From dddc07f0189d722fc07f70ae0c1308dcc4fd0978 Mon Sep 17 00:00:00 2001 From: Dan Goodliffe Date: Sun, 2 Feb 2025 03:18:43 +0000 Subject: Flip edges if better instead of splitting them when cutting triangle strip edge --- game/geoData.cpp | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) (limited to 'game/geoData.cpp') diff --git a/game/geoData.cpp b/game/geoData.cpp index 448ff67..1430cb6 100644 --- a/game/geoData.cpp +++ b/game/geoData.cpp @@ -537,10 +537,21 @@ GeoData::setHeights(const std::span triangleStrip, const } return nullptr; }; + const auto shouldFlip + = [this](const HalfedgeHandle next, const GlobalPosition2D startPoint) -> std::optional { + if (const auto nextEdge = edge_handle(next); is_flip_ok(nextEdge)) { + const auto opposite_point + = point(to_vertex_handle(next_halfedge_handle(opposite_halfedge_handle(next)))).xy(); + if (distance<2>(startPoint, opposite_point) < length<2>(next)) { + return nextEdge; + } + } + return std::nullopt; + }; // Cut along each edge of triangleStrip AB, AC, BC, BD, CD, CE etc std::map *> boundaryTriangles; - auto doBoundaryPart = [this, &boundaryTriangles, &vertexDistFrom, &opts, &addVertexForNormalUpdate]( + auto doBoundaryPart = [this, &boundaryTriangles, &vertexDistFrom, &opts, &addVertexForNormalUpdate, &shouldFlip]( VertexHandle start, VertexHandle end, const Triangle<3> & triangle) { boundaryTriangles.emplace(start, &triangle); const auto endPoint = point(end); @@ -563,9 +574,11 @@ GeoData::setHeights(const std::span triangleStrip, const start = nextDist.first; return true; } - else { - start = split_copy(edge_handle(next), positionOnTriangle(*intersection, triangle)); + else if (const auto nextEdge = shouldFlip(next, startPoint)) { + flip(*nextEdge); + return true; } + start = split_copy(edge_handle(next), positionOnTriangle(*intersection, triangle)); addVertexForNormalUpdate(start); boundaryTriangles.emplace(start, &triangle); return true; -- cgit v1.2.3