Merge remote-tracking branch 'origin/terrain'

22 files changed, 528 insertions, 364 deletions

diff --git a/game/geoData.cpp b/game/geoData.cpp
index 76550cc..97f4a26 100644
--- a/game/geoData.cpp
+++ b/game/geoData.cpp
@@ -1,215 +1,341 @@
 #include "geoData.h"
-#include "gfx/image.h"
-#include <algorithm>
-#include <array>
-#include <cmath>
-#include <cstddef>
+#include <fstream>
 #include <glm/gtx/intersect.hpp>
-#include <initializer_list>
-#include <limits>
 #include <maths.h>
-#include <random>
-#include <ray.h>
-#include <stb/stb_image.h>
-#include <stdexcept>
-#include <util.h>
 
-GeoData::GeoData(Limits l, float s) :
-	limit {std::move(l)}, size {(limit.second - limit.first) + 1}, scale {s}, nodes {[this]() {
-		return (static_cast<std::size_t>(size.x * size.y));
-	}()}
+GeoData
+GeoData::loadFromAsciiGrid(const std::filesystem::path & input)
 {
-}
-
-void
-GeoData::generateRandom()
-{
-	// We acknowledge this is terrible :)
-
-	// Add hills
-	std::mt19937 gen(std::random_device {}());
-	std::uniform_int_distribution<> rxpos(limit.first.x + 2, limit.second.x - 2),
-			rypos(limit.first.y + 2, limit.second.y - 2);
-	std::uniform_int_distribution<> rsize(10, 30);
-	std::uniform_real_distribution<float> rheight(1, 3);
-	for (int h = 0; h < 500;) {
-		const glm::ivec2 hpos {rxpos(gen), rypos(gen)};
-		const glm::ivec2 hsize {rsize(gen), rsize(gen)};
-		if (const auto lim1 = hpos - hsize; lim1.x > limit.first.x && lim1.y > limit.first.y) {
-			if (const auto lim2 = hpos + hsize; lim2.x < limit.second.x && lim2.y < limit.second.y) {
-				const auto height = rheight(gen);
-				const glm::ivec2 hsizesqrd {hsize.x * hsize.x, hsize.y * hsize.y};
-				for (auto y = lim1.y; y < lim2.y; y += 1) {
-					for (auto x = lim1.x; x < lim2.x; x += 1) {
-						const auto dist {hpos - glm::ivec2 {x, y}};
-						const glm::ivec2 distsqrd {dist.x * dist.x, dist.y * dist.y};
-						const auto out {ratio(sq(x - hpos.x), sq(hsize.x)) + ratio(sq(y - hpos.y), sq(hsize.y))};
-						if (out <= 1.0F) {
-							auto & node {nodes[at({x, y})]};
-							const auto m {1.F / (7.F * out - 8.F) + 1.F};
-							node.height += height * m;
-						}
-					}
-				}
-				h += 1;
-			}
+	size_t ncols = 0, nrows = 0, xllcorner = 0, yllcorner = 0, cellsize = 0;
+	std::map<std::string_view, size_t *> properties {
+			{"ncols", &ncols},
+			{"nrows", &nrows},
+			{"xllcorner", &xllcorner},
+			{"yllcorner", &yllcorner},
+			{"cellsize", &cellsize},
+	};
+	std::ifstream f {input};
+	while (!properties.empty()) {
+		std::string property;
+		f >> property;
+		f >> *properties.at(property);
+		properties.erase(property);
+	}
+	xllcorner *= 1000;
+	yllcorner *= 1000;
+	cellsize *= 1000;
+	std::vector<VertexHandle> vertices;
+	vertices.reserve(ncols * nrows);
+	GeoData mesh;
+	mesh.lowerExtent = {xllcorner, yllcorner, std::numeric_limits<GlobalDistance>::max()};
+	mesh.upperExtent = {xllcorner + (cellsize * (ncols - 1)), yllcorner + (cellsize * (nrows - 1)),
+			std::numeric_limits<GlobalDistance>::min()};
+	for (size_t row = 0; row < nrows; ++row) {
+		for (size_t col = 0; col < ncols; ++col) {
+			float heightf = 0;
+			f >> heightf;
+			const auto height = static_cast<GlobalDistance>(std::round(heightf * 1000.F));
+			mesh.upperExtent.z = std::max(mesh.upperExtent.z, height);
+			mesh.lowerExtent.z = std::min(mesh.lowerExtent.z, height);
+			vertices.push_back(mesh.add_vertex({xllcorner + (col * cellsize), yllcorner + (row * cellsize), height}));
 		}
 	}
-}
+	if (!f.good()) {
+		throw std::runtime_error("Couldn't read terrain file");
+	}
+	for (size_t row = 1; row < nrows; ++row) {
+		for (size_t col = 1; col < ncols; ++col) {
+			mesh.add_face({
+					vertices[ncols * (row - 1) + (col - 1)],
+					vertices[ncols * (row - 0) + (col - 0)],
+					vertices[ncols * (row - 0) + (col - 1)],
+			});
+			mesh.add_face({
+					vertices[ncols * (row - 1) + (col - 1)],
+					vertices[ncols * (row - 1) + (col - 0)],
+					vertices[ncols * (row - 0) + (col - 0)],
+			});
+		}
+	}
+	mesh.update_vertex_normals_only();
 
-void
-GeoData::loadFromImages(const std::filesystem::path & fileName, float scale_)
+	return mesh;
+};
+
+GeoData
+GeoData::createFlat(GlobalPosition2D lower, GlobalPosition2D upper, GlobalDistance h)
 {
-	const Image map {fileName.c_str(), STBI_grey};
-	size = {map.width, map.height};
-	limit = {{0, 0}, size - glm::uvec2 {1, 1}};
-	const auto points {size.x * size.y};
-	scale = scale_;
-	nodes.resize(points);
+	GeoData mesh;
 
-	std::transform(map.data.data(), map.data.data() + points, nodes.begin(), [](auto d) {
-		return Node {(d * 0.1F) - 1.5F};
-	});
+	mesh.lowerExtent = {lower, h};
+	mesh.upperExtent = {upper, h};
+
+	const auto ll = mesh.add_vertex({lower.x, lower.y, h}), lu = mesh.add_vertex({lower.x, upper.y, h}),
+			   ul = mesh.add_vertex({upper.x, lower.y, h}), uu = mesh.add_vertex({upper.x, upper.y, h});
+
+	mesh.add_face(ll, uu, lu);
+	mesh.add_face(ll, ul, uu);
+
+	mesh.update_vertex_normals_only();
+
+	return mesh;
 }
 
-GeoData::Quad
-GeoData::quad(glm::vec2 wcoord) const
+OpenMesh::FaceHandle
+GeoData::findPoint(GlobalPosition2D p) const
 {
-	constexpr static const std::array<glm::vec2, 4> corners {{{0, 0}, {0, 1}, {1, 0}, {1, 1}}};
-	return transform_array(transform_array(corners,
-								   [coord = (wcoord / scale)](const auto c) {
-									   return glm::vec2 {std::floor(coord.x), std::floor(coord.y)} + c;
-								   }),
-			[this](const auto c) {
-				return (c * scale) || nodes[at(c)].height;
-			});
+	return findPoint(p, *faces_begin());
 }
 
-glm::vec3
-GeoData::positionAt(const glm::vec2 wcoord) const
+GeoData::PointFace::PointFace(const GlobalPosition2D p, const GeoData * mesh) :
+	PointFace {p, mesh, *mesh->faces_begin()}
 {
-	const auto point {quad(wcoord)};
-	const glm::vec2 frac = (wcoord - !point.front()) / scale;
-	auto edge = [&point, &frac](auto offset) {
-		return point[offset].z + ((point[offset + 2].z - point[offset].z) * frac.x);
-	};
-	const auto heightFloor = edge(0U), heightCeil = edge(1U),
-			   heightMid = heightFloor + ((heightCeil - heightFloor) * frac.y);
-
-	return wcoord || heightMid;
 }
 
-GeoData::RayTracer::RayTracer(glm::vec2 p0, glm::vec2 p1) : RayTracer {p0, p1, glm::abs(p1)} { }
-
-GeoData::RayTracer::RayTracer(glm::vec2 p0, glm::vec2 p1, glm::vec2 d) :
-	RayTracer {p0, d, byAxis(p0, p1, d, 0), byAxis(p0, p1, d, 1)}
+GeoData::PointFace::PointFace(const GlobalPosition2D p, const GeoData * mesh, FaceHandle start) :
+	PointFace {p, mesh->findPoint(p, start)}
 {
 }
 
-GeoData::RayTracer::RayTracer(
-		glm::vec2 p0, glm::vec2 d_, std::pair<float, float> xdata, std::pair<float, float> ydata) :
-	p {glm::floor(p0)},
-	d {d_}, error {xdata.second - ydata.second}, inc {xdata.first, ydata.first}
+GeoData::FaceHandle
+GeoData::PointFace::face(const GeoData * mesh, FaceHandle start) const
 {
+	if (_face.is_valid()) {
+		assert(mesh->triangleContainsPoint(point, _face));
+		return _face;
+	}
+	else {
+		return (_face = mesh->findPoint(point, start));
+	}
 }
 
