From 2220ba2f11705ea9a4e480603d43ab7ed4cf5a89 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 21 Nov 2013 17:12:12 +0200
Subject: [PATCH] Add editable terrain objects

These will soon replace the base object in layout.  It's still a bit
rough along the edges, especially the editing tool.  References to
surface materials are also just a hint of things to come.
---
 data/terrain.tech               |   7 +
 source/3d/layout.cpp            |   3 +
 source/3d/terrain.cpp           | 190 +++++++++++++++++++
 source/3d/terrain.h             |  45 +++++
 source/designer/designer.cpp    |   9 +
 source/designer/terraintool.cpp |  90 +++++++++
 source/designer/terraintool.h   |  32 ++++
 source/engineer/engineer.cpp    |   1 +
 source/libr2c2/catalogue.cpp    |  12 ++
 source/libr2c2/catalogue.h      |   1 +
 source/libr2c2/layout.cpp       |  23 +++
 source/libr2c2/layout.h         |   1 +
 source/libr2c2/terrain.cpp      | 317 ++++++++++++++++++++++++++++++++
 source/libr2c2/terrain.h        | 118 ++++++++++++
 source/libr2c2/terraintype.cpp  |  51 +++++
 source/libr2c2/terraintype.h    |  50 +++++
 terrain.dat                     |   9 +
 17 files changed, 959 insertions(+)
 create mode 100644 data/terrain.tech
 create mode 100644 source/3d/terrain.cpp
 create mode 100644 source/3d/terrain.h
 create mode 100644 source/designer/terraintool.cpp
 create mode 100644 source/designer/terraintool.h
 create mode 100644 source/libr2c2/terrain.cpp
 create mode 100644 source/libr2c2/terrain.h
 create mode 100644 source/libr2c2/terraintype.cpp
 create mode 100644 source/libr2c2/terraintype.h
 create mode 100644 terrain.dat

diff --git a/data/terrain.tech b/data/terrain.tech
new file mode 100644
index 0000000..35fb0e0
--- /dev/null
+++ b/data/terrain.tech
@@ -0,0 +1,7 @@
+pass ""
+{
+	material
+	{
+		diffuse 0.88 0.9 0.6 1.0;
+	};
+};
diff --git a/source/3d/layout.cpp b/source/3d/layout.cpp
index be19b00..fdb4dfc 100644
--- a/source/3d/layout.cpp
+++ b/source/3d/layout.cpp
@@ -1,6 +1,7 @@
 #include "beamgate.h"
 #include "layout.h"
 #include "signal.h"
+#include "terrain.h"
 #include "track.h"
 #include "utility.h"
 #include "vehicle.h"
@@ -86,6 +87,8 @@ void Layout3D::object_added(Object &o)
 		new Vehicle3D(*this, *v);
 	else if(BeamGate *g = dynamic_cast<BeamGate *>(&o))
 		new BeamGate3D(*this, *g);
+	else if(Terrain *r = dynamic_cast<Terrain *>(&o))
+		new Terrain3D(*this, *r);
 }
 
 void Layout3D::object_removed(Object &o)
diff --git a/source/3d/terrain.cpp b/source/3d/terrain.cpp
new file mode 100644
index 0000000..8fbaa98
--- /dev/null
+++ b/source/3d/terrain.cpp
@@ -0,0 +1,190 @@
+#include <msp/gl/renderer.h>
+#include "libr2c2/terraintype.h"
+#include "layout.h"
+#include "terrain.h"
+
+using namespace Msp;
+
+namespace R2C2 {
+
+unsigned Terrain3D::surface_indices[] =
+{
+	0, 1, 3, 0, 3, 2,
+	1, 3, 2, 1, 2, 0
+};
+
+unsigned Terrain3D::wall_indices[] =
+{
+	1, 4, 5, 1, 5, 3,
+	3, 7, 6, 3, 6, 2
+};
+
+Terrain3D::Terrain3D(Layout3D &l, Terrain &t):
+	Object3D(l, t),
+	terrain(t),
+	mesh((GL::VERTEX3, GL::NORMAL3)),
+	tech(layout.get_catalogue().get<GL::Technique>("terrain.tech"))
+{
+	terrain.signal_size_changed.connect(sigc::mem_fun(this, &Terrain3D::size_changed));
+	terrain.signal_tile_changed.connect(sigc::bind<2>(sigc::mem_fun(this, &Terrain3D::tile_changed), true));
+
+	create_mesh();
+
+	layout.get_scene().add(*this);
+}
+
+Terrain3D::~Terrain3D()
+{
+	layout.get_scene().remove(*this);
+}
+
+Vector Terrain3D::get_node() const
+{
+	float ts = terrain.get_type().get_tile_size();
+	return terrain.get_position()+Vector(terrain.get_width()*ts/2, terrain.get_height()*ts/2, 0);
+}
+
+void Terrain3D::create_mesh()
+{
+	mesh.clear();
+
+	GL::MeshBuilder bld(mesh);
