void CollisionSolver::SolveParticleSphereCollision(CollisionMesh& particle,
const CollisionMesh& sphere)
{
D3DXVECTOR3 sphereToParticle = particle.GetPosition() - sphere.GetPosition();
const float lengthSqr = D3DXVec3LengthSq(&sphereToParticle);
const float combinedRadius = sphere.GetRadius() + particle.GetRadius();
if (lengthSqr < (combinedRadius*combinedRadius))
{
const float length = std::sqrt(lengthSqr);
sphereToParticle /= length;
particle.ResolveCollision(sphereToParticle * fabs(combinedRadius-length),
sphere.GetVelocity(), sphere.GetShape());
}
}
void CollisionSolver::SolveParticleCollision(CollisionMesh& particleA,
CollisionMesh& particleB)
{
D3DXVECTOR3 particleToParticle = particleB.GetPosition() - particleA.GetPosition();
const float lengthSqr = D3DXVec3LengthSq(&particleToParticle);
const float combinedRadius = particleA.GetRadius() + particleB.GetRadius();
if (lengthSqr < (combinedRadius*combinedRadius))
{
const float length = std::sqrt(lengthSqr);
particleToParticle /= std::sqrt(length);
const D3DXVECTOR3 translation = particleToParticle*fabs(combinedRadius-length);
particleA.ResolveCollision(-translation);
particleB.ResolveCollision(translation);
}
}
void CollisionSolver::SolveParticleHullCollision(CollisionMesh& particle,
const CollisionMesh& hull)
{
// Determine if within a rough radius of the convex hull
const D3DXVECTOR3 sphereToParticle = particle.GetPosition() - hull.GetPosition();
const float lengthSqr = D3DXVec3LengthSq(&sphereToParticle);
const float extendedParticleRadius = particle.GetRadius() * 2.0f;
const float combinedRadius = hull.GetRadius() + extendedParticleRadius;
if (lengthSqr < (combinedRadius*combinedRadius))
{
Simplex simplex;
if(AreConvexHullsColliding(particle, hull, simplex))
{
simplex.GenerateFaces();
const D3DXVECTOR3 penetration = GetConvexHullPenetration(particle, hull, simplex);
particle.ResolveCollision(penetration, hull.GetVelocity(), hull.GetShape());
}
}
}