Mesh split, bogeys follow rails.

Wow. This commit is too big. It:

* splits obj loaded meshes into individual named objects.
* moves obj to mesh(es) code into new file obj.impl.cpp, removing the
  clutter from mesh
* removes Physical for providing the wrong level of abstraction
* bit of a hack to adjust loaded models to offset rail vehicle bogeys to
  0 centre, and then applies their calculated position to the mesh

All in all, quite a lot of mess... But the result is the rail vehicle
bogeys now follow the rails quite authentically.

5 files changed, 52 insertions, 50 deletions

diff --git a/gfx/models/mesh.cpp b/gfx/models/mesh.cpp
index 25a4b58..c829f4e 100644
--- a/gfx/models/mesh.cpp
+++ b/gfx/models/mesh.cpp
@@ -7,15 +7,6 @@
 #include <resource.h>

 #include <vector>

 

-Mesh::Mesh(const std::filesystem::path & fileName) : Mesh(ObjParser {Resource::mapPath(fileName)}) { }

-

-Mesh::Mesh(const ObjParser & obj) : Mesh(packObjParser(obj), GL_TRIANGLES) { }

-

-Mesh::Mesh(std::pair<std::vector<Vertex>, std::vector<unsigned int>> && vandi, GLenum m) :

-	Mesh(vandi.first, vandi.second, m)

-{

-}

-

 Mesh::Mesh(std::span<Vertex> vertices, std::span<unsigned int> indices, GLenum m) :

 	m_vertexArrayObject {}, m_vertexArrayBuffers {}, m_numIndices {indices.size()}, mode {m}

 {

@@ -42,34 +33,6 @@ Mesh::Mesh(std::span<Vertex> vertices, std::span<unsigned int> indices, GLenum m
 	glBindVertexArray(0);

 }

 

-Mesh::Data

-Mesh::packObjParser(const ObjParser & obj)

-{

-	std::vector<Vertex> vertices;

-	std::vector<ObjParser::FaceElement> vertexOrder;

-	std::vector<unsigned int> indices;

-	std::for_each(obj.faces.begin(), obj.faces.end(), [&](const ObjParser::Face & face) {

-		for (auto idx = 2U; idx < face.size(); idx += 1) {

-			auto f = [&](auto idx) {

-				const auto & fe {face[idx]};

-				if (const auto existing = std::find(vertexOrder.begin(), vertexOrder.end(), fe);

-						existing != vertexOrder.end()) {

-					indices.push_back(std::distance(vertexOrder.begin(), existing));

-				}

-				else {

-					indices.push_back(vertices.size());

-					vertices.emplace_back(obj.vertices[fe.x - 1], obj.texCoords[fe.y - 1], -obj.normals[fe.z - 1]);

-					vertexOrder.emplace_back(fe);

-				}

-			};

-			f(0);

-			f(idx);

-			f(idx - 1);

-		}

-	});

-	return std::make_pair(vertices, indices);

-}

-

 Mesh::~Mesh()

 {

 	glDeleteBuffers(NUM_BUFFERS, m_vertexArrayBuffers.data());

diff --git a/gfx/models/mesh.h b/gfx/models/mesh.h
index 4982145..ea3a26b 100644
--- a/gfx/models/mesh.h
+++ b/gfx/models/mesh.h
@@ -17,9 +17,6 @@ enum MeshBufferPositions { POSITION_VB, TEXCOORD_VB, NORMAL_VB, INDEX_VB };
 

 class Mesh {

 public:

-	using Data = std::pair<std::vector<Vertex>, std::vector<unsigned int>>;

-	explicit Mesh(const std::filesystem::path & fileName);

-	explicit Mesh(const ObjParser & obj);

 	Mesh(std::span<Vertex> vertices, std::span<unsigned int> indices, GLenum = GL_TRIANGLES);

 	virtual ~Mesh();

 

@@ -29,10 +26,6 @@ public:
 	void Draw() const;

 

 private:

-	explicit Mesh(Data && vandi, GLenum = GL_TRIANGLES);

-

-	static Data packObjParser(const ObjParser &);

-

 	static constexpr unsigned int NUM_BUFFERS {4};

 

 	GLuint m_vertexArrayObject;

@@ -40,5 +33,6 @@ private:
 	size_t m_numIndices;

 	GLenum mode;

 };

+using MeshPtr = std::shared_ptr<const Mesh>;

 