+	unsigned width = terrain.get_width();
+	unsigned height = terrain.get_height();
+	bld.begin(GL::TRIANGLES);
+	for(unsigned y=0; y<height; ++y)
+		for(unsigned x=0; x<width; ++x)
+		{
+			const Terrain::Tile &tile = terrain.get_tile(x, y);
+			Vector nodes[8];
+			gather_nodes(x, y, nodes);
+
+			const unsigned *indices = surface_indices+tile.secondary_axis*6;
+			build_triangle(bld, nodes, indices);
+			build_triangle(bld, nodes, indices+3);
+
+			if(x+1<width)
+			{
+				build_triangle(bld, nodes, wall_indices);
+				build_triangle(bld, nodes, wall_indices+3);
+			}
+
+			if(y+1<height)
+			{
+				build_triangle(bld, nodes, wall_indices+6);
+				build_triangle(bld, nodes, wall_indices+9);
+			}
+		}
+	bld.end();
+}
+
+void Terrain3D::gather_nodes(unsigned x, unsigned y, Vector *nodes)
+{
+	const Terrain::Tile &tile = terrain.get_tile(x, y);
+	float ts = terrain.get_type().get_tile_size();
+
+	for(unsigned i=0; i<4; ++i)
+		nodes[i] = Vector((x+i%2)*ts, (y+i/2)*ts, tile.nodes[i].elevation);
+
+	if(x+1<terrain.get_width())
+	{
+		const Terrain::Tile &neighbor = terrain.get_tile(x+1, y);
+		nodes[4] = Vector((x+1)*ts, y*ts, neighbor.nodes[0].elevation);
+		nodes[5] = Vector((x+1)*ts, (y+1)*ts, neighbor.nodes[2].elevation);
+	}
+
+	if(y+1<terrain.get_height())
+	{
+		const Terrain::Tile &neighbor = terrain.get_tile(x, y+1);
+		nodes[6] = Vector(x*ts, (y+1)*ts, neighbor.nodes[0].elevation);
+		nodes[7] = Vector((x+1)*ts, (y+1)*ts, neighbor.nodes[1].elevation);
+	}
+}
+
+void Terrain3D::build_triangle(GL::PrimitiveBuilder &bld, const Vector *nodes, const unsigned *indices)
+{
+	bld.normal(normalize(cross(nodes[indices[1]]-nodes[indices[0]], nodes[indices[2]]-nodes[indices[0]])));
+	for(unsigned i=0; i<3; ++i)
+		bld.vertex(nodes[indices[i]]);
+}
+
+void Terrain3D::update_triangle(unsigned offset, const Vector *nodes, const unsigned *indices)
+{
+	const GL::VertexFormat &format = mesh.get_vertices().get_format();
+	unsigned position_offset = format.offset(GL::VERTEX3);
+	unsigned normal_offset = format.offset(GL::NORMAL3);
+
+	Vector normal = normalize(cross(nodes[indices[1]]-nodes[indices[0]], nodes[indices[2]]-nodes[indices[0]]));
+	for(unsigned i=0; i<3; ++i)
+	{
+		float *vertex = mesh.modify_vertex(offset+i);
+		for(unsigned j=0; j<3; ++j)
+		{
+			vertex[position_offset+j] = nodes[indices[i]][j];
+			vertex[normal_offset+j] = normal[j];
+		}
+	}
+}
+
+void Terrain3D::size_changed(unsigned, unsigned)
+{
+	create_mesh();
+}
+
+void Terrain3D::tile_changed(unsigned x, unsigned y, bool propagate)
+{
+	Vector nodes[8];
+	gather_nodes(x, y, nodes);
+
+	unsigned base = y*(terrain.get_width()*18-6);
+	if(y+1==terrain.get_height())
+		base += x*12;
+	else
+		base += x*18;
+
+	const Terrain::Tile &tile = terrain.get_tile(x, y);
+	const unsigned *indices = surface_indices+tile.secondary_axis*6;
+	update_triangle(base, nodes, indices);
+	update_triangle(base+3, nodes, indices+3);
+
+	if(x+1<terrain.get_width())
+	{
+		base += 6;
+		update_triangle(base, nodes, wall_indices);
+		update_triangle(base+3, nodes, wall_indices+3);
+	}
+
+	if(y+1<terrain.get_height())
+	{
+		base += 6;
+		update_triangle(base, nodes, wall_indices+6);
+		update_triangle(base+3, nodes, wall_indices+9);
+	}
+
+	if(propagate)
+	{
+		if(x>0)
+			tile_changed(x-1, y, false);
+		if(y>0)
+			tile_changed(x, y-1, false);
+	}
+}
+
+void Terrain3D::render(GL::Renderer &renderer, const GL::Tag &tag) const
+{
+	if(!tech.has_pass(tag))
+		return;
+
+	GL::Renderer::Push push(renderer);
+
+	renderer.matrix_stack() *= matrix;
+
+	const GL::RenderPass &pass = tech.get_pass(tag);
+	renderer.set_material(pass.get_material());
+	renderer.set_texturing(pass.get_texturing());
+	renderer.set_shader_program(pass.get_shader_program(), pass.get_shader_data());
