Started working on this 'arena tester' tool that would let me load an enemy and test them, but then realized I could just make it so I can spawn enemies in the game. I'm keeping the arena around as it will be useful later as a scriptable testing tool, but for now just spawn and test.

tools/arena_fsm.cpp

@@ -0,0 +1,120 @@
+#include "gui_fsm.hpp"
+#include <iostream>
+#include <chrono>
+#include <numeric>
+#include <functional>
+#include "components.hpp"
+#include <numbers>
+#include "systems.hpp"
+#include "events.hpp"
+#include "sound.hpp"
+#include <fmt/xchar.h>
+#include "arena_fsm.hpp"
+
+namespace arena {
+  using namespace components;
+
+  FSM::FSM(std::string enemy_name) :
+    $enemy_name(enemy_name),
+    $window(sf::VideoMode({SCREEN_WIDTH, SCREEN_HEIGHT}), "Arena Battle Tester"),
+    $font{FONT_FILE_NAME}
+    {
+    }
+
+  void FSM::event(Event ev) {
+    switch($state) {
+      FSM_STATE(State, START, ev);
+      FSM_STATE(State, IDLE, ev);
+      FSM_STATE(State, END, ev);
+    }
+  }
+
+  void FSM::START(Event ) {
+    run_systems();
+    $level = $level_mgr.current();
+
+    auto entity_id = $level_mgr.spawn_enemy($enemy_name);
+
+    $arena_ui = make_shared<ArenaUI>($level.world, entity_id);
+    $arena_ui->init();
+    state(State::IDLE);
+  }
+
+  void FSM::END(Event ev) {
+    dbc::log(fmt::format("END: received event after done: {}", int(ev)));
+  }
+
+  void FSM::IDLE(Event ev) {
+    using enum Event;
+
+    switch(ev) {
+      case QUIT:
+        $window.close();
+        state(State::END);
+        return; // done
+      case CLOSE:
+        dbc::log("Nothing to close.");
+        break;
+      case TICK:
+        // do nothing
+        break;
+      case ATTACK:
+        dbc::log("ATTACK!");
+        break;
+      default:
+        dbc::sentinel("unhandled event in IDLE");
+    }
+  }
+
+  void FSM::keyboard_mouse() {
+    while(const auto ev = $window.pollEvent()) {
+      if(ev->is<sf::Event::Closed>()) {
+        event(Event::QUIT);
+      }
+
+      if(const auto* mouse = ev->getIf<sf::Event::MouseButtonPressed>()) {
+        if(mouse->button == sf::Mouse::Button::Left) {
+          sf::Vector2f pos = $window.mapPixelToCoords(mouse->position);
+          (void)pos;
+        }
+      }
+
+      if(const auto* key = ev->getIf<sf::Event::KeyPressed>()) {
+        using KEY = sf::Keyboard::Scan;
+
+        switch(key->scancode) {
+          case KEY::Escape:
+            event(Event::CLOSE);
+            break;
+          case KEY::Space:
+            event(Event::ATTACK);
+            break;
+          default:
+            break; // ignored
+        }
+      }
+    }
+  }
+
+  void FSM::draw_gui() {
+    if($arena_ui != nullptr) {
+      $arena_ui->render($window);
+    }
+  }
+
+  void FSM::render() {
+    $window.clear();
+    draw_gui();
+    $window.display();
+  }
+
+  void FSM::run_systems() {
+  }
+
+  bool FSM::active() {
+    return !in_state(State::END);
+  }
+
+  void FSM::handle_world_events() {
+  }
+}