love2d.love/src/modules/physics/box2d/Body.cpp

/**
* Copyright (c) 2006-2011 LOVE Development Team
*
* This software is provided 'as-is', without any express or implied
* warranty.  In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
*    claim that you wrote the original software. If you use this software
*    in a product, an acknowledgment in the product documentation would be
*    appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
*    misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
**/

#include "Body.h"

#include <common/math.h>
#include <common/Memoizer.h>

#include "Shape.h"
#include "Fixture.h"
#include "World.h"
#include "Physics.h"

namespace love
{
namespace physics
{
namespace box2d
{
	Body::Body(World * world, b2Vec2 p, Body::Type type)
		: world(world)
	{
		world->retain();
		b2BodyDef def;
		def.position = Physics::scaleDown(p);
		body = world->world->CreateBody(&def);
		// Box2D body holds a reference to the love Body.
		this->retain();
		this->setType(type);
		Memoizer::add(body, this);
	}

	Body::Body(b2Body * b)
		: body(b)
	{
		world = (World *)Memoizer::find(b->GetWorld());
		world->retain();
		// Box2D body holds a reference to the love Body.
		this->retain();
		Memoizer::add(body, this);
	}

	Body::~Body()
	{
		world->release();
		body = 0;
	}

	float Body::getX()
	{
		return Physics::scaleUp(body->GetPosition().x);
	}

	float Body::getY()
	{
		return Physics::scaleUp(body->GetPosition().y);
	}

	void Body::getPosition(float & x_o, float & y_o)
	{
		b2Vec2 v = Physics::scaleUp(body->GetPosition());
		x_o = v.x;
		y_o = v.y;
	}

	void Body::getLinearVelocity(float & x_o, float & y_o)
	{
		b2Vec2 v = Physics::scaleUp(body->GetLinearVelocity());
		x_o = v.x;
		y_o = v.y;
	}

	float Body::getAngle()
	{
		return body->GetAngle();
	}

	void Body::getWorldCenter(float & x_o, float & y_o)
	{
		b2Vec2 v = Physics::scaleUp(body->GetWorldCenter());
		x_o = v.x;
		y_o = v.y;
	}

	void Body::getLocalCenter(float & x_o, float & y_o)
	{
		b2Vec2 v = Physics::scaleUp(body->GetLocalCenter());
		x_o = v.x;
		y_o = v.y;
	}

	float Body::getAngularVelocity() const
	{
		return body->GetAngularVelocity();
	}

	float Body::getMass() const
	{
		return body->GetMass();
	}

	float Body::getInertia() const
	{
		return body->GetInertia();
	}

	int Body::getMassData(lua_State * L)
	{
		b2MassData data;
		body->GetMassData(&data);
		b2Vec2 center = Physics::scaleUp(data.center);
		lua_pushnumber(L, center.x);
		lua_pushnumber(L, center.y);
		lua_pushnumber(L, data.mass);
		lua_pushnumber(L, data.I);
		return 4;
	}

	float Body::getAngularDamping() const
	{
		return body->GetAngularDamping();
	}

	float Body::getLinearDamping() const
	{
		return body->GetLinearDamping();
	}

	float Body::getGravityScale() const
	{
		return body->GetGravityScale();
	}

	Body::Type Body::getType() const
	{
		switch (body->GetType())
		{
			case b2_staticBody:
				return BODY_STATIC;
				break;
			case b2_dynamicBody:
				return BODY_DYNAMIC;
				break;
			case b2_kinematicBody:
				return BODY_KINEMATIC;
				break;
			default:
				return BODY_INVALID;
				break;
		}
	}

	void Body::applyLinearImpulse(float jx, float jy)
	{
		body->ApplyLinearImpulse(Physics::scaleDown(b2Vec2(jx, jy)), body->GetWorldCenter());
	}

	void Body::applyLinearImpulse(float jx, float jy, float rx, float ry)
	{
		body->ApplyLinearImpulse(Physics::scaleDown(b2Vec2(jx, jy)), Physics::scaleDown(b2Vec2(rx, ry)));
	}

