From 190eb1f107768929543a6be04fd1c3a19911d209 Mon Sep 17 00:00:00 2001
From: veclavtalica <veclavtalica@tutamail.com>
Date: Tue, 24 Dec 2024 10:03:19 +0300
Subject: [PATCH] twnlua: use stb_ds.h for enum conversions

---
 apps/twnlua/bindgen.py | 35 ++++++++++++++++++++++++++---------
 apps/twnlua/game.c     |  2 ++
 2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/apps/twnlua/bindgen.py b/apps/twnlua/bindgen.py
index 1211fc1..bfafcf5 100755
--- a/apps/twnlua/bindgen.py
+++ b/apps/twnlua/bindgen.py
@@ -32,11 +32,13 @@ def default(parameter):
 
 
 print('#include "twn_game_api.h"\n')
+print('#define STB_DS_IMPLEMENTATION') # TODO: reuse implementation from the engine
+print('#include <stb_ds.h>')
 print('#include <lua.h>')
 print('#include <lualib.h>')
 print('#include <lauxlib.h>\n')
-print('#include <string.h>\n')
 
+storages, converters, initializers, deinitializers = [], [], [], []
 
 for typename, typedesc in api["types"].items():
     converter = "static %s to_%s(lua_State *L, int idx) {\n" % (typename, typename.lower())
@@ -53,21 +55,29 @@ for typename, typedesc in api["types"].items():
                 raise BaseException("Unhandled converter field type '%s'" % (field["type"]))
             converter += "    lua_pop(L, 1);\n";
 
-    # todo: use a hashtable instead
+    # TODO: wild idea: use compile time built hash table
     elif "enums" in typedesc:
+        storages += ["struct %sHashItem { char *key; %s value; };\nstatic struct %sHashItem *%s_map = NULL;\n" % (typename, typename, typename, typename.lower())]
+
+        # TODO: use arena
+        for enum in typedesc["enums"]:
+            initializer = "    shput(%s_map, \"%s\", %s);" % (typename.lower(), enum, typedesc["enums"][enum])
+            initializers += [initializer]
+
+        deinitializers += ["    shfree(%s_map);" % typename.lower()]
+
         converter += "    char *value = lua_tostring(L, -1);\n";
-        for index, enum in enumerate(typedesc["enums"]):
-            if index == 0:
-                converter += "    if (strncmp(\"%s\", value, sizeof(\"%s\")) == 0)\n" % (enum, enum)
-            else:
-                converter += "    else if (strncmp(\"%s\", value, sizeof(\"%s\")) == 0)\n" % (enum, enum)
-            converter += "        %s = %s;\n" % (typename.lower(), typedesc["enums"][enum])
+        converter += "        %s = shget(%s_map, value);\n" % (typename.lower(), typename.lower())
         converter += "    lua_pop(L, 1);\n";
 
     converter += "    return %s;\n}\n" % (typename.lower())
-    print(converter)
+    converters += [converter]
 
+print('\n'.join(storages))
+print("void bindgen_init(void) {\n" + '\n'.join(initializers) + "\n}\n")
+print('\n'.join(converters))
 
+bindings = []
 for procedure, procedure_desc in api["procedures"].items():
     binding = "static int binding_%s(lua_State *L) {\n" % procedure
     binding += "    luaL_checktype(L, 1, LUA_TTABLE);\n"
@@ -118,6 +128,7 @@ for procedure, procedure_desc in api["procedures"].items():
 loader = "void bindgen_load_%s(lua_State *L) {\n" % api["name"]
 modules = set(api["procedures"][procedure]["module"] for procedure in api["procedures"])
 for module in modules:
+    loader += "    bindgen_init();\n"
     loader += "    lua_newtable(L);\n"
     for procedure, procedure_desc in api["procedures"].items():
         if procedure_desc["module"] == module:
@@ -128,3 +139,9 @@ for module in modules:
 
 loader += "}"
 print(loader)
+
+
+unloader = "void bindgen_unload_%s(lua_State *L) {\n" % api["name"]
+unloader += '\n'.join(deinitializers)
+unloader += "}"
+print(unloader)
diff --git a/apps/twnlua/game.c b/apps/twnlua/game.c
index 824436e..5da7dd4 100644
--- a/apps/twnlua/game.c
+++ b/apps/twnlua/game.c
@@ -12,6 +12,7 @@
 
 /* generated by bindgen.py */
 void bindgen_load_twn(lua_State *L);
+void bindgen_unload_twn(lua_State *L);
 
 
 /* require will go through physicsfs exclusively so that scripts can be in the data dir */
@@ -119,6 +120,7 @@ void game_tick(void) {
 
 void game_end(void) {
     State *state = ctx.udata;
+    bindgen_unload_twn(state->L);
     lua_close(state->L);
     free(state);
 }