4 files changed, 155 insertions, 1 deletions
diff --git a/engines/illusions/illusions.cpp b/engines/illusions/illusions.cpp
index 07983030c0..091b381993 100644
--- a/engines/illusions/illusions.cpp
+++ b/engines/illusions/illusions.cpp
@@ -26,6 +26,7 @@
 #include "illusions/camera.h"
 #include "illusions/graphics.h"
 #include "illusions/input.h"
+#include "illusions/updatefunctions.h"
 
 #include "audio/audiostream.h"
 #include "common/config-manager.h"
diff --git a/engines/illusions/module.mk b/engines/illusions/module.mk
index bfe521b49d..0fb336c595 100644
--- a/engines/illusions/module.mk
+++ b/engines/illusions/module.mk
@@ -7,7 +7,8 @@ MODULE_OBJS := \
 	graphics.o \
 	illusions.o \
 	input.o \
-	resourcesystem.o
+	resourcesystem.o \
+	updatefunctions.o
 
 # This module can be built as a plugin
 ifeq ($(ENABLE_ILLUSIONS), DYNAMIC_PLUGIN)
diff --git a/engines/illusions/updatefunctions.cpp b/engines/illusions/updatefunctions.cpp
new file mode 100644
index 0000000000..9eb626c5ba
--- /dev/null
+++ b/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
diff --git a/engines/illusions/updatefunctions.h b/engines/illusions/updatefunctions.h
new file mode 100644
index 0000000000..bd8aef3548
--- /dev/null
+++ b/engines/illusions/updatefunctions.h
@@ -0,0 +1,72 @@
+/* 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.
+ *
+ */
+
+#ifndef ILLUSIONS_UPDATEFUNCTIONS_H
+#define ILLUSIONS_UPDATEFUNCTIONS_H
+
+#include "common/func.h"
+#include "common/list.h"
+
+namespace Illusions {
+
+enum {
+	kUFNext         = 1,  // Run next update funtion
+	kUFTerminate    = 2   // Terminate update function
+};
+
+typedef Common::Functor0<int> UpdateFunctionCallback;
+
+class UpdateFunction {
+public:
+	int _priority;
+	uint32 _tag;
+	UpdateFunctionCallback *_callback;
+	UpdateFunction() : _priority(0), _tag(0), _callback(0) {}
+	~UpdateFunction() { delete _callback; }
+	int run() { return (*_callback)(); }
+};
+
+class UpdateFunctions {
+public:
+	UpdateFunctions();
+	~UpdateFunctions();
+	void add(int priority, uint32 tag, UpdateFunctionCallback *callback);
+	void update();
+protected:
+	typedef Common::List<UpdateFunction*> UpdateFunctionList;
+	typedef UpdateFunctionList::iterator UpdateFunctionListIterator;
+
+	struct FindInsertionPosition : public Common::UnaryFunction<const UpdateFunction*, bool> {
+		int _priority;
+		FindInsertionPosition(int priority) : _priority(priority) {}
+		bool operator()(const UpdateFunction *updateFunction) const {
+			return updateFunction->_priority > _priority;
+		}
+	};
+
+	Common::List<UpdateFunction*> _updateFunctions;
+	uint32 _lastTimerUpdateTime;
+};
+
+} // End of namespace Illusions
+
+#endif // ILLUSIONS_UPDATEFUNCTIONS_H