#include "Log.hh"
+struct SpringForce
+{
+ explicit SpringForce(Mf::Vector2 x) :
+ location(x) {}
+
+ const Mf::Vector2& operator () (const Mf::LinearState<2>& state)
+ {
+ Mf::Vector2 x = state.position - location;
+ Mf::Scalar mag = x.length();
+ Mf::Scalar d = 50.0;
+
+ // spring:
+ //current.force += -15.0 * x - 1.5 * current.velocity;
+ force = -20.0 * (mag - d) * (x / mag) - 2.0 * state.velocity;
+
+ return force;
+ }
+
+private:
+
+ Mf::Vector2 force;
+ Mf::Vector2 location;
+};
+
+struct WindResistenceForce
+{
+ const Mf::Vector2& operator () (const Mf::LinearState<2>& state)
+ {
+ force = -2.0 * state.velocity;
+ return force;
+ }
+
+private:
+
+ Mf::Vector2 force;
+};
+
+
Character::Character(const std::string& name) :
tilemap_(name),
animation_(name)
{
+ current.init();
+
current.mass = 1.0;
current.inverseMass = 1.0 / current.mass;
// gravity
- current.force = Mf::Vector2(0.0, -120.0);
+ current.force = Mf::Vector2(0.0, 000.0);
+ current.forces.push_back(SpringForce(Mf::Vector2(500.0, 200.0)));
+ current.forces.push_back(WindResistenceForce());
+ current.forces.push_back(Mf::LinearState<2>::GravityForce(-2000.0));
// starting position
current.position = Mf::Vector2(64.0, 64.0);
{
previous = current;
- Mf::Vector2 x = current.position - Mf::Vector2(500.0, 200.0);
- Mf::Scalar mag = x.length();
- Mf::Scalar d = 50.0;
-
- // gravity:
- current.force = Mf::Vector2(0.0, -2000.0);
- // spring:
- //current.force += -15.0 * x - 1.5 * current.velocity;
- current.force += -20.0 * (mag - d) * (x / mag) - 2.0 * current.velocity;
- // internal:
- current.force += userForce;
- current.recalculate();
+ //Mf::Vector2 x = current.position - Mf::Vector2(500.0, 200.0);
+ //Mf::Scalar mag = x.length();
+ //Mf::Scalar d = 50.0;
+
+ //// gravity:
+ //current.force = Mf::Vector2(0.0, -2000.0);
+ //// spring:
+ ////current.force += -15.0 * x - 1.5 * current.velocity;
+ //current.force += -20.0 * (mag - d) * (x / mag) - 2.0 * current.velocity;
+ //// internal:
+ //current.force += userForce;
+ //current.recalculate();
//std::cout << "force: " << current.momentum << std::endl;
- Mf::euler<State,Derivative>(current, t, dt);
+ //Mf::euler<State,Derivative>(current, t, dt);
+
+ //current.force = Mf::Vector2(0.0, -2000.0);
+ current.force = userForce;
+ current.integrate(t, dt);
animation_.update(t, dt);
}
void Character::draw(Mf::Scalar alpha) const
{
- State state = cml::lerp(previous, current, alpha);
+ Mf::Vector2 position = cml::lerp(previous.position, current.position, alpha);
//glColor3f(1.0f, 1.0f, 1.0f);
tilemap_.bind();
glBegin(GL_TRIANGLE_FAN);
glTexCoord2f(coords[0], coords[1]);
- glVertex3(state.position[0]-s, state.position[1]-s, z);
+ glVertex3(position[0]-s, position[1]-s, z);
glTexCoord2f(coords[2], coords[3]);
- glVertex3(state.position[0]+s, state.position[1]-s, z);
+ glVertex3(position[0]+s, position[1]-s, z);
glTexCoord2f(coords[4], coords[5]);
- glVertex3(state.position[0]+s, state.position[1]+s, z);
+ glVertex3(position[0]+s, position[1]+s, z);
glTexCoord2f(coords[6], coords[7]);
- glVertex3(state.position[0]-s, state.position[1]+s, z);
+ glVertex3(position[0]-s, position[1]+s, z);
glEnd();
//glColor3f(0.0f, 0.0f, 0.0f);
#ifndef _MOOF_RK4_HH_
#define _MOOF_RK4_HH_
+#include <vector>
+
+#include <boost/bind.hpp>
+#include <boost/function.hpp>
+
#include <Moof/Math.hh>
namespace Mf {
+
// Generic implementations of a few simple integrators. To use, you need one
// type representing the state and another containing the derivatives of the
// primary state variables. The state class must implement these methods:
//
// void getDerivative(Derivative_Type& derivative, Scalar absoluteTime);
-// void applyDerivative(const Derivative_Type& derivative, Scalar deltaTime);
+// void step(const Derivative_Type& derivative, Scalar deltaTime);
//
// Additionally, the derivative class must overload a few operators:
//
}
template<typename S, typename D>
-inline D evaluate(const S& state, Scalar t, Scalar dt, const D& derivative)
+inline D evaluate(S state, Scalar t, Scalar dt, const D& derivative)
{
- S temp = state;
