bool MFCollision_SphereSphereTest(const MFVector &pos1, float radius1, const MFVector &pos2, float radius2, MFCollisionResult *pResult)
{
MFVector diff = pos2 - pos1;
if(!pResult)
{
return diff.MagSquared3() < radius1*radius1 + radius2*radius2;
}
else
{
float length = diff.Magnitude3();
float totalRadius = radius1 + radius2;
pResult->bCollide = length < totalRadius;
if(pResult->bCollide)
{
pResult->depth = totalRadius - length;
pResult->normal = -diff.Normalise3();
pResult->intersectionPoint = diff * ((length / totalRadius) * (radius1 / radius2));
}
return pResult->bCollide;
}
}
void MFCollision_CalculateDynamicBoundingVolume(MFCollisionItem *pItem)
{
switch(pItem->pTemplate->type)
{
case MFCT_Mesh:
{
MFCollisionMesh *pMesh = (MFCollisionMesh*)pItem->pTemplate->pCollisionTemplateData;
MFBoundingVolume &vol = pItem->pTemplate->boundingVolume;
vol.min = vol.max = vol.boundingSphere = MakeVector(pMesh->pTriangles[0].verts[0], 0.0f);
for(int a=0; a<pMesh->numTris; a++)
{
MFCollisionTriangle &tri = pMesh->pTriangles[a];
for(int b=0; b<3; b++)
{
vol.min = MFMin(vol.min, tri.verts[b]);
vol.max = MFMin(vol.max, tri.verts[b]);
vol.min.w = vol.max.w = 0.0f;
// if point is outside bounding sphere
MFVector diff = tri.verts[b] - vol.boundingSphere;
float mag = diff.MagSquared3();
if(mag > vol.boundingSphere.w*vol.boundingSphere.w)
{
// fit sphere to include point
mag = MFSqrt(mag) - vol.boundingSphere.w;
mag *= 0.5f;
diff.Normalise3();
vol.boundingSphere.Mad3(diff, mag, vol.boundingSphere);
vol.boundingSphere.w += mag;
}
}
}
break;
}
default:
MFDebug_Assert(false, "Invalid item type");
}
}
MF_API void MFParticleSystem_AddParticle(MFParticleEmitter *pEmitter)
{
MFParticleEmitterParameters *pE = &pEmitter->params;
MFParticleSystem *pParticleSystem = pE->pParticleSystem;
MFParticle *pNew = NULL;
if(pParticleSystem->particles.GetLength() < pParticleSystem->params.maxActiveParticles)
pNew = pParticleSystem->particles.Create();
if(pNew)
{
MFParticleParameters *pP = &pParticleSystem->params;
pNew->colour = pP->colour;
pNew->life = pP->life;
pNew->rot = 0.0f;
pNew->size = pP->size;
switch(pE->type)
{
case MFET_Point:
pNew->pos = pE->position.GetTrans();
break;
case MFET_Sphere:
case MFET_Disc:
{
MFVector offset;
do
{
offset = MakeVector(MFRand_Range(-pE->radius, pE->radius), MFRand_Range(-pE->radius, pE->radius), MFRand_Range(-pE->radius, pE->radius));
}
while(offset.MagSquared3() > pE->radius*pE->radius);
if(pE->type == MFET_Disc)
{
// flatten it on to the disc
float dist = offset.Dot3(pE->position.GetYAxis());
offset -= pE->position.GetYAxis()*dist;
}
pNew->pos = pE->position.GetTrans() + offset;
break;
}
}
switch(pE->behaviour)
{
case MFEB_Direction:
pNew->velocity.Normalise3(pE->startVector);
break;
case MFEB_TargetAttract:
pNew->velocity.Normalise3(pE->startVector - pE->position.GetTrans());
break;
case MFEB_TargetRepel:
pNew->velocity.Normalise3(pE->position.GetTrans() - pE->startVector);
break;
}
pNew->velocity *= pE->velocity + MFRand_Range(-pE->velocityScatter, pE->velocityScatter);
if(pE->directionScatter)
{
MFVector scatter;
do
{
scatter = MakeVector(MFRand_Range(-1, 1), MFRand_Range(-1, 1), MFRand_Range(-1, 1));
float dist = scatter.Dot3(pE->position.GetYAxis());
scatter -= pE->position.GetYAxis()*dist;
}
while(scatter.MagSquared3() < 0.000001f);
scatter.Normalise3();
MFMatrix scatterMat;
scatterMat.SetRotation(scatter, MFRand_Unit()*pE->directionScatter);
pNew->velocity = ApplyMatrixH(pNew->velocity, scatterMat);
}
}
}
