From 04078dbb3fe4acd09d150e016c2b2e0d5d036950 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Sun, 5 Nov 2023 13:07:32 +0000
Subject: Add methods to walk the boundary of the terrain mesh
---
game/geoData.cpp | 45 +++++++++++++++++++++++++++++++++++++++++++++
game/geoData.h | 6 ++++++
2 files changed, 51 insertions(+)
(limited to 'game')
diff --git a/game/geoData.cpp b/game/geoData.cpp
index c58658a..f9c11bf 100644
--- a/game/geoData.cpp
+++ b/game/geoData.cpp
@@ -218,6 +218,43 @@ GeoData::walkUntil(const PointFace & from, const glm::vec2 to, const std::functi
}
}
+void
+GeoData::boundaryWalk(const std::function<void(HalfedgeHandle)> & op) const
+{
+ boundaryWalk(op, findBoundaryStart());
+}
+
+void
+GeoData::boundaryWalk(const std::function<void(HalfedgeHandle)> & op, HalfedgeHandle start) const
+{
+ assert(is_boundary(start));
+ boundaryWalkUntil(
+ [&op](auto heh) {
+ op(heh);
+ return false;
+ },
+ start);
+}
+
+void
+GeoData::boundaryWalkUntil(const std::function<bool(HalfedgeHandle)> & op) const
+{
+ boundaryWalkUntil(op, findBoundaryStart());
+}
+
+void
+GeoData::boundaryWalkUntil(const std::function<bool(HalfedgeHandle)> & op, HalfedgeHandle start) const
+{
+ assert(is_boundary(start));
+ if (!op(start)) {
+ for (auto heh = next_halfedge_handle(start); heh != start; heh = next_halfedge_handle(heh)) {
+ if (op(heh)) {
+ break;
+ }
+ }
+ }
+}
+
bool
GeoData::triangleContainsPoint(const glm::vec2 p, const Triangle<2> & t)
{
@@ -230,3 +267,11 @@ GeoData::triangleContainsPoint(const glm::vec2 p, FaceHandle face) const
{
return triangleContainsPoint(p, triangle<2>(face));
}
+
+GeoData::HalfedgeHandle
+GeoData::findBoundaryStart() const
+{
+ return *std::find_if(halfedges_begin(), halfedges_end(), [this](const auto heh) {
+ return is_boundary(heh);
+ });
+}
diff --git a/game/geoData.h b/game/geoData.h
index b8561d0..15d7e24 100644
--- a/game/geoData.h
+++ b/game/geoData.h
@@ -78,6 +78,11 @@ public:
void walk(const PointFace & from, const glm::vec2 to, const std::function<void(FaceHandle)> & op) const;
void walkUntil(const PointFace & from, const glm::vec2 to, const std::function<bool(FaceHandle)> & op) const;
+ void boundaryWalk(const std::function<void(HalfedgeHandle)> &) const;
+ void boundaryWalk(const std::function<void(HalfedgeHandle)> &, HalfedgeHandle start) const;
+ void boundaryWalkUntil(const std::function<bool(HalfedgeHandle)> &) const;
+ void boundaryWalkUntil(const std::function<bool(HalfedgeHandle)> &, HalfedgeHandle start) const;
+
[[nodiscard]] auto
getExtents() const
{
@@ -94,6 +99,7 @@ protected:
[[nodiscard]] static bool triangleContainsPoint(const glm::vec2, const Triangle<2> &);
[[nodiscard]] bool triangleContainsPoint(const glm::vec2, FaceHandle) const;
+ [[nodiscard]] HalfedgeHandle findBoundaryStart() const;
private:
glm::vec3 lowerExtent {}, upperExtent {};
--
cgit v1.2.3