Added first version of ScriptEngine, allowing Lua script to set propety values

src/scripting/scriptengine.cpp

@@ -0,0 +1,177 @@
+/*****************************************************************************************
+ *                                                                                       *
+ * OpenSpace                                                                             *
+ *                                                                                       *
+ * Copyright (c) 2014                                                                    *
+ *                                                                                       *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
+ * software and associated documentation files (the "Software"), to deal in the Software *
+ * without restriction, including without limitation the rights to use, copy, modify,    *
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
+ * permit persons to whom the Software is furnished to do so, subject to the following   *
+ * conditions:                                                                           *
+ *                                                                                       *
+ * The above copyright notice and this permission notice shall be included in all copies *
+ * or substantial portions of the Software.                                              *
+ *                                                                                       *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
+ * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
+ * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
+ * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
+ ****************************************************************************************/
+
+#include <openspace/scripting/scriptengine.h>
+
+#include <ghoul/logging/logmanager.h>
+#include <ghoul/misc/crc32.h>
+
+namespace {
+    const std::string _loggerCat = "ScriptEngine";
+    
+    const std::string _openspaceLibraryName = "openspace";
+}
+
+ScriptEngine::ScriptEngine()
+    : _state(nullptr)
+{
+}
+
+bool ScriptEngine::initialize() {
+    _state = luaL_newstate();
+    LDEBUG("Creating Lua state");
+    if (_state == nullptr) {
+        LFATAL("Error creating new Lua state: Memory allocation error");
+        return false;
+    }
+    LDEBUG("Open Lua libraries");
+    luaL_openlibs(_state);
+    
+    LDEBUG("Add OpenSpace modules");
+    
+    lua_newtable(_state);
+    lua_setglobal(_state, _openspaceLibraryName.c_str());
+    
+    return true;
+}
+
+void ScriptEngine::deinitialize() {
+    lua_close(_state);
+    _state = nullptr;
+}
+
+bool ScriptEngine::addLibrary(const ScriptEngine::LuaLibrary& library) {
+    assert(_state);
+    if (library.functions.empty()) {
+        LERROR("Lua library '" << library.name << "' does not have any functions");
+        return false;
+    }
+
+    lua_getglobal(_state, _openspaceLibraryName.c_str());
+    if (library.name.empty()) {
+        addLibraryFunctions(library, true);
+    }
+    else {
+        const bool allowed = isLibraryNameAllowed(library.name);
+        if (!allowed)
+            return false;
+        
+        lua_pushstring(_state, library.name.c_str());
+        lua_newtable(_state);
+        addLibraryFunctions(library, false);
+        lua_settable(_state, -3);
+        
+        _registeredLibraries.insert(ghoul::hashCRC32(library.name));
+    }
+    return true;
+}
+
+bool ScriptEngine::runScript(std::string script) {
+    int status = luaL_loadstring(_state, script.c_str());
+    if (status != LUA_OK) {
+        LERROR("Error loading script: '" << lua_tostring(_state, -1) << "'");
+        return false;
+    }
+    
+    LDEBUG("Executing script");
+    if (lua_pcall(_state, 0, LUA_MULTRET, 0)) {
+        LERROR("Error executing script: " << lua_tostring(_state, -1));
+        return false;
+    }
+    
+    return true;
+}
+
+bool ScriptEngine::hasLibrary(const std::string& name)
+{
+    const unsigned int hash = ghoul::hashCRC32(name);
+    return (_registeredLibraries.find(hash) != _registeredLibraries.end());
+}
+
+bool ScriptEngine::isLibraryNameAllowed(const std::string& name)
+{
+    bool result = false;
+    lua_getglobal(_state, _openspaceLibraryName.c_str());
+    const bool hasOpenSpaceLibrary = lua_istable(_state, -1);
+    if (!hasOpenSpaceLibrary) {
+        LFATAL("OpenSpace library was not created in initialize method");
+        return false;
+    }
+    lua_getfield(_state, -1, name.c_str());
+    const int type = lua_type(_state, -1);
+    switch (type) {
+        case LUA_TNONE:
+        case LUA_TNIL:
+            result = true;
+            break;
+        case LUA_TBOOLEAN:
+            LERROR("Library name '" << name << "' specifies a boolean");
+            break;
+        case LUA_TLIGHTUSERDATA:
+            LERROR("Library name '" << name << "' specifies a light user data");
+            break;
+        case LUA_TNUMBER:
+            LERROR("Library name '" << name << "' specifies a number");
+            break;
+        case LUA_TSTRING:
+            LERROR("Library name '" << name << "' specifies a string");
+            break;
+        case LUA_TTABLE: {
+            if (hasLibrary(name))
+                LERROR("Library with name '" << name << "' has been registered before");
+            else
+                LERROR("Library name '" << name << "' specifies a table");
+            break;
+        }
+        case LUA_TFUNCTION:
+            LERROR("Library name '" << name << "' specifies a function");
+            break;
+        case LUA_TUSERDATA:
+            LERROR("Library name '" << name << "' specifies a user data");
+            break;
+        case LUA_TTHREAD:
+            LERROR("Library name '" << name << "' specifies a thread");
+            break;
+    }
+    
+    lua_pop(_state, 1);
+    return result;
+}
+
+void ScriptEngine::addLibraryFunctions(const LuaLibrary& library, bool replace)
+{
+    for (std::pair<std::string, lua_CFunction> p : library.functions) {
+        if (!replace) {
+            lua_getfield(_state, -1, p.first.c_str());
+            const bool isNil = lua_isnil(_state, -1);
+            if (!isNil) {
+                LERROR("Function name '" << p.first << "' was already assigned");
+                return;
+            }
+        }
+        lua_pushstring(_state, p.first.c_str());
+        lua_pushcfunction(_state, p.second);
+        lua_settable(_state, -3);
+    }
+}