add entity events: on_spawn, on_despawn

res/content/base/scripts/drop.lua

@@ -0,0 +1,7 @@
+function on_spawn(eid)
+    print("spawn", eid)
+end
+
+function on_despawn(eid)
+    print("despawn", eid)
+end

src/content/ContentLoader.cpp

@@ -321,6 +321,11 @@ void ContentLoader::loadEntity(EntityDef& def, const std::string& full, const st
     auto folder = pack->folder;
     auto configFile = folder/fs::path("entities/"+name+".json");
     if (fs::exists(configFile)) loadEntity(def, full, configFile);
+
+    auto scriptfile = folder/fs::path("scripts/"+def.scriptName+".lua");
+    if (fs::is_regular_file(scriptfile)) {
+        scripting::load_entity_script(env, full, scriptfile, def.rt.funcsset);
+    }
 }
 
 void ContentLoader::loadBlock(Block& def, const std::string& full, const std::string& name) {

src/logic/scripting/scripting.cpp

@@ -13,6 +13,8 @@
 #include "../../logic/BlocksController.hpp"
 #include "../../logic/LevelController.hpp"
 #include "../../objects/Player.hpp"
+#include "../../objects/EntityDef.hpp"
+#include "../../objects/Entities.hpp"
 #include "../../util/stringutil.hpp"
 #include "../../util/timeutil.hpp"
 #include "../../util/timeutil.hpp"
@@ -225,6 +227,22 @@ bool scripting::on_item_break_block(Player* player, const ItemDef* item, int x,
     });
 }
 
+bool scripting::on_entity_spawn(const EntityDef& def, entityid_t eid) {
+    std::string name = def.name + ".spawn";
+    return lua::emit_event(lua::get_main_thread(), name, [eid] (auto L) {
+        lua::pushinteger(L, eid);
+        return 1;
+    });
+}
+
+bool scripting::on_entity_despawn(const EntityDef& def, entityid_t eid) {
+    std::string name = def.name + ".despawn";
+    return lua::emit_event(lua::get_main_thread(), name, [eid] (auto L) {
+        lua::pushinteger(L, eid);
+        return 1;
+    });
+}
+
 void scripting::on_ui_open(
     UiDocument* layout,
     std::vector<dynamic::Value> args
@@ -308,6 +326,14 @@ void scripting::load_item_script(const scriptenv& senv, const std::string& prefi
     funcsset.on_block_break_by = register_event(env, "on_block_break_by", prefix+".blockbreakby");
 }
 
+void scripting::load_entity_script(const scriptenv& senv, const std::string& prefix, const fs::path& file, entity_funcs_set& funcsset) {
+    int env = *senv;
+    load_script(env, "entity", file);
+    funcsset.init = register_event(env, "init", prefix+".init");
+    funcsset.on_spawn = register_event(env, "on_spawn", prefix+".spawn");
+    funcsset.on_despawn = register_event(env, "on_despawn", prefix+".despawn");
+}
+
 void scripting::load_world_script(const scriptenv& senv, const std::string& prefix, const fs::path& file) {
     int env = *senv;
     load_script(env, "world", file);

src/logic/scripting/scripting.hpp

@@ -27,9 +27,12 @@ class Inventory;
 class UiDocument;
 struct block_funcs_set;
 struct item_funcs_set;
+struct entity_funcs_set;
 struct uidocscript;
 class BlocksController;
 class LevelController;
+class Entity;
+struct EntityDef;
 
 namespace scripting {
     extern Engine* engine;
@@ -73,6 +76,10 @@ namespace scripting {
     /// @return true if prevents default action
     bool on_item_break_block(Player* player, const ItemDef* item, int x, int y, int z);
 
+    bool on_entity_spawn(const EntityDef& def, entityid_t eid);
+
+    bool on_entity_despawn(const EntityDef& def, entityid_t eid);
+
     /// @brief Called on UI view show
     void on_ui_open(
         UiDocument* layout, 
@@ -89,14 +96,28 @@ namespace scripting {
     /// @param prefix pack id
     /// @param file item script file
     /// @param funcsset block callbacks set
-    void load_block_script(const scriptenv& env, const std::string& prefix, const fs::path& file, block_funcs_set& funcsset);
+    void load_block_script(
+        const scriptenv& env, 
+        const std::string& prefix,
+        const fs::path& file,
+        block_funcs_set& funcsset);
 