+
+	mesh.draw(renderer);
+}
+
+} // namespace R2C2
diff --git a/source/3d/terrain.h b/source/3d/terrain.h
new file mode 100644
index 0000000..2cd9854
--- /dev/null
+++ b/source/3d/terrain.h
@@ -0,0 +1,45 @@
+#ifndef R2C2_3D_TERRAIN_H_
+#define R2C2_3D_TERRAIN_H_
+
+#include <msp/gl/mesh.h>
+#include <msp/gl/primitivebuilder.h>
+#include <msp/gl/renderable.h>
+#include <msp/gl/technique.h>
+#include "libr2c2/terrain.h"
+#include "object.h"
+
+namespace R2C2 {
+
+class Terrain3D: public Object3D, public Msp::GL::Renderable
+{
+private:
+	Terrain &terrain;
+	Msp::GL::Mesh mesh;
+	const Msp::GL::Technique &tech;
+
+	static unsigned surface_indices[];
+	static unsigned wall_indices[];
+
+public:
+	Terrain3D(Layout3D &, Terrain &);
+	virtual ~Terrain3D();
+
+	virtual Vector get_node() const;
+	virtual bool is_visible() const { return true; }
+
+private:
+	void create_mesh();
+	void gather_nodes(unsigned, unsigned, Vector *);
+	void build_triangle(Msp::GL::PrimitiveBuilder &, const Vector *, const unsigned *);
+	void update_triangle(unsigned, const Vector *, const unsigned *);
+
+	void size_changed(unsigned, unsigned);
+	void tile_changed(unsigned, unsigned, bool);
+
+public:
+	virtual void render(Msp::GL::Renderer &, const Msp::GL::Tag &) const;
+};
+
+} // namespace R2C2
+
+#endif
diff --git a/source/designer/designer.cpp b/source/designer/designer.cpp
index 6ae9c07..32fe423 100644
--- a/source/designer/designer.cpp
+++ b/source/designer/designer.cpp
@@ -17,6 +17,7 @@
 #include <msp/time/units.h>
 #include <msp/time/utils.h>
 #include "libr2c2/route.h"
+#include "libr2c2/terrain.h"
 #include "libr2c2/tracktype.h"
 #include "libr2c2/zone.h"
 #include "3d/path.h"
@@ -35,6 +36,7 @@
 #include "selection.h"
 #include "slopetool.h"
 #include "svgexporter.h"
+#include "terraintool.h"
 #include "trackbar.h"
 #include "zonebar.h"
 #include "zoneproperties.h"
@@ -61,6 +63,7 @@ Designer::Designer(int argc, char **argv):
 
 	// Setup catalogue and layout
 	DataFile::load(catalogue, "tracks.dat");
+	DataFile::load(catalogue, "terrain.dat");
 
 	cat_layout_3d = new Layout3D(catalogue.get_layout());
 
@@ -428,6 +431,12 @@ void Designer::key_press(unsigned key)
 		svg_export();
 	else if(key==Msp::Input::KEY_P)
 		object_properties();
+	else if(key==Msp::Input::KEY_TAB)
+	{
+		Object *obj = selection.get_object();
+		if(Terrain *terrain = dynamic_cast<Terrain *>(obj))
+			use_tool(new TerrainTool(*this, keyboard, mouse, *terrain));
+	}
 }
 
 template<typename T>
diff --git a/source/designer/terraintool.cpp b/source/designer/terraintool.cpp
new file mode 100644
index 0000000..46076ec
--- /dev/null
+++ b/source/designer/terraintool.cpp
@@ -0,0 +1,90 @@
+#include <cmath>
+#include <msp/gl/meshbuilder.h>
+#include <msp/input/keys.h>
+#include "designer.h"
+#include "terraintool.h"
+
+using namespace std;
+using namespace Msp;
+using namespace R2C2;
+
+TerrainTool::TerrainTool(Designer &d, Input::Keyboard &k, Input::Mouse &m, Terrain &t):
+	Tool(d, k, m),
+	terrain(t),
+	marker((GL::VERTEX3, GL::COLOR4_UBYTE)),
+	dragging(false),
+	drag_start(0)
+{
+	designer.get_layout_3d().get_scene().add(*this);
+
+	float ts = terrain.get_type().get_tile_size();
+	GL::MeshBuilder bld(marker);
+	bld.begin(GL::TRIANGLE_STRIP);
+	bld.vertex(-ts/2, 0, -ts/4);
+	bld.vertex(ts/2, 0, -ts/4);
+	bld.vertex(-ts/2, 0, ts/4);
+	bld.vertex(ts/2, 0, ts/4);
+	bld.end();
+	bld.begin(GL::TRIANGLE_STRIP);
+	bld.vertex(0, -ts/2, -ts/4);
+	bld.vertex(0, ts/2, -ts/4);
+	bld.vertex(0, -ts/2, ts/4);
+	bld.vertex(0, ts/2, ts/4);
+	bld.end();
+}
+
+TerrainTool::~TerrainTool()
+{
+	designer.get_layout_3d().get_scene().remove(*this);
+}
+
+void TerrainTool::button_press(unsigned btn)
+{
+	if(btn==1)
+	{
+		dragging = true;
