add loaders (WIP)

res/scripts/post_content.lua

@@ -1,3 +1,6 @@
+local app = __vc_app
+local internals = __vc_internals
+
 local user_props = file.read_combined_object("config/user-props.toml")
 local names = {
     "parent", "caption", "texture", "texture-faces", "model", "model-name",
@@ -42,7 +45,7 @@ local function make_read_only(t)
         __newindex = function()
             error("table is read-only")
         end
-    })    
+    })
 end
 
 make_read_only(block.properties)
@@ -85,3 +88,33 @@ cache_names(block)
 cache_names(item)
 
 __vc_scripts_registry.build_registry()
+
+local packs = app.get_content()
+table.insert(packs, 1, "core")
+
+for i, packid in ipairs(packs) do
+    local loaders_dir = packid..":scripts/loaders"
+    if not file.isdir(loaders_dir) then
+        goto continue
+    end
+    local files = file.list(loaders_dir)
+    for _, path in ipairs(files) do
+        if file.ext(path) == "json" then
+            debug.log("registering loader "..path)
+            local dto = json.parse(file.read(path))
+            local module = setmetatable({}, {__index=internals.get_pack_env(packid)})
+            local module_path = file.join(file.parent(path), file.stem(path)..".lua")
+            if not file.exists(module_path) then
+                error("loader "..path.." missing module "..module_path)
+            end
+            load(file.read(module_path), module_path, "t", module)()
+            if rawget(module, "execute") == nil then
+                error("loader "..path.." missing function 'execute'")
+            end
+            if dto.type == "compiler" then
+                internals.register_compiler(packid, dto.extensions, module)
+            end
+        end
+    end
+    ::continue::
+end

res/scripts/stdlib.lua

@@ -392,6 +392,7 @@ end
 
 ffi = nil
 __vc_app = nil
+__vc_internals = nil
 __vc_lock_internal_modules()
 __vc_lock_internal_modules = nil
 __vc_update_coroutines = nil

res/scripts/stdmin.lua

@@ -154,6 +154,20 @@ package = {
 }
 local __cached_scripts = {}
 local __warnings_hidden = {}
+local __compilers = {}
+
+function __vc_internals.register_compiler(sourcepack, extensions, module)
+    local compiler = {
+        packid = sourcepack,
+        extensions = extensions,
+        module = module,
+    }
+    for i, ext in ipairs(extensions) do
+        if not __compilers[ext] then
+            __compilers[ext] = compiler
+        end
+    end
+end
 
 function on_deprecated_call(name, alternatives)
     if __warnings_hidden[name] then
@@ -200,6 +214,21 @@ end
 
 local __internal_locked = false
 
+local default_compiler = {
+    module = {
+        execute = function(code, path, env)
+            local script, err = load(code, path)
+            if script == nil then
+                error(err)
+            end
+            if env then
+                script = setfenv(script, env)
+            end
+            return script
+        end
+    }
+}
+
 -- Load script with caching
 --
 -- path - script path `contentpack:filename`. 
@@ -211,6 +240,9 @@ function __load_script(path, nocache, env)
     local is_internal = (packname == "res" or packname == "core")
        and filename:find("modules/internal") == 1
 
+    local ext = path:match("%.([^:/\\]+)$")
+    local compiler = __compilers[ext] or default_compiler
+
     nocache = nocache or is_internal
 
     if is_internal and __internal_locked then
@@ -225,13 +257,7 @@ function __load_script(path, nocache, env)
         error("script '"..filename.."' not found in '"..packname.."'")
     end
 
-    local script, err = load(file.read(path), path)
+    local script = compiler.module.execute(file.read(path), path, env)
-    if script == nil then
-        error(err)
-    end
-    if env then
-        script = setfenv(script, env)
-    end
     local result = script()
     if not nocache then
         __cached_scripts[path] = script
@@ -245,6 +271,9 @@ function __vc_lock_internal_modules()
 end
 
 local __pack_envs = __vc__pack_envs
+function __vc_internals.get_pack_env(packid)
+    return __pack_envs[packid]
+end
 __vc__pack_envs = nil
 
 function require(path)
@@ -277,6 +306,13 @@ function __scripts_cleanup(non_reset_packs)
         __pack_envs[packname] = nil
         ::continue::
     end
+    for ext, compiler in pairs(__compilers) do
+        if table.has(non_reset_packs, compiler.packid) then
+            goto continue
+        end
+        __compilers[ext] = nil
+        ::continue::
+    end
 end
 
 function __vc__error(msg, frame, n, lastn)

src/assets/AssetsLoader.cpp

@@ -220,7 +220,6 @@ void AssetsLoader::processPreloadList(AssetType tag, const dv::value& list) {
 }
 
 void AssetsLoader::processPreloadConfig(const io::path& file) {
-    logger.debug() << "===== PRELOAD FILE: " << file.string();
     auto root = io::read_json(file);
     processPreloadList(AssetType::ATLAS, root["atlases"]);
     processPreloadList(AssetType::FONT, root["fonts"]);

src/logic/scripting/lua/lua_engine.cpp

@@ -74,6 +74,11 @@ static void create_libs(State* L, StateType stateType) {
     getglobal(L, "__vc_app");
     setregistry(L, "app");
 
+    createtable(L, 0, 0);
+    pushvalue(L, -1);
+    setglobal(L, "__vc_internals");
+    setregistry(L, "internals");
+
     if (stateType == StateType::SCRIPT) {
         getregistry(L, "app");
         setglobal(L, "app");

src/logic/scripting/scripting.cpp

@@ -288,7 +288,23 @@ void scripting::on_content_load(Content* content) {
         lua::setfield(L, "properties");
         lua::pop(L);
     }
-    load_script("post_content.lua", true);
+
+    lua::getregistry(L, "app");
+    lua::setglobal(L, "__vc_app");
+    lua::getregistry(L, "internals");
+    lua::setglobal(L, "__vc_internals");
+    try {
+        load_script("post_content.lua", true);
+    } catch (const std::exception&) {
+        lua::pushnil(L);
+        lua::setglobal(L, "__vc_app");
+        throw;
+    }
+    lua::pushnil(L);
+    lua::setglobal(L, "__vc_app");
+    lua::pushnil(L);
+    lua::setglobal(L, "__vc_internals");
+
     load_script("stdcmd.lua", true);
 }