Files
Seele/src/Engine/Physics/PhysicsSystem.h
T

144 lines
4.9 KiB
C++

#pragma once
#include <entt/entt.hpp>
#include "MinimalEngine.h"
#include "Component/Transform.h"
#include "Component/RigidBody.h"
#include "Component/Collider.h"
#include "CollisionSystem.h"
namespace Seele
{
class PhysicsSystem
{
public:
PhysicsSystem(entt::registry& registry);
~PhysicsSystem();
void update(float deltaTime);
private:
struct Body
{
entt::entity id = entt::entity();
float inverseMass = 0.0f;
Vector centerOfMass = Vector();
Matrix3 iBody = Matrix3(), iBodyInv = Matrix3();
Vector scale = Vector();
Vector x = Vector();
Quaternion q = Quaternion();
Vector P = Vector();
Vector L = Vector();
Matrix3 iInv = Matrix3();
Matrix3 R = Matrix3();
Vector v = Vector();
Vector omega = Vector();
Vector force = Vector();
Vector torque = Vector();
Matrix4 matrix = Matrix4();
Vector ptVelocity(Vector p) const {return v + glm::cross(omega, p - x + centerOfMass);}
void updateMatrix() {
Matrix4 scaleMatrix = glm::scale(Matrix4(1), scale);
Matrix4 rotationMatrix = glm::mat4_cast(q);
Matrix4 translationMatrix = glm::translate(Matrix4(1), x);
matrix = translationMatrix * rotationMatrix * scaleMatrix;
}
Body()
{}
Body(entt::entity id, const Component::RigidBody& physics, const Component::Collider& collider, const Component::Transform& transform)
: id(id)
, inverseMass(1 / (physics.mass * glm::length(transform.getScale())))
, centerOfMass(collider.physicsMesh.centerOfMass)
, iBody(collider.physicsMesh.bodyInertia)
, iBodyInv(glm::inverse(collider.physicsMesh.bodyInertia))
, scale(transform.getScale())
, x(transform.getPosition())
, q(transform.getRotation())
, P(physics.linearMomentum)
, L(physics.angularMomentum)
, iInv(glm::mat3())
, R(glm::mat3())
, v(Vector())
, omega(Vector())
, force(physics.force)
, torque(physics.torque)
{
v = P * inverseMass;
R = glm::mat3_cast(glm::normalize(q));
iInv = R * iBodyInv * glm::transpose(R);
omega = iInv * L;
}
Body(entt::entity id, const Component::Collider& collider, const Component::Transform& transform)
: id(id)
, inverseMass(0)
, centerOfMass(collider.physicsMesh.centerOfMass)
, iBody(glm::mat3(0))
, iBodyInv(glm::mat3(0))
, scale(transform.getScale())
, x(transform.getPosition())
, q(transform.getRotation())
, P(Vector(0))
, L(Vector(0))
, iInv(glm::mat3())
, R(glm::mat3())
, v(Vector())
, omega(Vector())
, force(Vector(0))
, torque(Vector(0))
{
R = glm::mat3_cast(glm::normalize(q));
iInv = R * iBodyInv * glm::transpose(R);
omega = iInv * L;
}
};
struct Contact
{
entt::entity a, b;
glm::vec3 p;
glm::vec3 n;
glm::vec3 ea;
glm::vec3 eb;
bool vf;
};
static constexpr size_t FLOATS_PER_RB = 13;
entt::registry& registry;
CollisionSystem collisionSystem;
bool pause = false;
void serializeRB(const Body& rb, float* y) const;
void deserializeRB(Body& rb, const float* y) const;
void serializeArray(const Array<Body>& bodies, Array<float>& x) const;
void deserializeArray(Array<Body>& bodies, const Array<float>& x) const;
void readRigidBodies(Array<Body>& bodies) const;
void writeRigidBodies(const Array<Body>& bodies) const;
Body readRigidBody(entt::entity entity) const;
void writeRigidBody(const Body& body) const;
Array<Body> integratePhysics(const Array<Body>& bodies, const float t0, const float tdelta) const;
void rewindCollisions(const Array<Body>& t0Bodies, const float t0, const float t1, size_t remainingDepth);
void calculateContacts(entt::entity id1, const Component::ShapeBase& shape1, entt::entity id2, const Component::ShapeBase& shape2, Array<Contact>& contacts) const;
void resolveRestingContacts(const Array<Contact>& contacts) const;
void resolvePenetratingContact(const Contact& c, Body& a, Body& b) const;
Vector computeNdot(const Contact& c, const Body& a, const Body& b) const;
float computeAij(const Contact& ci, const Contact& cj) const;
void computeAMatrix(const Array<Contact>& contacts, Array<Array<float>>& amat) const;
void computeBVector(const Array<Contact>& contacts, Array<float>& avec) const;
void solveQP(const Array<Array<float>>& A, const Array<float>& b, Array<float>& f) const;
};
} // namespace Seele