add entity event: on_grounded

res/content/base/scripts/drop.lua

@@ -5,3 +5,7 @@ end
 function on_despawn(eid)
     print("despawn", eid)
 end
+
+function on_grounded(eid)
+    Transform.set_rot(eid, mat4.rotate({0, 1, 0}, math.random()*360))
+end

res/content/base/scripts/hud.lua

@@ -9,6 +9,8 @@ function on_hud_open()
         local eid = entity.spawn("base:drop", ppos)
         local throw_force = vec3.mul(player.get_dir(pid), DROP_FORCE)
         Rigidbody.set_vel(eid, vec3.add(throw_force, vec3.add(pvel, DROP_INIT_VEL)))
-        Transform.set_rot(eid, mat4.rotate({0, 1, 0}, math.random() * 360))
+        Transform.set_rot(eid, 
+            mat4.rotate(mat4.rotate(mat4.rotate({0, 1, 0}, math.random() * 360), 
+            {1, 0, 0}, math.random() * 360), {0, 0, 1}, math.random() * 360))
     end)
 end

src/logic/scripting/scripting.cpp

@@ -243,6 +243,14 @@ bool scripting::on_entity_despawn(const EntityDef& def, entityid_t eid) {
     });
 }
 
+bool scripting::on_entity_grounded(const EntityDef& def, entityid_t eid) {
+    std::string name = def.name + ".grounded";
+    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
@@ -332,6 +340,7 @@ void scripting::load_entity_script(const scriptenv& senv, const std::string& pre
     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");
+    funcsset.on_grounded = register_event(env, "on_grounded", prefix+".grounded");
 }
 
 void scripting::load_world_script(const scriptenv& senv, const std::string& prefix, const fs::path& file) {

src/logic/scripting/scripting.hpp

@@ -77,8 +77,8 @@ namespace scripting {
     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);
+    bool on_entity_grounded(const EntityDef& def, entityid_t eid);
 
     /// @brief Called on UI view show
     void on_ui_open(

src/objects/Entities.cpp

@@ -61,13 +61,14 @@ void Entities::clean() {
 }
 
 void Entities::updatePhysics(float delta){
-    auto view = registry.view<Transform, Rigidbody>();
+    auto view = registry.view<EntityId, Transform, Rigidbody>();
     auto physics = level->physics.get();
-    for (auto [entity, transform, rigidbody] : view.each()) {
+    for (auto [entity, eid, transform, rigidbody] : view.each()) {
         if (!rigidbody.enabled) {
             continue;
         }
         auto& hitbox = rigidbody.hitbox;
+        bool grounded = hitbox.grounded;
         physics->step(
             level->chunks.get(),
             &hitbox,
@@ -80,8 +81,8 @@ void Entities::updatePhysics(float delta){
         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) {
-            //hitbox.velocity.y = 10;
+        if (hitbox.grounded && !grounded) {
+            scripting::on_entity_grounded(eid.def, eid.uid);
         }
     }
 }

src/objects/Entities.hpp

@@ -85,6 +85,7 @@ class Entities {
     entityid_t nextID = 1;
 public:
     Entities(Level* level);
+
     void clean();
     void updatePhysics(float delta);
 

src/objects/EntityDef.hpp

@@ -10,6 +10,7 @@ struct entity_funcs_set {
     bool init : 1;
     bool on_spawn : 1;
     bool on_despawn : 1;
+    bool on_grounded : 1;
 };
 
 struct EntityDef {