Empty-string anim queues are now allowed

Docs/Module-Dependencies-in-Luprex.md

@@ -14,23 +14,24 @@ the `.cpp` file (not the `.hpp`), it is marked **(cpp-only)**.
 - **debugcollector** → util
 - **streambuffer** → eng-malloc, luastack, util
 - **table** → luastack
-- **pprint** → luastack, table, util
-- **drivenengine** → enginewrapper, invocation, streambuffer, util
+- **keywords** → luastack, util(cpp-only)
+- **pprint** → luastack, table(cpp-only), util(cpp-only)
 - **json** → luastack, util
-- **http** → drivenengine, json(cpp-only), luastack, streambuffer
-- **planemap** → luastack, util
+- **invocation** → enginewrapper, streambuffer
+- **drivenengine** → enginewrapper, invocation, streambuffer, util, animqueue(cpp-only)
 - **luasnap** → luastack, streambuffer
 - **serializelua** → luastack, streambuffer
 - **sched** → luastack, streambuffer
 - **idalloc** → debugcollector, luastack, streambuffer
-- **invocation** → enginewrapper, streambuffer
-- **source** → debugcollector, luastack, luasnap, streambuffer, table(cpp-only), traceback, util
 - **animqueue** → debugcollector, luastack, streambuffer, util
 - **printbuffer** → debugcollector, invocation, streambuffer, util
-- **world** → animqueue, debugcollector, http, idalloc, invocation, luasnap, luastack, planemap, printbuffer, pprint, sched, serializelua, source, streambuffer, table, traceback
+- **source** → debugcollector, luastack, streambuffer, util, luasnap(cpp-only), table(cpp-only), traceback(cpp-only)
+- **planemap** → luastack, util
+- **http** → drivenengine, keywords, luastack, streambuffer, json(cpp-only), util(cpp-only)
+- **world** → animqueue, debugcollector, http, idalloc, invocation, luasnap, luastack, planemap, printbuffer, pprint(cpp-only), sched, serializelua(cpp-only), source, streambuffer, table(cpp-only), traceback(cpp-only)
 - **lpxclient** → drivenengine, invocation, printbuffer, util, world
 - **lpxserver** → drivenengine, luastack, printbuffer, util, world
-- **eng-tests** → drivenengine, streambuffer, world
+- **unit-testing** → drivenengine(cpp-only), streambuffer(cpp-only), traceback(cpp-only), world(cpp-only)
 
 ## Observations
 
@@ -38,20 +39,15 @@ the `.cpp` file (not the `.hpp`), it is marked **(cpp-only)**.
 
 `http.hpp` includes `drivenengine.hpp` because it uses
 `SharedChannel` (defined in drivenengine). Meanwhile, `world`
-depends on both `http` and `drivenengine`, and `drivenengine`
-depends on `world`. This creates a layering tangle:
+depends on both `http` and `drivenengine`, but `drivenengine` no
+longer depends on `world` (that circular dependency was broken).
+The remaining concern is that `SharedChannel` is an I/O concept
+from the driver boundary. Moving `SharedChannel` and `Channel`
+into a smaller, lower-level header (perhaps `enginewrapper.hpp`
+or a new `channel.hpp`) would let `http` drop its dependency on
+`drivenengine` entirely.
 
-```
-world -> http -> drivenengine -> world
-```
-
-The `SharedChannel` type (`std::shared_ptr<Channel>`) is really an
-I/O concept from the driver boundary. Moving `SharedChannel` and
-`Channel` into a smaller, lower-level header (perhaps
-`enginewrapper.hpp` or a new `channel.hpp`) would let `http` drop
-its dependency on `drivenengine` entirely.
-
-### world is a mega-consumer (16 dependencies)
+### world is a mega-consumer
 
 `world` depends on nearly every other module. This is expected for
 the central game-state container, but it does make `world` hard to

Source/Integration/AnimQueue.cpp

@@ -420,7 +420,15 @@ const FlxAnimationStep *FlxAnimTracker::FindAnimation(int64 hash) const
 }
 
 void FlxAnimTracker::Update(std::string_view encqueue) {
-	check(!encqueue.empty());
+	// An empty encqueue represents a blank queue: one step with hash=0, empty body.
+	//
+	if (encqueue.empty()) {
+		if (AQ.Num() == 1 && AQ[0].Hash == 0) return;
+		Changed = true;
+		AQ.Empty();
+		AQ.Emplace(0, std::string_view());
+		return;
+	}
 
 	// If the first hash matches, we don't bother updating at all.
 	//

luprex/cpp/core/animqueue.cpp

@@ -12,13 +12,6 @@
 #include <cstdlib>
 
 
-util::SharedStdString AnimQueue::blankqueue_;
-
-void AnimQueue::initialize_module() {
-    AnimQueue queue;
-    blankqueue_ = queue.get_encoded_queue();
-}
-
 static int64_t hash_encstep(int64_t prev, std::string_view s) {
     // We drop the most significant bit to ensure that the value
     // can be represented as a nonnegative int64.

luprex/cpp/core/animqueue.hpp

@@ -364,17 +364,6 @@ public:
     //
     util::SharedStdString get_encoded_queue() const { return encqueue_; }
 
-    // Get a serialized representation of a blank queue.
-    //
-    // Since an animqueue must have at least one step, the blank queue
-    // contains a single default step.
-    //
-    static util::SharedStdString get_encoded_blank_queue() { return blankqueue_; }
-
-    // Initialize the animqueue module.
-    //
-    static void initialize_module();
-    
 private:
     struct QueueRange {
         int size;
@@ -425,9 +414,6 @@ private:
     //
     util::SharedStdString encqueue_;
 
-    // The blank animation queue.
-    //
-    static util::SharedStdString blankqueue_;
 };
 
 

luprex/cpp/core/drivenengine.cpp

@@ -852,10 +852,9 @@ static void default_get_tangibles_near(EngineWrapper *, uint64_t, double, double
 }
 
 static void default_get_animation_queues(EngineWrapper *, uint32_t count, const int64_t *, uint32_t *lengths, const char **strings) {
-    util::SharedStdString blank = AnimQueue::get_encoded_blank_queue();
     for (int i = 0; i < int(count); i++) {
-        lengths[i] = blank->size();
-        strings[i] = blank->c_str();
+        lengths[i] = 0;
+        strings[i] = "";
     }
 }
 

luprex/cpp/core/world-core.cpp

@@ -1264,7 +1264,6 @@ void World::rollback() {
 // 
 void engine_initialization() {
     SourceDB::register_lua_builtins();
-    AnimQueue::initialize_module();
 }
 
 static DrivenEngineInitializerReg eireg(engine_initialization);
@@ -1280,13 +1279,15 @@ void World::get_animation_queues(uint32_t count, const int64_t *ids, uint32_t *l
     for (int i = 0; i < int(count); i++) {
         Tangible *tan = tangible_get(ids[i]);
         if (tan == nullptr) {
-            wrapper_anim_queues_[i] = AnimQueue::get_encoded_blank_queue();
+            wrapper_anim_queues_[i] = nullptr;
+            lengths[i] = 0;
+            strings[i] = "";
         } else {
             wrapper_anim_queues_[i] = tan->anim_queue_.get_encoded_queue();
-        }
             lengths[i] = wrapper_anim_queues_[i]->size();
             strings[i] = wrapper_anim_queues_[i]->c_str();
         }
+    }
 }
 
 void World::get_tangibles_near(uint64_t tanid, double rx, double ry, double rz, uint32_t *count, int64_t **ids) {