//----------------------------------------------------------------//
bool USSurface2D::GetRayHit ( ZLVec2D& loc, ZLVec2D& ray, float& time ) {
float d;
d = ray.Dot ( this->mNorm );
if ( d == 0.0f ) return false; // ray is parallel
time = ( loc.Dot ( this->mNorm ) + this->mDist ) / -d;
return true;
}
//----------------------------------------------------------------//
bool USSurface2D::GetHit ( ZLVec2D& sphereLoc, ZLVec2D& move, SurfaceHit2D& hit ) {
// The usual stuff...
ZLVec2D unitMove = move;
unitMove.Norm ();
if ( unitMove.Dot ( this->mNorm ) >= -0.001f ) return false;
if ( ZLDist::PointToPlane2D ( sphereLoc, *this ) <= 0.0f ) return false;
// Get the point of first contact on the polygon...
ZLVec2D pofcop = this->mNorm;
pofcop.Reverse ();
pofcop.Add ( sphereLoc );
this->ClampPoint ( pofcop );
// Send a ray from the point on the surface to intersect the circle.
// The ray is the inverse of the move vec.
ZLVec2D inverseMove = move;
inverseMove.Reverse ();
float t0, t1;
u32 sectType;
sectType = ZLSect::VecToCircle ( t0, t1, pofcop, inverseMove, sphereLoc, 1.0f );
// Bail if the point will not intersect the sphere.
if ( sectType == ZLSect::SECT_PARALLEL ) return false;
if ( t0 >= hit.mTime ) return false;
// Bail if the point will graze the sphere.
if ( sectType == ZLSect::SECT_TANGENT ) return false;
// Bail if the point will stay outside of the sphere.
if (( t0 > 1.0f ) || ( t1 < 0.0f )) return false;
// OMG! We hit something!
float time = t0;
hit.mTime = time;
inverseMove.Scale ( t0 );
hit.mPoint = pofcop;
hit.mPoint.Add ( inverseMove );
hit.mNorm = sphereLoc;
hit.mNorm.Sub ( hit.mPoint );
hit.mNorm.Norm ();
if ( unitMove.Dot ( hit.mNorm ) >= -0.001f ) return false;
return true;
}
//----------------------------------------------------------------//
bool USSurface2D::GetTouch ( ZLVec2D& sphereLoc, ZLSurfaceTouch2D& touch ) {
// The usual stuff...
float dist = ZLDist::PointToPlane2D ( sphereLoc, *this );
if ( dist <= 0.0f ) return false;
if ( dist > 1.001f ) return false;
// Get the point of first contact on the polygon...
ZLVec2D pofcop = this->mNorm;
pofcop.Reverse ();
pofcop.Add ( sphereLoc );
this->ClampPoint ( pofcop );
ZLVec2D ray = pofcop;
ray.Sub ( sphereLoc );
dist = ray.NormSafe ();
if ( dist >= touch.mDist ) return false;
float dot = ray.Dot ( touch.mFinger );
if ( dot < 0.85f ) return false;
// we have a touch...
touch.mDist = dist;
touch.mPoint = pofcop;
touch.mTouch = true;
touch.mHit = !touch.mPrevTouch;
//touch.mNorm = this->GetNorm ();
return true;
}
//----------------------------------------------------------------//
bool USSurface2D::GetRayHit ( ZLVec2D& loc, ZLVec2D& ray, float pad, float& time ) {
float d;
d = ray.Dot ( this->mNorm );
if ( d == 0.0f ) return false;
time = ( loc.Dot ( this->mNorm ) + this->mDist ) / -d;
// now get the point of impact
ZLVec2D sect = ray;
sect.Scale ( time );
sect.Add ( loc );
float dot = this->mTangent.Dot ( sect );
if ( dot < ( this->mP0 - pad )) return false;
if ( dot > ( this->mP1 + pad )) return false;
return true;
}