+		drag_start = pointer.y;
+	}
+}
+
+void TerrainTool::button_release(unsigned btn)
+{
+	if(btn==1)
+		dragging = false;
+}
+
+void TerrainTool::pointer_motion()
+{
+	if(dragging)
+	{
+		float d = (pointer.y-drag_start)*20;
+
+		if(abs(d)>1)
+		{
+			float elev = terrain.get_node_elevation(highlight_node);
+			float eg = terrain.get_type().get_elevation_granularity();
+			elev += eg*d;
+			terrain.set_node_elevation(highlight_node, elev, true);
+			marker_position = terrain.get_node_position(highlight_node);
+
+			drag_start = pointer.y;
+		}
+	}
+	else
+	{
+		Ray ray = designer.get_view().create_ray(pointer.x, pointer.y);
+		highlight_node = terrain.get_closest_node(ray);
+		marker_position = terrain.get_node_position(highlight_node);
+	}
+}
+
+void TerrainTool::render(GL::Renderer &renderer, const GL::Tag &tag) const
+{
+	if(tag.id)
+		return;
+
+	GL::Renderer::Push push(renderer);
+
+	renderer.matrix_stack() *= GL::Matrix::translation(marker_position);
+	marker.draw(renderer);
+}
diff --git a/source/designer/terraintool.h b/source/designer/terraintool.h
new file mode 100644
index 0000000..f5f8354
--- /dev/null
+++ b/source/designer/terraintool.h
@@ -0,0 +1,32 @@
+#ifndef TERRAINTOOL_H_
+#define TERRAINTOOL_H_
+
+#include <msp/gl/mesh.h>
+#include <msp/gl/renderable.h>
+#include "libr2c2/terrain.h"
+#include "tool.h"
+
+class TerrainTool: public Tool, public Msp::GL::Renderable
+{
+private:
+	R2C2::Terrain &terrain;
+	Msp::GL::Mesh marker;
+	R2C2::Terrain::NodeCoordinates highlight_node;
+	R2C2::Vector marker_position;
+	bool dragging;
+	float drag_start;
+
+public:
+	TerrainTool(Designer &, Msp::Input::Keyboard &, Msp::Input::Mouse &, R2C2::Terrain &);
+	virtual ~TerrainTool();
+
+private:
+	virtual void button_press(unsigned);
+	virtual void button_release(unsigned);
+	virtual void pointer_motion();
+
+public:
+	virtual void render(Msp::GL::Renderer &, const Msp::GL::Tag &) const;
+};
+
+#endif
diff --git a/source/engineer/engineer.cpp b/source/engineer/engineer.cpp
index d0c879c..49edd48 100644
--- a/source/engineer/engineer.cpp
+++ b/source/engineer/engineer.cpp
@@ -71,6 +71,7 @@ Engineer::Engineer(int argc, char **argv):
 	DataFile::load(catalogue, "tracks.dat");
 	DataFile::load(catalogue, "locos.dat");
 	DataFile::load(catalogue, "wagons.dat");
+	DataFile::load(catalogue, "terrain.dat");
 	DataFile::load(layout, options.layout_fn);
 
 	if(layout.has_driver())
diff --git a/source/libr2c2/catalogue.cpp b/source/libr2c2/catalogue.cpp
index 221a6f0..779e210 100644
--- a/source/libr2c2/catalogue.cpp
+++ b/source/libr2c2/catalogue.cpp
@@ -3,6 +3,7 @@
 #include <msp/datafile/parser.h>
 #include "catalogue.h"
 #include "signaltype.h"
+#include "terraintype.h"
 #include "tracktype.h"
 #include "vehicletype.h"
 
@@ -49,6 +50,7 @@ Catalogue::Loader::Loader(Catalogue &c):
 	add("rail_profile", &Loader::rail_profile);
 	add("scale", &Loader::scale);
 	add("signal", &Loader::signal);
+	add("terrain", &Loader::terrain);
 	add("track", &Loader::track);
 	add("track_technique", &Catalogue::track_technique);
 	add("vehicle", &Loader::vehicle);
@@ -89,6 +91,16 @@ void Catalogue::Loader::signal(ArticleNumber art_nr)
 	obj.add(*sig.release());
 }
 
+void Catalogue::Loader::terrain(ArticleNumber art_nr)
+{
+	if(obj.objects.count(art_nr))
+		throw key_error(art_nr);
+
+	RefPtr<TerrainType> ter = new TerrainType(art_nr);
+	load_sub(*ter);
+	obj.add(*ter.release());
+}
+
 void Catalogue::Loader::track(ArticleNumber art_nr)
 {
 	if(obj.objects.count(art_nr))
diff --git a/source/libr2c2/catalogue.h b/source/libr2c2/catalogue.h
index dcde9f3..5a91560 100644
--- a/source/libr2c2/catalogue.h
+++ b/source/libr2c2/catalogue.h
@@ -25,6 +25,7 @@ public:
 		void rail_profile();
 		void scale(float, float);
