/**************************************************************************** Copyright (c) 2013-2016 Chukong Technologies Inc. Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd. Copyright (c) 2019-present Axmol Engine contributors (see AUTHORS.md). https://axmol.dev/ Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. ****************************************************************************/ #include "physics/PhysicsBody.h" #if defined(AX_ENABLE_PHYSICS) # include # include # include # include "chipmunk/chipmunk_private.h" # include "2d/Scene.h" # include "physics/PhysicsShape.h" # include "physics/PhysicsJoint.h" # include "physics/PhysicsWorld.h" # include "physics/PhysicsHelper.h" static void internalBodySetMass(cpBody* body, cpFloat mass) { cpBodyActivate(body); body->m = mass; body->m_inv = 1.0f / mass; // cpAssertSaneBody(body); } static void internalBodyUpdateVelocity(cpBody* body, cpVect gravity, cpFloat damping, cpFloat dt) { cpBodyUpdateVelocity(body, cpvzero, damping, dt); // Skip kinematic bodies. if (cpBodyGetType(body) == CP_BODY_TYPE_KINEMATIC) return; cpAssertSoft(body->m > 0.0f && body->i > 0.0f, "Body's mass and moment must be positive to simulate. (Mass: %f Moment: f)", body->m, body->i); ax::PhysicsBody* physicsBody = static_cast(body->userData); if (physicsBody->isGravityEnabled()) body->v = cpvclamp(cpvadd(cpvmult(body->v, damping), cpvmult(cpvadd(gravity, cpvmult(body->f, body->m_inv)), dt)), physicsBody->getVelocityLimit()); else body->v = cpvclamp(cpvadd(cpvmult(body->v, damping), cpvmult(cpvmult(body->f, body->m_inv), dt)), physicsBody->getVelocityLimit()); cpFloat w_limit = physicsBody->getAngularVelocityLimit(); body->w = cpfclamp(body->w * damping + body->t * body->i_inv * dt, -w_limit, w_limit); // Reset forces. body->f = cpvzero; // to check body sanity cpBodySetTorque(body, 0.0f); } NS_AX_BEGIN extern const float PHYSICS_INFINITY; const std::string PhysicsBody::COMPONENT_NAME = "PhysicsBody"; namespace { static const float MASS_DEFAULT = 1.0; static const float MOMENT_DEFAULT = 200; } // namespace PhysicsBody::PhysicsBody() : _world(nullptr) , _cpBody(nullptr) , _dynamic(true) , _rotationEnabled(true) , _gravityEnabled(true) , _massDefault(true) , _momentDefault(true) , _mass(MASS_DEFAULT) , _area(0.0f) , _density(0.0f) , _moment(MOMENT_DEFAULT) , _velocityLimit(PHYSICS_INFINITY) , _angularVelocityLimit(PHYSICS_INFINITY) , _isDamping(false) , _linearDamping(0.0f) , _angularDamping(0.0f) , _tag(0) , _massSetByUser(false) , _momentSetByUser(false) , _rotationOffset(0) , _recordedRotation(0.0f) , _recordedAngle(0.0) , _recordScaleX(1.f) , _recordScaleY(1.f) , _fixedUpdate(false) { _name = COMPONENT_NAME; } PhysicsBody::~PhysicsBody() { for (auto&& joint : _joints) { PhysicsBody* other = joint->getBodyA() == this ? joint->getBodyB() : joint->getBodyA(); other->removeJoint(joint); delete joint; } if (_cpBody) { cpBodyFree(_cpBody); } } PhysicsBody* PhysicsBody::create() { PhysicsBody* body = new PhysicsBody(); if (body->init()) { body->autorelease(); return body; } AX_SAFE_DELETE(body); return nullptr; } PhysicsBody* PhysicsBody::create(float mass) { PhysicsBody* body = new PhysicsBody(); if (body) { body->_mass = mass; body->_massDefault = false; if (body->init()) { body->autorelease(); return body; } } AX_SAFE_DELETE(body); return nullptr; } PhysicsBody* PhysicsBody::create(float mass, float moment) { PhysicsBody* body = new PhysicsBody(); if (body) { body->_mass = mass; body->_massDefault = false; body->_moment = moment; body->_momentDefault = false; if (body->init()) { body->autorelease(); return body; } } AX_SAFE_DELETE(body); return nullptr; } PhysicsBody* PhysicsBody::createCircle(float radius, const PhysicsMaterial& material, const Vec2& offset) { PhysicsBody* body = new PhysicsBody(); if (body->init()) { body->addShape(PhysicsShapeCircle::create(radius, material, offset)); body->autorelease(); return