godot/servers/physics_2d/body_2d_sw.cpp

/*************************************************************************/
/*  body_2d_sw.cpp                                                       */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2016 Juan Linietsky, Ariel Manzur.                 */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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#include "body_2d_sw.h"
#include "space_2d_sw.h"
#include "area_2d_sw.h"
#include "physics_2d_server_sw.h"

void Body2DSW::_update_inertia() {

	if (!user_inertia && get_space() && !inertia_update_list.in_list())
		get_space()->body_add_to_inertia_update_list(&inertia_update_list);

}



void Body2DSW::update_inertias() {

	//update shapes and motions

	switch(mode) {

		case Physics2DServer::BODY_MODE_RIGID: {

			if(user_inertia) break;

			//update tensor for allshapes, not the best way but should be somehow OK. (inspired from bullet)
			float total_area=0;

			for (int i=0;i<get_shape_count();i++) {

				total_area+=get_shape_aabb(i).get_area();
			}

			real_t _inertia=0;

			for (int i=0;i<get_shape_count();i++) {

				const Shape2DSW* shape=get_shape(i);

				float area=get_shape_aabb(i).get_area();

				float mass = area * this->mass / total_area;

				Matrix32 mtx = get_shape_transform(i);
				Vector2 scale = mtx.get_scale();
				_inertia += shape->get_moment_of_inertia(mass,scale) + mass * mtx.get_origin().length_squared();
				//Rect2 ab = get_shape_aabb(i);
				//_inertia+=mass*ab.size.dot(ab.size)/12.0f;



			}

			if (_inertia!=0)
				_inv_inertia=1.0/_inertia;
			else
				_inv_inertia=0.0; //wathever

			if (mass)
				_inv_mass=1.0/mass;
			else
				_inv_mass=0;

		} break;
		case Physics2DServer::BODY_MODE_KINEMATIC:
		case Physics2DServer::BODY_MODE_STATIC: {

			_inv_inertia=0;
			_inv_mass=0;
		} break;
		case Physics2DServer::BODY_MODE_CHARACTER: {

			_inv_inertia=0;
			_inv_mass=1.0/mass;

		} break;
	}
	//_update_inertia_tensor();

	//_update_shapes();

}



void Body2DSW::set_active(bool p_active) {

	if (active==p_active)
		return;

	active=p_active;
	if (!p_active) {
		if (get_space())
			get_space()->body_remove_from_active_list(&active_list);
	} else {
		if (mode==Physics2DServer::BODY_MODE_STATIC)
			return; //static bodies can't become active
		if (get_space())
			get_space()->body_add_to_active_list(&active_list);

		//still_time=0;
	}
/*
	if (!space)
		return;

	for(int i=0;i<get_shape_count();i++) {
		Shape &s=shapes[i];
		if (s.bpid>0) {
			get_space()->get_broadphase()->set_active(s.bpid,active);
		}
	}
*/
}



void Body2DSW::set_param(Physics2DServer::BodyParameter p_param, float p_value) {

	switch(p_param) {
		case Physics2DServer::BODY_PARAM_BOUNCE: {

			bounce=p_value;
		} break;
		case Physics2DServer::BODY_PARAM_FRICTION: {

			friction=p_value;
		} break;
		case Physics2DServer::BODY_PARAM_MASS: {
			ERR_FAIL_COND(p_value<=0);
			mass=p_value;
			_update_inertia();

		} break;
		case Physics2DServer::BODY_PARAM_INERTIA: {
			if(p_value<=0) {
				user_inertia = false;
				_update_inertia();
			} else {
				user_inertia = true;
				_inv_inertia = 1.0 / p_value;
			}
		} break;
		case Physics2DServer::BODY_PARAM_GRAVITY_SCALE: {
			gravity_scale=p_value;
		} break;
		case Physics2DServer::BODY_PARAM_LINEAR_DAMP: {

			linear_damp=p_value;
		} break;
		case Physics2DServer::BODY_PARAM_ANGULAR_DAMP: {

