Calculate gravity based on distance from body to gravity point (2D)

scene/2d/area_2d.cpp

@@ -52,6 +52,17 @@ bool Area2D::is_gravity_a_point() const{
 	return gravity_is_point;
 }
 
+void Area2D::set_gravity_distance_scale(real_t p_scale){
+
+	gravity_distance_scale=p_scale;
+	Physics2DServer::get_singleton()->area_set_param(get_rid(),Physics2DServer::AREA_PARAM_GRAVITY_DISTANCE_SCALE,p_scale);
+
+}
+
+real_t Area2D::get_gravity_distance_scale() const{
+	return gravity_distance_scale;
+}
+
 void Area2D::set_gravity_vector(const Vector2& p_vec){
 
 	gravity_vec=p_vec;
@@ -550,6 +561,9 @@ void Area2D::_bind_methods() {
 	ObjectTypeDB::bind_method(_MD("set_gravity_is_point","enable"),&Area2D::set_gravity_is_point);
 	ObjectTypeDB::bind_method(_MD("is_gravity_a_point"),&Area2D::is_gravity_a_point);
 
+	ObjectTypeDB::bind_method(_MD("set_gravity_distance_scale","distance_scale"),&Area2D::set_gravity_distance_scale);
+	ObjectTypeDB::bind_method(_MD("get_gravity_distance_scale"),&Area2D::get_gravity_distance_scale);
+
 	ObjectTypeDB::bind_method(_MD("set_gravity_vector","vector"),&Area2D::set_gravity_vector);
 	ObjectTypeDB::bind_method(_MD("get_gravity_vector"),&Area2D::get_gravity_vector);
 
@@ -600,6 +614,7 @@ void Area2D::_bind_methods() {
 
 	ADD_PROPERTYNZ( PropertyInfo(Variant::INT,"space_override",PROPERTY_HINT_ENUM,"Disabled,Combine,Replace"),_SCS("set_space_override_mode"),_SCS("get_space_override_mode"));
 	ADD_PROPERTY( PropertyInfo(Variant::BOOL,"gravity_point"),_SCS("set_gravity_is_point"),_SCS("is_gravity_a_point"));
+	ADD_PROPERTY( PropertyInfo(Variant::REAL,"gravity_distance_scale", PROPERTY_HINT_RANGE,"0,1024,0.001"),_SCS("set_gravity_distance_scale"),_SCS("get_gravity_distance_scale"));
 	ADD_PROPERTY( PropertyInfo(Variant::VECTOR2,"gravity_vec"),_SCS("set_gravity_vector"),_SCS("get_gravity_vector"));
 	ADD_PROPERTY( PropertyInfo(Variant::REAL,"gravity",PROPERTY_HINT_RANGE,"-1024,1024,0.01"),_SCS("set_gravity"),_SCS("get_gravity"));
 	ADD_PROPERTY( PropertyInfo(Variant::REAL,"linear_damp",PROPERTY_HINT_RANGE,"0,1024,0.001"),_SCS("set_linear_damp"),_SCS("get_linear_damp"));
@@ -618,6 +633,7 @@ Area2D::Area2D() : CollisionObject2D(Physics2DServer::get_singleton()->area_crea
 	set_gravity(98);;
 	set_gravity_vector(Vector2(0,1));
 	gravity_is_point=false;
+	gravity_distance_scale=0;
 	linear_damp=0.1;
 	angular_damp=1;
 	locked=false;

scene/2d/area_2d.h

@@ -49,6 +49,7 @@ private:
 	Vector2 gravity_vec;
 	real_t gravity;
 	bool gravity_is_point;
+	real_t gravity_distance_scale;
 	real_t linear_damp;
 	real_t angular_damp;
 	uint32_t collision_mask;
@@ -132,6 +133,9 @@ public:
 	void set_gravity_is_point(bool p_enabled);
 	bool is_gravity_a_point() const;
 
+	void set_gravity_distance_scale(real_t p_scale);
+	real_t get_gravity_distance_scale() const;
+
 	void set_gravity_vector(const Vector2& p_vec);
 	Vector2 get_gravity_vector() const;
 

scene/3d/area.cpp

@@ -42,6 +42,7 @@ Area::SpaceOverride Area::get_space_override_mode() const{
 }
 
 void Area::set_gravity_is_point(bool p_enabled){
+
 	gravity_is_point=p_enabled;
 	PhysicsServer::get_singleton()->area_set_param(get_rid(),PhysicsServer::AREA_PARAM_GRAVITY_IS_POINT,p_enabled);
 

