Add more comments to utils class, modify ExtPlayerWidget to strip colour codes from names and display group name ahead of players.

ClassicalSharp/2D/Widgets/ExtPlayerListWidget.cs

@@ -7,25 +7,31 @@ namespace ClassicalSharp {
 	public class ExtPlayerListWidget : PlayerListWidget {
 		
 		public ExtPlayerListWidget( Game game, Font font ) : base( game, font ) {
+			textures = new Texture[512];
+			titleFont = new Font( "Arial", 12, FontStyle.Underline );
 		}
 		
-		PlayerInfo[] info = new PlayerInfo[256];
+		PlayerInfo[] info = new PlayerInfo[512];
 		class PlayerInfo {
 			
-			public string Name;			
+			public string ListName;
+			public string PlayerName;
 			public string GroupName;
 			public byte GroupRank;
 			public byte NameId;
+			public bool IsGroup = false;
 			
 			public PlayerInfo( CpeListInfo p ) {
-				Name = p.ListName;
+				ListName = Utils.StripColours( p.ListName );
+				PlayerName = Utils.StripColours( p.PlayerName );
 				NameId = p.NameId;
 				GroupName = p.GroupName;
 				GroupRank = p.GroupRank;
 			}
 			
-			public override string ToString() {
+			public PlayerInfo( string groupName ) {
-				return NameId + ":" + Name + "(" + GroupName + "," + GroupRank + ")";
+				GroupName = groupName;
+				IsGroup = true;
 			}
 		}
 		
@@ -35,18 +41,16 @@ namespace ClassicalSharp {
 			public bool JustComparingGroups = true;
 			
 			public int Compare( PlayerInfo x, PlayerInfo y ) {
-				if( JustComparingGroups ) {
+				if( JustComparingGroups )
 					return x.GroupName.CompareTo( y.GroupName );
-				}
 				
 				int rankOrder = x.GroupRank.CompareTo( y.GroupRank );
-				if( rankOrder != 0 ) {
+				return rankOrder != 0 ? rankOrder :
-					return rankOrder;
+					x.ListName.CompareTo( y.ListName );
-				}
-				return x.Name.CompareTo( y.Name );
 			}
 		}
 		
+		Font titleFont;
 		public override void Init() {
 			base.Init();
 			game.Events.CpeListInfoAdded += PlayerListInfoAdded;
@@ -59,12 +63,13 @@ namespace ClassicalSharp {
 			game.Events.CpeListInfoAdded -= PlayerListInfoAdded;
 			game.Events.CpeListInfoChanged -= PlayerListInfoChanged;
 			game.Events.CpeListInfoRemoved -= PlayerListInfoRemoved;
+			titleFont.Dispose();
 		}
 		
 		void PlayerListInfoChanged( object sender, IdEventArgs e ) {
 			for( int i = 0; i < namesCount; i++ ) {
 				PlayerInfo pInfo = info[i];
-				if( pInfo.NameId == e.Id ) {
+				if( !pInfo.IsGroup && pInfo.NameId == e.Id ) {
 					Texture tex = textures[i];
 					graphicsApi.DeleteTexture( ref tex );
 					AddPlayerInfo( game.CpePlayersList[e.Id], i );
@@ -77,7 +82,7 @@ namespace ClassicalSharp {
 		void PlayerListInfoRemoved( object sender, IdEventArgs e ) {
 			for( int i = 0; i < namesCount; i++ ) {
 				PlayerInfo pInfo = info[i];
-				if( pInfo.NameId == e.Id ) {
+				if( !pInfo.IsGroup && pInfo.NameId == e.Id ) {
 					Texture tex = textures[i];
 					graphicsApi.DeleteTexture( ref tex );
 					RemoveItemAt( textures, i );
@@ -120,7 +125,11 @@ namespace ClassicalSharp {
 		
 		protected override void SortInfoList() {
 			if( namesCount == 0 ) return;
+			
 			// Sort the list into groups
+			for( int i = 0; i < namesCount; i++ ) {
+				if( info[i].IsGroup ) DeleteGroup( ref i );
+			}
 			comparer.JustComparingGroups = true;
 			Array.Sort( info, textures, 0, namesCount, comparer );
 			
@@ -128,12 +137,40 @@ namespace ClassicalSharp {
 			comparer.JustComparingGroups = false;
 			int index = 0;
 			while( index < namesCount ) {
+				AddGroup( info[index].GroupName, ref index );
 				int count = GetGroupCount( index );
 				Array.Sort( info, textures, index, count, comparer );
 				index += count;
 			}
 		}
 		