-std::pair<float, float>
-GeoData::RayTracer::byAxis(glm::vec2 p0, glm::vec2 p1, glm::vec2 d, glm::length_t axis)
+GeoData::FaceHandle
+GeoData::PointFace::face(const GeoData * mesh) const
 {
-	using Limits = std::numeric_limits<typename glm::vec2::value_type>;
-	static_assert(Limits::has_infinity);
-	if (d[axis] == 0) {
-		return {0, Limits::infinity()};
+	return face(mesh, *mesh->faces_begin());
+}
+
+namespace {
+	template<template<typename> typename Op>
+	[[nodiscard]] constexpr inline auto
+	pointLineOp(const GlobalPosition2D p, const GlobalPosition2D e1, const GlobalPosition2D e2)
+	{
+		return Op {}(CalcDistance(e2.x - e1.x) * CalcDistance(p.y - e1.y),
+				CalcDistance(e2.y - e1.y) * CalcDistance(p.x - e1.x));
+	}
+
+	constexpr auto pointLeftOfLine = pointLineOp<std::greater>;
+	constexpr auto pointLeftOfOrOnLine = pointLineOp<std::greater_equal>;
+
+	static_assert(pointLeftOfLine({1, 2}, {1, 1}, {2, 2}));
+	static_assert(pointLeftOfLine({2, 1}, {2, 2}, {1, 1}));
+	static_assert(pointLeftOfLine({2, 2}, {1, 2}, {2, 1}));
+	static_assert(pointLeftOfLine({1, 1}, {2, 1}, {1, 2}));
+	static_assert(pointLeftOfOrOnLine({310000000, 490000000}, {310000000, 490000000}, {310050000, 490050000}));
+	static_assert(pointLeftOfOrOnLine({310000000, 490000000}, {310050000, 490050000}, {310000000, 490050000}));
+	static_assert(pointLeftOfOrOnLine({310000000, 490000000}, {310000000, 490050000}, {310000000, 490000000}));
+
+	[[nodiscard]] constexpr inline bool
+	linesCross(
+			const GlobalPosition2D a1, const GlobalPosition2D a2, const GlobalPosition2D b1, const GlobalPosition2D b2)
+	{
+		return (pointLeftOfLine(a2, b1, b2) == pointLeftOfLine(a1, b2, b1))
+				&& (pointLeftOfLine(b1, a1, a2) == pointLeftOfLine(b2, a2, a1));
 	}
-	else if (p1[axis] > 0) {
-		return {1, (std::floor(p0[axis]) + 1.F - p0[axis]) * d[1 - axis]};
+
+	static_assert(linesCross({1, 1}, {2, 2}, {1, 2}, {2, 1}));
+	static_assert(linesCross({2, 2}, {1, 1}, {1, 2}, {2, 1}));
+
+	[[nodiscard]] constexpr inline bool
+	linesCrossLtR(
+			const GlobalPosition2D a1, const GlobalPosition2D a2, const GlobalPosition2D b1, const GlobalPosition2D b2)
+	{
+		return pointLeftOfLine(a2, b1, b2) && pointLeftOfLine(a1, b2, b1) && pointLeftOfLine(b1, a1, a2)
+				&& pointLeftOfLine(b2, a2, a1);
 	}
-	else {
-		return {-1, (p0[axis] - std::floor(p0[axis])) * d[1 - axis]};
+
+	static_assert(linesCrossLtR({1, 1}, {2, 2}, {1, 2}, {2, 1}));
+	static_assert(!linesCrossLtR({2, 2}, {1, 1}, {1, 2}, {2, 1}));
+
+	constexpr GlobalPosition3D
+	positionOnTriangle(const GlobalPosition2D point, const GeoData::Triangle<3> & t)
+	{
+		const CalcPosition3D a = t[1] - t[0], b = t[2] - t[0];
+		const auto n = crossInt(a, b);
+		return {point, ((n.x * t[0].x) + (n.y * t[0].y) + (n.z * t[0].z) - (n.x * point.x) - (n.y * point.y)) / n.z};
 	}
+
+	static_assert(positionOnTriangle({7, -2}, {{1, 2, 3}, {1, 0, 1}, {-2, 1, 0}}) == GlobalPosition3D {7, -2, 3});
 }
 
-glm::vec2
-GeoData::RayTracer::next()
+OpenMesh::FaceHandle
+GeoData::findPoint(GlobalPosition2D p, OpenMesh::FaceHandle f) const
 {
-	const glm::vec2 cur {p};
-
-	static constexpr const glm::vec2 m {1, -1};
-	const int axis = (error > 0) ? 1 : 0;
-	p[axis] += inc[axis];
-	error += d[1 - axis] * m[axis];
+	while (f.is_valid() && !triangleContainsPoint(p, triangle<2>(f))) {
+		for (auto next = cfh_iter(f); next.is_valid(); ++next) {
+			f = opposite_face_handle(*next);
+			if (f.is_valid()) {
+				const auto e1 = point(to_vertex_handle(*next));
+				const auto e2 = point(to_vertex_handle(opposite_halfedge_handle(*next)));
+				if (pointLeftOfLine(p, e1, e2)) {
+					break;
+				}
+			}
+			f.reset();
+		}
+	}
+	return f;
+}
 
-	return cur;
+GlobalPosition3D
+GeoData::positionAt(const PointFace & p) const
+{
+	return positionOnTriangle(p.point, triangle<3>(p.face(this)));
 }
 
-std::optional<glm::vec3>
+[[nodiscard]] std::optional<GlobalPosition3D>
 GeoData::intersectRay(const Ray & ray) const
 {
-	if (glm::length(!ray.direction) <= 0) {
-		return {};
-	}
-	RayTracer rt {ray.start / scale, ray.direction};
-	while (true) {
-		const auto n {rt.next() * scale};
-		try {
-			const auto point = quad(n);
-			for (auto offset : {0U, 1U}) {
-				glm::vec2 bary;
-				float distance;
-				if (glm::intersectRayTriangle(ray.start, ray.direction, point[offset], point[offset + 1],
-							point[offset + 2], bary, distance)) {
-					return point[offset] + ((point[offset + 1] - point[offset]) * bary[0])
-							+ ((point[offset + 2] - point[offset]) * bary[1]);
+	return intersectRay(ray, findPoint(ray.start));
+}
+
+[[nodiscard]] std::optional<GlobalPosition3D>
+GeoData::intersectRay(const Ray & ray, FaceHandle face) const
+{
+	std::optional<GlobalPosition3D> out;
+	walkUntil(PointFace {ray.start, face},
+			ray.start.xy() + (ray.direction.xy() * RelativePosition2D(upperExtent.xy() - lowerExtent.xy())),
+			[&out, &ray, this](FaceHandle face) {
+				BaryPosition bari {};
+				float dist {};
+				const auto t = triangle<3>(face);
+				if (glm::intersectRayTriangle<RelativePosition3D::value_type, glm::defaultp>(
+							ray.start, ray.direction, t[0], t[1], t[2], bari, dist)) {
+					out = t * bari;
+					return true;
 				}
-			}
+				return false;
+			});
+	return out;
+}
+
+void
+GeoData::walk(const PointFace & from, const GlobalPosition2D to, const std::function<void(FaceHandle)> & op) const
+{
+	walkUntil(from, to, [&op](const auto & fh) {
+		op(fh);
+		return false;
+	});
+}
+
+void
+GeoData::walkUntil(const PointFace & from, const GlobalPosition2D to, const std::function<bool(FaceHandle)> & op) const
+{
+	auto f = from.face(this);
+	if (!f.is_valid()) {
+		const auto entryEdge = findEntry(from.point, to);
+		if (!entryEdge.is_valid()) {
+			return;
 		}
-		catch (std::range_error &) {
-			const auto rel = n / !ray.direction;
-			if (rel.x > 0 && rel.y > 0) {
-				return {};
+		f = opposite_face_handle(entryEdge);
+	}
+	FaceHandle previousFace;
+	while (f.is_valid() && !op(f)) {
+		for (auto next = cfh_iter(f); next.is_valid(); ++next) {
+			f = opposite_face_handle(*next);
+			if (f.is_valid() && f != previousFace) {
+				const auto e1 = point(to_vertex_handle(*next));
+				const auto e2 = point(to_vertex_handle(opposite_halfedge_handle(*next)));
+				if (linesCrossLtR(from.point, to, e1, e2)) {
+					previousFace = f;
+					break;
+				}
 			}
+			f.reset();
 		}
 	}
+}
+
+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);
+}
 
-	return {};
+void
+GeoData::boundaryWalkUntil(const std::function<bool(HalfedgeHandle)> & op) const
+{
+	boundaryWalkUntil(op, findBoundaryStart());
 }
 
-unsigned int
-GeoData::at(glm::ivec2 coord) const
+void
+GeoData::boundaryWalkUntil(const std::function<bool(HalfedgeHandle)> & op, HalfedgeHandle start) const
 {
-	if (coord.x < limit.first.x || coord.x > limit.second.x || coord.y < limit.first.y || coord.y > limit.second.y) {
-		throw std::range_error {"Coordinates outside GeoData limits"};
+	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;
+			}
+		}
 	}
-	const glm::uvec2 offset = coord - limit.first;
-	return offset.x + (offset.y * size.x);
 }
 