			angular_damp=p_value;
		} break;
		default:{}
	}
}

float Body2DSW::get_param(Physics2DServer::BodyParameter p_param) const {

	switch(p_param) {
		case Physics2DServer::BODY_PARAM_BOUNCE: {

			return bounce;
		} break;
		case Physics2DServer::BODY_PARAM_FRICTION: {

			return friction;
		} break;
		case Physics2DServer::BODY_PARAM_MASS: {
			return mass;
		} break;
		case Physics2DServer::BODY_PARAM_INERTIA: {
			return _inv_inertia==0 ? 0 : 1.0 / _inv_inertia;
		} break;
		case Physics2DServer::BODY_PARAM_GRAVITY_SCALE: {
			return gravity_scale;
		} break;
		case Physics2DServer::BODY_PARAM_LINEAR_DAMP: {

			return linear_damp;
		} break;
		case Physics2DServer::BODY_PARAM_ANGULAR_DAMP: {

			return angular_damp;
		} break;
		default:{}
	}

	return 0;
}

void Body2DSW::set_mode(Physics2DServer::BodyMode p_mode) {

	Physics2DServer::BodyMode prev=mode;
	mode=p_mode;

	switch(p_mode) {
	//CLEAR UP EVERYTHING IN CASE IT NOT WORKS!
		case Physics2DServer::BODY_MODE_STATIC:
		case Physics2DServer::BODY_MODE_KINEMATIC: {

			_set_inv_transform(get_transform().affine_inverse());
			_inv_mass=0;
			_set_static(p_mode==Physics2DServer::BODY_MODE_STATIC);
			set_active(p_mode==Physics2DServer::BODY_MODE_KINEMATIC && contacts.size());
			linear_velocity=Vector2();
			angular_velocity=0;
			if (mode==Physics2DServer::BODY_MODE_KINEMATIC && prev!=mode) {
				first_time_kinematic=true;
			}
		} break;
		case Physics2DServer::BODY_MODE_RIGID: {

			_inv_mass=mass>0?(1.0/mass):0;
			_set_static(false);

		} break;
		case Physics2DServer::BODY_MODE_CHARACTER: {

			_inv_mass=mass>0?(1.0/mass):0;
			_set_static(false);
		} break;
	}

	_update_inertia();
	//if (get_space())
//		_update_queries();

}
Physics2DServer::BodyMode Body2DSW::get_mode() const {

	return mode;
}

void Body2DSW::_shapes_changed() {

	_update_inertia();
	wakeup_neighbours();
}

void Body2DSW::set_state(Physics2DServer::BodyState p_state, const Variant& p_variant) {

	switch(p_state)	{
		case Physics2DServer::BODY_STATE_TRANSFORM: {


			if (mode==Physics2DServer::BODY_MODE_KINEMATIC) {

				new_transform=p_variant;
				//wakeup_neighbours();
				set_active(true);
				if (first_time_kinematic) {
					_set_transform(p_variant);
					_set_inv_transform(get_transform().affine_inverse());
					first_time_kinematic=false;
				}
			} else if (mode==Physics2DServer::BODY_MODE_STATIC) {
				_set_transform(p_variant);
				_set_inv_transform(get_transform().affine_inverse());
				wakeup_neighbours();
			} else {
				Matrix32 t = p_variant;
				t.orthonormalize();
				new_transform=get_transform(); //used as old to compute motion
				if (t==new_transform)
					break;
				_set_transform(t);
				_set_inv_transform(get_transform().inverse());

			}
			wakeup();

		} break;
		case Physics2DServer::BODY_STATE_LINEAR_VELOCITY: {

			//if (mode==Physics2DServer::BODY_MODE_STATIC)
			//	break;
			linear_velocity=p_variant;
			wakeup();

		} break;
		case Physics2DServer::BODY_STATE_ANGULAR_VELOCITY: {
			//if (mode!=Physics2DServer::BODY_MODE_RIGID)
			//	break;
			angular_velocity=p_variant;
			wakeup();

