The game engine now has two bonuses for long build streaks. +10% max hp or 1 free death. I'll be adding more but that's enough to work on the real UI.

game_engine.cpp

@@ -12,7 +12,7 @@ using namespace fmt;
 using namespace std;
 
 GameEngine::GameEngine(int hp) : starting_hp(hp) {
-  hit_points = starting_hp;
+  hit_points = max_hp();
 };
 
 int GameEngine::determine_damage(string &type) {
@@ -25,8 +25,17 @@ int GameEngine::determine_damage(string &type) {
 }
 
 void GameEngine::reset() {
+  println("!!!!!!! RESET hit_points={}, max={}", hit_points, max_hp());
+  if(free_death) {
+    hit_points = max_hp() * 0.5f;
+  } else {
     streak = 0;
-  hit_points = starting_hp;
+    hit_points = max_hp();
+  }
+
+  println("!!!!!!!! AFTER RESET hit_points={}, max={}", hit_points, max_hp());
+
+  free_death = false;
 }
 
 bool GameEngine::hit(string &type) {
@@ -37,12 +46,12 @@ bool GameEngine::hit(string &type) {
 }
 
 void GameEngine::heal() {
-  hit_points = hit_points * 1.10;
-  if(hit_points > 100) hit_points = 100;
+  hit_points = hit_points * 1.10f;
+  if(hit_points > max_hp()) hit_points = max_hp();
 }
 
 bool GameEngine::is_dead() {
-  return hit_points <= 0;
+  return free_death ? false : hit_points <= 0;
 }
 
 void GameEngine::start(GameEvent ev) {
@@ -63,7 +72,9 @@ void GameEngine::in_round(GameEvent ev, string &hit_type) {
   switch(ev) {
     case GameEvent::HIT:
       hit(hit_type);
-      if(is_dead()) {
+
+      // NOTE: don't use is_dead to avoid free_death
+      if(hit_points <= 0) {
         state(GameState::DEAD);
       } else {
         state(GameState::IN_ROUND);
@@ -103,6 +114,22 @@ void GameEngine::success(GameEvent ev) {
 void GameEngine::failure(GameEvent ev) {
   assert(ev == GameEvent::BUILD_DONE && "failure state expected BUILD_DONE");
   ++rounds;
-  streak = 0;
+  // streak is handled by reset()
   state(GameState::IDLE);
 }
+
+int GameEngine::max_hp() {
+  return starting_hp * hp_bonus;
+}
+
+void GameEngine::add_bonus(GameBonus bonus) {
+  switch(bonus) {
+    case GameBonus::MORE_HP:
+      hp_bonus += 0.10f;
+      hit_points = max_hp();
+      break;
+    case GameBonus::FREE_DEATH:
+      free_death = true;
+      break;
+  }
+}

game_engine.hpp

@@ -19,6 +19,10 @@ enum class GameEvent {
   BUILD_DONE, BUILD_FAILED, HIT
 };
 
+enum class GameBonus {
+  MORE_HP, FREE_DEATH
+};
+
 class GameEngine : DeadSimpleFSM<GameState, GameEvent> {
 
   std::map<string, int> damage_types{
@@ -33,6 +37,8 @@ class GameEngine : DeadSimpleFSM<GameState, GameEvent> {
   int hits_taken = 0;
   int rounds = 0;
   int streak = 0;
+  float hp_bonus = 1.0f;
+  bool free_death = false;
 
   GameEngine(int hp);
 
@@ -82,4 +88,6 @@ class GameEngine : DeadSimpleFSM<GameState, GameEvent> {
   void heal();
   bool hit(string &type);
   void reset();
+  void add_bonus(GameBonus bonus);
+  int max_hp();
 };

tests/game_engine.cpp

@@ -36,7 +36,44 @@ TEST_CASE("game engine death cycle", "[game_engine]") {
 }
 
 TEST_CASE("game can do success build", "[game_engine]") {
+  GameEngine game{10};
+
   // test fails on purpose right now
-  GameEngine game{100};
+  for(int i = 0; i < 10; i++) {
+    game.event(GameEvent::BUILD_START);
+    game.event(GameEvent::BUILD_SUCCESS);
+    REQUIRE(game.hits_taken == 0);
+    REQUIRE(game.hit_points == game.starting_hp);
+    // confirm streaks, hit_taken, rounds are maintained
+    REQUIRE(game.streak == i);
+    REQUIRE(game.rounds == i);
     REQUIRE(game.is_dead() == false);
+    game.event(GameEvent::BUILD_DONE);
+  }
+
+  // if you hit a streak of 10 then you get one of two bonuses
+  // 1. 10% more hp
+  // 2. 1 free death
+
+  game.add_bonus(GameBonus::MORE_HP);
+  REQUIRE(game.max_hp() > game.starting_hp);
+  REQUIRE(game.hit_points == game.starting_hp * game.hp_bonus);
+  REQUIRE(game.hit_points == game.max_hp());
+
+  game.add_bonus(GameBonus::FREE_DEATH);
+  REQUIRE(game.free_death == true);
+
+  game.event(GameEvent::BUILD_START);
+  game.event(GameEvent::HIT, "error");
+  game.event(GameEvent::HIT, "error");
+  game.event(GameEvent::HIT, "error");
+
+  REQUIRE(game.is_dead() == false);
+  REQUIRE(game.streak == 10);
+  game.event(GameEvent::BUILD_FAILED);
+  game.event(GameEvent::BUILD_DONE);
+
+  REQUIRE(game.streak == 10);
+  REQUIRE(game.free_death == false);
+  REQUIRE(game.hit_points == int(game.max_hp() * 0.5f));
 }