	void Body::applyAngularImpulse(float impulse)
	{
		// Angular impulse is in kg*m^2/s, meaning it needs to be scaled twice
		body->ApplyAngularImpulse(Physics::scaleDown(Physics::scaleDown(impulse)));
	}

	void Body::applyTorque(float t)
	{
		// Torque is in N*m, or kg*m^2/s^2, meaning it also needs to be scaled twice
		body->ApplyTorque(Physics::scaleDown(Physics::scaleDown(t)));
	}

	void Body::applyForce(float fx, float fy, float rx, float ry)
	{
		body->ApplyForce(Physics::scaleDown(b2Vec2(fx, fy)), Physics::scaleDown(b2Vec2(rx, ry)));
	}

	void Body::applyForce(float fx, float fy)
	{
		body->ApplyForce(Physics::scaleDown(b2Vec2(fx, fy)), body->GetWorldCenter());
	}

	void Body::setX(float x)
	{
		body->SetTransform(Physics::scaleDown(b2Vec2(x, getY())), getAngle());
	}

	void Body::setY(float y)
	{
		body->SetTransform(Physics::scaleDown(b2Vec2(getX(), y)), getAngle());
	}

	void Body::setLinearVelocity(float x, float y)
	{
		body->SetLinearVelocity(Physics::scaleDown(b2Vec2(x, y)));
	}

	void Body::setAngle(float d)
	{
		body->SetTransform(body->GetPosition(), d);
	}

	void Body::setAngularVelocity(float r)
	{
		body->SetAngularVelocity(r);
	}

	void Body::setPosition(float x, float y)
	{
		body->SetTransform(Physics::scaleDown(b2Vec2(x, y)), body->GetAngle());
	}

	void Body::setAngularDamping(float d)
	{
		body->SetAngularDamping(d);
	}

	void Body::setLinearDamping(float d)
	{
		body->SetLinearDamping(d);
	}

	void Body::resetMassData()
	{
		body->ResetMassData();
	}

	void Body::setMassData(float x, float y, float m, float i)
	{
		b2MassData massData;
		massData.center = Physics::scaleDown(b2Vec2(x, y));
		massData.mass = m;
		massData.I = i;
		body->SetMassData(&massData);
	}

	void Body::setInertia(float i)
	{
		b2MassData massData;
		massData.center = body->GetLocalCenter();
		massData.mass = body->GetMass();
		massData.I = i;
		body->SetMassData(&massData);
	}

	void Body::setGravityScale(float scale)
	{
		body->SetGravityScale(scale);
	}

	void Body::setType(Body::Type type)
	{
		switch (type)
		{
			case Body::BODY_STATIC:
				body->SetType(b2_staticBody);
				break;
			case Body::BODY_DYNAMIC:
				body->SetType(b2_dynamicBody);
				break;
			case Body::BODY_KINEMATIC:
				body->SetType(b2_kinematicBody);
				break;
			default:
				break;
		}
	}

	void Body::getWorldPoint(float x, float y, float & x_o, float & y_o)
	{
		b2Vec2 v = Physics::scaleUp(body->GetWorldPoint(Physics::scaleDown(b2Vec2(x, y))));
		x_o = v.x;
		y_o = v.y;
	}

	void Body::getWorldVector(float x, float y, float & x_o, float & y_o)
	{
		b2Vec2 v = Physics::scaleUp(body->GetWorldVector(Physics::scaleDown(b2Vec2(x, y))));
		x_o = v.x;
		y_o = v.y;
	}

	int Body::getWorldPoints(lua_State * L)
	{
		int argc = lua_gettop(L);
		int vcount = (int)argc/2;
		// at least one point
		love::luax_assert_argc(L, 2);

