void JelloMesh::Update(double dt, const World& world, const vec3& externalForces)
{
m_externalForces = externalForces;
CheckForCollisions(m_vparticles, world);
ComputeForces(m_vparticles);
ResolveContacts(m_vparticles);
ResolveCollisions(m_vparticles);
switch (m_integrationType)
{
case EULER: EulerIntegrate(dt); break;
case MIDPOINT: MidPointIntegrate(dt); break;
case RK4: RK4Integrate(dt); break;
}
}
void CPhysEnv::Simulate(float DeltaTime, BOOL running)
{
float CurrentTime = 0.0f;
float TargetTime = DeltaTime;
tParticle *tempSys;
int collisionState;
while(CurrentTime < DeltaTime)
{
if (running)
{
ComputeForces(m_CurrentSys);
// IN ORDER TO MAKE THINGS RUN FASTER, I HAVE THIS LITTLE TRICK
// IF THE SYSTEM IS DOING A BINARY SEARCH FOR THE COLLISION POINT,
// I FORCE EULER'S METHOD ON IT. OTHERWISE, LET THE USER CHOOSE.
// THIS DOESN'T SEEM TO EFFECT STABILITY EITHER WAY
if (m_CollisionRootFinding)
{
EulerIntegrate(TargetTime-CurrentTime);
}
else
{
switch (m_IntegratorType)
{
case EULER_INTEGRATOR:
EulerIntegrate(TargetTime-CurrentTime);
break;
case MIDPOINT_INTEGRATOR:
MidPointIntegrate(TargetTime-CurrentTime);
break;
case HEUN_INTEGRATOR:
HeunIntegrate(TargetTime-CurrentTime);
break;
case RK4_INTEGRATOR:
RK4Integrate(TargetTime-CurrentTime);
break;
case RK4_ADAPTIVE_INTEGRATOR:
RK4AdaptiveIntegrate(TargetTime-CurrentTime);
break;
case FEHLBERG:
FehlbergIntegrate(TargetTime-CurrentTime);
break;
}
}
}
collisionState = CheckForCollisions(m_TargetSys);
if(collisionState == PENETRATING)
{
// TELL THE SYSTEM I AM LOOKING FOR A COLLISION SO IT WILL USE EULER
m_CollisionRootFinding = TRUE;
// we simulated too far, so subdivide time and try again
TargetTime = (CurrentTime + TargetTime) / 2.0f;
// blow up if we aren't moving forward each step, which is
// probably caused by interpenetration at the frame start
assert(fabs(TargetTime - CurrentTime) > EPSILON);
}
else
{
// either colliding or clear
if(collisionState == COLLIDING)
{
int Counter = 0;
do
{
ResolveCollisions(m_TargetSys);
Counter++;
} while((CheckForCollisions(m_TargetSys) ==
COLLIDING) && (Counter < 100));
assert(Counter < 100);
m_CollisionRootFinding = FALSE; // FOUND THE COLLISION POINT
}
// we made a successful step, so swap configurations
// to "save" the data for the next step
CurrentTime = TargetTime;
TargetTime = DeltaTime;
// SWAP MY TWO PARTICLE SYSTEM BUFFERS SO I CAN DO IT AGAIN
tempSys = m_CurrentSys;
m_CurrentSys = m_TargetSys;
m_TargetSys = tempSys;
}
}
}