-unsigned int
-GeoData::at(int x, int y) const
+GeoData::HalfedgeHandle
+GeoData::findEntry(const GlobalPosition2D from, const GlobalPosition2D to) const
 {
-	return at({x, y});
+	HalfedgeHandle entry;
+	boundaryWalkUntil([this, from, to, &entry](auto he) {
+		const auto e1 = point(to_vertex_handle(he));
+		const auto e2 = point(to_vertex_handle(opposite_halfedge_handle(he)));
+		if (linesCrossLtR(from, to, e1, e2)) {
+			entry = he;
+			return true;
+		}
+		return false;
+	});
+	return entry;
 }
 
-GeoData::Limits
-GeoData::getLimit() const
+bool
+GeoData::triangleContainsPoint(const GlobalPosition2D p, const Triangle<2> & t)
 {
-	return limit;
+	return pointLeftOfOrOnLine(p, t[0], t[1]) && pointLeftOfOrOnLine(p, t[1], t[2])
+			&& pointLeftOfOrOnLine(p, t[2], t[0]);
 }
 
-float
-GeoData::getScale() const
+bool
+GeoData::triangleContainsPoint(const GlobalPosition2D p, FaceHandle face) const
 {
-	return scale;
+	return triangleContainsPoint(p, triangle<2>(face));
 }
 
-glm::uvec2
-GeoData::getSize() const
+GeoData::HalfedgeHandle
+GeoData::findBoundaryStart() const
 {
-	return size;
+	return *std::find_if(halfedges_begin(), halfedges_end(), [this](const auto heh) {
+		return is_boundary(heh);
+	});
 }
 
-std::span<const GeoData::Node>
-GeoData::getNodes() const
+void
+GeoData::update_vertex_normals_only()
 {
-	return nodes;
+	for (auto vh : all_vertices()) {
+		Normal3D n;
+		calc_vertex_normal_correct(vh, n);
+		this->set_normal(vh, glm::normalize(n));
+	}
 }
diff --git a/game/geoData.h b/game/geoData.h
index f9a7d7b..d4d0fb3 100644
--- a/game/geoData.h
+++ b/game/geoData.h
@@ -1,62 +1,112 @@
 #pragma once
 
-#include <array>
+#include "collections.h" // IWYU pragma: keep IterableCollection
+#include "config/types.h"
+#include "ray.h"
+#include <OpenMesh/Core/Mesh/TriMesh_ArrayKernelT.hh>
 #include <filesystem>
-#include <glm/glm.hpp>
+#include <glm/vec2.hpp>
 #include <optional>
-#include <span>
-#include <utility>
-#include <vector>
+#include <thirdparty/openmesh/glmcompat.h>
 
-class Ray;
+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 GeoData {
-public:
-	struct Node {
-		float height {-1.5F};
-	};
+class GeoData : public OpenMesh::TriMesh_ArrayKernelT<GeoDataTraits> {
+private:
+	GeoData() = default;
 
-	using Quad = std::array<glm::vec3, 4>;
+public:
+	static GeoData loadFromAsciiGrid(const std::filesystem::path &);
+	static GeoData createFlat(GlobalPosition2D lower, GlobalPosition2D upper, GlobalDistance h);
 
-	using Limits = std::pair<glm::ivec2, glm::ivec2>;
+	struct PointFace {
+		// NOLINTNEXTLINE(hicpp-explicit-conversions)
+		PointFace(const GlobalPosition2D p) : point {p} { }
 
-	explicit GeoData(Limits limit, float scale = 10.F);
+		PointFace(const GlobalPosition2D p, FaceHandle face) : point {p}, _face {face} { }
 
-	void generateRandom();
-	void loadFromImages(const std::filesystem::path &, float scale);
+		PointFace(const GlobalPosition2D p, const GeoData *);
+		PointFace(const GlobalPosition2D p, const GeoData *, FaceHandle start);
 
-	[[nodiscard]] glm::vec3 positionAt(glm::vec2) const;
-	[[nodiscard]] std::optional<glm::vec3> intersectRay(const Ray &) const;
+		const GlobalPosition2D point;
+		[[nodiscard]] FaceHandle face(const GeoData *) const;
+		[[nodiscard]] FaceHandle face(const GeoData *, FaceHandle start) const;
 
-	[[nodiscard]] unsigned int at(glm::ivec2) const;
-	[[nodiscard]] unsigned int at(int x, int y) const;
-	[[nodiscard]] Quad quad(glm::vec2) const;
+		[[nodiscard]] bool
+		isLocated() const
+		{
+			return _face.is_valid();
+		}
 
-	[[nodiscard]] Limits getLimit() const;
-	[[nodiscard]] glm::uvec2 getSize() const;
-	[[nodiscard]] float getScale() const;
-	[[nodiscard]] std::span<const Node> getNodes() const;
+	private:
+		mutable FaceHandle _face {};
+	};
 
-	class RayTracer {
-	public:
-		RayTracer(glm::vec2 p0, glm::vec2 p1);
+	template<glm::length_t Dim> struct Triangle : public glm::vec<3, glm::vec<Dim, GlobalDistance>> {
+		using base = glm::vec<3, glm::vec<Dim, GlobalDistance>>;
+		using base::base;
 
-		glm::vec2 next();
+		template<IterableCollection Range> Triangle(const GeoData * m, Range range)
+		{
+			assert(std::distance(range.begin(), range.end()) == 3);
+			std::transform(range.begin(), range.end(), &base::operator[](0), [m](auto vh) {
+				return m->point(vh);
+			});
+		}
 
-	private:
-		RayTracer(glm::vec2 p0, glm::vec2 p1, glm::vec2 d);
-		RayTracer(glm::vec2 p0, glm::vec2 d, std::pair<float, float>, std::pair<float, float>);
-		static std::pair<float, float> byAxis(glm::vec2 p0, glm::vec2 p1, glm::vec2 d, glm::length_t);
-
-		glm::vec2 p;
-		const glm::vec2 d;
-		float error;
-		glm::vec2 inc;
+		glm::vec<Dim, GlobalDistance>
+		operator*(BaryPosition bari) const
+		{
+			const auto & t {*this};
+			return t[0] + GlobalPosition<Dim>(RelativePosition<Dim>(t[1] - t[0]) * bari.x)
+					+ GlobalPosition<Dim>(RelativePosition<Dim>(t[2] - t[1]) * bari.y);
+		}
 	};
 
+	[[nodiscard]] FaceHandle findPoint(GlobalPosition2D) const;
+	[[nodiscard]] FaceHandle findPoint(GlobalPosition2D, FaceHandle start) const;
+
+	[[nodiscard]] GlobalPosition3D positionAt(const PointFace &) const;
+	[[nodiscard]] std::optional<GlobalPosition3D> intersectRay(const Ray &) const;
+	[[nodiscard]] std::optional<GlobalPosition3D> intersectRay(const Ray &, FaceHandle start) const;
+
+	void walk(const PointFace & from, const GlobalPosition2D to, const std::function<void(FaceHandle)> & op) const;
+	void walkUntil(const PointFace & from, const GlobalPosition2D 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]] HalfedgeHandle findEntry(const GlobalPosition2D from, const GlobalPosition2D to) const;
+
+	[[nodiscard]] auto
+	getExtents() const
+	{
+		return std::tie(lowerExtent, upperExtent);
+	}
+
 protected:
-	Limits limit {}; // Base grid limits first(x,y) -> second(x,y)
-	glm::uvec2 size {};
-	float scale {1};
-	std::vector<Node> nodes;
+	template<glm::length_t Dim>
+	[[nodiscard]] Triangle<Dim>
+	triangle(FaceHandle f) const
+	{
+		return {this, fv_range(f)};
+	}
+
+	[[nodiscard]] static bool triangleContainsPoint(const GlobalPosition2D, const Triangle<2> &);
+	[[nodiscard]] bool triangleContainsPoint(const GlobalPosition2D, FaceHandle) const;
+	[[nodiscard]] HalfedgeHandle findBoundaryStart() const;
+
+	void update_vertex_normals_only();
+
+private:
+	GlobalPosition3D lowerExtent {}, upperExtent {};
 };
diff --git a/game/network/link.cpp b/game/network/link.cpp
index bb27a52..703a1ca 100644
--- a/game/network/link.cpp
+++ b/game/network/link.cpp
@@ -8,10 +8,10 @@
 
 Link::Link(End a, End b, float l) : ends {{std::move(a), std::move(b)}}, length {l} { }
 