body; } AX_SAFE_DELETE(body); return nullptr; } PhysicsBody* PhysicsBody::createBox(const Vec2& size, const PhysicsMaterial& material, const Vec2& offset) { PhysicsBody* body = new PhysicsBody(); if (body->init()) { body->addShape(PhysicsShapeBox::create(size, material, offset)); body->autorelease(); return body; } AX_SAFE_DELETE(body); return nullptr; } PhysicsBody* PhysicsBody::createPolygon(const Vec2* points, int count, const PhysicsMaterial& material, const Vec2& offset) { PhysicsBody* body = new PhysicsBody(); if (body->init()) { body->addShape(PhysicsShapePolygon::create(points, count, material, offset)); body->autorelease(); return body; } AX_SAFE_DELETE(body); return nullptr; } PhysicsBody* PhysicsBody::createEdgeSegment(const Vec2& a, const Vec2& b, const PhysicsMaterial& material, float border /* = 1*/) { PhysicsBody* body = new PhysicsBody(); if (body->init()) { body->addShape(PhysicsShapeEdgeSegment::create(a, b, material, border)); body->setDynamic(false); body->autorelease(); return body; } AX_SAFE_DELETE(body); return nullptr; } PhysicsBody* PhysicsBody::createEdgeBox(const Vec2& size, const PhysicsMaterial& material, float border /* = 1*/, const Vec2& offset) { PhysicsBody* body = new PhysicsBody(); if (body->init()) { body->addShape(PhysicsShapeEdgeBox::create(size, material, border, offset)); body->setDynamic(false); body->autorelease(); return body; } AX_SAFE_DELETE(body); return nullptr; } PhysicsBody* PhysicsBody::createEdgePolygon(const Vec2* points, int count, const PhysicsMaterial& material, float border /* = 1*/) { PhysicsBody* body = new PhysicsBody(); if (body->init()) { body->addShape(PhysicsShapeEdgePolygon::create(points, count, material, border)); body->setDynamic(false); body->autorelease(); return body; } AX_SAFE_DELETE(body); return nullptr; } PhysicsBody* PhysicsBody::createEdgeChain(const Vec2* points, int count, const PhysicsMaterial& material, float border /* = 1*/) { PhysicsBody* body = new PhysicsBody(); if (body->init()) { body->addShape(PhysicsShapeEdgeChain::create(points, count, material, border)); body->setDynamic(false); body->autorelease(); return body; } AX_SAFE_DELETE(body); return nullptr; } bool PhysicsBody::init() { do { _cpBody = cpBodyNew(_mass, _moment); internalBodySetMass(_cpBody, _mass); cpBodySetUserData(_cpBody, this); cpBodySetVelocityUpdateFunc(_cpBody, internalBodyUpdateVelocity); AX_BREAK_IF(_cpBody == nullptr); return true; } while (false); return false; } void PhysicsBody::removeJoint(PhysicsJoint* joint) { auto it = std::find(_joints.begin(), _joints.end(), joint); if (it != _joints.end()) { _joints.erase(it); } } void PhysicsBody::setDynamic(bool dynamic) { if (dynamic != _dynamic) { _dynamic = dynamic; if (dynamic) { cpBodySetType(_cpBody, CP_BODY_TYPE_DYNAMIC); internalBodySetMass(_cpBody, _mass); cpBodySetMoment(_cpBody, _moment); } else { cpBodySetType(_cpBody, CP_BODY_TYPE_KINEMATIC); } } } void PhysicsBody::setRotationEnable(bool enable) { if (_rotationEnabled != enable) { cpBodySetMoment(_cpBody, enable ? _moment : PHYSICS_INFINITY); _rotationEnabled = enable; } } void PhysicsBody::setGravityEnable(bool enable) { _gravityEnabled = enable; } void PhysicsBody::setRotation(float rotation) { _recordedRotation = rotation; _recordedAngle = -(rotation + _rotationOffset) * (M_PI / 180.0); cpBodySetAngle(_cpBody, _recordedAngle); } void PhysicsBody::setScale(float scaleX, float scaleY) { for (auto&& shape : _shapes) { _area -= shape->getArea(); if (!_massSetByUser) addMass(-shape->getMass()); if (!_momentSetByUser) addMoment(-shape->getMoment()); shape->setScale(scaleX, scaleY); _area += shape->getArea(); if (!_massSetByUser) addMass(shape->getMass()); if (!