/// Pass:
/// frameKnot - the index of a knot; negative to index from the end.
/// offset - specified relative to the knot+frame, as a %age of brush size.
/// twist - in degrees-per-meter; rotates based on distance from initial knot
/// pressureAffectsOffset - true if the offset should be modulated by pressure, too.
/// For example, the rungs of a double-helix should be closer to the parent
/// when pressure makes the brush smaller; but maybe a tickertape should remain
/// constant-size and pressure only affects the stuff written on the tape.
public PbChildWithOffset(int frameKnot, AttachFrame frame, TrTransform offset, float twist,
bool pressureAffectsOffset = true)
: base(frameKnot, frame)
{
m_offset = offset;
m_twist = twist;
m_pressureAffectsOffset = pressureAffectsOffset;
}
public TrTransform GetFrame(AttachFrame frame)
{
switch (frame)
{
case AttachFrame.Pointer: return(CanvasFromTool);
case AttachFrame.LineTangent: return(CanvasFromTangent);
default: throw new NotImplementedException();
}
}
/// If frameKnot is < 0, it is relative to a knot at the current end of the stroke.
public PbChildWithKnotBasedFrame(int frameKnot, AttachFrame frame)
{
m_frameKnot = frameKnot;
m_frame = frame;
}
protected Plane m_plane; // in knot space
/// Plane is in the frame of the knot
public PbChildKnotBasedMirror(int frameKnot, AttachFrame frame, Plane plane)
: base(frameKnot, frame)
{
m_plane = plane;
}