servers/physics_2d/area_2d_sw.cpp

@@ -120,6 +120,7 @@ void Area2DSW::set_param(Physics2DServer::AreaParameter p_param, const Variant&
 		case Physics2DServer::AREA_PARAM_GRAVITY: gravity=p_value; ; break;
 		case Physics2DServer::AREA_PARAM_GRAVITY_VECTOR: gravity_vector=p_value; ; break;
 		case Physics2DServer::AREA_PARAM_GRAVITY_IS_POINT: gravity_is_point=p_value; ; break;
+		case Physics2DServer::AREA_PARAM_GRAVITY_DISTANCE_SCALE: gravity_distance_scale=p_value; ; break;
 		case Physics2DServer::AREA_PARAM_GRAVITY_POINT_ATTENUATION:  point_attenuation=p_value; ; break;
 		case Physics2DServer::AREA_PARAM_LINEAR_DAMP: linear_damp=p_value; ; break;
 		case Physics2DServer::AREA_PARAM_ANGULAR_DAMP: angular_damp=p_value; ; break;
@@ -136,6 +137,7 @@ Variant Area2DSW::get_param(Physics2DServer::AreaParameter p_param) const {
 		case Physics2DServer::AREA_PARAM_GRAVITY: return gravity;
 		case Physics2DServer::AREA_PARAM_GRAVITY_VECTOR: return gravity_vector;
 		case Physics2DServer::AREA_PARAM_GRAVITY_IS_POINT: return gravity_is_point;
+		case Physics2DServer::AREA_PARAM_GRAVITY_DISTANCE_SCALE: return gravity_distance_scale;
 		case Physics2DServer::AREA_PARAM_GRAVITY_POINT_ATTENUATION: return  point_attenuation;
 		case Physics2DServer::AREA_PARAM_LINEAR_DAMP: return linear_damp;
 		case Physics2DServer::AREA_PARAM_ANGULAR_DAMP: return angular_damp;
@@ -248,6 +250,7 @@ Area2DSW::Area2DSW() : CollisionObject2DSW(TYPE_AREA), monitor_query_list(this),
 	gravity=9.80665;
 	gravity_vector=Vector2(0,-1);
 	gravity_is_point=false;
+	gravity_distance_scale=0;
 	point_attenuation=1;
 
 	angular_damp=1.0;

servers/physics_2d/area_2d_sw.h

@@ -46,6 +46,7 @@ class Area2DSW : public CollisionObject2DSW{
 	float gravity;
 	Vector2 gravity_vector;
 	bool gravity_is_point;
+	float gravity_distance_scale;
 	float point_attenuation;
 	float linear_damp;
 	float angular_damp;
@@ -139,6 +140,9 @@ public:
 	_FORCE_INLINE_ void set_gravity_as_point(bool p_enable) { gravity_is_point=p_enable; }
 	_FORCE_INLINE_ bool is_gravity_point() const { return gravity_is_point; }
 
+	_FORCE_INLINE_ void set_gravity_distance_scale(float scale) { gravity_distance_scale=scale; }
+	_FORCE_INLINE_ float get_gravity_distance_scale() const { return gravity_distance_scale; }
+
 	_FORCE_INLINE_ void set_point_attenuation(float p_point_attenuation) { point_attenuation=p_point_attenuation; }
 	_FORCE_INLINE_ float get_point_attenuation() const { return point_attenuation; }
 

servers/physics_2d/body_2d_sw.cpp

@@ -383,9 +383,12 @@ void Body2DSW::set_space(Space2DSW *p_space){
 void Body2DSW::_compute_area_gravity(const Area2DSW *p_area) {
 
 	if (p_area->is_gravity_point()) {
-
-		gravity += (p_area->get_transform().xform(p_area->get_gravity_vector()) - get_transform().get_origin()).normalized() * p_area->get_gravity();
-
+		if(p_area->get_gravity_distance_scale() > 0) {
+			Vector2 v = p_area->get_transform().xform(p_area->get_gravity_vector()) - get_transform().get_origin();
+			gravity += v.normalized() * (p_area->get_gravity() / Math::pow(v.length() * p_area->get_gravity_distance_scale()+1, 2) );
+		} else {
+			gravity += (p_area->get_transform().xform(p_area->get_gravity_vector()) - get_transform().get_origin()).normalized() * p_area->get_gravity();
+		}
 	} else {
 		gravity += p_area->get_gravity_vector() * p_area->get_gravity();
 	}

servers/physics_2d_server.cpp

@@ -657,6 +657,7 @@ void Physics2DServer::_bind_methods() {
 	BIND_CONSTANT( AREA_PARAM_GRAVITY );
 	BIND_CONSTANT( AREA_PARAM_GRAVITY_VECTOR );
 	BIND_CONSTANT( AREA_PARAM_GRAVITY_IS_POINT );
+	BIND_CONSTANT( AREA_PARAM_GRAVITY_DISTANCE_SCALE );
 	BIND_CONSTANT( AREA_PARAM_GRAVITY_POINT_ATTENUATION );
 	BIND_CONSTANT( AREA_PARAM_LINEAR_DAMP);
 	BIND_CONSTANT( AREA_PARAM_ANGULAR_DAMP);

servers/physics_2d_server.h

@@ -306,6 +306,7 @@ public:
 		AREA_PARAM_GRAVITY,
 		AREA_PARAM_GRAVITY_VECTOR,
 		AREA_PARAM_GRAVITY_IS_POINT,
+		AREA_PARAM_GRAVITY_DISTANCE_SCALE,
 		AREA_PARAM_GRAVITY_POINT_ATTENUATION,
 		AREA_PARAM_LINEAR_DAMP,
 		AREA_PARAM_ANGULAR_DAMP,