Working on web, change python to lua

src/ScriptEngine.cpp

@@ -1,74 +1,60 @@
 #include "ScriptEngine.h"
 #include "Game.h"
-#include <pybind11/embed.h>
 #include <iostream>
-#include <fstream>
 
-namespace py = pybind11;
-
-// Static pointer used by the embedded module (set before interpreter starts).
-static ZL::Game* s_game = nullptr;
-
-// The embedded module must be defined at file scope before the interpreter
-// is started.  It exposes a minimal surface: one function per scripting command.
-PYBIND11_EMBEDDED_MODULE(game_api, m) {
-    m.doc() = "Game scripting API";
-
-    // npc_walk_to(index, x, y, z, on_arrived=None)
-    // Tells the NPC at `index` to walk to (x,y,z).
-    // on_arrived is an optional Python callable invoked once when the NPC arrives.
-    // It can call npc_walk_to again (or anything else) to chain behaviour.
-    m.def("npc_walk_to", [](int index, float x, float y, float z, py::object on_arrived) {
-        if (!s_game) {
-            std::cerr << "[script] game_api.npc_walk_to: engine not ready\n";
-            return;
-        }
-        auto& npcs = s_game->npcs;
-        if (index < 0 || index >= static_cast<int>(npcs.size())) {
-            std::cerr << "[script] game_api.npc_walk_to: index " << index
-                      << " out of range (0.." << npcs.size() - 1 << ")\n";
-            return;
-        }
-        std::function<void()> cb;
-        if (!on_arrived.is_none()) {
-            cb = [on_arrived]() {
-                try {
-                    on_arrived();
-                } catch (const py::error_already_set& e) {
-                    std::cerr << "[script] on_arrived callback error:\n" << e.what() << "\n";
-                }
-            };
-        }
-        npcs[index]->setTarget(Eigen::Vector3f(x, y, z), std::move(cb));
-    },
-    py::arg("index"), py::arg("x"), py::arg("y"), py::arg("z"),
-    py::arg("on_arrived") = py::none(),
-    "Command NPC[index] to walk to (x,y,z). on_arrived is called when the NPC arrives.");
-}
+#define SOL_ALL_SAFETIES_ON 1
+#include <sol/sol.hpp>
 
 namespace ZL {
 
+struct ScriptEngine::Impl {
+    sol::state lua;
+};
+
 ScriptEngine::ScriptEngine() = default;
 ScriptEngine::~ScriptEngine() = default;
 
 void ScriptEngine::init(Game* game) {
-    s_game = game;
-    interpreter = std::make_unique<py::scoped_interpreter>();
-    runScript("resources/start.py");
+    impl = std::make_unique<Impl>();
+    sol::state& lua = impl->lua;
+
+    lua.open_libraries(sol::lib::base, sol::lib::math, sol::lib::string, sol::lib::table);
+
+    auto api = lua.create_named_table("game_api");
+
+    // npc_walk_to(index, x, y, z [, on_arrived])
+    // on_arrived is an optional Lua function called when the NPC reaches the target.
+    // It can call npc_walk_to again (or anything else) to chain behaviour.
+    api.set_function("npc_walk_to",
+        [game](int index, float x, float y, float z, sol::object on_arrived) {
+            auto& npcs = game->npcs;
+            if (index < 0 || index >= static_cast<int>(npcs.size())) {
+                std::cerr << "[script] npc_walk_to: index " << index
+                          << " out of range (0.." << npcs.size() - 1 << ")\n";
+                return;
+            }
+            std::function<void()> cb;
+            if (on_arrived.is<sol::protected_function>()) {
+                sol::protected_function fn = on_arrived.as<sol::protected_function>();
+                cb = [fn]() mutable {
+                    auto result = fn();
+                    if (!result.valid()) {
+                        sol::error err = result;
+                        std::cerr << "[script] on_arrived error: " << err.what() << "\n";
+                    }
+                };
+            }
+            npcs[index]->setTarget(Eigen::Vector3f(x, y, z), std::move(cb));
+        });
+
+    runScript("resources/start.lua");
 }
 
 void ScriptEngine::runScript(const std::string& path) {
-    std::ifstream file(path);
-    if (!file.is_open()) {
-        std::cerr << "[script] Could not open script: " << path << "\n";
-        return;
-    }
-    std::string source((std::istreambuf_iterator<char>(file)),
-                        std::istreambuf_iterator<char>());
-    try {
-        py::exec(source);
-    } catch (const py::error_already_set& e) {
-        std::cerr << "[script] Error in " << path << ":\n" << e.what() << "\n";
+    auto result = impl->lua.safe_script_file(path, sol::script_pass_on_error);
+    if (!result.valid()) {
+        sol::error err = result;
+        std::cerr << "[script] Error in " << path << ": " << err.what() << "\n";
     }
 }