Added code to probe 'interface'

luprex/cpp/world.cpp

@@ -2,6 +2,8 @@
 #include "world.hpp"
 #include "idalloc.hpp"
 #include "animqueue.hpp"
+#include "gui.hpp"
+#include "traceback.hpp"
 #include <iostream>
 
 LuaDefineType(World);
@@ -131,6 +133,54 @@ World *World::fetch(lua_State *L) {
     return w;
 }
 
+void World::update_gui(int64_t actor_id, int64_t place_id, Gui *gui) {
+    gui->clear();
+    lua_State *L = get_lua_state();
+
+    LuaVar actor, place, ugui, func, tangibles;
+    LuaStack LS(L, actor, place, ugui, func, tangibles);
+
+    // Get the actor and place.
+    LS.getfield(tangibles, LuaRegistry, "tangibles");
+    LS.rawget(actor, tangibles, actor_id);
+    LS.rawget(place, tangibles, place_id);
+    if (!LS.istable(actor) || !LS.istable(place)) {
+        LS.result();
+        return;
+    }
+
+    // Get the interface closure.
+    LS.getfield(func, place, "interface");
+    if (!LS.isfunction(func)) {
+        LS.result();
+        return;
+    }
+
+    // Construct the userdata with the GUI pointer.
+    LS.newpointer<Gui>(ugui, gui, false);
+
+    // Call the interface function.
+    lua_pushvalue(L, func.index());
+    lua_pushvalue(L, actor.index());
+    lua_pushvalue(L, place.index());
+    lua_pushvalue(L, ugui.index());
+    int status = traceback_pcall(L, 3, 0);
+    if (status != 0) {
+        gui->clear();
+        std::cerr << lua_tostring(L, -1);
+        LS.result();
+        return;
+    }
+    
+    // Nuke the userdata, in case somebody saved a pointer to it.
+    LS.clearuserdata(ugui);
+
+    // And we're done.
+    LS.result();
+}
+    
+
+
 LuaDefine(tangible_get, "c") {
     LuaArg id;
     LuaRet database;