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PhysicsRigidBody.cpp
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PhysicsRigidBody.cpp
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#include "Base.h"
#include "PhysicsRigidBody.h"
#include "PhysicsController.h"
#include "Game.h"
#include "Image.h"
#include "MeshPart.h"
#include "Node.h"
namespace gameplay
{
PhysicsRigidBody::PhysicsRigidBody(Node* node, const PhysicsCollisionShape::Definition& shape, const Parameters& parameters)
: PhysicsCollisionObject(node), _body(NULL), _mass(parameters.mass), _constraints(NULL), _inDestructor(false)
{
GP_ASSERT(Game::getInstance()->getPhysicsController());
GP_ASSERT(_node);
// Create our collision shape.
Vector3 centerOfMassOffset;
_collisionShape = Game::getInstance()->getPhysicsController()->createShape(node, shape, ¢erOfMassOffset);
GP_ASSERT(_collisionShape && _collisionShape->getShape());
// Create motion state object.
_motionState = new PhysicsMotionState(node, (centerOfMassOffset.lengthSquared() > MATH_EPSILON) ? ¢erOfMassOffset : NULL);
// If the mass is non-zero, then the object is dynamic so we calculate the local
// inertia. However, if the collision shape is a triangle mesh, we don't calculate
// inertia since Bullet doesn't currently support this.
btVector3 localInertia(0.0, 0.0, 0.0);
if (parameters.mass != 0.0 && _collisionShape->getType() != PhysicsCollisionShape::SHAPE_MESH)
_collisionShape->getShape()->calculateLocalInertia(parameters.mass, localInertia);
// Create the Bullet physics rigid body object.
btRigidBody::btRigidBodyConstructionInfo rbInfo(parameters.mass, _motionState, _collisionShape->getShape(), localInertia);
rbInfo.m_friction = parameters.friction;
rbInfo.m_restitution = parameters.restitution;
rbInfo.m_linearDamping = parameters.linearDamping;
rbInfo.m_angularDamping = parameters.angularDamping;
// Create + assign the new bullet rigid body object.
_body = bullet_new<btRigidBody>(rbInfo);
// Set other initially defined properties.
setKinematic(parameters.kinematic);
setAnisotropicFriction(parameters.anisotropicFriction);
setAngularFactor(parameters.angularFactor);
setLinearFactor(parameters.linearFactor);
// Add ourself to the physics world.
Game::getInstance()->getPhysicsController()->addCollisionObject(this);
if (_collisionShape->getType() == PhysicsCollisionShape::SHAPE_HEIGHTFIELD)
{
// Add a listener on the node's transform so we can track dirty changes to calculate
// an inverse matrix for transforming heightfield points between world and local space.
_node->addListener(this);
}
}
PhysicsRigidBody::~PhysicsRigidBody()
{
GP_ASSERT(Game::getInstance()->getPhysicsController());
GP_ASSERT(_collisionShape);
GP_ASSERT(_node);
// Clean up all constraints linked to this rigid body.
_inDestructor = true;
if (_constraints)
{
for (unsigned int i = 0; i < _constraints->size(); ++i)
{
SAFE_DELETE((*_constraints)[i]);
}
SAFE_DELETE(_constraints);
}
// Remove collision object from physics controller.
Game::getInstance()->getPhysicsController()->removeCollisionObject(this, true);
// Clean up the rigid body and its related objects.
SAFE_DELETE(_body);
// Unregister node listener (only registered for heihgtfield collision shape types).
if (_collisionShape->getType() == PhysicsCollisionShape::SHAPE_HEIGHTFIELD)
{
_node->removeListener(this);
}
}
PhysicsCollisionObject::Type PhysicsRigidBody::getType() const
{
return PhysicsCollisionObject::RIGID_BODY;
}
btCollisionObject* PhysicsRigidBody::getCollisionObject() const
{
return _body;
}
void PhysicsRigidBody::applyForce(const Vector3& force, const Vector3* relativePosition)
{
// If the force is significant enough, activate the rigid body
// to make sure that it isn't sleeping and apply the force.
