game tick continuity gen. start removing static constraint lookup

src/entity.c

@@ -77,21 +77,6 @@ void entity_store_copy_replace(struct entity_store *dest, struct entity_store *s
     dest->entities = dest_entities;
 }
 
-void entity_store_release_all_entities(struct entity_store *store)
-{
-#if 0
-    store->allocated = 0;
-    store->reserved = 0;
-    store->first_free = entity_nil_handle();
-    arena_pop_to(&store->arena, STORE_ENTITIES_OFFSET);
-    store_make_root(store);
-#else
-    struct entity *root = entity_from_handle(store, store->root);
-    entity_release(store, root);
-    store_make_root(store);
-#endif
-}
-
 /* ========================== *
  * Allocation
  * ========================== */

src/entity.h

@@ -436,7 +436,6 @@ INLINE b32 entity_is_valid_and_active(struct entity *ent)
 struct entity_store *entity_store_alloc(void);
 void entity_store_release(struct entity_store *store);
 void entity_store_copy_replace(struct entity_store *dest, struct entity_store *src);
-void entity_store_release_all_entities(struct entity_store *store);
 
 /* Entity */
 struct entity *entity_alloc(struct entity *parent);

src/game.c

@@ -24,6 +24,7 @@ GLOBAL struct {
 
     /* TODO: Remove this (testing) */
     b32 extra_spawn;
+    b32 should_reset_level;
 
     /* Game thread input */
     struct sys_mutex game_cmds_mutex;
@@ -39,6 +40,7 @@ GLOBAL struct {
     /* Ticks */
     struct sys_mutex prev_tick_mutex;
     struct atomic_u64 prev_tick_id;
+    struct atomic_u64 prev_tick_continuity_gen;
     struct world prev_tick;
     struct world tick;
 } G = ZI, DEBUG_ALIAS(G, G_game);
@@ -49,6 +51,7 @@ GLOBAL struct {
 
 INTERNAL APP_EXIT_CALLBACK_FUNC_DEF(game_shutdown);
 INTERNAL SYS_THREAD_ENTRY_POINT_FUNC_DEF(game_thread_entry_point, arg);
+INTERNAL void reset_world(void);
 
 struct game_startup_receipt game_startup(struct mixer_startup_receipt *mixer_sr,
                                          struct sprite_startup_receipt *sheet_sr,
@@ -79,14 +82,15 @@ struct game_startup_receipt game_startup(struct mixer_startup_receipt *mixer_sr,
     G.game_cmds_mutex = sys_mutex_alloc();
     G.game_cmds_arena = arena_alloc(GIGABYTE(64));
 
-    /* Initialize ticks */
-    world_alloc(&G.tick);
+    /* Initialize empty world */
+    reset_world();
+
+    /* Initialize prev tick */
     world_alloc(&G.prev_tick);
     /* FIXME: Make the world struct itself readonly as well */
     arena_set_readonly(&G.prev_tick.entity_store->arena);
     G.prev_tick_mutex = sys_mutex_alloc();
 
-    G.tick.timescale = GAME_TIMESCALE;
     G.game_thread = sys_thread_alloc(&game_thread_entry_point, NULL, STR("[P2] Game thread"));
     app_register_exit_callback(&game_shutdown);
 
@@ -139,6 +143,22 @@ INTERNAL void activate_now(struct entity *ent)
     ++ent->continuity_gen;
 }
 
+/* ========================== *
+ * Reset
+ * ========================== */
+
+INTERNAL void reset_world(void)
+{
+    if (G.tick.entity_store) {
+        /* Release world */
+        world_release(&G.tick);
+    }
+    /* Re-create world */
+    world_alloc(&G.tick);
+    G.tick.continuity_gen = atomic_u64_eval(&G.prev_tick_continuity_gen) + 1;
+    G.tick.timescale = GAME_TIMESCALE;
+}
+
 /* ========================== *
  * Test
  * ========================== */
@@ -206,8 +226,7 @@ INTERNAL void spawn_test_entities(f32 offset)
         entity_set_xform(e, xf);
 
 
-        e->linear_ground_friction = 250;
-        e->angular_ground_friction = 200;
+        e->linear_ground_friction = 250;e->angular_ground_friction = 200;
 
         //e->control_force = 500;
         e->control_force = 500;
@@ -1351,6 +1370,7 @@ INTERNAL void publish_game_tick(void)
     }
     arena_set_readonly(&G.prev_tick.entity_store->arena);
     atomic_u64_eval_exchange(&G.prev_tick_id, G.prev_tick.tick_id);
+    atomic_u64_eval_exchange(&G.prev_tick_continuity_gen, G.prev_tick.continuity_gen);
     sys_mutex_unlock(&lock);
 }
 