 		void signal(ArticleNumber);
+		void terrain(ArticleNumber);
 		void track(ArticleNumber);
 		void vehicle(ArticleNumber);
 	};
diff --git a/source/libr2c2/layout.cpp b/source/libr2c2/layout.cpp
index c23ad38..0025ec3 100644
--- a/source/libr2c2/layout.cpp
+++ b/source/libr2c2/layout.cpp
@@ -13,6 +13,7 @@
 #include "route.h"
 #include "signal.h"
 #include "signaltype.h"
+#include "terrain.h"
 #include "track.h"
 #include "trackcircuit.h"
 #include "tracktype.h"
@@ -135,6 +136,12 @@ const set<Vehicle *> &Layout::get_all<Vehicle>() const
 	return objects.get<Vehicle>();
 }
 
+template<>
+const set<Terrain *> &Layout::get_all<Terrain>() const
+{
+	return objects.get<Terrain>();
+}
+
 template<>
 const set<TrackChain *> &Layout::get_all<TrackChain>() const
 {
@@ -414,6 +421,15 @@ void Layout::save(const string &fn) const
 		writer.write(st);
 	}
 
+	const set<Terrain *> &terrains = objects.get<Terrain>();
+	for(set<Terrain *>::const_iterator i=terrains.begin(); i!=terrains.end(); ++i)
+	{
+		DataFile::Statement st("terrain");
+		st.append((*i)->get_type().get_article_number());
+		(*i)->save(st.sub);
+		writer.write(st);
+	}
+
 	const set<BeamGate *> &gates = objects.get<BeamGate>();
 	for(set<BeamGate *>::const_iterator i=gates.begin(); i!=gates.end(); ++i)
 	{
@@ -534,6 +550,7 @@ Layout::Loader::Loader(Layout &l):
 	add("beamgate", &Loader::beamgate);
 	add("route", &Loader::route);
 	add("signal", &Loader::signal);
+	add("terrain", &Loader::terrain);
 	add("track", &Loader::track);
 	add("train", &Loader::train);
 	add("turnout", &Loader::turnout);
@@ -558,6 +575,12 @@ void Layout::Loader::signal(ArticleNumber art_nr)
 	load_sub(*sig);
 }
 
+void Layout::Loader::terrain(ArticleNumber art_nr)
+{
+	Terrain *ter = new Terrain(obj, obj.catalogue.get<TerrainType>(art_nr));
+	load_sub(*ter);
+}
+
 void Layout::Loader::track(ArticleNumber art_nr)
 {
 	Track *trk = new Track(obj, obj.catalogue.get<TrackType>(art_nr));
diff --git a/source/libr2c2/layout.h b/source/libr2c2/layout.h
index d1428cf..498a45a 100644
--- a/source/libr2c2/layout.h
+++ b/source/libr2c2/layout.h
@@ -36,6 +36,7 @@ public:
 		void beamgate();
 		void route();
 		void signal(ArticleNumber);
+		void terrain(ArticleNumber);
 		void track(ArticleNumber);
 		void train(ArticleNumber, unsigned, const std::string &);
 		void turnout(unsigned, unsigned);
diff --git a/source/libr2c2/terrain.cpp b/source/libr2c2/terrain.cpp
new file mode 100644
index 0000000..e84c7cd
--- /dev/null
+++ b/source/libr2c2/terrain.cpp
@@ -0,0 +1,317 @@
+#include <msp/geometry/box.h>
+#include <msp/geometry/transformedshape.h>
+#include "layout.h"
+#include "terrain.h"
+#include "terraintype.h"
+
+using namespace std;
+using namespace Msp;
+
+namespace R2C2 {
+
+Terrain::Terrain(Layout &l, const TerrainType &t):
+	Object(l),
+	type(t),
+	width(0),
+	height(0)
+{
+	set_size(1, 1);
+
+	layout.add(*this);
+}
+
+Terrain::~Terrain()
+{
+	layout.remove(*this);
+}
+
+Terrain *Terrain::clone(Layout *to_layout) const
+{
+	Terrain *terrain = new Terrain((to_layout ? *to_layout : layout), type);
+	terrain->set_size(width, height);
+	for(unsigned i=0; i<tiles.size(); ++i)
+		terrain->tiles[i] = tiles[i];
+	return terrain;
+}
+
+void Terrain::set_position(const Vector &p)
+{
+	position = p;
+	signal_moved.emit();
+}
+
+void Terrain::set_rotation(const Angle &r)
+{
+	rotation = r;
+	signal_moved.emit();
+}
+
+void Terrain::set_size(unsigned w, unsigned h)
+{
+	if(!w || !h)
+		throw invalid_argument("Terrain::set_size");
+
+	vector<Tile> new_tiles(w*h);
+	for(unsigned y=0; (y<h && y<height); ++y)
+		for(unsigned x=0; (x<w && x<width); ++x)
+			new_tiles[x+y*w] = tiles[x+y*width];
+
+	width = w;
+	height = h;
+	swap(tiles, new_tiles);
+
+	delete shape;