-LinkCurve::LinkCurve(glm::vec3 c, float r, Arc a) : centreBase {c}, radius {r}, arc {std::move(a)} { }
+LinkCurve::LinkCurve(Position3D c, float r, Arc a) : centreBase {c}, radius {r}, arc {std::move(a)} { }
 
 bool
-operator<(const glm::vec3 & a, const glm::vec3 & b)
+operator<(const Position3D & a, const Position3D & b)
 {
 	// NOLINTNEXTLINE(hicpp-use-nullptr,modernize-use-nullptr)
 	return std::tie(a.x, a.y, a.z) < std::tie(b.x, b.y, b.z);
@@ -46,9 +46,9 @@ LinkCurve::positionAt(float dist, unsigned char start) const
 	const auto es {std::make_pair(ends[start].node.get(), ends[1 - start].node.get())};
 	const auto as {std::make_pair(arc[start], arc[1 - start])};
 	const auto ang {as.first + ((as.second - as.first) * frac)};
-	const auto relPos {!sincosf(ang) * radius};
+	const auto relPos {(sincosf(ang) || 0.F) * radius};
 	const auto relClimb {vehiclePositionOffset()
-			+ glm::vec3 {0, 0, es.first->pos.z - centreBase.z + ((es.second->pos.z - es.first->pos.z) * frac)}};
+			+ Position3D {0, 0, es.first->pos.z - centreBase.z + ((es.second->pos.z - es.first->pos.z) * frac)}};
 	const auto pitch {vector_pitch({0, 0, (es.second->pos.z - es.first->pos.z) / length})};
 	return Location {relPos + relClimb + centreBase, {pitch, normalize(ang + dirOffset[start]), 0}};
 }
@@ -60,14 +60,14 @@ LinkCurve::intersectRay(const Ray & ray) const
 	const auto & e1p {ends[1].node->pos};
 	const auto slength = round_frac(length / 2.F, 5.F);
 	const auto segs = std::round(15.F * slength / std::pow(radius, 0.7F));
-	const auto step {glm::vec3 {arc_length(arc), e1p.z - e0p.z, slength} / segs};
+	const auto step {Position3D {arc_length(arc), e1p.z - e0p.z, slength} / segs};
 	const auto trans {glm::translate(centreBase)};
 
 	auto segCount = static_cast<std::size_t>(std::lround(segs)) + 1;
-	std::vector<glm::vec3> points;
+	std::vector<Position3D> points;
 	points.reserve(segCount);
-	for (glm::vec3 swing = {arc.first, centreBase.z - e0p.z, 0.F}; segCount; swing += step, --segCount) {
-		const auto t {trans * glm::rotate(half_pi - swing.x, up) * glm::translate(glm::vec3 {radius, 0.F, swing.y})};
+	for (Position3D swing = {arc.first, centreBase.z - e0p.z, 0.F}; segCount; swing += step, --segCount) {
+		const auto t {trans * glm::rotate(half_pi - swing.x, up) * glm::translate(Position3D {radius, 0.F, swing.y})};
 		points.emplace_back(t * glm::vec4 {0, 0, 0, 1});
 	}
 	return ray.passesCloseToEdges(points, 1.F);
diff --git a/game/network/link.h b/game/network/link.h
index 0d66c42..78d3e91 100644
--- a/game/network/link.h
+++ b/game/network/link.h
@@ -17,12 +17,12 @@ class Ray;
 // it has location
 class Node : public StdTypeDefs<Node> {
 public:
-	explicit Node(glm::vec3 p) noexcept : pos(p) {};
+	explicit Node(Position3D p) noexcept : pos(p) {};
 	virtual ~Node() noexcept = default;
 	NO_COPY(Node);
 	NO_MOVE(Node);
 
-	glm::vec3 pos;
+	Position3D pos;
 };
 
 // Generic network link
@@ -51,14 +51,14 @@ public:
 	float length;
 
 protected:
-	[[nodiscard]] virtual glm::vec3
+	[[nodiscard]] virtual Position3D
 	vehiclePositionOffset() const
 	{
 		return {};
 	}
 };
 
-bool operator<(const glm::vec3 & a, const glm::vec3 & b);
+bool operator<(const Position3D & a, const Position3D & b);
 bool operator<(const Node & a, const Node & b);
 
 class LinkStraight : public virtual Link {
@@ -77,14 +77,14 @@ LinkStraight::~LinkStraight() = default;
 class LinkCurve : public virtual Link {
 public:
 	inline ~LinkCurve() override = 0;
-	LinkCurve(glm::vec3, float, Arc);
+	LinkCurve(Position3D, float, Arc);
 	NO_COPY(LinkCurve);
 	NO_MOVE(LinkCurve);
 
 	[[nodiscard]] Location positionAt(float dist, unsigned char start) const override;
 	[[nodiscard]] bool intersectRay(const Ray &) const override;
 
-	glm::vec3 centreBase;
+	Position3D centreBase;
 	float radius;
 	Arc arc;
 };
diff --git a/game/network/network.cpp b/game/network/network.cpp
index 083b08e..1ff5b26 100644
--- a/game/network/network.cpp
+++ b/game/network/network.cpp
@@ -14,13 +14,13 @@
 Network::Network(const std::string & tn) : texture {Texture::cachedTexture.get(tn)} { }
 
 Node::Ptr
-Network::nodeAt(glm::vec3 pos)
+Network::nodeAt(Position3D pos)
 {
 	return newNodeAt(pos).first;
 }
 
 Network::NodeInsertion
-Network::newNodeAt(glm::vec3 pos)
+Network::newNodeAt(Position3D pos)
 {
 	if (auto [n, i] = candidateNodeAt(pos); i == NodeIs::NotInNetwork) {
 		return {*nodes.insert(std::move(n)).first, i};
@@ -31,7 +31,7 @@ Network::newNodeAt(glm::vec3 pos)
 }
 
 Node::Ptr
-Network::findNodeAt(glm::vec3 pos) const
+Network::findNodeAt(Position3D pos) const
 {
 	if (const auto n = nodes.find(pos); n != nodes.end()) {
 		return *n;
@@ -40,7 +40,7 @@ Network::findNodeAt(glm::vec3 pos) const
 }
 
 Network::NodeInsertion
-Network::candidateNodeAt(glm::vec3 pos) const
+Network::candidateNodeAt(Position3D pos) const
 {
 	if (const auto n = nodes.find(pos); n != nodes.end()) {
 		return {*n, NodeIs::InNetwork};
@@ -54,7 +54,7 @@ Network::intersectRayNodes(const Ray & ray) const
 	// Click within 2m of a node
 	if (const auto node = std::find_if(nodes.begin(), nodes.end(),
 				[&ray](const Node::Ptr & node) {
-					glm::vec3 ipos, inorm;
+					Position3D ipos, inorm;
 					return glm::intersectRaySphere(ray.start, ray.direction, node->pos, 2.F, ipos, inorm);
 				});
 			node != nodes.end()) {
@@ -79,7 +79,7 @@ Network::joinLinks(const Link::Ptr & l, const Link::Ptr & ol)
 }
 
 Link::Nexts
-Network::routeFromTo(const Link::End & start, glm::vec3 dest) const
+Network::routeFromTo(const Link::End & start, Position3D dest) const
 {
 	auto destNode {findNodeAt(dest)};
 	if (!destNode) {
@@ -95,12 +95,12 @@ Network::routeFromTo(const Link::End & end, const Node::Ptr & dest) const
 }
 
 GenCurveDef
-Network::genCurveDef(const glm::vec3 & start, const glm::vec3 & end, float startDir)
+Network::genCurveDef(const Position3D & start, const Position3D & end, float startDir)
 {
 	const auto diff {end - start};
 	const auto vy {vector_yaw(diff)};
 	const auto dir = pi + startDir;
-	const auto flatStart {!start}, flatEnd {!end};
+	const auto flatStart {start.xy()}, flatEnd {end.xy()};
 	const auto n2ed {(vy * 2) - dir - pi};
 	const auto centre {find_arc_centre(flatStart, dir, flatEnd, n2ed)};
 
@@ -111,11 +111,11 @@ Network::genCurveDef(const glm::vec3 & start, const glm::vec3 & end, float start
 }
 
 std::pair<GenCurveDef, GenCurveDef>
-Network::genCurveDef(const glm::vec3 & start, const glm::vec3 & end, float startDir, float endDir)
+Network::genCurveDef(const Position3D & start, const Position3D & end, float startDir, float endDir)
 {
 	startDir += pi;
 	endDir += pi;
-	const glm::vec2 flatStart {!start}, flatEnd {!end};
+	const Position2D flatStart {start.xy()}, flatEnd {end.xy()};
 	auto midheight = [&](auto mid) {
 		const auto sm = glm::distance(flatStart, mid), em = glm::distance(flatEnd, mid);
 		return start.z + ((end.z - start.z) * (sm / (sm + em)));
@@ -125,7 +125,7 @@ Network::genCurveDef(const glm::vec3 & start, const glm::vec3 & end, float start
 		const auto c1 = flatStart + sincosf(startDir + half_pi) * radius;
 		const auto c2 = flatEnd + sincosf(endDir + half_pi) * radius;
 		const auto mid = (c1 + c2) / 2.F;
-		const auto midh = mid ^ midheight(mid);
+		const auto midh = mid || midheight(mid);
 		return {{start, midh, c1}, {end, midh, c2}};
 	}
 	else {
@@ -133,7 +133,7 @@ Network::genCurveDef(const glm::vec3 & start, const glm::vec3 & end, float start
 		const auto c1 = flatStart + sincosf(startDir - half_pi) * radius;
 		const auto c2 = flatEnd + sincosf(endDir - half_pi) * radius;
 		const auto mid = (c1 + c2) / 2.F;
-		const auto midh = mid ^ midheight(mid);
+		const auto midh = mid || midheight(mid);
 		return {{midh, start, c1}, {midh, end, c2}};
 	}
 }
diff --git a/game/network/network.h b/game/network/network.h
index b9316eb..8af06a9 100644
--- a/game/network/network.h
+++ b/game/network/network.h
@@ -16,7 +16,7 @@ class Texture;
 class SceneShader;
 class Ray;
 