+		void DeleteGroup( ref int i ) {
+			graphicsApi.DeleteTexture( ref textures[i] );		
+			RemoveItemAt( info, i );
+			RemoveItemAt( textures, i );
+			
+			namesCount--;
+			i--;
+		}
+		
+		void AddGroup( string group, ref int index ) {
+			DrawTextArgs args = new DrawTextArgs( group, true );
+			Texture tex = game.Drawer2D.MakeTextTexture( titleFont, 0, 0, ref args );
+			PlayerInfo pInfo = new PlayerInfo( group );
+			
+			PushDown( info, index, pInfo );
+			PushDown( textures, index, tex );
+			index++;
+			namesCount++;
+		}
+		
+		void PushDown<T>( T[] array, int index, T value ) {
+			for( int i = array.Length - 1; i > index; i-- ) {
+				array[i] = array[i - 1];
+			}
+			array[index] = value;
+		}
+		
 		int GetGroupCount( int startIndex ) {
 			string group = info[startIndex].GroupName;
 			int count = 0;

ClassicalSharp/2D/Widgets/NormalPlayerListWidget.cs

@@ -7,6 +7,7 @@ namespace ClassicalSharp {
 	public sealed class NormalPlayerListWidget : PlayerListWidget {
 		
 		public NormalPlayerListWidget( Game game, Font font ) : base( game, font ) {
+			textures = new Texture[256];
 		}
 		
 		PlayerInfo[] info = new PlayerInfo[256];		
@@ -16,7 +17,7 @@ namespace ClassicalSharp {
 			public byte PlayerId;
 			
 			public PlayerInfo( Player p ) {
-				Name = p.DisplayName;
+				Name = Utils.StripColours( p.DisplayName );
 				PlayerId = p.ID;
 			}
 		}

ClassicalSharp/2D/Widgets/PlayerListWidget.cs

@@ -15,7 +15,7 @@ namespace ClassicalSharp {
 		protected const int boundsSize = 10;
 		protected const int namesPerColumn = 20;
 		protected int namesCount = 0;
-		protected Texture[] textures = new Texture[256];
+		protected Texture[] textures;
 		protected int columns;
 		protected int xMin, xMax, yHeight;
 		protected static FastColour tableCol = new FastColour( 20, 20, 20, 220 );
@@ -115,31 +115,30 @@ namespace ClassicalSharp {
 		
 		protected void SortPlayerInfo() {
 			SortInfoList();			
-			int centreX = game.Width / 2;
 			CalcMaxColumnHeight();
 			int y = game.Height / 2 - yHeight / 2;		
-			
 			int midCol = columns / 2;
+			
+			int centreX = game.Width / 2;
 			int offset = 0;
 			if( columns % 2 != 0 ) {
 				// For an odd number of columns, the middle column is centred.
 				offset = Utils.CeilDiv( GetColumnWidth( midCol ), 2 );
 			}		
 			
-			int x = centreX - offset;			
+			xMin = centreX - offset;			
 			for( int col = midCol - 1; col >= 0; col-- ) {
-				x -= GetColumnWidth( col );
+				xMin -= GetColumnWidth( col );
-				SetColumnPos( col, x, y );
+				SetColumnPos( col, xMin, y );
 			}			
-			xMin = x;
+			xMax = centreX - offset;
-			
-			x = centreX - offset;
 			for( int col = midCol; col < columns; col++ ) {
-				SetColumnPos( col, x, y );
+				SetColumnPos( col, xMax, y );
-				x += GetColumnWidth( col );
+				xMax += GetColumnWidth( col );
 			}
-			xMax = x;
+			
 			UpdateTableDimensions();
+			MoveTo( X, game.Height / 4 );
 		}
 	}
 }

