Calculate gravity based on distance from body to gravity point

5 files changed, 15 insertions, 3 deletions

diff --git a/servers/physics/area_sw.cpp b/servers/physics/area_sw.cpp
index de241c948b..aa1c530221 100644
--- a/servers/physics/area_sw.cpp
+++ b/servers/physics/area_sw.cpp
@@ -98,6 +98,7 @@ void AreaSW::set_param(PhysicsServer::AreaParameter p_param, const Variant& p_va
 		case PhysicsServer::AREA_PARAM_GRAVITY: gravity=p_value; ; break;
 		case PhysicsServer::AREA_PARAM_GRAVITY_VECTOR: gravity_vector=p_value; ; break;
 		case PhysicsServer::AREA_PARAM_GRAVITY_IS_POINT: gravity_is_point=p_value; ; break;
+		case PhysicsServer::AREA_PARAM_GRAVITY_DISTANCE_SCALE: gravity_distance_scale=p_value; ; break;
 		case PhysicsServer::AREA_PARAM_GRAVITY_POINT_ATTENUATION:  point_attenuation=p_value; ; break;
 		case PhysicsServer::AREA_PARAM_DENSITY: density=p_value; ; break;
 		case PhysicsServer::AREA_PARAM_PRIORITY: priority=p_value; ; break;
@@ -113,6 +114,7 @@ Variant AreaSW::get_param(PhysicsServer::AreaParameter p_param) const {
 		case PhysicsServer::AREA_PARAM_GRAVITY: return gravity;
 		case PhysicsServer::AREA_PARAM_GRAVITY_VECTOR: return gravity_vector;
 		case PhysicsServer::AREA_PARAM_GRAVITY_IS_POINT: return gravity_is_point;
+		case PhysicsServer::AREA_PARAM_GRAVITY_DISTANCE_SCALE: return gravity_distance_scale;
 		case PhysicsServer::AREA_PARAM_GRAVITY_POINT_ATTENUATION: return  point_attenuation;
 		case PhysicsServer::AREA_PARAM_DENSITY: return density;
 		case PhysicsServer::AREA_PARAM_PRIORITY: return priority;
@@ -177,6 +179,7 @@ AreaSW::AreaSW() : CollisionObjectSW(TYPE_AREA), monitor_query_list(this),  move
 	gravity=9.80665;
 	gravity_vector=Vector3(0,-1,0);
 	gravity_is_point=false;
+	gravity_distance_scale=0;
 	point_attenuation=1;
 	density=0.1;
 	priority=0;
diff --git a/servers/physics/area_sw.h b/servers/physics/area_sw.h
index 87843b93c9..a875472f6b 100644
--- a/servers/physics/area_sw.h
+++ b/servers/physics/area_sw.h
@@ -45,6 +45,7 @@ class AreaSW : public CollisionObjectSW{
 	float gravity;
 	Vector3 gravity_vector;
 	bool gravity_is_point;
+	float gravity_distance_scale;
 	float point_attenuation;
 	float density;
 	int priority;
@@ -125,6 +126,9 @@ 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; }
 
diff --git a/servers/physics/body_sw.cpp b/servers/physics/body_sw.cpp
index 1cc0b763a4..5a528ecf94 100644
--- a/servers/physics/body_sw.cpp
+++ b/servers/physics/body_sw.cpp
@@ -362,9 +362,12 @@ void BodySW::set_space(SpaceSW *p_space){
 void BodySW::_compute_area_gravity(const AreaSW *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) {
+			Vector3 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();
 	}
diff --git a/servers/physics_server.cpp b/servers/physics_server.cpp
index 4feb1b5269..e02601af41 100644
--- a/servers/physics_server.cpp
+++ b/servers/physics_server.cpp
@@ -681,6 +681,7 @@ void PhysicsServer::_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_DENSITY );
 	BIND_CONSTANT( AREA_PARAM_PRIORITY );
diff --git a/servers/physics_server.h b/servers/physics_server.h
index ffb462af22..05b64da804 100644
--- a/servers/physics_server.h
+++ b/servers/physics_server.h
@@ -298,6 +298,7 @@ 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_DENSITY,
 		AREA_PARAM_PRIORITY