Area2D

Inherits: CollisionObject2D < Node2D < CanvasItem < Node < Object

Category: Core

Brief Description

General purpose area detection and influence for 2D physics.

Member Functions

float get_angular_damp ( ) const
int get_collision_layer ( ) const
bool get_collision_layer_bit ( int bit ) const
int get_collision_mask ( ) const
bool get_collision_mask_bit ( int bit ) const
float get_gravity ( ) const
float get_gravity_distance_scale ( ) const
Vector2 get_gravity_vector ( ) const
float get_linear_damp ( ) const
Array get_overlapping_areas ( ) const
Array get_overlapping_bodies ( ) const
float get_priority ( ) const
int get_space_override_mode ( ) const
bool is_gravity_a_point ( ) const
bool is_monitorable ( ) const
bool is_monitoring ( ) const
bool overlaps_area ( Object area ) const
bool overlaps_body ( Object body ) const
void set_angular_damp ( float angular_damp )
void set_collision_layer ( int collision_layer )
void set_collision_layer_bit ( int bit, bool value )
void set_collision_mask ( int collision_mask )
void set_collision_mask_bit ( int bit, bool value )
void set_gravity ( float gravity )
void set_gravity_distance_scale ( float distance_scale )
void set_gravity_is_point ( bool enable )
void set_gravity_vector ( Vector2 vector )
void set_linear_damp ( float linear_damp )
void set_monitorable ( bool enable )
void set_monitoring ( bool enable )
void set_priority ( float priority )
void set_space_override_mode ( int enable )

Signals

  • area_entered ( Object area )

This signal is triggered only once when an area enters this area. The only parameter passed is the area that entered this area.

This signal is triggered only once when an area exits this area. The only parameter passed is the area that exited this area.

  • area_shape_entered ( int area_id, Object area, int area_shape, int self_shape )

This signal triggers only once when an area enters this area. The first parameter is the area’s RID. The second one is the area as an object. The third one is the index of the shape entering this area, and the fourth one is the index of the shape in this area that reported the entering.

  • area_shape_exited ( int area_id, Object area, int area_shape, int self_shape )

This signal triggers only once when an area exits this area. The first parameter is the area’s RID. The second one is the area as an object. The third one is the index of the shape entering this area, and the fourth one is the index of the shape in this area that reported the entering.

  • body_entered ( Object body )

This signal is triggered only once when a body enters this area. The only parameter passed is the body that entered this area.

This signal is triggered only once when a body exits this area. The only parameter passed is the body that exited this area.

  • body_shape_entered ( int body_id, Object body, int body_shape, int area_shape )

This signal triggers only once when a body enters this area. The first parameter is the body’s RID. The second one is the body as an object. The third one is the index of the shape of the body that entered this area, and the fourth one is the index of the shape in this area that reported the entering.

  • body_shape_exited ( int body_id, Object body, int body_shape, int area_shape )

This signal triggers only once when a body exits this area. The first parameter is the body’s RID. The second one is the body as an object. The third one is the index of the shape exiting this area, and the fourth one is the index of the shape in this area that reported the exit.

Member Variables

Description

General purpose area detection for 2D physics. Areas can be used for detection of objects that enter/exit them, as well as overriding space parameters (changing gravity, damping, etc). For this, use any space override different from AREA_SPACE_OVERRIDE_DISABLE and point gravity at the center of mass.

Member Function Description

  • float get_angular_damp ( ) const

Return the angular damp rate.

  • int get_collision_layer ( ) const

Return the physics layer this area is in.

  • bool get_collision_layer_bit ( int bit ) const

Return an individual bit on the layer mask.

  • int get_collision_mask ( ) const

Return the physics layers this area can scan for collisions.

  • bool get_collision_mask_bit ( int bit ) const

Return an individual bit on the collision mask.

  • float get_gravity ( ) const

Return the gravity intensity.

  • float get_gravity_distance_scale ( ) const

Return the falloff factor for point gravity.

  • Vector2 get_gravity_vector ( ) const

Return the gravity vector. If gravity is a point (see is_gravity_a_point), this will be the attraction center.

  • float get_linear_damp ( ) const

Return the linear damp rate.

  • Array get_overlapping_areas ( ) const

Return a list of the areas that are totally or partially inside this area.

  • Array get_overlapping_bodies ( ) const

Return a list of the bodies (PhysicsBody2D) that are totally or partially inside this area.

  • float get_priority ( ) const

Return the processing order of this area.

  • int get_space_override_mode ( ) const

Return the space override mode.

