dassaf4
commented
1 year ago Details:
- When the input CurveVector is a closed region, we already have ClipPlaneSet::ClipPlanarRegion. Given a region input, it returns a single region output.
- When the input CurveVector is open, the result can be multiple (disjoint) CurveVectors. What is the preferred return type for this?
- I've seen disjoint curves packaged into one CurveVectorPtr that has
BOUNDARY_TYPE_None, however the doc for this enum type discourages this, preferring insteadbvector<CurveVectorPtr>. This kind of rules out one method for both open and closed inputs, unless we want to return the single closed result as the only entry in the bvector, which I guess could work. But at the very least, it means a new method, because we cannot change the signature of the existing one. - The problem with returning a CurveVectorPtr per clipped open curve piece is that there is no record of the provenance of that piece in the context of the original open curve, e.g., the fractional parameter span of the clipped piece in the original curve's [0,1] parameter space. This is why I like
CurveLocationDetailPair, an array of which is returned byClipPlaneSet::AppendCrossings---each entry in this array describes a pair of locations on the input curve representing the start and end of a clipped piece. If you have such an array, you can easily build up a bvectorof the clipped pieces by calling CurveVector::CloneBetweenDirectedFractions(detail0, detail1)on eachCurveLocationDetailPair.
- I've seen disjoint curves packaged into one CurveVectorPtr that has
- When the input CurveVector is open, we also have the option to ignore certain ClipPlanes in the clipper. I believe there are a couple of flags on the clipper (or clip plane) that determine this. There should be methods on ClipPlane that return visibility flags or some such. At the least, we should honor plane visibility and skip those that are hidden/invisible. We could also provide an input flag to ignore them and clip to all planes. Again, look for precedent in the API.
- So I propose two new methods:
- Main method:
void ClipCurveVector(CurveVectorCR curve, bvector<CurveVectorPtr>& clippedCurves) constcalls the existingClipPlanarRegionmethod ifCurveVector::IsAnyRegionType()is true, otherwise the new open method (below). - Open method:
bool ClipOpenPath(CurveVectorCR openCurve, bvector<CurveVectorPtr>* pClippedCurves = nullptr, bvector<CurveLocationDetailPair>* pClippedDetails = nullptr) const. Both optional returned arrays should be sorted by the original open path's global parameterization, or if boundaryType None, by the ordering of its primitives. Return false ifopenCurve.IsAnyRegionType()returns true; otherwise, callsAppendCrossings+CloneBetweenDirectedFractionsas described above. Note: this method should handle input of non-region boundaryType, i.e., Open or None.
- Main method:
saeeedtorabi
For imodel02 (connectors).