void extrude( btHullTriangle t0, int v )
{
int3 t = t0.v;
int n = m_tris.Count;
btHullTriangle ta = allocateTriangle( v, t[1], t[2] );
ta.n = new int3( t0.n[0], n + 1, n + 2 );
m_tris[t0.n[0]].neib( t[1], t[2] , n + 0 );
btHullTriangle tb = allocateTriangle( v, t[2], t[0] );
tb.n = new int3( t0.n[1], n + 2, n + 0 );
m_tris[t0.n[1]].neib( t[2], t[0] , n + 1 );
btHullTriangle tc = allocateTriangle( v, t[0], t[1] );
tc.n = new int3( t0.n[2], n + 0, n + 1 );
m_tris[t0.n[2]].neib( t[0], t[1] , n + 2 );
checkit( ta );
checkit( tb );
checkit( tc );
if( hasvert( m_tris[ta.n[0]].v, v ) ) removeb2b( ta, m_tris[ta.n[0]] );
if( hasvert( m_tris[tb.n[0]].v, v ) ) removeb2b( tb, m_tris[tb.n[0]] );
if( hasvert( m_tris[tc.n[0]].v, v ) ) removeb2b( tc, m_tris[tc.n[0]] );
deAllocateTriangle( t0 );
}
void deAllocateTriangle( btHullTriangle tri )
{
Debug.Assert( m_tris[tri.id] == tri );
m_tris[tri.id] = null;
}
btHullTriangle allocateTriangle( int a, int b, int c )
{
btHullTriangle tr = new btHullTriangle( a, b, c );
tr.id = m_tris.Count;
m_tris.Add( tr );
return tr;
}
void checkit( btHullTriangle t )
{
int i;
Debug.Assert( m_tris[t.id] == t );
for( i = 0; i < 3; i++ )
{
int i1 = ( i + 1 ) % 3;
int i2 = ( i + 2 ) % 3;
int a = ( t.v )[i1];
int b = ( t.v )[i2];
// release compile fix
Debug.Assert( a != b );
Debug.Assert( m_tris[t.n[i]].neib( b, a ) == t.id );
}
}
void removeb2b( btHullTriangle s, btHullTriangle t )
{
b2bfix( s, t );
deAllocateTriangle( s );
deAllocateTriangle( t );
}
void b2bfix( btHullTriangle s, btHullTriangle t )
{
int i;
for( i = 0; i < 3; i++ )
{
int i1 = ( i + 1 ) % 3;
int i2 = ( i + 2 ) % 3;
int a = ( s.v )[i1];
int b = ( s.v )[i2];
Debug.Assert( m_tris[s.neib( a, b )].neib( b, a ) == s.id );
Debug.Assert( m_tris[t.neib( a, b )].neib( b, a ) == t.id );
m_tris[s.neib( a, b )].neib( b, a, t.neib( b, a ) );
m_tris[t.neib( b, a )].neib( a, b, s.neib( a, b ) );
}
}