-template<size_t... n> using GenDef = std::tuple<glm::vec<n, float>...>;
+template<size_t... n> using GenDef = std::tuple<glm::vec<n, Distance>...>;
 using GenCurveDef = GenDef<3, 3, 2>;
 
 class Network {
@@ -26,32 +26,32 @@ public:
 	virtual ~Network() = default;
 	DEFAULT_MOVE_NO_COPY(Network);
 
-	[[nodiscard]] Node::Ptr findNodeAt(glm::vec3) const;
-	[[nodiscard]] Node::Ptr nodeAt(glm::vec3);
+	[[nodiscard]] Node::Ptr findNodeAt(Position3D) const;
+	[[nodiscard]] Node::Ptr nodeAt(Position3D);
 	enum class NodeIs { InNetwork, NotInNetwork };
 	using NodeInsertion = std::pair<Node::Ptr, NodeIs>;
-	[[nodiscard]] NodeInsertion newNodeAt(glm::vec3);
-	[[nodiscard]] NodeInsertion candidateNodeAt(glm::vec3) const;
+	[[nodiscard]] NodeInsertion newNodeAt(Position3D);
+	[[nodiscard]] NodeInsertion candidateNodeAt(Position3D) const;
 	[[nodiscard]] virtual Link::Ptr intersectRayLinks(const Ray &) const = 0;
 	[[nodiscard]] virtual Node::Ptr intersectRayNodes(const Ray &) const;
 
-	[[nodiscard]] Link::Nexts routeFromTo(const Link::End &, glm::vec3) const;
+	[[nodiscard]] Link::Nexts routeFromTo(const Link::End &, Position3D) const;
 	[[nodiscard]] Link::Nexts routeFromTo(const Link::End &, const Node::Ptr &) const;
 
-	virtual Link::CCollection candidateStraight(glm::vec3, glm::vec3) = 0;
-	virtual Link::CCollection candidateJoins(glm::vec3, glm::vec3) = 0;
-	virtual Link::CCollection candidateExtend(glm::vec3, glm::vec3) = 0;
-	virtual Link::CCollection addStraight(glm::vec3, glm::vec3) = 0;
-	virtual Link::CCollection addJoins(glm::vec3, glm::vec3) = 0;
-	virtual Link::CCollection addExtend(glm::vec3, glm::vec3) = 0;
+	virtual Link::CCollection candidateStraight(Position3D, Position3D) = 0;
+	virtual Link::CCollection candidateJoins(Position3D, Position3D) = 0;
+	virtual Link::CCollection candidateExtend(Position3D, Position3D) = 0;
+	virtual Link::CCollection addStraight(Position3D, Position3D) = 0;
+	virtual Link::CCollection addJoins(Position3D, Position3D) = 0;
+	virtual Link::CCollection addExtend(Position3D, Position3D) = 0;
 
 	[[nodiscard]] virtual float findNodeDirection(Node::AnyCPtr) const = 0;
 
 protected:
 	static void joinLinks(const Link::Ptr & l, const Link::Ptr & ol);
-	static GenCurveDef genCurveDef(const glm::vec3 & start, const glm::vec3 & end, float startDir);
+	static GenCurveDef genCurveDef(const Position3D & start, const Position3D & end, float startDir);
 	static std::pair<GenCurveDef, GenCurveDef> genCurveDef(
-			const glm::vec3 & start, const glm::vec3 & end, float startDir, float endDir);
+			const Position3D & start, const Position3D & end, float startDir, float endDir);
 
 	using Nodes = std::set<Node::Ptr, PtrMemberSorter<Node::Ptr, &Node::pos>>;
 	Nodes nodes;
@@ -71,7 +71,7 @@ protected:
 public:
 	template<typename L, typename... Params>
 	std::shared_ptr<L>
-	candidateLink(glm::vec3 a, glm::vec3 b, Params &&... params)
+	candidateLink(Position3D a, Position3D b, Params &&... params)
 		requires std::is_base_of_v<T, L>
 	{
 		const auto node1 = candidateNodeAt(a).first, node2 = candidateNodeAt(b).first;
@@ -80,7 +80,7 @@ public:
 
 	template<typename L, typename... Params>
 	std::shared_ptr<L>
-	addLink(glm::vec3 a, glm::vec3 b, Params &&... params)
+	addLink(Position3D a, Position3D b, Params &&... params)
 		requires std::is_base_of_v<T, L>
 	{
 		const auto node1 = nodeAt(a), node2 = nodeAt(b);
@@ -89,12 +89,12 @@ public:
 		return l;
 	}
 
-	Link::CCollection candidateStraight(glm::vec3 n1, glm::vec3 n2) override;
-	Link::CCollection candidateJoins(glm::vec3, glm::vec3) override;
-	Link::CCollection candidateExtend(glm::vec3, glm::vec3) override;
-	Link::CCollection addStraight(glm::vec3 n1, glm::vec3 n2) override;
-	Link::CCollection addJoins(glm::vec3, glm::vec3) override;
-	Link::CCollection addExtend(glm::vec3, glm::vec3) override;
+	Link::CCollection candidateStraight(Position3D n1, Position3D n2) override;
+	Link::CCollection candidateJoins(Position3D, Position3D) override;
+	Link::CCollection candidateExtend(Position3D, Position3D) override;
+	Link::CCollection addStraight(Position3D n1, Position3D n2) override;
+	Link::CCollection addJoins(Position3D, Position3D) override;
+	Link::CCollection addExtend(Position3D, Position3D) override;
 
 	[[nodiscard]] float findNodeDirection(Node::AnyCPtr) const override;
 
diff --git a/game/network/network.impl.h b/game/network/network.impl.h
index 045335f..8e9e85c 100644
--- a/game/network/network.impl.h
+++ b/game/network/network.impl.h
@@ -54,14 +54,14 @@ NetworkOf<T>::findNodeDirection(Node::AnyCPtr n) const
 
 template<typename T>
 Link::CCollection
-NetworkOf<T>::candidateStraight(glm::vec3 n1, glm::vec3 n2)
+NetworkOf<T>::candidateStraight(Position3D n1, Position3D n2)
 {
 	return {candidateLink<typename T::StraightLink>(n1, n2)};
 }
 
 template<typename T>
 Link::CCollection
-NetworkOf<T>::candidateJoins(glm::vec3 start, glm::vec3 end)
+NetworkOf<T>::candidateJoins(Position3D start, Position3D end)
 {
 	if (glm::distance(start, end) < 2.F) {
 		return {};
@@ -75,7 +75,7 @@ NetworkOf<T>::candidateJoins(glm::vec3 start, glm::vec3 end)
 
 template<typename T>
 Link::CCollection
-NetworkOf<T>::candidateExtend(glm::vec3 start, glm::vec3 end)
+NetworkOf<T>::candidateExtend(Position3D start, Position3D end)
 {
 	const auto [cstart, cend, centre] = genCurveDef(start, end, findNodeDirection(candidateNodeAt(start).first));
 	return {candidateLink<typename T::CurveLink>(cstart, cend, centre)};
@@ -83,14 +83,14 @@ NetworkOf<T>::candidateExtend(glm::vec3 start, glm::vec3 end)
 
 template<typename T>
 Link::CCollection
-NetworkOf<T>::addStraight(glm::vec3 n1, glm::vec3 n2)
+NetworkOf<T>::addStraight(Position3D n1, Position3D n2)
 {
 	return {addLink<typename T::StraightLink>(n1, n2)};
 }
 
 template<typename T>
 Link::CCollection
-NetworkOf<T>::addJoins(glm::vec3 start, glm::vec3 end)
+NetworkOf<T>::addJoins(Position3D start, Position3D end)
 {
 	if (glm::distance(start, end) < 2.F) {
 		return {};
@@ -103,7 +103,7 @@ NetworkOf<T>::addJoins(glm::vec3 start, glm::vec3 end)
 
 template<typename T>
 Link::CCollection
-NetworkOf<T>::addExtend(glm::vec3 start, glm::vec3 end)
+NetworkOf<T>::addExtend(Position3D start, Position3D end)
 {
 	const auto [cstart, cend, centre] = genCurveDef(start, end, findNodeDirection(nodeAt(start)));
 	return {addLink<typename T::CurveLink>(cstart, cend, centre)};
diff --git a/game/network/rail.cpp b/game/network/rail.cpp
index 5a4f1e1..303f1c8 100644
--- a/game/network/rail.cpp
+++ b/game/network/rail.cpp
@@ -18,7 +18,7 @@
 template class NetworkOf<RailLink>;
 
 constexpr auto RAIL_CROSSSECTION_VERTICES {5U};
-constexpr glm::vec3 RAIL_HEIGHT {0, 0, .25F};
+constexpr Size3D RAIL_HEIGHT {0, 0, 250.F};
 
