rConicTo
Adds conic from last point towards vector (dx1, dy1), to vector (dx2, dy2), weighted by w. Control is last point plus vector (dx1, dy1). End is last point plus vector (dx2, dy2).
Return
this builder for chaining
Parameters
dx1
offset from last point to conic control on x-axis
dy1
offset from last point to conic control on y-axis
dx2
offset from last point to conic end on x-axis
dy2
offset from last point to conic end on y-axis
w
weight of added conic