Sergey Sharybin
f00f959d52
This solves threading conflict which happens when having multiple objects using Curve Deform modifier with the same curve datablock. This conflict was caused by the fact that curve_deform_verts() used to temporary override curve's flags to make it path is there. Actually, it was setting CU_FOLLOW flag temporary which was only used where_on_path() (only in terms that this temporary assignment only affected this function) but it is now commented out for a while, so no reason to set this flag temporary, If it's ever to be done, we'll need to pass flags as an additional function argument. For the path creation i've extended DegNode structure which now holds extra bits which indicates what additional data depending on the graph topology is to be evaluated. Currently this is only used to indicate that curve needs path to be evaluated regardless to cu->flag state. This is so Curve Deform modifier is always happy. In the future this flag might also be used to indicate whether bmesh verts are to update (see recent commit to 3-vertex parent crash fix) or to indicate that the object is the motherball etc.