added troll class, cleaned up shade, vampire, and goblin classes

src/troll.cc

@@ -0,0 +1,36 @@
+#include "troll.h"
+
+troll::troll(RNG *rng, const position &pos):
+	character{rng, race::rtroll, pos} {
+	gold = 0;
+	hostile = true;
+}
+
+result troll::attack(const direction dir, character_list &chlist) {
+	position tmp{pos + MOVE[dir]};
+
+	if (HP + REGAIN_HP > HP_CAP) {
+		HP = HP_CAP;
+	} else {
+		HP += REGAIN_HP;
+	}
+
+	for (auto &ch : chlist)
+		if (tmp == ch->get_position()) {
+			auto res = ch->get_hit(race, ATK, base_hit_rate);
+			return res;
+		}
+
+	return result::fine;
+}
+
+result troll::get_hit(const enum race &race, const int atk,
+		     const fraction hitrate) {
+	if (rng->trial(hitrate))
+		HP = std::max(HP - calc_dmg(atk, DEF), 0);
+
+	if (HP == 0)
+		return result::died;
+
+	return result::hit;
+}