NazaraEngine/SDK/src/NDK/Systems/PhysicsSystem.cpp

139 lines
4.1 KiB
C++

// Copyright (C) 2015 Jérôme Leclercq
// This file is part of the "Nazara Development Kit"
// For conditions of distribution and use, see copyright notice in Prerequesites.hpp
#include <NDK/Systems/PhysicsSystem.hpp>
#include <Nazara/Physics/PhysObject.hpp>
#include <NDK/Components/CollisionComponent.hpp>
#include <NDK/Components/NodeComponent.hpp>
#include <NDK/Components/PhysicsComponent.hpp>
namespace Ndk
{
/*!
* \ingroup NDK
* \class Ndk::PhysicsSystem
* \brief NDK class that represents the physics system
*
* \remark This system is enabled if the entity has the trait: NodeComponent and any of these two: CollisionComponent or PhysicsComponent
* \remark Static objects do not have a velocity specified by the physical engine
*/
/*!
* \brief Constructs an PhysicsSystem object by default
*/
PhysicsSystem::PhysicsSystem()
{
Requires<NodeComponent>();
RequiresAny<CollisionComponent, PhysicsComponent>();
}
/*!
* \brief Constructs a PhysicsSystem object by copy semantic
*
* \param system PhysicsSystem to copy
*/
PhysicsSystem::PhysicsSystem(const PhysicsSystem& system) :
System(system),
m_world()
{
}
void PhysicsSystem::CreatePhysWorld() const
{
NazaraAssert(!m_world, "Physics world should not be created twice");
m_world = std::make_unique<Nz::PhysWorld>();
}
/*!
* \brief Operation to perform when entity is validated for the system
*
* \param entity Pointer to the entity
* \param justAdded Is the entity newly added
*/
void PhysicsSystem::OnEntityValidation(Entity* entity, bool justAdded)
{
// It's possible our entity got revalidated because of the addition/removal of a PhysicsComponent
if (!justAdded)
{
// We take the opposite array from which the entity should belong to
auto& entities = (entity->HasComponent<PhysicsComponent>()) ? m_staticObjects : m_dynamicObjects;
entities.Remove(entity);
}
auto& entities = (entity->HasComponent<PhysicsComponent>()) ? m_dynamicObjects : m_staticObjects;
entities.Insert(entity);
if (!m_world)
CreatePhysWorld();
}
/*!
* \brief Operation to perform when system is updated
*
* \param elapsedTime Delta time used for the update
*/
void PhysicsSystem::OnUpdate(float elapsedTime)
{
if (!m_world)
return;
m_world->Step(elapsedTime);
for (const Ndk::EntityHandle& entity : m_dynamicObjects)
{
NodeComponent& node = entity->GetComponent<NodeComponent>();
PhysicsComponent& phys = entity->GetComponent<PhysicsComponent>();
Nz::PhysObject& physObj = phys.GetPhysObject();
node.SetRotation(physObj.GetRotation(), Nz::CoordSys_Global);
node.SetPosition(physObj.GetPosition(), Nz::CoordSys_Global);
}
float invElapsedTime = 1.f / elapsedTime;
for (const Ndk::EntityHandle& entity : m_staticObjects)
{
CollisionComponent& collision = entity->GetComponent<CollisionComponent>();
NodeComponent& node = entity->GetComponent<NodeComponent>();
Nz::PhysObject* physObj = collision.GetStaticBody();
Nz::Quaternionf oldRotation = physObj->GetRotation();
Nz::Vector3f oldPosition = physObj->GetPosition();
Nz::Quaternionf newRotation = node.GetRotation(Nz::CoordSys_Global);
Nz::Vector3f newPosition = node.GetPosition(Nz::CoordSys_Global);
// To move static objects and ensure their collisions, we have to specify them a velocity
// (/!\: the physical motor does not apply the speed on static objects)
if (newPosition != oldPosition)
{
physObj->SetPosition(newPosition);
physObj->SetVelocity((newPosition - oldPosition) * invElapsedTime);
}
else
physObj->SetVelocity(Nz::Vector3f::Zero());
if (newRotation != oldRotation)
{
Nz::Quaternionf transition = newRotation * oldRotation.GetConjugate();
Nz::EulerAnglesf angles = transition.ToEulerAngles();
Nz::Vector3f angularVelocity(Nz::ToRadians(angles.pitch * invElapsedTime),
Nz::ToRadians(angles.yaw * invElapsedTime),
Nz::ToRadians(angles.roll * invElapsedTime));
physObj->SetRotation(oldRotation);
physObj->SetAngularVelocity(angularVelocity);
}
else
physObj->SetAngularVelocity(Nz::Vector3f::Zero());
}
}
SystemIndex PhysicsSystem::systemIndex;
}