ILLUSIONS: Add UpdateFunctions class

engines/illusions/updatefunctions.cpp

@@ -0,0 +1,80 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#include "illusions/updatefunctions.h"
+#include "common/algorithm.h"
+#include "common/system.h"
+
+namespace Illusions {
+
+uint32 getCurrentTime() {
+	// TODO, move to own file with other time related code
+	return g_system->getMillis();
+}
+
+// UpdateFunctions
+
+UpdateFunctions::UpdateFunctions() {
+}
+
+UpdateFunctions::~UpdateFunctions() {
+	// Free update functions
+	for (UpdateFunctionListIterator it = _updateFunctions.begin(); it != _updateFunctions.end(); ++it)
+		delete *it;
+}
+
+void UpdateFunctions::add(int priority, uint32 tag, UpdateFunctionCallback *callback) {
+	UpdateFunction *updateFunction = new UpdateFunction();
+	updateFunction->_priority = priority;
+	updateFunction->_tag = tag;
+	updateFunction->_callback = callback;
+	UpdateFunctionListIterator insertionPos = Common::find_if(_updateFunctions.begin(), _updateFunctions.end(),
+		FindInsertionPosition(priority));
+	_updateFunctions.insert(insertionPos, updateFunction);
+}
+
+void UpdateFunctions::update() {
+
+	// Avoid running updates multiple times in the current time slice
+	while (_lastTimerUpdateTime == getCurrentTime())
+		g_system->delayMillis(10); // CHECKME Timer resolution
+	_lastTimerUpdateTime = getCurrentTime();
+
+	UpdateFunctionListIterator it = _updateFunctions.begin();
+	while (it != _updateFunctions.end()) {
+		int r = (*it)->run();
+		switch (r) {
+		case kUFNext:
+			++it;
+			break;
+		case kUFTerminate:
+			delete *it;
+			it = _updateFunctions.erase(it);
+			break;
+		default:
+			break;
+		}
+	}
+
+}
+
+} // End of namespace Illusions