     /// @brief Load script associated with an Item
     /// @param env environment
     /// @param prefix pack id
     /// @param file item script file
     /// @param funcsset item callbacks set
-    void load_item_script(const scriptenv& env, const std::string& prefix, const fs::path& file, item_funcs_set& funcsset);
+    void load_item_script(
+        const scriptenv& env,
+        const std::string& prefix,
+        const fs::path& file, 
+        item_funcs_set& funcsset);
+
+    void load_entity_script(
+        const scriptenv& env,
+        const std::string& prefix,
+        const fs::path& file,
+        entity_funcs_set& funcsset);
     
     /// @brief Load package-specific world script 
     /// @param env environment

src/objects/Entities.cpp

@@ -9,6 +9,7 @@
 #include "../graphics/core/Model.hpp"
 #include "../maths/FrustumCulling.hpp"
 #include "../objects/EntityDef.hpp"
+#include "../logic/scripting/scripting.hpp"
 
 #include <glm/ext/matrix_transform.hpp>
 
@@ -19,6 +20,12 @@ void Transform::refresh() {
     combined = combined * glm::mat4(rot);
 }
 
+void Entity::destroy() {
+    if (isValid()){
+        entities.despawn(id);
+    }
+}
+
 Entities::Entities(Level* level) : level(level) {
 }
 
@@ -26,13 +33,23 @@ entityid_t Entities::spawn(EntityDef& def, glm::vec3 pos) {
     auto entity = registry.create();
     glm::vec3 size(1);
     auto id = nextID++;
-    registry.emplace<EntityId>(entity, static_cast<entityid_t>(id));
+    registry.emplace<EntityId>(entity, static_cast<entityid_t>(id), def);
     registry.emplace<Transform>(entity, pos, size/4.0f, glm::mat3(1.0f));
     registry.emplace<Rigidbody>(entity, true, Hitbox {pos, def.hitbox});
     entities[id] = entity;
+    if (def.rt.funcsset.on_spawn) {
+        scripting::on_entity_spawn(def, id);
+    }
     return id;
 }
 
+void Entities::despawn(entityid_t id) {
+    if (auto entity = get(id)) {
+        scripting::on_entity_despawn(entity->getDef(), id);
+        registry.destroy(get(id)->getHandler());
+    }
+}
+
 void Entities::clean() {
     for (auto it = entities.begin(); it != entities.end();) {
         if (registry.valid(it->second)) {
@@ -60,7 +77,7 @@ void Entities::updatePhysics(float delta){
             1.0f,
             true
         );
-        hitbox.linear_damping = hitbox.grounded * 12;
+        hitbox.linearDamping = hitbox.grounded * 12;
         transform.pos = hitbox.position;
         //transform.rot = glm::rotate(glm::mat4(transform.rot), delta, glm::vec3(0, 1, 0));
         if (hitbox.grounded) {

src/objects/Entities.hpp

@@ -9,8 +9,11 @@
 #include <unordered_map>
 #include <entt/entity/registry.hpp>
 
+struct EntityDef;
+
 struct EntityId {
     entityid_t uid;
+    const EntityDef& def;
 };
 
 struct Transform {
@@ -33,15 +36,16 @@ class LineBatch;
 class ModelBatch;
 class Frustum;
 class Rig;
-struct EntityDef;
+class Entities;
 
 class Entity {
+    Entities& entities;
     entityid_t id;
     entt::registry& registry;
     const entt::entity entity;
 public:
-    Entity(entityid_t id, entt::registry& registry, const entt::entity entity)
-    : id(id), registry(registry), entity(entity) {}
+    Entity(Entities& entities, entityid_t id, entt::registry& registry, const entt::entity entity)
+    : entities(entities), id(id), registry(registry), entity(entity) {}
 
     entityid_t getID() const {
         return id;
@@ -51,6 +55,10 @@ public:
         return registry.valid(entity);
     }
 
+    const EntityDef& getDef() const {
+        return registry.get<EntityId>(entity).def;
+    }
+
     Transform& getTransform() const {
         return registry.get<Transform>(entity);
     }
@@ -63,9 +71,11 @@ public:
         return registry.get<EntityId>(entity).uid;
     }
 