@@ -1360,6 +1380,17 @@ INTERNAL void game_update(struct game_cmd_array game_cmds)
 
     struct temp_arena scratch = scratch_begin_no_conflict();
 
+    /* ========================== *
+     * Reset level if necessary
+     * ========================== */
+
+    if (G.should_reset_level) {
+        logf_info("Clearing level");
+        G.should_reset_level = false;
+        G.extra_spawn = false;
+        reset_world();
+    }
+
     /* ========================== *
      * Begin frame
      * ========================== */
@@ -1412,9 +1443,7 @@ INTERNAL void game_update(struct game_cmd_array game_cmds)
             /* Clear level */
             case GAME_CMD_KIND_CLEAR_ALL:
             {
-                logf_info("Clearing level");
-                entity_store_release_all_entities(store);
-                G.extra_spawn = false;
+                G.should_reset_level = true;
             } break;
 
             /* Spawn test */
@@ -2235,6 +2264,11 @@ u64 game_get_latest_tick_id(void)
     return atomic_u64_eval(&G.prev_tick_id);
 }
 
+u64 game_get_latest_tick_continuity_gen(void)
+{
+    return atomic_u64_eval(&G.prev_tick_continuity_gen);
+}
+
 void game_push_cmds(struct game_cmd_array cmd_array)
 {
     push_cmds(cmd_array);

src/game.h

@@ -57,6 +57,7 @@ struct game_startup_receipt game_startup(struct mixer_startup_receipt *mixer_sr,
 
 void game_get_latest_tick(struct world *dest);
 u64 game_get_latest_tick_id(void);
+u64 game_get_latest_tick_continuity_gen(void);
 
 void game_push_cmds(struct game_cmd_array cmd_array);
 

src/user.c

@@ -255,6 +255,9 @@ INTERNAL struct interp_ticks pull_ticks(f64 blend_time)
         }
     }
 
+    struct world *from_tick;
+    struct world *to_tick;
+    if (newest_tick && game_get_latest_tick_continuity_gen() == newest_tick->continuity_gen) {
         /* Pull new tick from game thread if necessary */
         if (!newest_tick || game_get_latest_tick_id() > newest_tick->tick_id) {
             struct blend_tick *latest_bt = blend_tick_alloc();
@@ -271,8 +274,8 @@ INTERNAL struct interp_ticks pull_ticks(f64 blend_time)
         }
 
         /* Find closest ticks to blend time */
-    struct world *from_tick = oldest_tick;
-    struct world *to_tick = newest_tick;
+        from_tick = oldest_tick;
+        to_tick = newest_tick;
         for (struct blend_tick *bt = G.head_blend_tick; bt; bt = bt->next) {
             f64 bt_time = sys_timestamp_seconds(bt->world.tick_ts);
 
@@ -305,6 +308,33 @@ INTERNAL struct interp_ticks pull_ticks(f64 blend_time)
 
             scratch_end(scratch);
         }
+    } else {
+        /* Latest tick is discontinuous */
+
+        /* Free all blend ticks */
+        {
+            struct temp_arena scratch = scratch_begin_no_conflict();
+            struct blend_tick **bts_to_free = arena_dry_push(scratch.arena, struct blend_tick *);
+            u64 bts_to_free_count = 0;
+            for (struct blend_tick *bt = G.head_blend_tick; bt; bt = bt->next) {
+                *arena_push(scratch.arena, struct blend_tick *) = bt;
+                ++bts_to_free_count;
+            }
+            for (u64 i = 0; i < bts_to_free_count; ++i) {
+                blend_tick_release(bts_to_free[i]);
+            }
+            scratch_end(scratch);
+        }
+
+        /* Allocate new blend tick */
+        struct blend_tick *bt = blend_tick_alloc();
+        struct world *tick = &bt->world;
+        game_get_latest_tick(tick);
+
+        from_tick = tick;
+        to_tick = tick;
+    }
+
 
     return (struct interp_ticks) {
         .from_tick = from_tick,

src/world.h

@@ -4,6 +4,7 @@
 #include "entity.h"
 
 struct world {
+    u64 continuity_gen;     /* Starts at 1 */
     u64 tick_id;            /* Starts at 1 */
     u64 tick_ts;            /* When was this tick simulated in program time */