 RailLinks::RailLinks() : NetworkOf<RailLink> {"rails.jpg"} { }
 
@@ -28,7 +28,7 @@ RailLinks::tick(TickDuration)
 }
 
 std::shared_ptr<RailLink>
-RailLinks::addLinksBetween(glm::vec3 start, glm::vec3 end)
+RailLinks::addLinksBetween(Position3D start, Position3D end)
 {
 	auto node1ins = newNodeAt(start), node2ins = newNodeAt(end);
 	if (node1ins.second == NodeIs::NotInNetwork && node2ins.second == NodeIs::NotInNetwork) {
@@ -45,7 +45,7 @@ RailLinks::addLinksBetween(glm::vec3 start, glm::vec3 end)
 	if (dir == vector_yaw(end - start)) {
 		return addLink<RailLinkStraight>(start, end);
 	}
-	const glm::vec2 flatStart {!start}, flatEnd {!end};
+	const Position2D flatStart {start.xy()}, flatEnd {end.xy()};
 	if (node2ins.second == NodeIs::InNetwork) {
 		auto midheight = [&](auto mid) {
 			const auto sm = glm::distance(flatStart, mid), em = glm::distance(flatEnd, mid);
@@ -57,7 +57,7 @@ RailLinks::addLinksBetween(glm::vec3 start, glm::vec3 end)
 			const auto c1 = flatStart + sincosf(dir + half_pi) * radius;
 			const auto c2 = flatEnd + sincosf(dir2 + half_pi) * radius;
 			const auto mid = (c1 + c2) / 2.F;
-			const auto midh = mid ^ midheight(mid);
+			const auto midh = mid || midheight(mid);
 			addLink<RailLinkCurve>(start, midh, c1);
 			return addLink<RailLinkCurve>(end, midh, c2);
 		}
@@ -66,7 +66,7 @@ RailLinks::addLinksBetween(glm::vec3 start, glm::vec3 end)
 			const auto c1 = flatStart + sincosf(dir - half_pi) * radius;
 			const auto c2 = flatEnd + sincosf(dir2 - half_pi) * radius;
 			const auto mid = (c1 + c2) / 2.F;
-			const auto midh = mid ^ midheight(mid);
+			const auto midh = mid || midheight(mid);
 			addLink<RailLinkCurve>(midh, start, c1);
 			return addLink<RailLinkCurve>(midh, end, c2);
 		}
@@ -100,15 +100,15 @@ RailLink::render(const SceneShader &) const
 	mesh->Draw();
 }
 
-constexpr const std::array<std::pair<glm::vec3, float>, RAIL_CROSSSECTION_VERTICES> railCrossSection {{
+constexpr const std::array<std::pair<Position3D, float>, RAIL_CROSSSECTION_VERTICES> railCrossSection {{
 		//   ___________
 		// _/           \_
 		//  left to right
-		{{-1.9F, 0.F, 0.F}, 0.F},
-		{{-.608F, 0.F, RAIL_HEIGHT.z}, 0.34F},
-		{{0, 0.F, RAIL_HEIGHT.z * .7F}, 0.5F},
-		{{.608F, 0.F, RAIL_HEIGHT.z}, 0.66F},
-		{{1.9F, 0.F, 0.F}, 1.F},
+		{{-1900.F, 0.F, 0.F}, 0.F},
+		{{-608.F, 0.F, RAIL_HEIGHT.z}, .34F},
+		{{0, 0.F, RAIL_HEIGHT.z * .7F}, .5F},
+		{{608.F, 0.F, RAIL_HEIGHT.z}, .66F},
+		{{1900.F, 0.F, 0.F}, 1.F},
 }};
 constexpr auto sleepers {5.F}; // There are 5 repetitions of sleepers in the texture
 
@@ -122,31 +122,31 @@ RailLinkStraight::RailLinkStraight(const Node::Ptr & a, const Node::Ptr & b) : R
 {
 }
 
-RailLinkStraight::RailLinkStraight(Node::Ptr a, Node::Ptr b, const glm::vec3 & diff) :
+RailLinkStraight::RailLinkStraight(Node::Ptr a, Node::Ptr b, const Position3D & diff) :
 	Link({std::move(a), vector_yaw(diff)}, {std::move(b), vector_yaw(-diff)}, glm::length(diff))
 {
 	if (glGenVertexArrays) {
 		std::vector<Vertex> vertices;
 		vertices.reserve(2 * railCrossSection.size());
-		const auto len = round_sleepers(length / 2.F);
+		const auto len = round_sleepers(length / 2000.F);
 		const auto e {flat_orientation(diff)};
 		for (auto ei : {1U, 0U}) {
 			const auto trans {glm::translate(ends[ei].node->pos) * e};
 			for (const auto & rcs : railCrossSection) {
-				const glm::vec3 m {(trans * glm::vec4 {rcs.first, 1})};
-				vertices.emplace_back(m, glm::vec2 {rcs.second, len * static_cast<float>(ei)}, up);
+				const Position3D m {(trans * (rcs.first || 1.F))};
+				vertices.emplace_back(m, Position2D {rcs.second, len * static_cast<float>(ei)}, up);
 			}
 		}
 		mesh = defaultMesh(vertices);
 	}
 }
 
-RailLinkCurve::RailLinkCurve(const Node::Ptr & a, const Node::Ptr & b, glm::vec2 c) :
-	RailLinkCurve(a, b, c ^ a->pos.z, {!c, a->pos, b->pos})
+RailLinkCurve::RailLinkCurve(const Node::Ptr & a, const Node::Ptr & b, Position2D c) :
+	RailLinkCurve(a, b, c || a->pos.z, {c || 0.F, a->pos, b->pos})
 {
 }
 
-RailLinkCurve::RailLinkCurve(const Node::Ptr & a, const Node::Ptr & b, glm::vec3 c, const Arc arc) :
+RailLinkCurve::RailLinkCurve(const Node::Ptr & a, const Node::Ptr & b, Position3D c, const Arc arc) :
 	Link({a, normalize(arc.first + half_pi)}, {b, normalize(arc.second - half_pi)},
 			(glm::length(a->pos - c)) * arc_length(arc)),
 	LinkCurve {c, glm::length(ends[0].node->pos - c), arc}
@@ -155,26 +155,26 @@ RailLinkCurve::RailLinkCurve(const Node::Ptr & a, const Node::Ptr & b, glm::vec3
 		const auto & e0p {ends[0].node->pos};
 		const auto & e1p {ends[1].node->pos};
 		const auto slength = round_sleepers(length / 2.F);
-		const auto segs = std::round(15.F * slength / std::pow(radius, 0.7F));
-		const auto step {glm::vec3 {arc_length(arc), e1p.z - e0p.z, slength} / segs};
+		const auto segs = std::round(slength / std::pow(radius, 0.7F));
+		const auto step {Position3D {arc_length(arc), e1p.z - e0p.z, slength / 1000.F} / segs};
 		const auto trans {glm::translate(centreBase)};
 
 		auto segCount = static_cast<std::size_t>(std::lround(segs)) + 1;
 		std::vector<Vertex> vertices;
 		vertices.reserve(segCount * railCrossSection.size());
-		for (glm::vec3 swing = {arc.first, centreBase.z - e0p.z, 0.F}; segCount; swing += step, --segCount) {
+		for (Position3D swing = {arc.first, centreBase.z - e0p.z, 0.F}; segCount; swing += step, --segCount) {
 			const auto t {
-					trans * glm::rotate(half_pi - swing.x, up) * glm::translate(glm::vec3 {radius, 0.F, swing.y})};
+					trans * glm::rotate(half_pi - swing.x, up) * glm::translate(Position3D {radius, 0.F, swing.y})};
 			for (const auto & rcs : railCrossSection) {
-				const glm::vec3 m {(t * glm::vec4 {rcs.first, 1})};
-				vertices.emplace_back(m, glm::vec2 {rcs.second, swing.z}, up);
+				const Position3D m {(t * (rcs.first || 1.F))};
+				vertices.emplace_back(m, Position2D {rcs.second, swing.z}, up);
 			}
 		}
 		mesh = defaultMesh(vertices);
 	}
 }
 
-glm::vec3
+Position3D
 RailLink::vehiclePositionOffset() const
 {
 	return RAIL_HEIGHT;
diff --git a/game/network/rail.h b/game/network/rail.h
index 6684801..4a1932f 100644
--- a/game/network/rail.h
+++ b/game/network/rail.h
@@ -32,7 +32,7 @@ public:
 	NO_MOVE(RailLink);
 
 protected:
-	[[nodiscard]] glm::vec3 vehiclePositionOffset() const override;
+	[[nodiscard]] Position3D vehiclePositionOffset() const override;
 	[[nodiscard]] static Mesh::Ptr defaultMesh(const std::span<Vertex> vertices);
 
 	Mesh::Ptr mesh;
@@ -45,22 +45,22 @@ public:
 	RailLinkStraight(const Node::Ptr &, const Node::Ptr &);
 
 private:
-	RailLinkStraight(Node::Ptr, Node::Ptr, const glm::vec3 & diff);
+	RailLinkStraight(Node::Ptr, Node::Ptr, const Position3D & diff);
 };
 
 class RailLinkCurve : public RailLink, public LinkCurve {
 public:
-	RailLinkCurve(const Node::Ptr &, const Node::Ptr &, glm::vec2);
+	RailLinkCurve(const Node::Ptr &, const Node::Ptr &, Position2D);
 
 private:
-	RailLinkCurve(const Node::Ptr &, const Node::Ptr &, glm::vec3, const Arc);
+	RailLinkCurve(const Node::Ptr &, const Node::Ptr &, Position3D, const Arc);
 };
 
 class RailLinks : public NetworkOf<RailLink>, public WorldObject {
 public:
 	RailLinks();
 
