From 75dd294732a5670eb1978515a02cac109d169b3b Mon Sep 17 00:00:00 2001 From: Morris Tabor <80684659+mortarroad@users.noreply.github.com> Date: Wed, 25 Aug 2021 14:18:45 +0200 Subject: [PATCH] Fix emitting duplicate edges for convex hulls Identical to https://github.com/godotengine/godot/pull/52059 --- core/math/convex_hull.cpp | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/core/math/convex_hull.cpp b/core/math/convex_hull.cpp index 21cb0efe20f..f67035c803b 100644 --- a/core/math/convex_hull.cpp +++ b/core/math/convex_hull.cpp @@ -2260,10 +2260,21 @@ Error ConvexHullComputer::convex_hull(const Vector &p_points, Geometry3 r_mesh.vertices = ch.vertices; - r_mesh.edges.resize(ch.edges.size()); + // Copy the edges over. There's two "half-edges" for every edge, so we pick only one of them. + r_mesh.edges.resize(ch.edges.size() / 2); + uint32_t edges_copied = 0; for (uint32_t i = 0; i < ch.edges.size(); i++) { - r_mesh.edges.write[i].a = (&ch.edges[i])->get_source_vertex(); - r_mesh.edges.write[i].b = (&ch.edges[i])->get_target_vertex(); + uint32_t a = (&ch.edges[i])->get_source_vertex(); + uint32_t b = (&ch.edges[i])->get_target_vertex(); + if (a < b) { // Copy only the "canonical" edge. For the reverse edge, this will be false. + ERR_BREAK(edges_copied >= (uint32_t)r_mesh.edges.size()); + r_mesh.edges.write[edges_copied].a = a; + r_mesh.edges.write[edges_copied].b = b; + edges_copied++; + } + } + if (edges_copied != (uint32_t)r_mesh.edges.size()) { + ERR_PRINT("Invalid edge count."); } r_mesh.faces.resize(ch.faces.size());