		for (int i = 0;i<vcount;i++)
		{
			float x = (float)lua_tonumber(L, i*2+1);
			float y = (float)lua_tonumber(L, i*2+2);
			b2Vec2 point = Physics::scaleUp(body->GetWorldPoint(Physics::scaleDown(b2Vec2(x, y))));
			lua_pushnumber(L, point.x);
			lua_pushnumber(L, point.y);
		}

		return argc;
	}

	void Body::getLocalPoint(float x, float y, float & x_o, float & y_o)
	{
		b2Vec2 v = Physics::scaleUp(body->GetLocalPoint(Physics::scaleDown(b2Vec2(x, y))));
		x_o = v.x;
		y_o = v.y;
	}

	void Body::getLocalVector(float x, float y, float & x_o, float & y_o)
	{
		b2Vec2 v = Physics::scaleUp(body->GetLocalVector(Physics::scaleDown(b2Vec2(x, y))));
		x_o = v.x;
		y_o = v.y;
	}

	void Body::getLinearVelocityFromWorldPoint(float x, float y, float & x_o, float & y_o)
	{
		b2Vec2 v = Physics::scaleUp(body->GetLinearVelocityFromWorldPoint(Physics::scaleDown(b2Vec2(x, y))));
		x_o = v.x;
		y_o = v.y;
	}

	void Body::getLinearVelocityFromLocalPoint(float x, float y, float & x_o, float & y_o)
	{
		b2Vec2 v = Physics::scaleUp(body->GetLinearVelocityFromLocalPoint(Physics::scaleDown(b2Vec2(x, y))));
		x_o = v.x;
		y_o = v.y;
	}

	bool Body::isBullet() const
	{
		return body->IsBullet();
	}

	void Body::setBullet(bool bullet)
	{
		return body->SetBullet(bullet);
	}

	bool Body::isActive() const
	{
		return body->IsActive();
	}

	bool Body::isAwake() const
	{
		return body->IsAwake();
	}

	void Body::setSleepingAllowed(bool allow)
	{
		body->SetSleepingAllowed(allow);
	}

	bool Body::isSleepingAllowed() const
	{
		return body->IsSleepingAllowed();
	}

	void Body::setActive(bool active)
	{
		body->SetActive(active);
	}

	void Body::setAwake(bool awake)
	{
		body->SetAwake(awake);
	}

	void Body::setFixedRotation(bool fixed)
	{
		body->SetFixedRotation(fixed);
	}

	bool Body::isFixedRotation() const
	{
		return body->IsFixedRotation();
	}

	World * Body::getWorld() const
	{
		return world;
	}

	int Body::getFixtureList(lua_State * L) const
	{
		lua_newtable(L);
		b2Fixture * f = body->GetFixtureList();
		int i = 1;
		do {
			if (!f)
				break;
			Fixture * fixture = (Fixture *)Memoizer::find(f);
			if (!fixture)
				throw love::Exception("A fixture has escaped Memoizer!");
			fixture->retain();
			luax_newtype(L, "Fixture", PHYSICS_FIXTURE_T, (void*)fixture);
			lua_rawseti(L, -2, i);
			i++;
		} while ((f = f->GetNext()));
		return 1;
	}

	b2Vec2 Body::getVector(lua_State * L)
	{
		love::luax_assert_argc(L, 2, 2);
		b2Vec2 v((float)lua_tonumber(L, 1), (float)lua_tonumber(L, 2));
		lua_pop(L, 2);
		return v;
	}

	int Body::pushVector(lua_State * L, const b2Vec2 & v)
	{
		lua_pushnumber(L, v.x);
		lua_pushnumber(L, v.y);
		return 2;
	}

	void Body::destroy()
	{
		if (world->world->IsLocked())
		{
			// Called during time step. Save reference for destruction afterwards.
			this->retain();
			world->destructBodies.push_back(this);
			return;
		}

		world->world->DestroyBody(body);
		Memoizer::remove(body);
		body = NULL;

		// Box2D body destroyed. Release its reference to the love Body.
		this->release();
	}

} // box2d
} // physics
} // love