		} break;
		case Physics2DServer::BODY_STATE_SLEEPING: {
			//?
			if (mode==Physics2DServer::BODY_MODE_STATIC || mode==Physics2DServer::BODY_MODE_KINEMATIC)
				break;
			bool do_sleep=p_variant;
			if (do_sleep) {
				linear_velocity=Vector2();
				//biased_linear_velocity=Vector3();
				angular_velocity=0;
				//biased_angular_velocity=Vector3();
				set_active(false);
			} else {
				if (mode!=Physics2DServer::BODY_MODE_STATIC)
					set_active(true);
			}
		} break;
		case Physics2DServer::BODY_STATE_CAN_SLEEP: {
			can_sleep=p_variant;
			if (mode==Physics2DServer::BODY_MODE_RIGID && !active && !can_sleep)
				set_active(true);

		} break;
	}

}
Variant Body2DSW::get_state(Physics2DServer::BodyState p_state) const {

	switch(p_state)	{
		case Physics2DServer::BODY_STATE_TRANSFORM: {
			return get_transform();
		} break;
		case Physics2DServer::BODY_STATE_LINEAR_VELOCITY: {
			return linear_velocity;
		} break;
		case Physics2DServer::BODY_STATE_ANGULAR_VELOCITY: {
			return angular_velocity;
		} break;
		case Physics2DServer::BODY_STATE_SLEEPING: {
			return !is_active();
		} break;
		case Physics2DServer::BODY_STATE_CAN_SLEEP: {
			return can_sleep;
		} break;
	}

	return Variant();
}


void Body2DSW::set_space(Space2DSW *p_space){

	if (get_space()) {

		wakeup_neighbours();

		if (inertia_update_list.in_list())
			get_space()->body_remove_from_inertia_update_list(&inertia_update_list);
		if (active_list.in_list())
			get_space()->body_remove_from_active_list(&active_list);
		if (direct_state_query_list.in_list())
			get_space()->body_remove_from_state_query_list(&direct_state_query_list);

	}

	_set_space(p_space);

	if (get_space()) {

		_update_inertia();
		if (active)
			get_space()->body_add_to_active_list(&active_list);
//		_update_queries();
		//if (is_active()) {
		//	active=false;
		//	set_active(true);
		//}

	}

	first_integration=false;
}

void Body2DSW::_compute_area_gravity_and_dampenings(const Area2DSW *p_area) {

	if (p_area->is_gravity_point()) {
		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();
	}

	area_linear_damp += p_area->get_linear_damp();
	area_angular_damp += p_area->get_angular_damp();
}

void Body2DSW::integrate_forces(real_t p_step) {

	if (mode==Physics2DServer::BODY_MODE_STATIC)
		return;

	Area2DSW *def_area = get_space()->get_default_area();
	// Area2DSW *damp_area = def_area;
	ERR_FAIL_COND(!def_area);

	int ac = areas.size();
	bool stopped = false;
	gravity = Vector2(0,0);
	area_angular_damp = 0;
	area_linear_damp = 0;
	if (ac) {
		areas.sort();
		const AreaCMP *aa = &areas[0];
		// damp_area = aa[ac-1].area;
		for(int i=ac-1;i>=0 && !stopped;i--) {
			Physics2DServer::AreaSpaceOverrideMode mode=aa[i].area->get_space_override_mode();
			switch (mode) {
				case Physics2DServer::AREA_SPACE_OVERRIDE_COMBINE:
				case Physics2DServer::AREA_SPACE_OVERRIDE_COMBINE_REPLACE: {
					_compute_area_gravity_and_dampenings(aa[i].area);
					stopped = mode==Physics2DServer::AREA_SPACE_OVERRIDE_COMBINE_REPLACE;
				} break;
				case Physics2DServer::AREA_SPACE_OVERRIDE_REPLACE:
				case Physics2DServer::AREA_SPACE_OVERRIDE_REPLACE_COMBINE: {
					gravity = Vector2(0,0);
					area_angular_damp = 0;
					area_linear_damp = 0;
					_compute_area_gravity_and_dampenings(aa[i].area);
					stopped = mode==Physics2DServer::AREA_SPACE_OVERRIDE_REPLACE;
				} break;
				default: {}
			}
		}
	}
	if( !stopped ) {
		_compute_area_gravity_and_dampenings(def_area);
	}
	gravity*=gravity_scale;