-	std::shared_ptr<RailLink> addLinksBetween(glm::vec3 start, glm::vec3 end);
+	std::shared_ptr<RailLink> addLinksBetween(Position3D start, Position3D end);
 
 private:
 	void tick(TickDuration elapsed) override;
diff --git a/game/scenary/foliage.cpp b/game/scenary/foliage.cpp
index 702a52c..c258b77 100644
--- a/game/scenary/foliage.cpp
+++ b/game/scenary/foliage.cpp
@@ -15,7 +15,8 @@ void
 Foliage::postLoad()
 {
 	texture = getTexture();
-	bodyMesh->configureVAO(instanceVAO).addAttribs<glm::mat4>(instances.bufferName(), 1);
+	bodyMesh->configureVAO(instanceVAO)
+			.addAttribs<LocationVertex, &LocationVertex::first, &LocationVertex::second>(instances.bufferName(), 1);
 }
 
 void
diff --git a/game/scenary/foliage.h b/game/scenary/foliage.h
index b72a9c2..bbb6200 100644
--- a/game/scenary/foliage.h
+++ b/game/scenary/foliage.h
@@ -15,7 +15,8 @@ class Foliage : public Asset, public Renderable, public StdTypeDefs<Foliage> {
 	glVertexArray instanceVAO;
 
 public:
-	mutable InstanceVertices<glm::mat4> instances;
+	using LocationVertex = std::pair<glm::mat4, GlobalPosition3D>;
+	mutable InstanceVertices<LocationVertex> instances;
 	void render(const SceneShader &) const override;
 	void shadows(const ShadowMapper &) const override;
 
diff --git a/game/scenary/plant.cpp b/game/scenary/plant.cpp
index 4fb3cb5..b39c28b 100644
--- a/game/scenary/plant.cpp
+++ b/game/scenary/plant.cpp
@@ -2,6 +2,6 @@
 #include "location.h"
 
 Plant::Plant(std::shared_ptr<const Foliage> type, const Location & position) :
-	type {std::move(type)}, location {this->type->instances.acquire(position.getTransform())}
+	type {std::move(type)}, location {this->type->instances.acquire(position.getRotationTransform(), position.pos)}
 {
 }
diff --git a/game/scenary/plant.h b/game/scenary/plant.h
index 82ab0e5..77c9ff7 100644
--- a/game/scenary/plant.h
+++ b/game/scenary/plant.h
@@ -7,7 +7,7 @@ class Location;
 
 class Plant : public WorldObject {
 	std::shared_ptr<const Foliage> type;
-	InstanceVertices<glm::mat4>::InstanceProxy location;
+	InstanceVertices<Foliage::LocationVertex>::InstanceProxy location;
 
 	void
 	tick(TickDuration) override
diff --git a/game/selectable.h b/game/selectable.h
index 31287d8..9732dca 100644
--- a/game/selectable.h
+++ b/game/selectable.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "config/types.h"
 #include <glm/glm.hpp>
 #include <special_members.h>
 
@@ -11,5 +12,5 @@ public:
 	virtual ~Selectable() = default;
 	DEFAULT_MOVE_COPY(Selectable);
 
-	[[nodiscard]] virtual bool intersectRay(const Ray &, glm::vec2 *, float *) const = 0;
+	[[nodiscard]] virtual bool intersectRay(const Ray &, Position2D *, float *) const = 0;
 };
diff --git a/game/terrain.cpp b/game/terrain.cpp
index f3bec1e..3778f3d 100644
--- a/game/terrain.cpp
+++ b/game/terrain.cpp
@@ -2,7 +2,6 @@
 #include "game/geoData.h"
 #include "gfx/models/texture.h"
 #include <algorithm>
-#include <array>
 #include <cache.h>
 #include <cstddef>
 #include <filesystem>
@@ -18,8 +17,8 @@
 #include <utility>
 #include <vector>
 
-Terrain::Terrain(std::shared_ptr<GeoData> gd) :
-	geoData {std::move(gd)}, grass {Texture::cachedTexture.get("grass.png")},
+Terrain::Terrain(std::shared_ptr<GeoData> tm) :
+	geoData {std::move(tm)}, grass {Texture::cachedTexture.get("grass.png")},
 	water {Texture::cachedTexture.get("water.png")}
 {
 	generateMeshes();
@@ -29,51 +28,23 @@ void
 Terrain::generateMeshes()
 {
 	std::vector<unsigned int> indices;
-	const auto isize = geoData->getSize() - glm::uvec2 {1, 1};
-	indices.reserve(static_cast<std::size_t>(isize.x * isize.y) * 6);
-
-	const auto limit = geoData->getLimit();
-	//  Indices
-	constexpr std::array<glm::ivec2, 6> indices_offsets {{
-			{0, 0},
-			{1, 0},
-			{1, 1},
-			{0, 0},
-			{1, 1},
-			{0, 1},
-	}};
-	for (auto y = limit.first.y; y < limit.second.y; y += 1) {
-		for (auto x = limit.first.x; x < limit.second.x; x += 1) {
-			std::transform(indices_offsets.begin(), indices_offsets.end(), std::back_inserter(indices),
-					[this, x, y](const auto off) {
-						return geoData->at(x + off.x, y + off.y);
-					});
-		}
-	}
-
-	const auto nodes = geoData->getNodes();
-	const auto scale = geoData->getScale();
+	indices.reserve(geoData->n_faces() * 3);
 	std::vector<Vertex> vertices;
-	vertices.reserve(nodes.size());
-	// Positions
-	for (auto y = limit.first.y; y <= limit.second.y; y += 1) {
-		for (auto x = limit.first.x; x <= limit.second.x; x += 1) {
-			const glm::vec2 xy {x, y};
-			vertices.emplace_back((xy * scale) ^ nodes[geoData->at(x, y)].height, xy, ::up);
-		}
-	}
-	// Normals
-	const glm::uvec2 size = geoData->getSize();
-	for (auto y = limit.first.y + 1; y < limit.second.y; y += 1) {
-		for (auto x = limit.first.x + 1; x < limit.second.x; x += 1) {
-			const auto n {geoData->at(x, y)};
-			const auto a = vertices[n - 1].pos;
-			const auto b = vertices[n - size.x].pos;
-			const auto c = vertices[n + 1].pos;
-			const auto d = vertices[n + size.x].pos;
-			vertices[n].normal = -glm::normalize(glm::cross(b - d, a - c));
-		}
-	}
+	vertices.reserve(geoData->n_vertices());
+	std::map<GeoData::VertexHandle, size_t> vertexIndex;
+	std::transform(geoData->vertices_begin(), geoData->vertices_end(), std::back_inserter(vertices),
+			[this, &vertexIndex](const GeoData::VertexHandle v) {
+				vertexIndex.emplace(v, vertexIndex.size());
+				const auto p = geoData->point(v);
+				return Vertex {p, p / 10000, geoData->normal(v)};
+			});
+	std::for_each(
+			geoData->faces_begin(), geoData->faces_end(), [this, &vertexIndex, &indices](const GeoData::FaceHandle f) {
+				std::transform(geoData->fv_begin(f), geoData->fv_end(f), std::back_inserter(indices),
+						[&vertexIndex](const GeoData::VertexHandle v) {
+							return vertexIndex[v];
+						});
+			});
 	meshes.create<Mesh>(vertices, indices);
 }
 
diff --git a/game/vehicles/linkHistory.cpp b/game/vehicles/linkHistory.cpp
index 2802109..e6bab36 100644
--- a/game/vehicles/linkHistory.cpp
+++ b/game/vehicles/linkHistory.cpp
@@ -8,7 +8,7 @@ LinkHistory::add(const Link::WPtr & l, unsigned char d)
 	links.insert(links.begin(), {l, d});
 	const auto lp = l.lock();
 	totalLen += lp->length;
-	while (totalLen >= 1000.F && !links.empty()) {
+	while (totalLen >= 1000000.F && !links.empty()) {
 		totalLen -= links.back().first.lock()->length;
 		links.pop_back();
 	}
diff --git a/game/vehicles/railVehicle.cpp b/game/vehicles/railVehicle.cpp
index 2d820b6..7e4b1ee 100644
--- a/game/vehicles/railVehicle.cpp
+++ b/game/vehicles/railVehicle.cpp
@@ -12,10 +12,22 @@
 #include <ray.h>
 