if (force.lengthSquared() > MATH_EPSILON)
{
GP_ASSERT(_body);
_body->activate();
if (relativePosition)
_body->applyForce(BV(force), BV(*relativePosition));
else
_body->applyCentralForce(BV(force));
}
}
void PhysicsRigidBody::applyImpulse(const Vector3& impulse, const Vector3* relativePosition)
{
// If the impulse is significant enough, activate the rigid body
// to make sure that it isn't sleeping and apply the impulse.
if (impulse.lengthSquared() > MATH_EPSILON)
{
GP_ASSERT(_body);
_body->activate();
if (relativePosition)
{
_body->applyImpulse(BV(impulse), BV(*relativePosition));
}
else
_body->applyCentralImpulse(BV(impulse));
}
}
void PhysicsRigidBody::applyTorque(const Vector3& torque)
{
// If the torque is significant enough, activate the rigid body
// to make sure that it isn't sleeping and apply the torque.
if (torque.lengthSquared() > MATH_EPSILON)
{
GP_ASSERT(_body);
_body->activate();
_body->applyTorque(BV(torque));
}
}
void PhysicsRigidBody::applyTorqueImpulse(const Vector3& torque)
{
// If the torque impulse is significant enough, activate the rigid body
// to make sure that it isn't sleeping and apply the torque impulse.
if (torque.lengthSquared() > MATH_EPSILON)
{
GP_ASSERT(_body);
_body->activate();
_body->applyTorqueImpulse(BV(torque));
}
}
PhysicsRigidBody* PhysicsRigidBody::create(Node* node, Properties* properties, const char* nspace)
{
// Check if the properties is valid and has a valid namespace.
if (!properties || !(strcmp(properties->getNamespace(), "collisionObject") == 0))
{
GP_ERROR("Failed to load rigid body from properties object: must be non-null object and have namespace equal to 'collisionObject'.");
return NULL;
}
// Check that the type is specified and correct.
const char* type = properties->getString("type");
if (!type)
{
GP_ERROR("Failed to load physics rigid body from properties object; required attribute 'type' is missing.");
return NULL;
}
if (strcmp(type, nspace) != 0)
{
GP_ERROR("Failed to load physics rigid body from properties object; attribute 'type' must be equal to '%s'.", nspace);
return NULL;
}
// Load the physics collision shape definition.
PhysicsCollisionShape::Definition* shape = PhysicsCollisionShape::Definition::create(node, properties);
if (shape == NULL)
{
GP_ERROR("Failed to create collision shape during rigid body creation.");
return NULL;
}
// Set the rigid body parameters to their defaults.
Parameters parameters;
Vector3* gravity = NULL;
// Load the defined rigid body parameters.
properties->rewind();
const char* name;
while ((name = properties->getNextProperty()) != NULL)
{
if (strcmp(name, "mass") == 0)
{
parameters.mass = properties->getFloat();
}
else if (strcmp(name, "friction") == 0)
{
parameters.friction = properties->getFloat();
}
else if (strcmp(name, "restitution") == 0)
{
parameters.restitution = properties->getFloat();
}
else if (strcmp(name, "linearDamping") == 0)
{
parameters.linearDamping = properties->getFloat();
}
else if (strcmp(name, "angularDamping") == 0)
{
parameters.angularDamping = properties->getFloat();
}
else if (strcmp(name, "kinematic") == 0)
{
parameters.kinematic = properties->getBool();
}
else if (strcmp(name, "anisotropicFriction") == 0)
{
properties->getVector3(NULL, ¶meters.anisotropicFriction);
}
else if (strcmp(name, "gravity") == 0)
{
gravity = new Vector3();
properties->getVector3(NULL, gravity);
}
else if (strcmp(name, "angularFactor") == 0)
{
properties->getVector3(NULL, ¶meters.angularFactor);
}
else if (strcmp(name, "linearFactor") == 0)
{
properties->getVector3(NULL, ¶meters.linearFactor);
}
else
{
// Ignore this case (the attributes for the rigid body's collision shape would end up here).
}
}
// Create the rigid body.
