redirect code in place

luprex/cpp/core/lpxserver.cpp

@@ -89,7 +89,29 @@ public:
         sb->overwrite_int32(tw_1, tw_2 - tw_1);
     }
 
+    void redirect(int64_t id1, int64_t id2) {
+        for (auto &client : clients_) {
+            if (client->actor_id_ == id1) {
+                bool ok = world_->redirected(id1, id2);
+                if (!ok) delete_client(client);
+            }
+        }
+    }
+
+    // Redirection is touchy: almost any world->invoke could
+    // call tangible.redirect.  After that point, the world is
+    // relying on us not to control the wrong character.
+    void process_redirects() {
+        if (world_->have_redirects()) {
+            World::Redirects redirects = world_->fetch_redirects();
+            for (const auto &pair : redirects) {
+                redirect(pair.first, pair.second);
+            }
+        }
+    }
+
     bool handle_invocation(UniqueClient &client) {
+        if (client == nullptr) return false;
         StreamBuffer *sb = client->channel_->in();
         if (sb->empty()) return false;
         int64_t tr_before = sb->total_reads();
@@ -131,6 +153,7 @@ public:
         //
         if (inv.actor() == client->actor_id_) {
             world_->invoke(inv);
+            process_redirects();
         }
         return true;
     }
@@ -183,8 +206,9 @@ public:
         // Get the clock.
         double clock = get_clock();
 
-        // Execute any queued invocations.
-        // We just feed these directly into the master model.
+        // Execute any delayed invocations.  These always
+        // come from the local command line. We just feed
+        // these directly into the master model.
         for (const Invocation &inv : delayed_invocations_) {
             world_->invoke(inv);
         }
@@ -225,6 +249,11 @@ public:
             if (next_tick_ < clock + 0.3) next_tick_ = clock + 0.3;
         }
 
+        // This handles any redirects triggered from the server command
+        // line or by the tick function.
+        process_redirects();
+        util::remove_nullptrs(clients_);
+
         // Traverse all existing channels, process any communication.
         for (UniqueClient &client : clients_) {
             if (client->channel_->closed()) {

luprex/cpp/core/world-accessor.cpp

@@ -282,8 +282,8 @@ LuaDefine(tangible_getclass, "tan",
 LuaDefine(tangible_delete, "tan", 
     "|Delete the specified tangible."
     "|"
-    "|This cannot be used to delete player tangibles,"
-    "|To delete a player, use tangible.redirect"
+    "|This cannot be used to delete actor tangibles,"
+    "|To delete a actor, use tangible.deleteactor"
     "|") {
     LuaArg tanobj;
     LuaDefStack LS(L, tanobj);
@@ -332,14 +332,16 @@ LuaDefine(tangible_deleteactor, "tan",
 LuaDefine(tangible_keepactor, "tan",
     "|Mark an actor tangible to not 'delete_on_disconnect'."
     "|"
-    "|When a client connects to the server, a login actor is created and the"
-    "|client is put in control of the login actor.  The client typically"
-    "|controls the login actor just long enough to type his username and password."
-    "|Then, he is redirected to the real actor."
+    "|When a client connects to the server, a new 'login' actor is "
+    "|created and the client is put in control of the login actor. "
+    "|The login actor typically presents a login dialog.  After the "
+    "|client types his name and password, tangible.redirect is used "
+    "|to tell the client to control the real actor."
     "|"
-    "|When the client is redirected to the real actor, the login actor is no longer"
-    "|needed.  The login actor has the flag 'delete_on_disconnect', so when the"
-    "|client detaches from the login actor, it is garbage collected."
+    "|When the client is redirected to the real actor, the login "
+    "|actor is no longer needed.  The login actor has the "
+    "|flag 'delete_on_disconnect', so when the client detaches "
+    "|from the login actor, it is garbage collected."
     "|"
     "|However, if the player clicks 'NEW PLAYER', then it is necessary to"
     "|convert the login actor into a permanent actor.  The most important step is to"
@@ -357,6 +359,38 @@ LuaDefine(tangible_keepactor, "tan",
     return LS.result();
 }
 
+LuaDefine(tangible_redirect, "actor1, actor2",
+    "|Cause the client controlling actor1 to take a control of actor2"
+    "|"
+    "|When a client connects to the server, a new 'login' actor is "
+    "|created and the client is put in control of the login actor. "
+    "|The login actor typically presents a login dialog.  After the "
+    "|client types his name and password, tangible.redirect is used "
+    "|to tell the client to control the real actor."
+    "|"
+    "|Actor1 must be currently logged in.  Actor2 must not be.  This "
+    "|function doesn't error check that the actors are valid: it just "
+    "|queues the redirect, then the system error checks later.  This "
+    "|is because conditions can change.  An invalid redirect will cause "
+    "|a disconnection."
+    "|") {
+    LuaArg lactor1, lactor2;
+    LuaDefStack LS(L, lactor1, lactor2);
+    World *w = World::fetch_global_pointer(L);
+    Tangible *actor1 = w->tangible_get(LS, lactor1, true);
+    Tangible *actor2 = w->tangible_get(LS, lactor2, true);
+    if (!actor1->is_controlled_) {
+        luaL_error(L, "Actor1 is not a controlled actor.");
+        return 0;
+    }
+    if ((!actor2->can_be_controlled_) || (actor2->is_controlled_)) {
+        luaL_error(L, "Actor2 is not an uncontrolled actor.");
+        return 0;
+    }
+    w->add_redirect(actor1->id(), actor2->id());
+    return LS.result();
+}
+
 LuaDefine(tangible_build, "config",
     "|Build a new tangible object."
     "|"

luprex/cpp/core/world-core.cpp

@@ -345,6 +345,17 @@ void World::disconnected(int64_t actor_id) {
     }
 }
 
+bool World::redirected(int64_t actor_id, int64_t new_id) {
+    disconnected(actor_id);
+    Tangible *tan = tangible_get(new_id);
+    if (tan && (tan->can_be_controlled_) && (!tan->is_controlled_)) {
+        tan->is_controlled_ = true;
+        return true;
+    } else {
+        return false;
+    }
+}
+
 eng::string World::probe_lua_expr(int64_t actor_id, std::string_view lua) {
     assert(stack_is_clear());
     lua_State *L = state();

luprex/cpp/core/world.hpp

@@ -243,10 +243,24 @@ public:
     //
     void disconnected(int64_t actor_id);
 
+    // Notify the world that the front end has implemented a
+    // redirect.  This can return null to indicate a last-minute
+    // failure, in which case the front end must disconnect.
+    //
+    bool redirected(int64_t actor_id, int64_t new_id);
+    
+    // Add a redirect.
+    //
+    void add_redirect(int64_t a, int64_t b) { redirects_.emplace(a,b); }
+    
     // Fetch all redirects and clear the redirects table.
     //
     Redirects fetch_redirects();
 
+    // Return true if there are any redirects.
+    //
+    bool have_redirects() const { return !redirects_.empty(); }
+
     // Probe an arbitrary lua expression.
     //
     // Any print-statements in the lua code are sent into