Avoid unnecessary dynamic_casts, LayerObject base class, remove `…

…CollisionListener` (#3110)

Unnecessary `dynamic_cast`s have been replaced with `static_cast`s, or the code requiring them has been improved.

## Add `LayerObject` class

`LayerObject` is a base class for all `GameObject`s which are shown under the `EditorLayersWidget`. Used to prevent multiple casts every single frame for every single layer icon when determining z-pos.

Closes #701.

## Remove `CollisionListener` class

The changes done by commit fa82f91 have been reverted. The reason is that `CollisionListener` was not used as a base anywhere beside `MovingObject`, and made it so `CollisionObject::collide()`/`collision()` had to use `dynamic_cast` to side-cast the `other` object's listener to a `GameObject`.

`CollisionObject` now contains the `MovingObject& m_parent` member, as opposed to `CollisionListener& m_listener`.

Additionally, the now base `MovingObject::collision...` functions now accept `MovingObject&` in arguments, instead of `GameObject&`. This saves on a few other casts along the way.

src/audio/sound_manager.cpp

@@ -217,7 +217,7 @@ SoundManager::manage_source(std::unique_ptr<SoundSource> source)
   assert(source);
   if (dynamic_cast<OpenALSoundSource*>(source.get()))
   {
-    std::unique_ptr<OpenALSoundSource> openal_source(dynamic_cast<OpenALSoundSource*>(source.release()));
+    std::unique_ptr<OpenALSoundSource> openal_source(static_cast<OpenALSoundSource*>(source.release()));
     m_sources.push_back(std::move(openal_source));
   }
 }

src/badguy/badguy.cpp

@@ -447,7 +447,7 @@ BadGuy::collision_tile(uint32_t tile_attributes)
 }
 
 HitResponse
-BadGuy::collision(GameObject& other, const CollisionHit& hit)
+BadGuy::collision(MovingObject& other, const CollisionHit& hit)
 {
   if (!is_active()) return ABORT_MOVE;
 
@@ -598,7 +598,7 @@ BadGuy::collision_badguy(BadGuy& badguy, const CollisionHit& hit)
 }
 
 bool
-BadGuy::collision_squished(GameObject& object)
+BadGuy::collision_squished(MovingObject& object)
 {
   // Frozen badguys can be killed with butt-jump.
   if (m_frozen)

src/badguy/badguy.hpp

@@ -78,7 +78,7 @@ class BadGuy : public MovingSprite,
   /** Called when a collision with another object occurred. The
       default implementation calls collision_player, collision_solid,
       collision_badguy and collision_squished */
-  virtual HitResponse collision(GameObject& other, const CollisionHit& hit) override;
+  virtual HitResponse collision(MovingObject& other, const CollisionHit& hit) override;
 
   /** Called when a collision with tile with special attributes
       occurred */
@@ -188,7 +188,7 @@ class BadGuy : public MovingSprite,
   /** Called when the player hit the badguy from above. You should
       return true if the badguy was squished, false if squishing
       wasn't possible */
-  virtual bool collision_squished(GameObject& object);
+  virtual bool collision_squished(MovingObject& object);
 
   /** Called when the badguy collided with a bullet */
   virtual HitResponse collision_bullet(Bullet& bullet, const CollisionHit& hit);

src/badguy/bouncing_snowball.cpp

@@ -118,7 +118,7 @@ BouncingSnowball::is_freezable() const
 }
 
 bool
-BouncingSnowball::collision_squished(GameObject& object)
+BouncingSnowball::collision_squished(MovingObject& object)
 {
   if (m_frozen)
     return BadGuy::collision_squished(object);

src/badguy/bouncing_snowball.hpp

@@ -49,7 +49,7 @@ class BouncingSnowball final : public BadGuy
   virtual bool is_freezable() const override;
 
 protected:
-  virtual bool collision_squished(GameObject& object) override;
+  virtual bool collision_squished(MovingObject& object) override;
   void turn_around();
 
 private:

src/badguy/captainsnowball.cpp

@@ -91,7 +91,7 @@ CaptainSnowball::collision_solid(const CollisionHit& hit)
 }
 
 bool
-CaptainSnowball::collision_squished(GameObject& object)
+CaptainSnowball::collision_squished(MovingObject& object)
 {
   set_action("squished", m_dir);
   kill_squished(object);

src/badguy/captainsnowball.hpp

@@ -37,7 +37,7 @@ class CaptainSnowball final : public WalkingBadguy
   bool might_climb(int width, int height) const;
 