_momentSetByUser) addMoment(shape->getMoment()); } } void PhysicsBody::setPosition(float positionX, float positionY) { cpVect tt; tt.x = positionX + _positionOffset.x; tt.y = positionY + _positionOffset.y; cpBodySetPosition(_cpBody, tt); } Vec2 PhysicsBody::getPosition() const { cpVect tt = cpBodyGetPosition(_cpBody); return Vec2(tt.x - _positionOffset.x, tt.y - _positionOffset.y); } void PhysicsBody::setPositionOffset(const Vec2& position) { if (!_positionOffset.equals(position)) { Vec2 pos = getPosition(); _positionOffset = position; setPosition(pos.x, pos.y); } } float PhysicsBody::getRotation() { if (_recordedAngle != cpBodyGetAngle(_cpBody)) { _recordedAngle = cpBodyGetAngle(_cpBody); _recordedRotation = -_recordedAngle * 180.0 / M_PI - _rotationOffset; } return _recordedRotation; } PhysicsShape* PhysicsBody::addShape(PhysicsShape* shape, bool addMassAndMoment /* = true*/) { if (shape == nullptr) return nullptr; // add shape to body if (_shapes.getIndex(shape) == -1) { shape->setBody(this); // calculate the area, mass, and density // area must update before mass, because the density changes depend on it. if (addMassAndMoment) { _area += shape->getArea(); addMass(shape->getMass()); addMoment(shape->getMoment()); } if (_world && cpBodyGetSpace(_cpBody)) { _world->addShape(shape); } _shapes.pushBack(shape); } return shape; } void PhysicsBody::applyForce(const Vec2& force, const Vec2& offset) { if (_dynamic && _mass != PHYSICS_INFINITY) { cpBodyApplyForceAtLocalPoint(_cpBody, PhysicsHelper::vec22cpv(force), PhysicsHelper::vec22cpv(offset)); } } void PhysicsBody::resetForces() { cpBodySetForce(_cpBody, PhysicsHelper::vec22cpv(Vec2(0, 0))); } void PhysicsBody::applyImpulse(const Vec2& impulse, const Vec2& offset) { cpBodyApplyImpulseAtLocalPoint(_cpBody, PhysicsHelper::vec22cpv(impulse), PhysicsHelper::vec22cpv(offset)); } void PhysicsBody::applyTorque(float torque) { cpBodySetTorque(_cpBody, torque); } void PhysicsBody::setMass(float mass) { if (mass <= 0) { return; } _mass = mass; _massDefault = false; _massSetByUser = true; // update density if (_mass == PHYSICS_INFINITY) { _density = PHYSICS_INFINITY; } else { if (_area > 0) { _density = _mass / _area; } else { _density = 0; } } // the static body's mass and moment is always infinity if (_dynamic) { internalBodySetMass(_cpBody, _mass); } } void PhysicsBody::addMass(float mass) { if (mass == PHYSICS_INFINITY) { _mass = PHYSICS_INFINITY; _massDefault = false; _density = PHYSICS_INFINITY; } else if (mass == -PHYSICS_INFINITY) { return; } else { if (_massDefault) { _mass = 0; _massDefault = false; } if (_mass + mass > 0) { _mass += mass; } else { _mass = MASS_DEFAULT; _massDefault = true; } if (_area > 0) { _density = _mass / _area; } else { _density = 0; } } // the static body's mass and moment is always infinity if (_dynamic) { internalBodySetMass(_cpBody, _mass); } } void PhysicsBody::addMoment(float moment) { if (moment == PHYSICS_INFINITY) { // if moment is PHYSICS_INFINITY, the moment of the body will become PHYSICS_INFINITY _moment = PHYSICS_INFINITY; _momentDefault = false; } else if (moment == -PHYSICS_INFINITY) { return; } else { // if moment of the body is PHYSICS_INFINITY is has no effect if (_moment != PHYSICS_INFINITY) { if (_momentDefault) { _moment = 0; _momentDefault = false; } if (_moment + moment > 0) { _moment += moment; } else { _moment = MOMENT_DEFAULT; _momentDefault = true; } } } // the static body's mass and moment is always infinity if (_rotationEnabled && _dynamic) { cpBodySetMoment(_cpBody, _moment); } } void PhysicsBody::setVelocity(const Vec2& velocity) { if (cpBodyGetType(_cpBody) == CP_BODY_TYPE_STATIC) { AXLOGD("physics warning: you can't set velocity for a static body."); return; } cpBodySetVelocity(_cpBody, PhysicsHelper::vec22cpv(velocity)); } Vec2 PhysicsBody::getVelocity() { return PhysicsHelper::cpv2vec2(cpBodyGetVelocity(_cpBody)); } Vec2 PhysicsBody::getVelocityAtLocalPoint(const Vec2& point) { return PhysicsHelper::cpv2vec2(cpBodyGetVelocityAtLocalPoint(_cpBody, PhysicsHelper::vec22cpv(point))); } Vec2 