Spawn some herbs at startup

agent.h

@@ -48,4 +48,16 @@ public:
 	~agent();
 };
 
+class herb : public agent {
+public:
+	herb(int id_, class map &map_)
+	: agent(id_, NULL, map_)
+	{
+		energy = world::herb_energy;
+		attr.move = 0;
+		attr.attack = 0;
+		attr.defense = 0;
+	}
+};
+
 #endif

main.cc

@@ -23,6 +23,7 @@ int
 main(int argc, char *argv[])
 {
 	class map map(argc < 2 ? 40 : atoi(argv[1]), argc < 3 ? 20 : atoi(argv[2]));
+	int herbs = argc < 4 ? map.w * map.h / world::herb_rate : atoi(argv[3]);
 
 	srandom(time(NULL));
 
@@ -44,6 +45,14 @@ main(int argc, char *argv[])
 	std::list<class agent *> agents;
 	int aid = 0;
 
+	/* Spawn herbs. */
+
+	for (int i = 0; i < herbs; i++) {
+		class agent *a = new class herb(aid++, map);
+		agents.push_back(a);
+		a->spawn();
+	}
+
 	/* Main tick loop. */
 
 	while (true) {

map.cc

@@ -32,6 +32,8 @@ tile::symbol(void)
 	if (agent) {
 		if (agent->dead)
 			return 'a';
+		if (agent->attr.move < 0.01)
+			return 'x';
 		return '0' + (agent->id % 10);
 	}
 	return type_symbol();

world.h

@@ -3,6 +3,8 @@
 
 struct world {
 	const static int newborn_energy = 5000;
+	const static int herb_energy = 1500;
+
 	const static int move_cost = -50;
 	const static int attack_cost = -400;
 	const static int defense_cost = -200;
@@ -15,6 +17,8 @@ struct world {
 	const static int dead_body_energy = 2000;
 	const static double dead_body_energy_carryover = 0.5;
 	const static int dead_decay = -10;
+
+	const static int herb_rate = 20; /* one herb per herb_rate tiles */
 };
 
 #endif