	// If less than 0, override dampenings with that of the Body2D
	if (angular_damp>=0)
		area_angular_damp = angular_damp;
	//else
	//	area_angular_damp=damp_area->get_angular_damp();

	if (linear_damp>=0)
		area_linear_damp = linear_damp;
	//else
	//	area_linear_damp=damp_area->get_linear_damp();

	Vector2 motion;
	bool do_motion=false;

	if (mode==Physics2DServer::BODY_MODE_KINEMATIC) {

		//compute motion, angular and etc. velocities from prev transform
		linear_velocity = (new_transform.elements[2] - get_transform().elements[2])/p_step;

		real_t rot = new_transform.affine_inverse().basis_xform(get_transform().elements[1]).angle();
		angular_velocity = rot / p_step;

		motion = new_transform.elements[2] - get_transform().elements[2];
		do_motion=true;

		//for(int i=0;i<get_shape_count();i++) {
		//	set_shape_kinematic_advance(i,Vector2());
		//	set_shape_kinematic_retreat(i,0);
		//}

	} else {
		if (!omit_force_integration && !first_integration) {
			//overriden by direct state query

			Vector2 force=gravity*mass;
			force+=applied_force;
			real_t torque=applied_torque;

			real_t damp = 1.0 - p_step * area_linear_damp;

			if (damp<0) // reached zero in the given time
				damp=0;

			real_t angular_damp = 1.0 - p_step * area_angular_damp;

			if (angular_damp<0) // reached zero in the given time
				angular_damp=0;

			linear_velocity*=damp;
			angular_velocity*=angular_damp;

			linear_velocity+=_inv_mass * force * p_step;
			angular_velocity+=_inv_inertia * torque * p_step;
		}

		if (continuous_cd_mode!=Physics2DServer::CCD_MODE_DISABLED) {

			motion = new_transform.get_origin() - get_transform().get_origin();
			//linear_velocity*p_step;
			do_motion=true;
		}
	}


	//motion=linear_velocity*p_step;

	first_integration=false;
	biased_angular_velocity=0;
	biased_linear_velocity=Vector2();

	if (do_motion) {//shapes temporarily extend for raycast
		_update_shapes_with_motion(motion);
	}

	// damp_area=NULL; // clear the area, so it is set in the next frame
	def_area=NULL; // clear the area, so it is set in the next frame
	contact_count=0;

}

void Body2DSW::integrate_velocities(real_t p_step) {

	if (mode==Physics2DServer::BODY_MODE_STATIC)
		return;

	if (fi_callback)
		get_space()->body_add_to_state_query_list(&direct_state_query_list);

	if (mode==Physics2DServer::BODY_MODE_KINEMATIC) {

		_set_transform(new_transform,false);
		_set_inv_transform(new_transform.affine_inverse());
		if (contacts.size()==0 && linear_velocity==Vector2() && angular_velocity==0)
			set_active(false); //stopped moving, deactivate
		return;
	}

	real_t total_angular_velocity = angular_velocity+biased_angular_velocity;
	Vector2 total_linear_velocity=linear_velocity+biased_linear_velocity;

	real_t angle = get_transform().get_rotation() - total_angular_velocity * p_step;
	Vector2 pos = get_transform().get_origin() + total_linear_velocity * p_step;

	_set_transform(Matrix32(angle,pos),continuous_cd_mode==Physics2DServer::CCD_MODE_DISABLED);
	_set_inv_transform(get_transform().inverse());

	if (continuous_cd_mode!=Physics2DServer::CCD_MODE_DISABLED)
		new_transform=get_transform();

	//_update_inertia_tensor();
}



void Body2DSW::wakeup_neighbours() {



	for(Map<Constraint2DSW*,int>::Element *E=constraint_map.front();E;E=E->next()) {

		const Constraint2DSW *c=E->key();
		Body2DSW **n = c->get_body_ptr();
		int bc=c->get_body_count();

		for(int i=0;i<bc;i++) {

			if (i==E->get())
				continue;
			Body2DSW *b = n[i];
			if (b->mode!=Physics2DServer::BODY_MODE_RIGID)
				continue;

			if (!b->is_active())
				b->set_active(true);
		}
	}
}

void Body2DSW::call_queries() {


	if (fi_callback) {

		Physics2DDirectBodyStateSW *dbs = Physics2DDirectBodyStateSW::singleton;
		dbs->body=this;