PhysicsRigidBody* body = new PhysicsRigidBody(node, *shape, parameters);
SAFE_DELETE(shape);
if (gravity)
{
body->setGravity(*gravity);
SAFE_DELETE(gravity);
}
return body;
}
void PhysicsRigidBody::setKinematic(bool kinematic)
{
GP_ASSERT(_body);
if (kinematic)
{
_body->setCollisionFlags(_body->getCollisionFlags() | btCollisionObject::CF_KINEMATIC_OBJECT);
_body->setActivationState(DISABLE_DEACTIVATION);
}
else
{
_body->setCollisionFlags(_body->getCollisionFlags() & ~btCollisionObject::CF_KINEMATIC_OBJECT);
_body->setActivationState(ACTIVE_TAG);
}
}
void PhysicsRigidBody::setEnabled(bool enable)
{
PhysicsCollisionObject::setEnabled(enable);
if (enable)
_body->setMotionState(_motionState);
}
float PhysicsRigidBody::getHeight(float x, float y, Vector3* normal) const
{
GP_ASSERT(_collisionShape);
// This function is only supported for heightfield rigid bodies.
if (_collisionShape->getType() != PhysicsCollisionShape::SHAPE_HEIGHTFIELD)
{
GP_ERROR("Attempting to get the height of a non-heightfield rigid body.");
return 0.0f;
}
GP_ASSERT(_collisionShape->_shapeData.heightfieldData);
GP_ASSERT(_node);
// Calculate the correct x, y position relative to the heightfield data.
if (_collisionShape->_shapeData.heightfieldData->inverseIsDirty)
{
_node->getWorldMatrix().invert(&_collisionShape->_shapeData.heightfieldData->inverse);
_collisionShape->_shapeData.heightfieldData->inverseIsDirty = false;
}
float w = _collisionShape->_shapeData.heightfieldData->width;
float h = _collisionShape->_shapeData.heightfieldData->height;
GP_ASSERT(w - 1);
GP_ASSERT(h - 1);
Vector3 v = _collisionShape->_shapeData.heightfieldData->inverse * Vector3(x, 0.0f, y);
x = (v.x + (0.5f * (w - 1))) * w / (w - 1);
y = (v.z + (0.5f * (h - 1))) * h / (h - 1);
// Check that the x, y position is within the bounds.
if (x < 0.0f || x > w || y < 0.0f || y > h)
{
GP_ERROR("Attempting to get height at point '%f, %f', which is outside the range of the heightfield with width %d and height %d.", x, y, w, h);
return 0.0f;
}
return PhysicsController::calculateHeight(_collisionShape->_shapeData.heightfieldData->heightData, w, h, x, y,
&_node->getWorldMatrix(), _collisionShape->_shapeData.heightfieldData->normalData, normal);
}
void PhysicsRigidBody::addConstraint(PhysicsConstraint* constraint)
{
GP_ASSERT(constraint);
if (_constraints == NULL)
_constraints = new std::vector<PhysicsConstraint*>();
_constraints->push_back(constraint);
}
void PhysicsRigidBody::removeConstraint(PhysicsConstraint* constraint)
{
// Ensure that the rigid body has constraints and that we are
// not currently in the rigid body's destructor (in this case,
// the constraints will be destroyed from there).
if (_constraints && !_inDestructor)
{
for (unsigned int i = 0; i < _constraints->size(); ++i)
{
if ((*_constraints)[i] == constraint)
{
_constraints->erase(_constraints->begin() + i);
break;
}
}
}
}
bool PhysicsRigidBody::supportsConstraints()
{
return (getShapeType() != PhysicsCollisionShape::SHAPE_HEIGHTFIELD && getShapeType() != PhysicsCollisionShape::SHAPE_MESH);
}
void PhysicsRigidBody::transformChanged(Transform* transform, long cookie)
{
if (getShapeType() == PhysicsCollisionShape::SHAPE_HEIGHTFIELD)
{
GP_ASSERT(_collisionShape && _collisionShape->_shapeData.heightfieldData);
_collisionShape->_shapeData.heightfieldData->inverseIsDirty = true;
}
}
}