-    void destroy() {
-        registry.destroy(entity);
+    entt::entity getHandler() const {
+        return entity;
     }
+
+    void destroy();
 };
 
 class Entities {
@@ -86,11 +96,13 @@ public:
     std::optional<Entity> get(entityid_t id) {
         const auto& found = entities.find(id);
         if (found != entities.end() && registry.valid(found->second)) {
-            return Entity(id, registry, found->second);
+            return Entity(*this, id, registry, found->second);
         }
         return std::nullopt;
     }
 
+    void despawn(entityid_t id);
+
     inline size_t size() const {
         return entities.size();
     }

src/objects/EntityDef.hpp

@@ -6,6 +6,12 @@
 
 #include "../typedefs.hpp"
 
+struct entity_funcs_set {
+    bool init : 1;
+    bool on_spawn : 1;
+    bool on_despawn : 1;
+};
+
 struct EntityDef {
     /// @brief Entity string id (with prefix included)
     std::string const name;
@@ -15,6 +21,7 @@ struct EntityDef {
     
     struct {
         entityid_t id;
+        entity_funcs_set funcsset;
     } rt;
     
     EntityDef(const std::string& name) : name(name) {}

src/objects/Player.cpp

@@ -110,9 +110,9 @@ void Player::updateInput(
         noclip = !noclip;
     }
 
-    hitbox->linear_damping = PLAYER_GROUND_DAMPING;
+    hitbox->linearDamping = PLAYER_GROUND_DAMPING;
     if (flight){
-        hitbox->linear_damping = PLAYER_AIR_DAMPING;
+        hitbox->linearDamping = PLAYER_AIR_DAMPING;
         hitbox->velocity.y *= 1.0f - delta * 9;
         if (input.jump){
             hitbox->velocity.y += speed * delta * 9;
@@ -122,7 +122,7 @@ void Player::updateInput(
         }
     }
     if (!hitbox->grounded) {
-        hitbox->linear_damping = PLAYER_AIR_DAMPING;
+        hitbox->linearDamping = PLAYER_AIR_DAMPING;
     }
 
     input.noclip = false;

src/objects/Player.hpp

@@ -11,10 +11,10 @@
 #include <glm/glm.hpp>
 
 class Camera;
-class Hitbox;
 class Inventory;
 class ContentLUT;
 class Level;
+struct Hitbox;
 struct EngineSettings;
 
 struct PlayerInput {

src/physics/Hitbox.cpp

@@ -4,5 +4,5 @@ Hitbox::Hitbox(glm::vec3 position, glm::vec3 halfsize)
   : position(position), 
     halfsize(halfsize), 
     velocity(0.0f,0.0f,0.0f), 
-    linear_damping(0.1f) 
+    linearDamping(0.1f) 
 {}

src/physics/Hitbox.hpp

@@ -3,12 +3,11 @@
 
 #include <glm/glm.hpp>
 
-class Hitbox {
-public:
+struct Hitbox {
     glm::vec3 position;
     glm::vec3 halfsize;
     glm::vec3 velocity;
-    float linear_damping;
+    float linearDamping;
     bool grounded = false;
 
     Hitbox(glm::vec3 position, glm::vec3 halfsize);

src/physics/PhysicsSolver.cpp

@@ -22,7 +22,7 @@ void PhysicsSolver::step(
     bool collisions
 ) {
     float dt = delta / static_cast<float>(substeps);
-    float linear_damping = hitbox->linear_damping;
+    float linearDamping = hitbox->linearDamping;
     float s = 2.0f/BLOCK_AABB_GRID;
 
     const glm::vec3& half = hitbox->halfsize;
@@ -41,8 +41,8 @@ void PhysicsSolver::step(
             colisionCalc(chunks, hitbox, vel, pos, half, 
                          (prevGrounded && gravityScale > 0.0f) ? 0.5f : 0.0f);
         }
-        vel.x *= glm::max(0.0f, 1.0f - dt * linear_damping);
-        vel.z *= glm::max(0.0f, 1.0f - dt * linear_damping);
+        vel.x *= glm::max(0.0f, 1.0f - dt * linearDamping);
+        vel.z *= glm::max(0.0f, 1.0f - dt * linearDamping);
 
         pos += vel * dt + gravity * gravityScale * dt * dt * 0.5f;
         if (hitbox->grounded && pos.y < py) {

src/physics/PhysicsSolver.hpp

@@ -7,8 +7,8 @@
 #include <glm/glm.hpp>
 
 class Block;
-class Hitbox;
 class Chunks;
+struct Hitbox;
 
 class PhysicsSolver {
     glm::vec3 gravity;