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.

1 files changed, 56 insertions, 6 deletions

diff --git a/game/vehicles/railloco.cpp b/game/vehicles/railloco.cpp
index 230fd4e..b47722e 100644
--- a/game/vehicles/railloco.cpp
+++ b/game/vehicles/railloco.cpp
@@ -1,14 +1,32 @@
 #include "railloco.h"
+#include "gfx/gl/shader.h"
 #include "gfx/gl/transform.h"
+#include "gfx/models/obj.h"
+#include "gfx/models/texture.h"
 #include <algorithm>
 #include <array>
+#include <cache.h>
 #include <glm/glm.hpp>
+#include <lib/resource.h>
 #include <maths.h>
 #include <memory>
+#include <set>
 #include <utility>
 #include <vector>
 
 void
+RailVehicle::render(const Shader & shader) const
+{
+	shader.setModel(location.GetModel());
+	texture->Bind();
+	bodyMesh->Draw();
+	for (const auto & bogey : bogeys) {
+		shader.setModel(bogey.location.GetModel());
+		bogey.mesh->Draw();
+	}
+}
+
+void
 RailLoco::move(TickDuration dur)
 {
 	linkDist += dur.count() * speed;
@@ -42,8 +60,8 @@ void
 RailLoco::updateRailVehiclePosition(RailVehicle * w, float trailBy) const
 {
 	const auto overhang {(w->length - w->wheelBase) / 2};
-	const auto b1Pos = getBogeyPosition(linkDist, trailBy += overhang);
-	const auto b2Pos = getBogeyPosition(linkDist, trailBy += wheelBase);
+	const auto & b1Pos = w->bogeys[0].location = getBogeyPosition(linkDist, trailBy += overhang);
+	const auto & b2Pos = w->bogeys[1].location = getBogeyPosition(linkDist, trailBy += wheelBase);
 	const auto diff = glm::normalize(b2Pos.GetPos() - b1Pos.GetPos());
 	w->location.GetPos() = (b1Pos.GetPos() + b2Pos.GetPos()) / 2.F;
 	w->location.GetRot() = {-vector_pitch(diff), vector_yaw(diff), 0};
@@ -71,16 +89,48 @@ RailLoco::updateWagons() const
 
 void RailWagon::tick(TickDuration) { }
 
-Brush47::Brush47(const LinkPtr & l) : RailLoco(l, "brush47.obj", "brush47.png")
+void
+bogeyOffset(ObjParser & o)
+{
+	// offset bogey positions so they can be set directly
+	for (int b = 1; b < 3; b++) { // bogey object index
+		std::set<std::pair<float, int>> vertexIds;
+		for (const auto & face : o.objects[b].second) {
+			for (const auto & faceElement : face) {
+				vertexIds.emplace(o.vertices[faceElement.x - 1].z, faceElement.x - 1);
+			}
+		}
+		auto offset = (vertexIds.begin()->first + vertexIds.rbegin()->first) / 2;
+		for (const auto & v : vertexIds) {
+			o.vertices[v.second].z -= offset;
+		}
+	}
+}
+
+Brush47::Brush47(const LinkPtr & l) : RailLoco(l, 0)
 {
-	wheelBase = 15.7F;
+	ObjParser o {Resource::mapPath("brush47.obj")};
+	bogeyOffset(o);
+	const auto m = o.createMeshes();
+	bodyMesh = m[0].second;
+	bogeys[0].mesh = m[1].second;
+	bogeys[1].mesh = m[2].second;
+	texture = Texture::cachedTexture.get(Resource::mapPath("brush47.png"));
+	wheelBase = 12.F;
 	length = 20.F;
 	linkDist = wheelBase;
 }
 
-Brush47Wagon::Brush47Wagon(const LinkPtr & l) : RailWagon(l, "brush47.obj", "brush47.png")
+Brush47Wagon::Brush47Wagon(const LinkPtr & l) : RailWagon(l, 0)
 {
-	wheelBase = 15.7F;
+	ObjParser o {Resource::mapPath("brush47.obj")};
+	bogeyOffset(o);
+	const auto m = o.createMeshes();
+	bodyMesh = m[0].second;
+	bogeys[0].mesh = m[1].second;
+	bogeys[1].mesh = m[2].second;
+	texture = Texture::cachedTexture.get(Resource::mapPath("brush47.png"));
+	wheelBase = 12.F;
 	length = 20.F;
 	linkDist = wheelBase;
 }