+	float ts = type.get_tile_size();
+	Vector dim(width*ts, height*ts, ts);
+	shape = new Geometry::TransformedShape<float, 3>(
+		Geometry::Box<float>(dim),
+		Transform::translation(dim/2.0f));
+
+	signal_size_changed.emit(width, height);
+}
+
+const Terrain::Tile &Terrain::get_tile(unsigned x, unsigned y) const
+{
+	if(x>=width || y>=height)
+		throw out_of_range("Terrain::get_tile");
+	return tiles[x+y*width];
+}
+
+void Terrain::set_node_elevation(const NodeCoordinates &c, float elev, bool joined)
+{
+	if(c.x>=width || c.y>=height || c.i>=4)
+		throw out_of_range("Terrain::set_node_elevation");
+
+	float eg = type.get_elevation_granularity();
+	elev = int(elev/eg+0.5)*eg;
+
+	if(joined)
+	{
+		float ref = tiles[c.x+c.y*width].nodes[c.i].elevation;
+		for(unsigned i=0; i<4; ++i)
+		{
+			unsigned x = c.x+c.i%2-i%2;
+			unsigned y = c.y+c.i/2-i/2;
+			if(x<width && y<height)
+			{
+				Tile &tile = tiles[x+y*width];
+				if(tile.nodes[i].elevation==ref)
+				{
+					tile.nodes[i].elevation = elev;
+					signal_tile_changed.emit(x, y);
+				}
+			}
+		}
+	}
+	else
+	{
+		tiles[c.x+c.y*width].nodes[c.i].elevation = elev;
+		signal_tile_changed.emit(c.x, c.y);
+	}
+}
+
+float Terrain::get_node_elevation(const NodeCoordinates &c) const
+{
+	if(c.x>=width || c.y>=height || c.i>=4)
+		throw out_of_range("Terrain::get_node_elevation");
+
+	return tiles[c.x+c.y*width].nodes[c.i].elevation;
+}
+
+Vector Terrain::get_node_position(const NodeCoordinates &c) const
+{
+	if(c.x>=width || c.y>=height || c.i>=4)
+		throw out_of_range("Terrain::get_node_position");
+
+	const Tile &tile = tiles[c.x+c.y*width];
+	float tile_size = type.get_tile_size();
+	Transform trans = Transform::translation(position)*
+		Transform::rotation(rotation, Vector(0, 0, 1));
+	return trans.transform(Vector((c.x+c.i%2)*tile_size, (c.y+c.i/2)*tile_size, tile.nodes[c.i].elevation));
+}
+
+Terrain::NodeCoordinates Terrain::get_closest_node(const Ray &ray) const
+{
+	NodeCoordinates coords;
+	float closest_dist = -1;
+	for(unsigned y=0; y<height; ++y)
+		for(unsigned x=0; x<width; ++x)
+			for(unsigned i=0; i<4; ++i)
+			{
+				NodeCoordinates c(x, y, i);
+				/* XXX This is not very efficient.  Should transform the ray to
+				local coordinate system. */
+				Vector node_pos = get_node_position(c);
+				Vector v = node_pos-ray.get_start();
+				float dist = (v-ray.get_direction()*dot(ray.get_direction(), v)).norm();
+				if(closest_dist<0 || dist<closest_dist)
+				{
+					coords = c;
+					closest_dist = dist;
+				}
+			}
+	return coords;
+}
+
+void Terrain::save(list<DataFile::Statement> &st) const
+{
+	st.push_back((DataFile::Statement("size"), width, height));
+	for(vector<Tile>::const_iterator i=tiles.begin(); i!=tiles.end(); ++i)
+	{
+		DataFile::Statement ss("tile");
+		i->save(ss.sub);
+		st.push_back(ss);
+	}
+}
+
+
+Terrain::Node::Node():
+	elevation(0),
+	ground(0),
+	wall(0)
+{ }
+
+void Terrain::Node::save(list<DataFile::Statement> &st) const
+{
+	st.push_back((DataFile::Statement("elevation"), elevation));
+	st.push_back((DataFile::Statement("ground"), ground));
+}
+
+
+Terrain::Tile::Tile():
+	secondary_axis(false)
+{ }
+
+void Terrain::Tile::save(list<DataFile::Statement> &st) const
+{
+	bool flat = true;
+	for(unsigned i=1; (flat && i<4); ++i)
+		flat = (nodes[i].elevation==nodes[0].elevation && nodes[i].ground==nodes[0].ground && nodes[i].wall==nodes[0].wall);
+	if(flat)
+	{
+		st.push_back((DataFile::Statement("elevation"), nodes[0].elevation));
+		st.push_back((DataFile::Statement("ground"), nodes[0].ground));
+	}
+	else
+	{
+		for(unsigned i=0; i<4; ++i)
+		{
+			DataFile::Statement ss("node");
+			ss.append(i);
+			nodes[i].save(ss.sub);
+			st.push_back(ss);
+		}
+	}
+}
+
+
+Terrain::NodeCoordinates::NodeCoordinates():
