required.
0..N0
boolean

Set boolean type value. Tag content is boolean value where true, yes, 1 are true values and false, no, 0 are false values. Attributes:

  • key: Key to assign value to. Required.
0..Nfalse
vector

Set floating point vector type value. Attributes:

  • key: Key to assign value to. Required.
  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
  • z: Z coordinate of vector. Optional. Defaults to 0.
0..N-
vector2

Set floating point vector2 type value. Attributes:

  • key: Key to assign value to. Required.
  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
0..N-
point

Set integer point type value. Attributes:

  • key: Key to assign value to. Required.
  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
0..N-
point3

Set integer point3 type value. Attributes:

  • key: Key to assign value to. Required.
  • x: X coordinate of vector. Optional. Defaults to 0.
  • y: Y coordinate of vector. Optional. Defaults to 0.
  • z: Z coordinate of vector. Optional. Defaults to 0.
0..N-
borderSize

Set integer borderSize type value. Attributes:

  • key: Key to assign value to. Required.
  • left: Left value. Optional. Defaults to 0.
  • top: Top value. Optional. Defaults to 0.
  • right: Right value. Optional. Defaults to 0.
  • bottom: Bottom value. Optional. Defaults to 0.
  • all: Set left, top, right and bottom to the same value. Optional. Convenience attribute.
0..N-
rectArea

Set integer rectArea type value. Attributes:

  • key: Key to assign value to. Required.
  • x1: Left value. Optional. Defaults to 0.
  • y1: Top value. Optional. Defaults to 0.
  • x2: Right value. Optional. Defaults to 0.
  • y2: Bottom value. Optional. Defaults to 0.
0..N-
floatRectArea

Set floating point rectArea type value. Attributes:

  • key: Key to assign value to. Required.
  • x1: Left value. Optional. Defaults to 0.
  • y1: Top value. Optional. Defaults to 0.
  • x2: Right value. Optional. Defaults to 0.
  • y2: Bottom value. Optional. Defaults to 0.
0..N-
color

Set floating point color4 type value. Color can be defined either using hex, r/g/b/a or ir/ig/ib/ia. Mixing is not possible. Attributes:

  • key: Key to assign value to. Required.
  • r: Red value in the range 0..1 with values outside range allowed. Optional. Defaults to 0.
  • g: Green value in the range 0..1 with values outside range allowed. Optional. Defaults to 0.
  • b: Blue value in the range 0..1 with values outside range allowed. Optional. Defaults to 0.
  • a: Alpha value in the range 0..1 with values outside range allowed. Optional. Defaults to 1.
  • hex: Set color using hex notation. Value can be #rrggbb or #rrggbbaa with components in the range from 00 to ff. Both upper and lower case are valid. Optional. Convenience attribute.
  • ir: Red value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
  • ig: Green value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
  • ib: Blue value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
  • ia: Alpha value in the range 0..255 with values outside range allowed. Optional. Convenience attribute.
0..N-
null

Set null value. Attributes:

  • key: Key to assign value to. Required.
0..N-
list

Set Array value. Attributes:

  • key: Key to assign value to. Required.
0..N-
map

Set Dictionary value. Attributes:

  • key: Key to assign value to. Required.
0..N-

Examples

This example creates a simple XML element class based on the SimpleElementClass. It modifies some element properties to use a specific model, skin and rig resource. The path are either absolute path (if starting with /) or relative to the directory the *.deeclass file is located in.

Show Example

This example creates a complex XML element class which is based on the GenericBehaviorElementClass. This allows adding behaviors inside the *.deeclass file avoiding the need to write an explicit script class to do the same. This is the example file used in the behavior factory video above.

Show Example

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dragengine/modules/dragonscript/behavior_elements.txt · Last modified: 2025/03/10 17:24 by dragonlord