Figured out the crash, but want to see what valgrind would say.

Makefile

@@ -78,7 +78,7 @@ story:
 	gdb --nx -x .gdbinit --batch --ex run --ex bt --ex q --args ./builddir/storyboard
 
 debug_animator:
-	gdb --nx -x .gdbinit --batch --ex run --ex bt --ex q --args ./builddir/animator.exe -s "rat_king_boss" -a "rat_king_boss" -b "test_background"
+	gdb --nx -x .gdbinit --batch --ex run --ex bt --ex q --args ./builddir/animator -s "rat_king_boss" -a "rat_king_boss" -b "test_background"
 
 animator:
 	./builddir/animator.exe -s "rat_king_boss" -a "rat_king_boss" -b "test_background"

animate2.cpp

@@ -86,7 +86,11 @@ namespace animate2 {
     } else {
       sequence.timer.restart();
       sequence.current++;
-      if(sequence.subframe > SUB_FRAME_SENSITIVITY) sequence.subframe = 0.0f;
+
+      if(sequence.subframe > SUB_FRAME_SENSITIVITY) {
+        sequence.subframe = 0.0f;
+      }
+
       frame_change = true;
     }
 

boss/fight.cpp

@@ -41,8 +41,6 @@ namespace boss {
     using enum game::Event;
 
     switch(ev) {
-      // this is only if using the debug X key to skip it
-      case TICK:
       case BOSS_START:
         $ui.status(L"PLAYER REQUESTS", L"COMMIT");
         $battle.ap_refresh();
@@ -177,7 +175,6 @@ namespace boss {
         $ui.animate_actor("player");
         break;
     }
-
   }
 
   void Fight::run_systems() {

scene.cpp

@@ -127,7 +127,9 @@ namespace scene {
   void Engine::play_animations() {
     for(auto& fixture : $fixtures) {
       if(fixture.anim.playing) {
+        fixture.anim.update();
         fixture.anim.apply(*fixture.st.sprite);
+        // REFACTOR:  fixture.anim.apply(*fixture.st.sprite);
       } else {
         fixture.effect = nullptr;
       }
@@ -135,9 +137,10 @@ namespace scene {
 
     for(auto& actor : $actors) {
       if(actor.anim.playing) {
+        actor.anim.update();
         actor.anim.apply(*actor.st.sprite);
         // REFACTOR: actor.anim.apply(actor.text, actor.pos);
-        if(actor.effect != nullptr) actor.anim.apply_effect(actor.effect);
+        // if(actor.effect != nullptr) actor.anim.apply_effect(actor.effect);
       } else {
         actor.effect = nullptr;
       }
@@ -173,13 +176,22 @@ namespace scene {
   }
 
   void Engine::set_end_cb(std::function<void()> cb) {
-    // REFACTOR:
+    for(auto& actor : $actors) {
-    // for(auto& actor : $actors) {
+      actor.anim.onLoop = [&](auto& seq, auto& tr) -> bool {
-    //   actor.anim.end_cb = cb;
+        seq.current = tr.toggled ? seq.frame_count - 1 : 0;
-    // }
+        cb();
+        return tr.looped;
+      };
+    }
   }
 
   void Engine::reset(sf::RenderTexture& view) {
     $camera.reset(view);
   }
+
+  void Engine::tick() {
+    for(auto& actor : $actors) {
+      auto [ticks, alpha] = actor.anim.commit();
+    }
+  }
 }

scene.hpp

@@ -58,5 +58,6 @@ namespace scene {
     void zoom(float mid_x, float mid_y, const std::string& style, float scale);
     void reset(sf::RenderTexture& view);
     void set_end_cb(std::function<void()> cb);
+    void tick();
   };
 }

tools/animator.cpp

@@ -312,12 +312,12 @@ int error_usage() {
 }
 
 int main(int argc, char* argv[]) {
-  shaders::init();
+  ai::init("ai");
+  animation::init();
   components::init();
   sfml::Backend backend;
   guecs::init(&backend);
-  ai::init("ai");
+  shaders::init();
-  animation::init();
 
   std::string sprite_name;
   std::string background;

tools/arena.cpp

@@ -50,13 +50,14 @@ int main(int, char*[]) {
   dbc::check(main->$world == world, "GameDB::current_world doesn't match boss fight world.");
 
   while(!main->in_state(boss::State::END)) {
+    main->$ui.$arena.tick();
+    main->render(window);
+
     if(main->handle_keyboard_mouse() ||
       main->handle_world_events())
     {
       return 0;
     }
-
-    main->render(window);
     window.display();
   }