 protected:
-  virtual bool collision_squished(GameObject& object) override;
+  virtual bool collision_squished(MovingObject& object) override;
 
 private:
   bool m_jumping;

src/badguy/corrupted_granito.cpp

@@ -78,7 +78,7 @@ CorruptedGranito::set_state(CorruptedGranitoState newState)
 }
 
 bool
-CorruptedGranito::collision_squished(GameObject& object)
+CorruptedGranito::collision_squished(MovingObject& object)
 {
   if (m_frozen)
     return BadGuy::collision_squished(object);

src/badguy/corrupted_granito.hpp

@@ -34,7 +34,7 @@ class CorruptedGranito final : public BadGuy
   virtual void initialize() override;
   virtual void collision_solid(const CollisionHit& hit) override;
   virtual HitResponse collision_badguy(BadGuy& badguy, const CollisionHit& hit) override;
-  virtual bool collision_squished(GameObject& object) override;
+  virtual bool collision_squished(MovingObject& object) override;
   virtual void active_update(float dt_sec) override;
 
   virtual void unfreeze(bool melt = true) override;

src/badguy/crusher.cpp

@@ -120,7 +120,7 @@ Crusher::on_type_change(int old_type)
 }
 
 HitResponse
-Crusher::collision(GameObject& other, const CollisionHit& hit)
+Crusher::collision(MovingObject& other, const CollisionHit& hit)
 {
   auto* player = dynamic_cast<Player*>(&other);
 
@@ -686,7 +686,7 @@ CrusherRoot::CrusherRoot(Vector position, Crusher::Direction direction, float de
 }
 
 HitResponse
-CrusherRoot::collision(GameObject& other, const CollisionHit& hit)
+CrusherRoot::collision(MovingObject& other, const CollisionHit& hit)
 {
   if (delay_gone())
   {

src/badguy/crusher.hpp

@@ -58,7 +58,7 @@ class Crusher final : public MovingSprite
 public:
   Crusher(const ReaderMapping& reader);
 
-  virtual HitResponse collision(GameObject& other, const CollisionHit& hit) override;
+  virtual HitResponse collision(MovingObject& other, const CollisionHit& hit) override;
   virtual void collision_solid(const CollisionHit& hit) override;
   virtual void update(float dt_sec) override;
   virtual void draw(DrawingContext& context) override;
@@ -118,7 +118,7 @@ class CrusherRoot : public MovingSprite
   CrusherRoot(Vector position, Crusher::Direction direction, float delay, int layer);
   virtual GameObjectClasses get_class_types() const override { return MovingSprite::get_class_types().add(typeid(CrusherRoot)); }
 
-  virtual HitResponse collision(GameObject& other, const CollisionHit& hit) override;
+  virtual HitResponse collision(MovingObject& other, const CollisionHit& hit) override;
   virtual void update(float dt_sec) override;
 
 private:

src/badguy/crystallo.cpp

@@ -70,7 +70,7 @@ Crystallo::active_update(float dt_sec)
 }
 
 bool
-Crystallo::collision_squished(GameObject& object)
+Crystallo::collision_squished(MovingObject& object)
 {
   set_action(m_dir == Direction::LEFT ? "shattered-left" : "shattered-right", /* loops = */ -1, ANCHOR_BOTTOM);
   kill_squished(object);

src/badguy/crystallo.hpp

@@ -41,7 +41,7 @@ class Crystallo final : public WalkingBadguy
   virtual void on_flip(float height) override;
 
 protected:
-  virtual bool collision_squished(GameObject& object) override;
+  virtual bool collision_squished(MovingObject& object) override;
 
 private:
   float m_radius;

src/badguy/dispenser.cpp

@@ -128,7 +128,7 @@ Dispenser::deactivate()
 }
 
 HitResponse
-Dispenser::collision(GameObject& other, const CollisionHit& hit)
+Dispenser::collision(MovingObject& other, const CollisionHit& hit)
 {
   auto bullet = dynamic_cast<Bullet*> (&other);
   if (bullet)

src/badguy/dispenser.hpp

@@ -86,7 +86,7 @@ class Dispenser final : public BadGuy
 protected:
   void add_object(std::unique_ptr<GameObject> object);
 