 #endif

diff --git a/gfx/models/obj.h b/gfx/models/obj.h
index 96c5e94..2921e34 100644
--- a/gfx/models/obj.h
+++ b/gfx/models/obj.h
@@ -11,6 +11,8 @@
 #include <memory>
 #include <vector>
 
+class Mesh;
+
 class ObjParser : yyFlexLexer {
 public:
 	explicit ObjParser(const std::filesystem::path & fileName) : ObjParser {std::make_unique<std::ifstream>(fileName)}
@@ -19,7 +21,9 @@ public:
 
 	explicit ObjParser(std::unique_ptr<std::istream> in) : yyFlexLexer(in.get())
 	{
+		assert(in);
 		ObjParser::yylex();
+		assert(in->good());
 	}
 
 	int yylex() override;
@@ -29,8 +33,13 @@ public:
 	std::vector<glm::vec3> normals;
 	using FaceElement = glm::vec<3, int>;
 	using Face = std::vector<FaceElement>;
-	std::vector<Face> faces;
+	using Faces = std::vector<Face>;
+	using Object = std::pair<std::string, Faces>;
+	std::vector<Object> objects;
 	glm::length_t axis {0};
+
+	using NamedMesh = std::pair<std::string, std::shared_ptr<const Mesh>>;
+	[[nodiscard]] std::vector<NamedMesh> createMeshes() const;
 };
 
 #endif
diff --git a/gfx/models/obj.impl.cpp b/gfx/models/obj.impl.cpp
new file mode 100644
index 0000000..e410058
--- /dev/null
+++ b/gfx/models/obj.impl.cpp
@@ -0,0 +1,36 @@
+#include "obj.h"
+#include <gfx/models/mesh.h>
+#include <gfx/models/vertex.hpp>
+
+std::vector<ObjParser::NamedMesh>
+ObjParser::createMeshes() const
+{
+	std::vector<ObjParser::NamedMesh> out;
+	out.reserve(objects.size());
+	for (const auto & obj : objects) {
+		std::vector<Vertex> overtices;
+		std::vector<ObjParser::FaceElement> vertexOrder;
+		std::vector<unsigned int> indices;
+		for (const auto & face : obj.second) {
+			for (auto idx = 2U; idx < face.size(); idx += 1) {
+				auto f = [&](auto idx) {
+					const auto & fe {face[idx]};
+					if (const auto existing = std::find(vertexOrder.begin(), vertexOrder.end(), fe);
+							existing != vertexOrder.end()) {
+						indices.push_back(std::distance(vertexOrder.begin(), existing));
+					}
+					else {
+						indices.push_back(overtices.size());
+						overtices.emplace_back(vertices[fe.x - 1], texCoords[fe.y - 1], -normals[fe.z - 1]);
+						vertexOrder.emplace_back(fe);
+					}
+				};
+				f(0);
+				f(idx);
+				f(idx - 1);
+			}
+		}
+		out.emplace_back(obj.first, std::make_shared<Mesh>(overtices, indices));
+	}
+	return out;
+}
diff --git a/gfx/models/obj.ll b/gfx/models/obj.ll
index 9329a5a..a9a857b 100644
--- a/gfx/models/obj.ll
+++ b/gfx/models/obj.ll
@@ -43,8 +43,8 @@ falsey (0|off)
 }
 <INITIAL>"f " {
   BEGIN(FACE);
-  faces.emplace_back();
-  faces.back().emplace_back();
+  objects.back().second.emplace_back();
+  objects.back().second.back().emplace_back();
   axis = 0;
 }
 <INITIAL>"mtllib " {
@@ -81,7 +81,7 @@ falsey (0|off)
   // fprintf(stderr, "MTLLIB <%s>\n", YYText());
 }
 <OBJECT>{linestring} {
-  // fprintf(stderr, "OBJECT <%s>\n", YYText());
+  objects.emplace_back(YYText(), Faces{});
 }
 <SMOOTH>{truthy} {
   // fprintf(stderr, "Set smooth\n");
@@ -99,13 +99,13 @@ falsey (0|off)
   texCoords.back()[axis++] = std::stof(YYText());
 }
 <FACE>{index} {
-  faces.back().back()[axis] = std::stoi(YYText());
+  objects.back().second.back().back()[axis] = std::stoi(YYText());
 }
 <FACE>\/ {
   axis++;
 }
 <FACE>[ \t] {
-  faces.back().emplace_back();
+  objects.back().second.back().emplace_back();
   axis = 0;
 }