- temp.applyDerivative(derivative, dt);
- return evaluate<S,D>(temp, t + dt);
+ state.step(derivative, dt);
+ return evaluate<S,D>(state, t + dt);
}
{
D a = evaluate<S,D>(state, t);
- state.applyDerivative(a, dt);
+ state.step(a, dt);
}
template<typename S, typename D>
inline void rk2(S& state, Scalar t, Scalar dt)
{
D a = evaluate<S,D>(state, t);
- D b = evaluate<S,D>(state, t, dt * 0.5, a);
+ D b = evaluate<S,D>(state, t, dt * SCALAR(0.5), a);
- state.applyDerivative(b, dt);
+ state.step(b, dt);
}
template<typename S, typename D>
inline void rk4(S& state, Scalar t, Scalar dt)
{
D a = evaluate<S,D>(state, t);
- D b = evaluate<S,D>(state, t, dt * 0.5, a);
- D c = evaluate<S,D>(state, t, dt * 0.5, b);
+ D b = evaluate<S,D>(state, t, dt * SCALAR(0.5), a);
+ D c = evaluate<S,D>(state, t, dt * SCALAR(0.5), b);
D d = evaluate<S,D>(state, t, dt, c);
- state.applyDerivative((a + (b + c) * 2.0 + d) * (1.0/6.0), dt);
+ state.step((a + (b + c) * SCALAR(2.0) + d) * SCALAR(1.0/6.0), dt);
}
+//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+
+template <int D = 3>
+struct LinearState
+{
+ typedef cml::vector< Scalar, cml::fixed<D> > Vector;
+ typedef boost::function<const Vector& (const LinearState&)> ForceFunction;
+
+ // primary
+
+ Vector position;
+ Vector momentum;
+
+ // secondary
+
+ Vector velocity;
+
+ // user
+ //
+ Vector force;
+ std::vector<ForceFunction> forces;
+
+ // constant
+
+ Scalar mass;
+ Scalar inverseMass;
+
+
+ void recalculateLinear()
+ {
+ velocity = momentum * inverseMass;
+ }
+
+
+ struct GravityForce
+ {
+ explicit GravityForce(Scalar a = -9.8)
+ {
+ force.zero();
+ acceleration = a;
+ }
+
+ const Vector& operator () (const LinearState& state)
+ {
+ force[1] = state.mass * acceleration;
+ return force;
+ }
+
+ private:
+
+ Vector force;
+ Scalar acceleration;
+ };
+
+
+ void init()
+ {
+ position.zero();
+ momentum.zero();
+
+ velocity.zero();
+
+ force.zero();
+ forces.clear();
+
+ mass = SCALAR(1.0);
+ inverseMass = 1.0 / mass;
+ }
+
+
+ struct Derivative
+ {
+ Vector velocity;
+ Vector force;
+
+ Derivative operator*(Scalar dt) const
+ {
+ Derivative derivative;
+ derivative.velocity = dt * velocity;
+ derivative.force = dt * force;
+ return derivative;
+ }
+
+ Derivative operator+(const Derivative& other) const
+ {
+ Derivative derivative;
+ derivative.velocity = velocity + other.velocity;
+ derivative.force = force + other.force;
+ return derivative;
+ }
+ };
+
+
+ Vector getForce() const
+ {
+ Vector f(force);
+
+ for (size_t i = 0; i < forces.size(); ++i)
+ {
+ f += forces[i](*this);
+ }
+
+ return f;
+ }
+
+ void getDerivative(Derivative& derivative, Scalar t) const
+ {
+ derivative.velocity = velocity;
+ derivative.force = getForce();
+ }
+
+ void step(const Derivative& derivative, Scalar dt)
+ {
+ position += dt * derivative.velocity;
+ momentum += dt * derivative.force;
+ recalculateLinear();
+ }
+};
+
+
+struct RotationalState2
+{
+ // primary
+
+ Scalar orientation;
+ Scalar angularMomentum;
+
+ // secondary
+
+ Scalar angularVelocity;
+
+ // constant
+
+ Scalar inertia;
+ Scalar inverseInertia;
+
+
+ void recalculateRotational()
+ {
+ angularVelocity = angularMomentum * inertia;
+ }
+
+
+ struct Derivative
+ {
+ Scalar angularVelocity;
+ Scalar torque;
+ };
+
+ void step(const Derivative& derivative, Scalar dt)
+ {
+ orientation += dt * derivative.angularVelocity;
+ angularMomentum += dt * derivative.torque;
+ recalculateRotational();
+ }
+};
+
+struct RotationalState3
+{
+ // primary
+
+ Quaternion orientation;
+ Vector3 angularMomentum;
+
+ // secondary
+
+ Quaternion spin;
+ Vector3 angularVelocity;
+
+ // constant
+
+ Scalar inertia;
+ Scalar inverseInertia;
+};
+
+
+struct State2 : public LinearState<2>, public RotationalState2
+{
+ void recalculate()
+ {
+ recalculateLinear();
+ recalculateRotational();
+ }
+
+ void integrate(Scalar t, Scalar dt)
+ {
+ rk4<LinearState<2>,LinearState<2>::Derivative>(*this, t, dt);
+ }
+};
+
+struct State3 : public LinearState<3>, public RotationalState3 {};
+
+
} // namespace Mf
#endif // _MOOF_RK4_HH_
projects / chaz / yoink / commitdiff