PhysicsBody::getVelocityAtWorldPoint(const Vec2& point) { return PhysicsHelper::cpv2vec2(cpBodyGetVelocityAtWorldPoint(_cpBody, PhysicsHelper::vec22cpv(point))); } void PhysicsBody::setAngularVelocity(float velocity) { if (cpBodyGetType(_cpBody) == CP_BODY_TYPE_STATIC) { AXLOGD("physics warning: you can't set angular velocity for a static body."); return; } cpBodySetAngularVelocity(_cpBody, velocity); } float PhysicsBody::getAngularVelocity() { return PhysicsHelper::cpfloat2float(cpBodyGetAngularVelocity(_cpBody)); } void PhysicsBody::setVelocityLimit(float limit) { _velocityLimit = limit; } float PhysicsBody::getVelocityLimit() { return _velocityLimit; } void PhysicsBody::setAngularVelocityLimit(float limit) { _angularVelocityLimit = limit; } float PhysicsBody::getAngularVelocityLimit() { return _angularVelocityLimit; } void PhysicsBody::setMoment(float moment) { _moment = moment; _momentDefault = false; _momentSetByUser = true; // the static body's mass and moment is always infinity if (_rotationEnabled && _dynamic) { cpBodySetMoment(_cpBody, _moment); } } PhysicsShape* PhysicsBody::getShape(int tag) const { for (auto&& shape : _shapes) { if (shape->getTag() == tag) { return shape; } } return nullptr; } void PhysicsBody::removeShape(int tag, bool reduceMassAndMoment /* = true*/) { for (auto&& shape : _shapes) { if (shape->getTag() == tag) { removeShape(shape, reduceMassAndMoment); return; } } } void PhysicsBody::removeShape(PhysicsShape* shape, bool reduceMassAndMoment /* = true*/) { if (_shapes.getIndex(shape) != -1) { // deduce the area, mass and moment // area must update before mass, because the density changes depend on it. if (reduceMassAndMoment) { _area -= shape->getArea(); addMass(-shape->getMass()); addMoment(-shape->getMoment()); } // remove if (_world) { _world->removeShape(shape); } // set shape->_body = nullptr make the shape->setBody will not trigger the _body->removeShape function call. shape->_body = nullptr; shape->setBody(nullptr); _shapes.eraseObject(shape); } } void PhysicsBody::removeAllShapes(bool reduceMassAndMoment /* = true*/) { for (auto&& child : _shapes) { PhysicsShape* shape = dynamic_cast(child); // deduce the area, mass and moment // area must update before mass, because the density changes depend on it. if (reduceMassAndMoment) { _area -= shape->getArea(); addMass(-shape->getMass()); addMoment(-shape->getMoment()); } if (_world) { _world->removeShape(shape); } // set shape->_body = nullptr make the shape->setBody will not trigger the _body->removeShape function call. shape->_body = nullptr; shape->setBody(nullptr); } _shapes.clear(); } void PhysicsBody::removeFromWorld() { removeFromPhysicsWorld(); } void PhysicsBody::setEnabled(bool enable) { if (_enabled != enable) { _enabled = enable; if (_world) { if (enable) { _world->addBodyOrDelay(this); } else { _world->removeBodyOrDelay(this); } } } } bool PhysicsBody::isResting() const { return cpBodyIsSleeping(_cpBody) != cpFalse; } void PhysicsBody::setResting(bool rest) const { if (rest && !isResting()) { cpBodySleep(_cpBody); } else if (!rest && isResting()) { cpBodyActivate(_cpBody); } } void PhysicsBody::update(float delta) { // damping compute if (!_fixedUpdate && _isDamping && _dynamic && !isResting()) { _cpBody->v.x *= cpfclamp(1.0f - delta * _linearDamping, 0.0f, 1.0f); _cpBody->v.y *= cpfclamp(1.0f - delta * _linearDamping, 0.0f, 1.0f); _cpBody->w *= cpfclamp(1.0f - delta * _angularDamping, 0.0f, 1.0f); } } void PhysicsBody::fixedUpdate(float delta) { if (_fixedUpdate && _isDamping && _dynamic && !isResting()) { _cpBody->v.x *= cpfclamp(1.0f - delta * _linearDamping, 0.0f, 1.0f); _cpBody->v.y *= cpfclamp(1.0f - delta * _linearDamping, 0.0f, 1.0f); _cpBody->w *= cpfclamp(1.0f - delta * _angularDamping, 0.0f, 1.0f); } } void PhysicsBody::setCategoryBitmask(int bitmask) { for (auto&& shape : _shapes) { shape->setCategoryBitmask(bitmask); } } int PhysicsBody::getCategoryBitmask() const { if (!