-  virtual HitResponse collision(GameObject& other, const CollisionHit& hit) override;
+  virtual HitResponse collision(MovingObject& other, const CollisionHit& hit) override;
   void launch_object();
 
   void on_type_change(int old_type) override;

src/badguy/flyingsnowball.cpp

@@ -50,7 +50,7 @@ FlyingSnowBall::activate()
 }
 
 bool
-FlyingSnowBall::collision_squished(GameObject& object)
+FlyingSnowBall::collision_squished(MovingObject& object)
 {
   set_action("squished", m_dir);
   m_physic.enable_gravity(true);

src/badguy/flyingsnowball.hpp

@@ -36,7 +36,7 @@ class FlyingSnowBall final : public BadGuy
   virtual bool is_snipable() const override { return true; }
 
 protected:
-  virtual bool collision_squished(GameObject& object) override;
+  virtual bool collision_squished(MovingObject& object) override;
   virtual std::vector<Direction> get_allowed_directions() const override;
 
 private:

src/badguy/ghosttree.cpp

@@ -245,7 +245,7 @@ GhostTree::draw(DrawingContext& context)
 }
 
 bool
-GhostTree::collides(GameObject& other, const CollisionHit& ) const
+GhostTree::collides(MovingObject& other, const CollisionHit& ) const
 {
   if (mystate != STATE_SUCKING) return false;
   if (dynamic_cast<Lantern*>(&other)) return true;
@@ -254,7 +254,7 @@ GhostTree::collides(GameObject& other, const CollisionHit& ) const
 }
 
 HitResponse
-GhostTree::collision(GameObject& other, const CollisionHit& )
+GhostTree::collision(MovingObject& other, const CollisionHit& )
 {
   if (mystate != STATE_SUCKING) return ABORT_MOVE;
 

src/badguy/ghosttree.hpp

@@ -33,8 +33,8 @@ class GhostTree final : public Boss
   virtual void active_update(float dt_sec) override;
   virtual void draw(DrawingContext& context) override;
 
-  virtual bool collides(GameObject& other, const CollisionHit& hit) const override;
-  virtual HitResponse collision(GameObject& other, const CollisionHit& hit) override;
+  virtual bool collides(MovingObject& other, const CollisionHit& hit) const override;
+  virtual HitResponse collision(MovingObject& other, const CollisionHit& hit) override;
 
   static std::string class_name() { return "ghosttree"; }
   virtual std::string get_class_name() const override { return class_name(); }

src/badguy/ghoul.cpp

@@ -45,7 +45,7 @@ Ghoul::Ghoul(const ReaderMapping& reader) :
 }
 
 bool
-Ghoul::collision_squished(GameObject& object)
+Ghoul::collision_squished(MovingObject& object)
 {
   auto player = Sector::get().get_nearest_player(m_col.m_bbox);
   if (player)

src/badguy/ghoul.hpp

@@ -49,7 +49,7 @@ class Ghoul final : public BadGuy,
   void move_to(const Vector& pos) override;
 
 protected:
-  bool collision_squished(GameObject& object) override;
+  bool collision_squished(MovingObject& object) override;
   std::vector<Direction> get_allowed_directions() const override;
 
 private:

src/badguy/goldbomb.hpp

@@ -38,6 +38,8 @@ class GoldBomb final : public MrBomb
   virtual GameObjectClasses get_class_types() const override { return WalkingBadguy::get_class_types().add(typeid(GoldBomb)); }
   virtual bool is_snipable() const override { return true; }
 
+  int get_coins_worth() const override { return 10; }
+
   virtual void explode() override;
 
 private:

src/badguy/granito.cpp

@@ -208,7 +208,7 @@ Granito::collision_player(Player& player, const CollisionHit& hit)
 }
 
 HitResponse
-Granito::collision(GameObject& other, const CollisionHit& hit)
+Granito::collision(MovingObject& other, const CollisionHit& hit)
 {
   if (hit.top)
     m_col.propagate_movement(m_col.get_movement());
@@ -529,7 +529,7 @@ Granito::try_jump()
   else
   {
     auto result_obj = std::get_if<CollisionObject*>(&result.hit);
-    if (result_obj && !dynamic_cast<Granito*>(&(*result_obj)->get_listener()))
+    if (result_obj && !dynamic_cast<Granito*>(&(*result_obj)->get_parent()))
       return false;
   }
 

src/badguy/granito.hpp

@@ -44,7 +44,7 @@ class Granito : public WalkingBadguy
   virtual void active_update(float dt_sec) override;
 
   virtual HitResponse collision_player(Player& player, const CollisionHit& hit) override;
-  virtual HitResponse collision(GameObject& other, const CollisionHit& hit) override;
+  virtual HitResponse collision(MovingObject& other, const CollisionHit& hit) override;
 
   static std::string class_name() { return "granito"; }
   virtual std::string get_class_name() const override { return class_name(); }