+	x(0),
+	y(0),
+	i(0)
+{ }
+
+Terrain::NodeCoordinates::NodeCoordinates(unsigned x_, unsigned y_, unsigned i_):
+	x(x_),
+	y(y_),
+	i(i_)
+{ }
+
+
+Terrain::Loader::Loader(Terrain &t):
+	DataFile::ObjectLoader<Terrain>(t),
+	next_tile(0)
+{
+	add("position", &Loader::position);
+	add("rotation", &Loader::rotation);
+	add("size", &Loader::size);
+	add("tile", &Loader::tile);
+	add("tile", &Loader::tile_coords);
+}
+
+void Terrain::Loader::position(float x, float y, float z)
+{
+	obj.set_position(Vector(x, y, z));
+}
+
+void Terrain::Loader::rotation(float a)
+{
+	obj.set_rotation(Angle::from_radians(a));
+}
+
+void Terrain::Loader::size(unsigned w, unsigned h)
+{
+	obj.set_size(w, h);
+}
+
+void Terrain::Loader::tile()
+{
+	if(next_tile>=obj.tiles.size())
+		throw runtime_error("Terrain::Loader::tile");
+
+	Tile &t = obj.tiles[next_tile];
+	Tile::Loader ldr(obj, t);
+	load_sub_with(ldr);
+	unsigned x = next_tile%obj.width;
+	unsigned y = next_tile/obj.width;
+	++next_tile;
+	obj.signal_tile_changed.emit(x, y);
+}
+
+void Terrain::Loader::tile_coords(unsigned x, unsigned y)
+{
+	if(x>=obj.width || y>=obj.height)
+		throw out_of_range("Terrain::Loader::tile");
+	next_tile = x+y*obj.width;
+	tile();
+}
+
+
+Terrain::Node::Loader::Loader(Terrain &t, Node &n):
+	DataFile::ObjectLoader<Node>(n),
+	terrain(t)
+{
+	add("ground", &Loader::ground);
+	add("elevation", &Node::elevation);
+}
+
+void Terrain::Node::Loader::ground(unsigned g)
+{
+	if(g>=terrain.type.get_n_surface_types())
+		throw out_of_range("Tile::Loader::surface");
+	obj.ground = g;
+}
+
+
+Terrain::Tile::Loader::Loader(Terrain &t, Tile &l):
+	DataFile::ObjectLoader<Tile>(l),
+	terrain(t)
+{
+	add("ground", &Loader::ground);
+	add("elevation", &Loader::elevation);
+	add("node", &Loader::node);
+}
+
+void Terrain::Tile::Loader::ground(unsigned g)
+{
+	if(g>=terrain.type.get_n_surface_types())
+		throw out_of_range("Tile::Loader::surface");
+	for(unsigned i=0; i<4; ++i)
+		obj.nodes[i].ground = g;
+}
+
+void Terrain::Tile::Loader::elevation(float h)
+{
+	for(unsigned i=0; i<4; ++i)
+		obj.nodes[i].elevation = h;
+}
+
+void Terrain::Tile::Loader::node(unsigned i)
+{
+	if(i>=4)
+		throw out_of_range("Tile::Loader::node");
+	Node::Loader ldr(terrain, obj.nodes[i]);
+	load_sub_with(ldr);
+}
+
+} // namespace R2C2
diff --git a/source/libr2c2/terrain.h b/source/libr2c2/terrain.h
new file mode 100644
index 0000000..837119e
--- /dev/null
+++ b/source/libr2c2/terrain.h
@@ -0,0 +1,118 @@
+#ifndef LIBR2C2_TERRAIN_H_
+#define LIBR2C2_TERRAIN_H_
+
+#include "object.h"
+#include "terraintype.h"
+
+namespace R2C2 {
+
+class Terrain: public Object
+{
+public:
+	class Loader: public Msp::DataFile::ObjectLoader<Terrain>
+	{
+	private:
+		unsigned next_tile;
+
+	public:
+		Loader(Terrain &);
+
+	private:
+		void position(float, float, float);
+		void rotation(float);
+		void size(unsigned, unsigned);
+		void tile();
+		void tile_coords(unsigned, unsigned);
+	};
+
+	struct Node
+	{
+		class Loader: public Msp::DataFile::ObjectLoader<Node>
+		{
+		private:
+			Terrain &terrain;
+
+		public:
+			Loader(Terrain &, Node &);
+
+		private:
+			void ground(unsigned);
+		};
+
+		float elevation;
+		unsigned ground;
+		unsigned wall;
+
+		Node();
+
+		void save(std::list<Msp::DataFile::Statement> &) const;
+	};
+
+	struct Tile
+	{
+		class Loader: public Msp::DataFile::ObjectLoader<Tile>
+		{
+		private:
+			Terrain &terrain;
+
+		public:
+			Loader(Terrain &, Tile &);
+
+		private:
+			void ground(unsigned);
+			void elevation(float);
+			void node(unsigned);
+		};
+
+		Node nodes[4];
+		bool secondary_axis;
+
+		Tile();
+
+		void save(std::list<Msp::DataFile::Statement> &) const;
+	};
+
+	struct NodeCoordinates
+	{
+		unsigned x, y;
