changes facing (and desireFacing) on Mobile and on Turreted. range is now 0..255

OpenRa.Game/Traits/Util.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace OpenRa.Game.Traits
+{
+	static class Util
+	{
+		public static void TickFacing( ref int facing, int desiredFacing, int rot )
+		{
+			var leftTurn = ( facing - desiredFacing ) & 0xFF;
+			var rightTurn = ( desiredFacing - facing ) & 0xFF;
+			if( Math.Min( leftTurn, rightTurn ) < rot )
+				facing = desiredFacing;
+			else if( rightTurn < leftTurn )
+				facing = ( facing + rot ) & 0xFF;
+			else
+				facing = ( facing - rot ) & 0xFF;
+		}
+
+		static float2[] fvecs = Graphics.Util.MakeArray<float2>( 32,
+			i => -float2.FromAngle( i / 16.0f * (float)Math.PI ) * new float2( 1f, 1.3f ) );
+
+		public static int GetFacing( float2 d, int currentFacing )
+		{
+			if( float2.WithinEpsilon( d, float2.Zero, 0.001f ) )
+				return currentFacing;
+
+			int highest = -1;
+			float highestDot = -1.0f;
+
+			for( int i = 0 ; i < fvecs.Length ; i++ )
+			{
+				float dot = float2.Dot( fvecs[ i ], d );
+				if( dot > highestDot )
+				{
+					highestDot = dot;
+					highest = i;
+				}
+			}
+
+			return highest * 8;
+		}
+
+	}
+}