src/badguy/haywire.cpp

@@ -64,7 +64,7 @@ Haywire::get_player_direction(const Player* player) const
 }
 
 bool
-Haywire::collision_squished(GameObject& object)
+Haywire::collision_squished(MovingObject& object)
 {
   if (m_frozen)
     return WalkingBadguy::collision_squished(object);

src/badguy/haywire.hpp

@@ -51,7 +51,7 @@ class Haywire final : public WalkingBadguy
   inline bool is_exploding() const { return m_is_exploding; }
 
 protected:
-  virtual bool collision_squished(GameObject& object) override;
+  virtual bool collision_squished(MovingObject& object) override;
   virtual void collision_solid(const CollisionHit& hit) override;
 
 private:

src/badguy/kamikazesnowball.cpp

@@ -40,7 +40,7 @@ KamikazeSnowball::initialize()
 }
 
 bool
-KamikazeSnowball::collision_squished(GameObject& object)
+KamikazeSnowball::collision_squished(MovingObject& object)
 {
   if (m_frozen)
     return BadGuy::collision_squished(object);
@@ -153,7 +153,7 @@ LeafShot::unfreeze(bool melt)
 }
 
 bool
-LeafShot::collision_squished(GameObject& object)
+LeafShot::collision_squished(MovingObject& object)
 {
   if (m_frozen)
     return BadGuy::collision_squished(object);

src/badguy/kamikazesnowball.hpp

@@ -37,7 +37,7 @@ class KamikazeSnowball : public BadGuy
   virtual bool is_snipable() const override { return true; }
 
 protected:
-  virtual bool collision_squished(GameObject& object) override;
+  virtual bool collision_squished(MovingObject& object) override;
   virtual HitResponse collision_player(Player& player, const CollisionHit& hit) override;
   virtual void kill_collision();
 
@@ -72,7 +72,7 @@ class LeafShot final : public KamikazeSnowball
   std::string get_default_sprite_name() const override;
 
 protected:
-  virtual bool collision_squished(GameObject& object) override;
+  virtual bool collision_squished(MovingObject& object) override;
 
 private:
   enum Type {

src/badguy/mole.cpp

@@ -69,7 +69,7 @@ Mole::collision_badguy(BadGuy& , const CollisionHit& )
 }
 
 bool
-Mole::collision_squished(GameObject& obj)
+Mole::collision_squished(MovingObject& obj)
 {
   set_state(DEAD);
 

src/badguy/mole.hpp

@@ -26,7 +26,7 @@ class Mole final : public BadGuy
 
   virtual void kill_fall() override;
   virtual HitResponse collision_badguy(BadGuy& , const CollisionHit& ) override;
-  virtual bool collision_squished(GameObject& object) override;
+  virtual bool collision_squished(MovingObject& object) override;
 
   virtual void activate() override;
   virtual void active_update(float) override;

src/badguy/mrbomb.cpp

@@ -75,7 +75,7 @@ MrBomb::collision_solid(const CollisionHit& hit)
 }
 
 HitResponse
-MrBomb::collision(GameObject& object, const CollisionHit& hit)
+MrBomb::collision(MovingObject& object, const CollisionHit& hit)
 {
   if (m_state == MB_STATE_TICKING)
   {
@@ -119,7 +119,7 @@ MrBomb::collision_badguy(BadGuy& badguy, const CollisionHit& hit)
 }
 
 bool
-MrBomb::collision_squished(GameObject& object)
+MrBomb::collision_squished(MovingObject& object)
 {
   if (m_frozen)
     return WalkingBadguy::collision_squished(object);

src/badguy/mrbomb.hpp

@@ -30,7 +30,7 @@ class MrBomb : public WalkingBadguy
          const std::string& glow_sprite = "images/creatures/mr_bomb/ticking_glow/ticking_glow.sprite");
 
   virtual void collision_solid(const CollisionHit& hit) override;
-  virtual HitResponse collision(GameObject& object, const CollisionHit& hit) override;
+  virtual HitResponse collision(MovingObject& object, const CollisionHit& hit) override;
   virtual HitResponse collision_player(Player& player, const CollisionHit& hit) override;
   virtual HitResponse collision_badguy(BadGuy& badguy, const CollisionHit& hit) override;
 
@@ -63,7 +63,7 @@ class MrBomb : public WalkingBadguy
 protected:
   void update_ticking(float dt_sec);
 
-  virtual bool collision_squished(GameObject& object) override;
+  virtual bool collision_squished(MovingObject& object) override;
 
 protected:
   enum State : uint8_t {