unlink existing parent when linking

src/entity.c

@@ -294,11 +294,15 @@ void entity_set_local_xform(struct entity *ent, struct xform xf)
  * Tree
  * ========================== */
 
-/* FIXME: Unlink existing */
 void entity_link_parent(struct entity *ent, struct entity *parent)
 {
     struct entity_store *store = entity_get_store(ent);
 
+    if (ent->parent.gen) {
+        /* Unlink from current parent */
+        entity_unlink_parent(ent);
+    }
+
     struct entity_handle handle = ent->handle;
     struct entity_handle parent_handle = parent->handle;
 

src/entity.h

@@ -49,20 +49,19 @@ struct entity_store {
 };
 
 struct entity {
+    /* ====================================================================== */
     /* Metadata */
+
     b32 valid;  /* Is this entity allocated in memory that can be written to (can always be read) */
     struct entity_handle handle;
     u64 continuity_gen;
     u64 props[(ENTITY_PROP_COUNT + 63) / 64];
     struct entity_handle next_free;
 
-    /* Special value stored in first entity in store array */
-    u64 store_offset;
-
     /* Is this the root entity */
     b32 is_root;
 
-    /* Is the parent the root entity */
+    /* Is entity a child of the root entity */
     b32 is_top;
 
     /* Tree */

src/game.c

@@ -530,7 +530,7 @@ INTERNAL void game_update(struct game_cmd_array game_cmds)
                 bullet->bullet_src = ent->handle;
                 bullet->bullet_src_pos = rel_pos;
                 bullet->bullet_src_dir = rel_dir;
-                bullet->bullet_impulse = 100;
+                bullet->bullet_impulse = 5;
 
                 entity_enable_prop(bullet, ENTITY_PROP_BULLET);
             }
@@ -618,14 +618,14 @@ INTERNAL void game_update(struct game_cmd_array game_cmds)
 
         if (entity_has_prop(ent, ENTITY_PROP_KINEMATIC)) {
             f32 dt = (f32)G.tick.dt;
-
-            /* Apply acceleration to velocity */
-            struct v2 a = v2_mul(ent->acceleration, dt);
-            ent->velocity = v2_add(ent->velocity, a);
-
-            /* Apply velocity to position */
             struct xform xf = entity_get_xform(ent);
+
+            /* Integrate acceleration to find velocity */
+            ent->velocity = v2_add(ent->velocity, v2_mul(ent->acceleration, dt));
+
+            /* Integrate velocity to find position */
             xf.og = v2_add(xf.og, v2_mul(ent->velocity, dt));
+
             entity_set_xform(ent, xf);
         }
     }