_shapes.empty()) { return _shapes.front()->getCategoryBitmask(); } else { return UINT_MAX; } } void PhysicsBody::setContactTestBitmask(int bitmask) { for (auto&& shape : _shapes) { shape->setContactTestBitmask(bitmask); } } int PhysicsBody::getContactTestBitmask() const { if (!_shapes.empty()) { return _shapes.front()->getContactTestBitmask(); } else { return 0x00000000; } } void PhysicsBody::setCollisionBitmask(int bitmask) { for (auto&& shape : _shapes) { shape->setCollisionBitmask(bitmask); } } int PhysicsBody::getCollisionBitmask() const { if (!_shapes.empty()) { return _shapes.front()->getCollisionBitmask(); } else { return UINT_MAX; } } void PhysicsBody::setGroup(int group) { for (auto&& shape : _shapes) { shape->setGroup(group); } } int PhysicsBody::getGroup() const { if (!_shapes.empty()) { return _shapes.front()->getGroup(); } else { return 0; } } void PhysicsBody::setRotationOffset(float rotation) { if (std::abs(_rotationOffset - rotation) > 0.5f) { float rot = getRotation(); _rotationOffset = rotation; setRotation(rot); } } Vec2 PhysicsBody::world2Local(const Vec2& point) { return PhysicsHelper::cpv2vec2(cpBodyWorldToLocal(_cpBody, PhysicsHelper::vec22cpv(point))); } Vec2 PhysicsBody::local2World(const Vec2& point) { return PhysicsHelper::cpv2vec2(cpBodyLocalToWorld(_cpBody, PhysicsHelper::vec22cpv(point))); } void PhysicsBody::beforeSimulation(const Mat4& parentToWorldTransform, const Mat4& nodeToWorldTransform, float scaleX, float scaleY, float rotation) { if (_recordScaleX != scaleX || _recordScaleY != scaleY) { _recordScaleX = scaleX; _recordScaleY = scaleY; setScale(scaleX, scaleY); } // set rotation if (_recordedRotation != rotation) { setRotation(rotation); } // set position auto worldPosition = _ownerCenterOffset; nodeToWorldTransform.transformVector(worldPosition.x, worldPosition.y, worldPosition.z, 1.f, &worldPosition); setPosition(worldPosition.x, worldPosition.y); _recordPosX = worldPosition.x; _recordPosY = worldPosition.y; if (_owner->getAnchorPoint() != Vec2::ANCHOR_MIDDLE) { parentToWorldTransform.getInversed().transformVector(worldPosition.x, worldPosition.y, worldPosition.z, 1.f, &worldPosition); _offset.x = worldPosition.x - _owner->getPositionX(); _offset.y = worldPosition.y - _owner->getPositionY(); } } void PhysicsBody::afterSimulation(const Mat4& parentToWorldTransform, float parentRotation) { // set Node position auto tmp = getPosition(); Vec3 positionInParent(tmp.x, tmp.y, 0.f); if (_recordPosX != positionInParent.x || _recordPosY != positionInParent.y) { parentToWorldTransform.getInversed().transformVector(positionInParent.x, positionInParent.y, positionInParent.z, 1.f, &positionInParent); _owner->setPosition(positionInParent.x - _offset.x, positionInParent.y - _offset.y); } // set Node rotation _owner->setRotation(getRotation() - parentRotation); } void PhysicsBody::onEnter() { addToPhysicsWorld(); } void PhysicsBody::onExit() { removeFromPhysicsWorld(); } void PhysicsBody::onAdd() { _owner->_physicsBody = this; auto contentSize = _owner->getContentSize(); _ownerCenterOffset.x = 0.5f * contentSize.width; _ownerCenterOffset.y = 0.5f * contentSize.height; setRotationOffset(_owner->getRotation()); // component may be added after onEnter() has been invoked, so we should add // this line to make sure physics body is added to physics world addToPhysicsWorld(); } void PhysicsBody::onRemove() { AXASSERT(_owner != nullptr, "_owner can't be nullptr"); removeFromPhysicsWorld(); _owner->_physicsBody = nullptr; } void PhysicsBody::addToPhysicsWorld() { if (_owner) { auto scene = _owner->getScene(); if (scene) scene->getPhysicsWorld()->addBody(this); } } void PhysicsBody::removeFromPhysicsWorld() { if (_owner) { auto scene = _owner->getScene(); if (scene) scene->getPhysicsWorld()->removeBody(this); } } NS_AX_END #endif // defined(AX_ENABLE_PHYSICS)