private void Integrate(CPosition position, CKinetic kinetic, Integrator integrator, float deltaTime)
{
switch (integrator)
{
case Integrator.SemiImplictEuler:
SemiImplictEulerIntegration();
break;
case Integrator.VelocityVerlet:
VelocityVerletIntegration();
break;
}
void SemiImplictEulerIntegration()
{
kinetic.Velocity += kinetic.Acceleration * deltaTime;
position.X += kinetic.Velocity.X * deltaTime;
position.Y += kinetic.Velocity.Y * deltaTime;
}
void VelocityVerletIntegration()
{
position.X += kinetic.Velocity.X * deltaTime + 0.5f * kinetic.Acceleration.X * deltaTime * deltaTime;
position.Y += kinetic.Velocity.Y * deltaTime + 0.5f * kinetic.Acceleration.Y * deltaTime * deltaTime;
kinetic.Velocity += kinetic.Acceleration * deltaTime;
}
}
private void Simultate(int entity)
{
CPosition position = (CPosition)positions[entity];
CKinetic kinetic = (CKinetic)kinetics[entity];
kinetic.Accumulator += (float)(Engine.TotalGameTime - kinetic.LastUpdate).TotalSeconds;
kinetic.LastUpdate = new TimeSpan(Engine.TotalGameTime.Ticks);
while (kinetic.Accumulator >= target)
{
Integrate(position, kinetic, integrator, target);
kinetic.Accumulator -= target;
}
}