From 56726a6c0538f82d786e6795ee2b72ed40f23906 Mon Sep 17 00:00:00 2001
From: Petr Baudis <pasky@ucw.cz>
Date: Sat, 26 Nov 2011 20:40:05 +0100
Subject: [PATCH] Get rid of class position

---
 agent.cc |  5 ++---
 agent.h  | 12 +++++++-----
 main.cc  |  2 +-
 map.cc   | 21 ++++++++++-----------
 map.h    | 43 ++++++++++++++++++++-----------------------
 5 files changed, 40 insertions(+), 43 deletions(-)

diff --git a/agent.cc b/agent.cc
index f0a944e..de7227f 100644
--- a/agent.cc
+++ b/agent.cc
@@ -6,10 +6,9 @@
 #include "map.h"
 
 void
-agent::put_at(struct position *pos)
+agent::put_at(class tile &t)
 {
-	class tile *t = &pos->map->tile_at(*pos);
-	if (!t->on_agent_enter(this)) {
+	if (!t.on_agent_enter(*this)) {
 		std::cerr << "Collision.";
 		exit(EXIT_FAILURE);
 	}
diff --git a/agent.h b/agent.h
index 4e5b8fc..aaf48ca 100644
--- a/agent.h
+++ b/agent.h
@@ -1,19 +1,21 @@
 #ifndef BRMLIFE__AGENT_H
 #define BRMLIFE__AGENT_H
 
-class position;
+#include "map.h"
 
 class agent {
 public:
 	int id;
-	class position *pos;
+	class tile *tile;
 
-	agent(int id_, class position &pos_) : id (id_), pos (&pos_)
+	agent(int id_, class tile &tile_) : id (id_), tile (&tile_)
 	{
-		put_at(pos);
+		put_at(tile_);
 	};
 
-	void put_at(struct position *pos);
+private:
+	/* Just for initial placement. */
+	void put_at(class tile &tile);
 };
 
 #endif
diff --git a/main.cc b/main.cc
index 5dc4b32..e9f14fd 100644
--- a/main.cc
+++ b/main.cc
@@ -8,7 +8,7 @@ main(int argc, char *argv[])
 {
 	class map map(10, 10);
 
-	class position agentpos(4, 4, map);
+	class tile &agentpos = map.tile_at(4, 4);
 	class agent agent(0, agentpos);
 
 	map.print_map();
diff --git a/map.cc b/map.cc
index a4fc0c5..8dbc7e6 100644
--- a/map.cc
+++ b/map.cc
@@ -5,17 +5,17 @@
 #include "map.h"
 
 bool
-tile::on_agent_enter(class agent *a)
+tile::on_agent_enter(class agent &a)
 {
 	if (agent) return false;
-	agent = a;
+	agent = &a;
 	return true;
 }
 
 void
-tile::on_agent_leave(class agent *a)
+tile::on_agent_leave(class agent &a)
 {
-	assert(a == agent);
+	assert(&a == agent);
 	agent = NULL;
 }
 
@@ -38,12 +38,12 @@ tile_ground::type_symbol(void)
 	return '.';
 }
 
-class position *
-position::next_in(int dir_x, int dir_y)
+class tile &
+tile::tile_in_dir(int dir_x, int dir_y)
 {
-	int x2 = (map->w + x + dir_x) % map->w;
-	int y2 = (map->h + y + dir_y) % map->h;
-	return new position(x2, y2, *map);
+	int x2 = (map.w + x + dir_x) % map.w;
+	int y2 = (map.h + y + dir_y) % map.h;
+	return map.tile_at(x2, y2);
 }
 
 
@@ -52,8 +52,7 @@ map::print_map(void)
 {
 	for (int y = 0; y < h; y++) {
 		for (int x = 0; x < w; x++) {
-			class position p = position(x, y, *this);
-			std::cout << tile_at(p).symbol();
+			std::cout << tile_at(x, y).symbol();
 		}
 		std::cout << '\n';
 	}
diff --git a/map.h b/map.h
index e9fc62e..9dddd0b 100644
--- a/map.h
+++ b/map.h
@@ -6,34 +6,29 @@ class map;
 
 class tile {
 public:
+	int x, y;
+	class map &map;
+
 	class agent *agent;
 
-	virtual bool on_agent_enter(class agent *);
-	virtual void on_agent_leave(class agent *);
-
-	virtual void on_tick(void);
+	tile(int x_, int y_, class map &map_) : x(x_), y(y_), map(map_), agent(NULL) {};
 
 	char symbol(void);
 	virtual char type_symbol(void) = 0;
+
+	class tile &tile_in_dir(int dir_x, int dir_y);
+
+	virtual bool on_agent_enter(class agent &);
+	virtual void on_agent_leave(class agent &);
+
+	virtual void on_tick(void);
 };
 
 class tile_ground : public tile {
-	char type_symbol(void);
-};
-
-class position {
 public:
-	int x, y;
-	class map *map;
-
-	position(int x_, int y_, class map &map_)
-	{
-		x = x_;
-		y = y_;
-		map = &map_;
-	};
-
-	class position *next_in(int dir_x, int dir_y);
+	tile_ground(int x_, int y_, struct map &map_) : tile(x_, y_, map_) {};
+private:
+	char type_symbol(void);
 };
 
 class map {
@@ -47,14 +42,16 @@ public:
 		h = h_;
 		tiles = new class tile * [w * h];
 
-		for (int i = 0; i < w * h; i++) {
-			tiles[i] = new tile_ground;
+		for (int y = 0; y < h; y++) {
+			for (int x = 0; x < w; x++) {
+				tiles[y * h + x] = new tile_ground(x, y, *this);
+			}
 		}
 	};
 
-	class tile &tile_at(class position &pos)
+	class tile &tile_at(int x, int y)
 	{
-		return *tiles[pos.y * h + pos.x];
+		return *tiles[y * h + x];
 	};
 
 	void print_map(void);