 RailVehicle::RailVehicle(RailVehicleClassPtr rvc) :
-	RailVehicleClass::Instance {rvc->instances.acquire()}, rvClass {std::move(rvc)}, location {&LV::body, *this},
+	RailVehicleClass::Instance {rvc->instances.acquire()}, rvClass {std::move(rvc)},
+	location {[this](const BufferedLocation * l) {
+		this->get()->body = l->getRotationTransform();
+		this->get()->bodyPos = l->position();
+	}},
 	bogies {{
-			{&LV::front, *this, glm::vec3 {0, rvClass->wheelBase / 2.F, 0}},
-			{&LV::back, *this, glm::vec3 {0, -rvClass->wheelBase / 2.F, 0}},
+			{[this](const BufferedLocation * l) {
+				 this->get()->front = l->getRotationTransform();
+				 this->get()->frontPos = l->position();
+			 },
+					Position3D {0, rvClass->wheelBase / 2.F, 0}},
+			{[this](const BufferedLocation * l) {
+				 this->get()->back = l->getRotationTransform();
+				 this->get()->backPos = l->position();
+			 },
+					Position3D {0, -rvClass->wheelBase / 2.F, 0}},
 	}}
 {
 }
@@ -26,29 +38,29 @@ RailVehicle::move(const Train * t, float & trailBy)
 	const auto overhang {(rvClass->length - rvClass->wheelBase) / 2};
 	const auto & b1Pos = bogies[0] = t->getBogiePosition(t->linkDist, trailBy += overhang);
 	const auto & b2Pos = bogies[1] = t->getBogiePosition(t->linkDist, trailBy += rvClass->wheelBase);
-	const auto diff = glm::normalize(b2Pos.position() - b1Pos.position());
-	location.setLocation((b1Pos.position() + b2Pos.position()) / 2.F, {vector_pitch(diff), vector_yaw(diff), 0});
-	trailBy += 0.6F + overhang;
+	const auto diff = glm::normalize(RelativePosition3D(b2Pos.position() - b1Pos.position()));
+	location.setLocation((b1Pos.position() + b2Pos.position()) / 2, {vector_pitch(diff), vector_yaw(diff), 0});
+	trailBy += 600.F + overhang;
 }
 
 bool
-RailVehicle::intersectRay(const Ray & ray, glm::vec2 * baryPos, float * distance) const
+RailVehicle::intersectRay(const Ray & ray, BaryPosition * baryPos, float * distance) const
 {
-	constexpr const auto X = 1.35F;
+	constexpr const auto X = 1350.F;
 	const auto Y = this->rvClass->length / 2.F;
-	constexpr const auto Z = 3.9F;
-	const auto moveBy = location.getTransform();
-	const std::array<glm::vec3, 8> cornerVertices {{
-			moveBy * glm::vec4 {-X, Y, 0, 1}, //  LFB
-			moveBy * glm::vec4 {X, Y, 0, 1}, //   RFB
-			moveBy * glm::vec4 {-X, Y, Z, 1}, //  LFT
-			moveBy * glm::vec4 {X, Y, Z, 1}, //   RFT
-			moveBy * glm::vec4 {-X, -Y, 0, 1}, // LBB
-			moveBy * glm::vec4 {X, -Y, 0, 1}, //  RBB
-			moveBy * glm::vec4 {-X, -Y, Z, 1}, // LBT
-			moveBy * glm::vec4 {X, -Y, Z, 1}, //  RBT
+	constexpr const auto Z = 3900.F;
+	const auto moveBy = location.getRotationTransform();
+	const std::array<Position3D, 8> cornerVertices {{
+			location.position() + GlobalPosition3D(moveBy * glm::vec4 {-X, Y, 0, 1}).xyz(), //  LFB
+			location.position() + GlobalPosition3D(moveBy * glm::vec4 {X, Y, 0, 1}).xyz(), //   RFB
+			location.position() + GlobalPosition3D(moveBy * glm::vec4 {-X, Y, Z, 1}).xyz(), //  LFT
+			location.position() + GlobalPosition3D(moveBy * glm::vec4 {X, Y, Z, 1}).xyz(), //   RFT
+			location.position() + GlobalPosition3D(moveBy * glm::vec4 {-X, -Y, 0, 1}).xyz(), // LBB
+			location.position() + GlobalPosition3D(moveBy * glm::vec4 {X, -Y, 0, 1}).xyz(), //  RBB
+			location.position() + GlobalPosition3D(moveBy * glm::vec4 {-X, -Y, Z, 1}).xyz(), // LBT
+			location.position() + GlobalPosition3D(moveBy * glm::vec4 {X, -Y, Z, 1}).xyz(), //  RBT
 	}};
-	static constexpr const std::array<glm::uvec3, 10> triangles {{
+	static constexpr const std::array<glm::vec<3, uint8_t>, 10> triangles {{
 			// Front
 			{0, 1, 2},
 			{1, 2, 3},
@@ -66,7 +78,7 @@ RailVehicle::intersectRay(const Ray & ray, glm::vec2 * baryPos, float * distance
 			{3, 6, 7},
 	}};
 	return std::any_of(
-			triangles.begin(), triangles.end(), [&cornerVertices, &ray, &baryPos, &distance](const glm::uvec3 idx) {
+			triangles.begin(), triangles.end(), [&cornerVertices, &ray, &baryPos, &distance](const auto & idx) {
 				return glm::intersectRayTriangle(ray.start, ray.direction, cornerVertices[idx[0]],
 						cornerVertices[idx[1]], cornerVertices[idx[2]], *baryPos, *distance);
 			});
diff --git a/game/vehicles/railVehicle.h b/game/vehicles/railVehicle.h
index be88142..8cbc49d 100644
--- a/game/vehicles/railVehicle.h
+++ b/game/vehicles/railVehicle.h
@@ -17,13 +17,12 @@ public:
 
 	void move(const Train *, float & trailBy);
 
-	[[nodiscard]] bool intersectRay(const Ray &, glm::vec2 *, float *) const override;
+	[[nodiscard]] bool intersectRay(const Ray &, BaryPosition *, float *) const override;
 
 	RailVehicleClassPtr rvClass;
 	using LV = RailVehicleClass::LocationVertex;
-	using BLocation = BufferedLocationT<glm::mat4 LV::*, RailVehicleClass::Instance &>;
-	BLocation location;
-	std::array<BLocation, 2> bogies;
+	BufferedLocationUpdater location;
+	std::array<BufferedLocationUpdater, 2> bogies;
 };
 
 using RailVehiclePtr = std::unique_ptr<RailVehicle>;
diff --git a/game/vehicles/railVehicleClass.cpp b/game/vehicles/railVehicleClass.cpp
index 324148c..3ca42db 100644
--- a/game/vehicles/railVehicleClass.cpp
+++ b/game/vehicles/railVehicleClass.cpp
@@ -35,13 +35,15 @@ void
 RailVehicleClass::postLoad()
 {
 	texture = getTexture();
-	bodyMesh->configureVAO(instanceVAO).addAttribs<LocationVertex, &LocationVertex::body>(instances.bufferName(), 1);
+	bodyMesh->configureVAO(instanceVAO)
+			.addAttribs<LocationVertex, &LocationVertex::body, &LocationVertex::bodyPos>(instances.bufferName(), 1);
 	bogies.front()
 			->configureVAO(instancesBogiesVAO.front())
-			.addAttribs<LocationVertex, &LocationVertex::front>(instances.bufferName(), 1);
+			.addAttribs<LocationVertex, &LocationVertex::front, &LocationVertex::frontPos>(instances.bufferName(), 1);
 	bogies.back()
 			->configureVAO(instancesBogiesVAO.back())
-			.addAttribs<LocationVertex, &LocationVertex::back>(instances.bufferName(), 1);
+			.addAttribs<LocationVertex, &LocationVertex::back, &LocationVertex::backPos>(instances.bufferName(), 1);
+	static_assert(sizeof(LocationVertex) == 228UL);
 }
 
 void
@@ -64,7 +66,7 @@ RailVehicleClass::shadows(const ShadowMapper & mapper) const
 	if (const auto count = static_cast<GLsizei>(instances.size())) {
 		mapper.dynamicPointInst.use();
 		bodyMesh->DrawInstanced(instanceVAO, count);
-		bogies.front()->DrawInstanced(instanceVAO, count);
-		bogies.back()->DrawInstanced(instanceVAO, count);
+		bogies.front()->DrawInstanced(instancesBogiesVAO.front(), count);
+		bogies.back()->DrawInstanced(instancesBogiesVAO.back(), count);
 	}
 }
diff --git a/game/vehicles/railVehicleClass.h b/game/vehicles/railVehicleClass.h
index 4668d7d..913feea 100644
--- a/game/vehicles/railVehicleClass.h
+++ b/game/vehicles/railVehicleClass.h
@@ -20,6 +20,7 @@ public:
 
 	struct LocationVertex {
 		glm::mat4 body, front, back;
+		GlobalPosition3D bodyPos, frontPos, backPos;
 	};
 
 	std::array<Mesh::Ptr, 2> bogies;
diff --git a/game/vehicles/train.cpp b/game/vehicles/train.cpp
index 6f3b036..13905a3 100644
--- a/game/vehicles/train.cpp
+++ b/game/vehicles/train.cpp
@@ -20,7 +20,7 @@ Train::getBogiePosition(float linkDist, float dist) const
 }
 
 bool
-Train::intersectRay(const Ray & ray, glm::vec2 * baryPos, float * distance) const
+Train::intersectRay(const Ray & ray, BaryPosition * baryPos, float * distance) const
 {
 	return applyOne(&RailVehicle::intersectRay, ray, baryPos, distance) != end();
 }
diff --git a/game/vehicles/train.h b/game/vehicles/train.h
index 20c3bc4..c77cd23 100644
--- a/game/vehicles/train.h
+++ b/game/vehicles/train.h
@@ -27,7 +27,7 @@ public:
 		return objects.front()->location;
 	}
 
-	[[nodiscard]] bool intersectRay(const Ray &, glm::vec2 *, float *) const override;
+	[[nodiscard]] bool intersectRay(const Ray &, BaryPosition *, float *) const override;
 
 	void tick(TickDuration elapsed) override;
 	void doActivity(Go *, TickDuration) override;