		Variant v=dbs;
		const Variant *vp[2]={&v,&fi_callback->callback_udata};


		Object *obj = ObjectDB::get_instance(fi_callback->id);
		if (!obj) {

			set_force_integration_callback(0,StringName());
		} else {
			Variant::CallError ce;
			if (fi_callback->callback_udata.get_type()) {

				obj->call(fi_callback->method,vp,2,ce);

			} else {
				obj->call(fi_callback->method,vp,1,ce);
			}
		}


	}

}


bool Body2DSW::sleep_test(real_t p_step)  {

	if (mode==Physics2DServer::BODY_MODE_STATIC || mode==Physics2DServer::BODY_MODE_KINEMATIC)
		return true; //
	else if (mode==Physics2DServer::BODY_MODE_CHARACTER)
		return !active; // characters and kinematic bodies don't sleep unless asked to sleep
	else if (!can_sleep)
		return false;




	if (Math::abs(angular_velocity)<get_space()->get_body_angular_velocity_sleep_treshold() && Math::abs(linear_velocity.length_squared()) < get_space()->get_body_linear_velocity_sleep_treshold()*get_space()->get_body_linear_velocity_sleep_treshold()) {

		still_time+=p_step;

		return still_time > get_space()->get_body_time_to_sleep();
	} else {

		still_time=0; //maybe this should be set to 0 on set_active?
		return false;
	}
}


void Body2DSW::set_force_integration_callback(ObjectID p_id,const StringName& p_method,const Variant& p_udata) {

	if (fi_callback) {

		memdelete(fi_callback);
		fi_callback=NULL;
	}


	if (p_id!=0) {

		fi_callback=memnew(ForceIntegrationCallback);
		fi_callback->id=p_id;
		fi_callback->method=p_method;
		fi_callback->callback_udata=p_udata;
	}

}

Body2DSW::Body2DSW() : CollisionObject2DSW(TYPE_BODY), active_list(this), inertia_update_list(this), direct_state_query_list(this) {


	mode=Physics2DServer::BODY_MODE_RIGID;
	active=true;
	angular_velocity=0;
	biased_angular_velocity=0;
	mass=1;
	user_inertia=false;
	_inv_inertia=0;
	_inv_mass=1;
	bounce=0;
	friction=1;
	omit_force_integration=false;
	applied_torque=0;
	island_step=0;
	island_next=NULL;
	island_list_next=NULL;
	_set_static(false);
	first_time_kinematic=false;
	linear_damp=-1;
	angular_damp=-1;
	area_angular_damp=0;
	area_linear_damp=0;
	contact_count=0;
	gravity_scale=1.0;
	using_one_way_cache=false;
	one_way_collision_max_depth=0.1;
	first_integration=false;

	still_time=0;
	continuous_cd_mode=Physics2DServer::CCD_MODE_DISABLED;
	can_sleep=false;
	fi_callback=NULL;

}

Body2DSW::~Body2DSW() {

	if (fi_callback)
		memdelete(fi_callback);
}

Physics2DDirectBodyStateSW *Physics2DDirectBodyStateSW::singleton=NULL;

Physics2DDirectSpaceState* Physics2DDirectBodyStateSW::get_space_state() {

	return body->get_space()->get_direct_state();
}


Variant Physics2DDirectBodyStateSW::get_contact_collider_shape_metadata(int p_contact_idx) const {

	ERR_FAIL_INDEX_V(p_contact_idx,body->contact_count,Variant());

	if (!Physics2DServerSW::singletonsw->body_owner.owns(body->contacts[p_contact_idx].collider)) {

		return Variant();
	}
	Body2DSW *other = Physics2DServerSW::singletonsw->body_owner.get(body->contacts[p_contact_idx].collider);

	int sidx = body->contacts[p_contact_idx].collider_shape;
	if (sidx<0 || sidx>=other->get_shape_count()) {

		return Variant();
	}


	return other->get_shape_metadata(sidx);
}