+		unsigned i;
+
+		NodeCoordinates();
+		NodeCoordinates(unsigned, unsigned, unsigned);
+	};
+
+	sigc::signal<void, unsigned, unsigned> signal_size_changed;
+	sigc::signal<void, unsigned, unsigned> signal_tile_changed;
+
+private:
+	const TerrainType &type;
+	unsigned width;
+	unsigned height;
+	std::vector<Tile> tiles;
+
+public:
+	Terrain(Layout &, const TerrainType &);
+	virtual ~Terrain();
+
+	virtual Terrain *clone(Layout *) const;
+
+	virtual const TerrainType &get_type() const { return type; }
+	virtual void set_position(const Vector &);
+	virtual void set_rotation(const Angle &);
+	virtual void set_tilt(const Angle &) { }
+
+	void set_size(unsigned, unsigned);
+	unsigned get_width() const { return width; }
+	unsigned get_height() const { return height; }
+	const Tile &get_tile(unsigned, unsigned) const;
+	void set_node_elevation(const NodeCoordinates &, float, bool = false);
+	float get_node_elevation(const NodeCoordinates &) const;
+	Vector get_node_position(const NodeCoordinates &) const;
+	NodeCoordinates get_closest_node(const Ray &) const;
+
+	void save(std::list<Msp::DataFile::Statement> &) const;
+};
+
+} // namespace R2C2
+
+#endif
diff --git a/source/libr2c2/terraintype.cpp b/source/libr2c2/terraintype.cpp
new file mode 100644
index 0000000..ce9551f
--- /dev/null
+++ b/source/libr2c2/terraintype.cpp
@@ -0,0 +1,51 @@
+#include <stdexcept>
+#include "terraintype.h"
+
+using namespace std;
+using namespace Msp;
+
+namespace R2C2 {
+
+TerrainType::TerrainType(const ArticleNumber &an):
+	ObjectType(an),
+	tile_size(1),
+	elevation_granularity(0.1)
+{ }
+
+const TerrainType::SurfaceType &TerrainType::get_surface_type(unsigned i) const
+{
+	if(i>=surface_types.size())
+		throw out_of_range("TerrainType::get_surface_type");
+	return surface_types[i];
+}
+
+
+TerrainType::SurfaceType::SurfaceType():
+	r(0.8),
+	g(0.8),
+	b(0.8)
+{ }
+
+
+TerrainType::Loader::Loader(TerrainType &tt):
+	DataFile::ObjectLoader<TerrainType>(tt)
+{
+	add("elevation_granularity", &TerrainType::elevation_granularity);
+	add("surface", &Loader::surface);
+	add("tile_size", &TerrainType::tile_size);
+}
+
+void TerrainType::Loader::surface()
+{
+	SurfaceType srf;
+	load_sub(srf);
+	obj.surface_types.push_back(srf);
+}
+
+
+TerrainType::SurfaceType::Loader::Loader(SurfaceType &st):
+	DataFile::ObjectLoader<SurfaceType>(st)
+{
+}
+
+} // namespace R2C2
diff --git a/source/libr2c2/terraintype.h b/source/libr2c2/terraintype.h
new file mode 100644
index 0000000..f0013ad
--- /dev/null
+++ b/source/libr2c2/terraintype.h
@@ -0,0 +1,50 @@
+#ifndef LIBR2C2_TERRAINTYPE_H_
+#define LIBR2C2_TERRAINTYPE_H_
+
+#include <vector>
+#include "objecttype.h"
+
+namespace R2C2 {
+
+class TerrainType: public ObjectType
+{
+public:
+	class Loader: public Msp::DataFile::ObjectLoader<TerrainType>
+	{
+	public:
+		Loader(TerrainType &);
+
+	private:
+		void surface();
+	};
+
+	struct SurfaceType
+	{
+		class Loader: public Msp::DataFile::ObjectLoader<SurfaceType>
+		{
+		public:
+			Loader(SurfaceType &);
+		};
+
+		float r, g, b;
+
+		SurfaceType();
+	};
+
+private:
+	std::vector<SurfaceType> surface_types;
+	float tile_size;
+	float elevation_granularity;
+
+public:
+	TerrainType(const ArticleNumber &);
+
+	unsigned get_n_surface_types() const { return surface_types.size(); }
+	const SurfaceType &get_surface_type(unsigned) const;
+	float get_tile_size() const { return tile_size; }
+	float get_elevation_granularity() const { return elevation_granularity; }
+};
+
+} // namespace R2C2
+
+#endif
diff --git a/terrain.dat b/terrain.dat
new file mode 100644
index 0000000..df47ef5
--- /dev/null
+++ b/terrain.dat
@@ -0,0 +1,9 @@
+terrain \100001
+{
+	surface
+	{
+	};
+
+	tile_size 0.05;
+	elevation_granularity 0.0125;
+};
-- 
2.43.0