www.pudn.com > IntroductionTo3DGameEngineDesign.rar > Expression.cs

using System; 
using System.Collections; 
using System.Xml; 
 
namespace GameAI 
{ 
	/// 
 
	/// Summary description for Expression. 
	/// 
 
	public class Expression 
	{ 
		#region Attributes 
		private ArrayList m_logic_list; 
		private bool m_and_values = true; 
		#endregion 
 
		#region Properties 
		public bool CombineByAnding { set { m_and_values = value; } } 
		#endregion 
 
		public Expression() 
		{ 
			m_logic_list = new ArrayList(); 
		} 
 
		public void Clear() 
		{ 
			m_logic_list.Clear(); 
		} 
 
		public void AddLogic( Logic logic ) 
		{ 
			m_logic_list.Add(logic); 
		} 
 
		public bool Evaluate() 
		{ 
			bool result = false; 
			bool first_logic = true; 
 
			foreach ( Logic logic in m_logic_list ) 
			{ 
				bool val = logic.Evaluate(); 
 
				if ( first_logic ) 
				{ 
					result = val; 
				} 
				else 
				{ 
					if ( m_and_values ) 
					{ 
						result = result && val; 
					} 
					else 
					{ 
						result = result || val; 
					} 
				} 
			} 
 
			return result; 
		} 
 
		public void Write( XmlTextWriter writer ) 
		{ 
			writer.WriteStartElement("Expression"); 
			writer.WriteElementString("AndValues", m_and_values.ToString()); 
			foreach ( Logic logic in m_logic_list ) 
			{ 
				logic.Write( writer ); 
			} 
			writer.WriteEndElement(); 
		} 
 
		public void Read ( XmlTextReader reader, Thinker thinker ) 
		{ 
			bool done = false; 
 
			while ( !done )  
			{ 
				reader.Read(); 
 
				if ( reader.NodeType == XmlNodeType.EndElement && 
					reader.Name == "Expression" ) 
				{ 
					done =true; 
				} 
					// Process a start of element node. 
				else if (reader.NodeType == XmlNodeType.Element)  
				{  
					// Process a text node. 
					if ( reader.Name == "Logic" )  
					{ 
						Logic logic = new Logic(); 
						logic.Read( reader, thinker ); 
						m_logic_list.Add( logic ); 
					} 
					else if ( reader.Name == "AndValues" ) 
					{ 
						while (reader.NodeType != XmlNodeType.Text)  
						{ 
							reader.Read(); 
						} 
						m_and_values = bool.Parse(reader.Value); 
					} 
				} 
			}// End while loop 
		} 
	} 
}