  • bool is_gravity_a_point ( ) const

Return whether gravity is a point. A point gravity will attract objects towards it, as opposed to a gravity vector, which moves them in a given direction.

  • bool is_monitorable ( ) const

Return whether this area can be detected by other, monitoring, areas.

  • bool is_monitoring ( ) const

Return whether this area detects bodies/areas entering/exiting it.

Return whether the area passed is totally or partially inside this area.

Return whether the body passed is totally or partially inside this area.

  • void set_angular_damp ( float angular_damp )

Set the rate at which objects stop spinning in this area, if there are not any other forces making it spin. The value is a fraction of its current speed, lost per second. Thus, a value of 1.0 should mean stopping immediately, and 0.0 means the object never stops.

In practice, as the fraction of speed lost gets smaller with each frame, a value of 1.0 does not mean the object will stop in exactly one second. Only when the physics calculations are done at 1 frame per second, it does stop in a second.

  • void set_collision_layer ( int collision_layer )

Set the physics layers this area is in.

Collidable objects can exist in any of 32 different layers. These layers are not visual, but more of a tagging system instead. A collidable can use these layers/tags to select with which objects it can collide, using set_collision_mask.

A contact is detected if object A is in any of the layers that object B scans, or object B is in any layer scanned by object A.

  • void set_collision_layer_bit ( int bit, bool value )

Set/clear individual bits on the layer mask. This makes getting an area in/out of only one layer easier.

  • void set_collision_mask ( int collision_mask )

Set the physics layers this area can scan for collisions.

  • void set_collision_mask_bit ( int bit, bool value )

Set/clear individual bits on the collision mask. This makes selecting the areas scanned easier.

  • void set_gravity ( float gravity )

Set the gravity intensity. This is useful to alter the force of gravity without altering its direction.

This value multiplies the gravity vector, whether it is the given vector (set_gravity_vector), or a calculated one (when using a center of gravity).

  • void set_gravity_distance_scale ( float distance_scale )

Set the falloff factor for point gravity. The greater this value is, the faster the strength of gravity decreases with the square of distance.

  • void set_gravity_is_point ( bool enable )

When overriding space parameters, this method sets whether this area has a center of gravity. To set/get the location of the center of gravity, use set_gravity_vector/get_gravity_vector.

  • void set_gravity_vector ( Vector2 vector )

Set the gravity vector. This vector does not have to be normalized.

If gravity is a point (see is_gravity_a_point), this will be the attraction center.

  • void set_linear_damp ( float linear_damp )

Set the rate at which objects stop moving in this area, if there are not any other forces moving it. The value is a fraction of its current speed, lost per second. Thus, a value of 1.0 should mean stopping immediately, and 0.0 means the object never stops.

In practice, as the fraction of speed lost gets smaller with each frame, a value of 1.0 does not mean the object will stop in exactly one second. Only when the physics calculations are done at 1 frame per second, it does stop in a second.

  • void set_monitorable ( bool enable )

Set whether this area can be detected by other, monitoring, areas. Only areas need to be marked as monitorable. Bodies are always so.

  • void set_monitoring ( bool enable )

Set whether this area can detect bodies/areas entering/exiting it.

  • void set_priority ( float priority )

Set the order in which the area is processed. Greater values mean the area gets processed first. This is useful for areas which have an space override different from AREA_SPACE_OVERRIDE_DISABLED or AREA_SPACE_OVERRIDE_COMBINE, as they replace values, and are thus order-dependent.

Areas with the same priority value get evaluated in an unpredictable order, and should be differentiated if evaluation order is to be important.

  • void set_space_override_mode ( int enable )

Set the space override mode. This mode controls how an area affects gravity and damp.

AREA_SPACE_OVERRIDE_DISABLED: This area does not affect gravity/damp. These are generally areas that exist only to detect collisions, and objects entering or exiting them.

AREA_SPACE_OVERRIDE_COMBINE: This area adds its gravity/damp values to whatever has been calculated so far. This way, many overlapping areas can combine their physics to make interesting effects.

AREA_SPACE_OVERRIDE_COMBINE_REPLACE: This area adds its gravity/damp values to whatever has been calculated so far. Then stops taking into account the rest of the areas, even the default one.

AREA_SPACE_OVERRIDE_REPLACE: This area replaces any gravity/damp, even the default one, and stops taking into account the rest of the areas.

AREA_SPACE_OVERRIDE_REPLACE_COMBINE: This area replaces any gravity/damp calculated so far, but keeps calculating the rest of the areas, down to the default one.