From ec29d7bb5e786549eaa960016ddf511fad010cc5 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Sun, 9 Feb 2025 15:23:15 +0000
Subject: Split GeoData mesh basics into a subclass

Declutters the class for terrain related things
---
 game/geoDataMesh.h | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 game/geoDataMesh.h

(limited to 'game/geoDataMesh.h')

diff --git a/game/geoDataMesh.h b/game/geoDataMesh.h
new file mode 100644
index 0000000..00db67c
--- /dev/null
+++ b/game/geoDataMesh.h
@@ -0,0 +1,83 @@
+#pragma once
+
+#include "config/types.h"
+#include "ray.h"
+#include "triangle.h"
+#include <OpenMesh/Core/Mesh/TriMesh_ArrayKernelT.hh>
+#include <source_location>
+#include <thirdparty/openmesh/glmcompat.h>
+#include <thirdparty/openmesh/helpers.h>
+
+struct GeoDataTraits : public OpenMesh::DefaultTraits {
+	FaceAttributes(OpenMesh::Attributes::Status);
+	EdgeAttributes(OpenMesh::Attributes::Status);
+	VertexAttributes(OpenMesh::Attributes::Normal | OpenMesh::Attributes::Status);
+	HalfedgeAttributes(OpenMesh::Attributes::Status);
+	using Point = GlobalPosition3D;
+	using Normal = Normal3D;
+};
+
+class GeoDataMesh : public OpenMesh::TriMesh_ArrayKernelT<GeoDataTraits> {
+public:
+	struct PointFace {
+		// NOLINTNEXTLINE(hicpp-explicit-conversions)
+		PointFace(GlobalPosition2D coord) : point {coord} { }
+
+		PointFace(GlobalPosition2D coord, FaceHandle face) : point {coord}, faceCache {face} { }
+
+		PointFace(GlobalPosition2D coord, const GeoDataMesh *);
+		PointFace(GlobalPosition2D coord, GeoDataMesh const *, FaceHandle start);
+
+		const GlobalPosition2D point;
+		[[nodiscard]] FaceHandle face(const GeoDataMesh *) const;
+		[[nodiscard]] FaceHandle face(const GeoDataMesh *, FaceHandle start) const;
+
+		[[nodiscard]] bool
+		isLocated() const
+		{
+			return faceCache.is_valid();
+		}
+
+	private:
+		mutable FaceHandle faceCache;
+	};
+
+	template<glm::length_t Dim> using Triangle = ::Triangle<Dim, GlobalDistance>;
+
+	[[nodiscard]] FaceHandle findPoint(GlobalPosition2D) const;
+	[[nodiscard]] FaceHandle findPoint(GlobalPosition2D, FaceHandle) const;
+
+	[[nodiscard]] GlobalPosition3D positionAt(const PointFace &) const;
+
+protected:
+	void sanityCheck(const std::source_location & = std::source_location::current()) const;
+
+	[[nodiscard]] bool faceContainsPoint(GlobalPosition2D, FaceHandle) const;
+	[[nodiscard]] HalfedgeHandle findBoundaryStart() const;
+	[[nodiscard]] RelativePosition3D difference(HalfedgeHandle) const;
+	using HalfEdgeVertices = std::pair<VertexHandle, VertexHandle>;
+	[[nodiscard]] HalfEdgeVertices toVertexHandles(HalfedgeHandle) const;
+	using HalfEdgePoints = std::pair<GlobalPosition3D, GlobalPosition3D>;
+	[[nodiscard]] HalfEdgePoints points(HalfEdgeVertices) const;
+
+	template<glm::length_t D>
+	[[nodiscard]] RelativeDistance
+	length(HalfedgeHandle heh) const
+	{
+		return ::distance<D, GlobalDistance, glm::defaultp>(
+				point(to_vertex_handle(heh)), point(from_vertex_handle(heh)));
+	}
+
+	[[nodiscard]] GlobalPosition3D centre(HalfedgeHandle) const;
+
+	template<glm::length_t Dim>
+	[[nodiscard]] Triangle<Dim>
+	triangle(FaceHandle face) const
+	{
+		Triangle<Dim> triangle;
+		std::ranges::transform(fv_range(face), triangle.begin(), [this](auto vertex) {
+			return point(vertex);
+		});
+		return triangle;
+	}
+};
-- 
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