SurfacePoint::inEdge: fix reversed tEdge for Vertex-typed points#248
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designbynumbers wants to merge 1 commit into
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SurfacePoint::inEdge: fix reversed tEdge for Vertex-typed points#248designbynumbers wants to merge 1 commit into
designbynumbers wants to merge 1 commit into
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The Vertex-typed branch returned the reflected edge parameter (tEdge=1 for the tail vertex, 0 for the tip), contradicting SurfacePoint::interpolate's convention (tEdge=0 at edge.halfedge().tailVertex(), 1 at the tip). This drove an off-by-reflection placement in IntegerCoordinatesIntrinsicTriangulation::computeEdgeSplitData's shared-edge (normalCoordinates < 0) branch, so every insertVertex on a shared intrinsic edge landed at parameter (1-t) instead of t. Upstream report: nmwsharp#245
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Minimal two-line fix for #245.
SurfacePoint::inEdgeon aVertex-typed point returns the reflected edgeparameter —
tEdge=1foredge.halfedge().tailVertex(),0for the tip —which contradicts the rest of
surface_point.ipp(interpolate, theSurfacePoint(Edge, double)ctor,nearestVertex), wheretEdge=0is the tailand
tEdge=1is the tip. Downstream this mis-places every shared-edgeinsertVertex(SurfacePoint(edge, t))at parameter(1 - t)instead oft,producing visible Steiner drift in an intrinsic-triangulation pipeline.
The fix swaps the two return values so the Vertex-typed branch matches the
documented convention.
Full writeup + single-triangle MWE: #245.
Note: I noticed the (unmerged)
int-tri-updatesbranch reworksinEdgemorebroadly — happy to defer to that approach if you'd rather pick it back up; this
is just the minimal correctness fix against current
master.Fixes #245.