/// <summary>
/// Clips a BSP node, returns a triangle list
/// </summary>
private static void ClippetyClip( Csg.BspNode node, float x, float y, float mX, float mY, TriBuilder builder )
{
if ( node == null )
{
return;
}
ClipNode( node.Quad, x, y, mX, mY, builder );
ClippetyClip( node.InFront, x, y, mX, mY, builder );
ClippetyClip( node.Behind, x, y, mX, mY, builder );
}
private static void ClipNode( Point3[] quad, float x, float y, float mX, float mY, TriBuilder builder )
{
// Loop endlessly (will keep clipping until quad is trivially accepted or rejected)
while ( true )
{
byte startClip = ClipCode( quad[ 0 ], x, y, mX, mY );
byte endClip = ClipCode( quad[ 1 ], x, y, mX, mY );
if ( ( startClip | endClip ) == 0 )
{
// Both points in chop rect - trivially accept
builder.AddQuad( quad[ 0 ], quad[ 1 ], quad[ 2 ], quad[ 3 ]);
return;
}
else if ( ( startClip & endClip ) != 0 )
{
// Both points on the same side outside the chop rect - trivially reject
return;
}
// One or both points outside the chop rect - clip one of them to the chop rect and start again
if ( startClip != 0 )
{
ClipQuad( true, quad, startClip, x, y, mX, mY );
}
else if ( endClip != 0 )
{
ClipQuad( false, quad, endClip, x, y, mX, mY );
}
}
}
