NazaraEngine/src/Nazara/Physics3D/PhysWorld3D.cpp

137 lines
3.8 KiB
C++

// Copyright (C) 2023 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
// This file is part of the "Nazara Engine - Physics3D module"
// For conditions of distribution and use, see copyright notice in Config.hpp
#include <Nazara/Physics3D/PhysWorld3D.hpp>
#include <Nazara/Physics3D/BulletHelper.hpp>
#include <Nazara/Utils/MemoryPool.hpp>
#include <Nazara/Utils/StackVector.hpp>
#include <BulletCollision/BroadphaseCollision/btDbvtBroadphase.h>
#include <BulletCollision/CollisionDispatch/btCollisionDispatcher.h>
#include <BulletCollision/CollisionDispatch/btDefaultCollisionConfiguration.h>
#include <BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.h>
#include <BulletDynamics/Dynamics/btDiscreteDynamicsWorld.h>
#include <cassert>
#include <Nazara/Physics3D/Debug.hpp>
namespace Nz
{
struct PhysWorld3D::BulletWorld
{
btDefaultCollisionConfiguration collisionConfiguration;
btCollisionDispatcher dispatcher;
btDbvtBroadphase broadphase;
btSequentialImpulseConstraintSolver constraintSolver;
btDiscreteDynamicsWorld dynamicWorld;
MemoryPool<btRigidBody> rigidBodyPool;
BulletWorld() :
dispatcher(&collisionConfiguration),
dynamicWorld(&dispatcher, &broadphase, &constraintSolver, &collisionConfiguration),
rigidBodyPool(256)
{
}
BulletWorld(const BulletWorld&) = delete;
BulletWorld(BulletWorld&&) = delete;
BulletWorld& operator=(const BulletWorld&) = delete;
BulletWorld& operator=(BulletWorld&&) = delete;
};
PhysWorld3D::PhysWorld3D() :
m_maxStepCount(50),
m_gravity(Vector3f::Zero()),
m_stepSize(Time::TickDuration(120)),
m_timestepAccumulator(Time::Zero())
{
m_world = std::make_unique<BulletWorld>();
}
PhysWorld3D::~PhysWorld3D() = default;
btDynamicsWorld* PhysWorld3D::GetDynamicsWorld()
{
return &m_world->dynamicWorld;
}
Vector3f PhysWorld3D::GetGravity() const
{
return FromBullet(m_world->dynamicWorld.getGravity());
}
std::size_t PhysWorld3D::GetMaxStepCount() const
{
return m_maxStepCount;
}
Time PhysWorld3D::GetStepSize() const
{
return m_stepSize;
}
void PhysWorld3D::SetGravity(const Vector3f& gravity)
{
m_world->dynamicWorld.setGravity(ToBullet(gravity));
}
void PhysWorld3D::SetMaxStepCount(std::size_t maxStepCount)
{
m_maxStepCount = maxStepCount;
}
void PhysWorld3D::SetStepSize(Time stepSize)
{
m_stepSize = stepSize;
}
void PhysWorld3D::Step(Time timestep)
{
m_timestepAccumulator += timestep;
btScalar stepSize = m_stepSize.AsSeconds<btScalar>();
std::size_t stepCount = 0;
while (m_timestepAccumulator >= m_stepSize && stepCount < m_maxStepCount)
{
m_world->dynamicWorld.stepSimulation(stepSize, 0, stepSize);
m_timestepAccumulator -= m_stepSize;
stepCount++;
}
}
btRigidBody* PhysWorld3D::AddRigidBody(std::size_t& rigidBodyIndex, FunctionRef<void(btRigidBody* body)> constructor)
{
btRigidBody* rigidBody = m_world->rigidBodyPool.Allocate(m_world->rigidBodyPool.DeferConstruct, rigidBodyIndex);
constructor(rigidBody);
m_world->dynamicWorld.addRigidBody(rigidBody);
// Small hack to order rigid bodies to make it cache friendly
auto& rigidBodies = m_world->dynamicWorld.getNonStaticRigidBodies();
if (rigidBodies.size() >= 2 && rigidBodies[rigidBodies.size() - 1] == rigidBody)
{
// Sort rigid bodies
btRigidBody** startPtr = &rigidBodies[0];
btRigidBody** endPtr = startPtr + rigidBodies.size();
btRigidBody** lastPtr = endPtr - 1;
auto it = std::lower_bound(startPtr, endPtr, rigidBody);
if (it != lastPtr)
{
std::move_backward(it, lastPtr, endPtr);
*it = rigidBody;
}
}
return rigidBody;
}
void PhysWorld3D::RemoveRigidBody(btRigidBody* rigidBody, std::size_t rigidBodyIndex)
{
// TODO: Improve deletion (since rigid bodies are sorted)
m_world->dynamicWorld.removeRigidBody(rigidBody); //< this does a linear search
m_world->rigidBodyPool.Free(rigidBodyIndex);
}
}