ClassicalSharp/Entities/LocalPlayer.cs

@@ -247,8 +247,8 @@ namespace ClassicalSharp {
 		internal float lastYaw, nextYaw, lastPitch, nextPitch;
 		public void SetInterpPosition( float t ) {
 			Position = Vector3.Lerp( lastPos, nextPos, t );
-			YawDegrees = Utils.InterpAngle( lastYaw, nextYaw, t );
+			YawDegrees = Utils.LerpAngle( lastYaw, nextYaw, t );
-			PitchDegrees = Utils.InterpAngle( lastPitch, nextPitch, t );
+			PitchDegrees = Utils.LerpAngle( lastPitch, nextPitch, t );
 		}
 		
 		internal void HandleKeyDown( Key key ) {

ClassicalSharp/Entities/NetPlayer.cs

@@ -34,8 +34,8 @@ namespace ClassicalSharp {
 			} else {
 				// Smoother interpolation by also adding midpoint.
 				Vector3 midPos = Vector3.Lerp( lastPos, serverPos, 0.5f );
-				float midYaw = Utils.InterpAngle( lastYaw, serverYaw, 0.5f );
+				float midYaw = Utils.LerpAngle( lastYaw, serverYaw, 0.5f );
-				float midPitch = Utils.InterpAngle( lastPitch, serverPitch, 0.5f );
+				float midPitch = Utils.LerpAngle( lastPitch, serverPitch, 0.5f );
 				AddState( new State( tickCount, midPos, midYaw, midPitch ) );
 				AddState( new State( tickCount, serverPos, serverYaw, serverPitch ) );
 			}
@@ -88,8 +88,8 @@ namespace ClassicalSharp {
 
 		public override void Render( double deltaTime, float t ) {
 			Position = Vector3.Lerp( oldState.pos, newState.pos, t );
-			YawDegrees = Utils.InterpAngle( oldState.yaw, newState.yaw, t );
+			YawDegrees = Utils.LerpAngle( oldState.yaw, newState.yaw, t );
-			PitchDegrees = Utils.InterpAngle( oldState.pitch, newState.pitch, t );
+			PitchDegrees = Utils.LerpAngle( oldState.pitch, newState.pitch, t );
 			
 			GetCurrentAnimState( t );
 			RenderModel( deltaTime );

ClassicalSharp/Network/NetworkProcessor.CPE.cs

@@ -136,6 +136,7 @@ namespace ClassicalSharp {
 				CpeListInfo oldInfo = game.CpePlayersList[nameId];
 				CpeListInfo info = new CpeListInfo( (byte)nameId, playerName, listName, groupName, groupRank );
 				game.CpePlayersList[nameId] = info;
+				//Console.WriteLine( nameId + ": " + groupRank + " , " + groupName + " : " + listName );
 				
 				if( oldInfo != null ) {
 					game.Events.RaiseCpeListInfoChanged( (byte)nameId );

ClassicalSharp/Rendering/MapRenderer.Occlusion.cs

@@ -40,25 +40,24 @@ namespace ClassicalSharp {
 				chunkIn.DistanceFlags |= (mapLoc.Z < 0 || mapLoc.Z >= game.Map.Length) ? flagZ : (byte)0;
 			}
 			
+			Console.WriteLine( "SRC    {0}", cx + "," + cy + "," + cz );
 			QueueChunk( cx - 1, cy, cz, queue );
 			QueueChunk( cx + 1, cy, cz, queue );
 			QueueChunk( cx, cy - 1, cz, queue );
 			QueueChunk( cx, cy + 1, cz, queue );
 			QueueChunk( cx, cy, cz - 1, queue );
 			QueueChunk( cx, cy, cz + 1, queue );
-			ProcessQueue( chunkPos, queue );
+			ProcessQueue( queue );
 			chunkIn.OcclusionFlags = chunkInOcclusionFlags;
 		}
 		
-		void ProcessQueue( Vector3I p, ChunkQueue queue ) {
+		void ProcessQueue( ChunkQueue queue ) {
+			Vector3I p = chunkPos;
 			while( queue.Size > 0 ) {
 				ChunkInfo chunk = queue.Dequeue();
 				int x1 = chunk.CentreX - 8, x2 = chunk.CentreX + 8;
 				int y1 = chunk.CentreY - 8, y2 = chunk.CentreY + 8;
 				int z1 = chunk.CentreZ - 8, z2 = chunk.CentreZ + 8;
-				int cx = chunk.CentreX >> 4;
-				int cy = chunk.CentreY >> 4;
-				int cz = chunk.CentreZ >> 4;
 				
 				int xOffset, yOffset, zOffset;
 				int dx = Math.Max( x1 - p.X, Math.Max( 0, p.X - x2 ) );
@@ -92,9 +91,14 @@ namespace ClassicalSharp {
 				
 				chunk.Occluded = true;
 				int distMin = Math.Min( distX, Math.Min( distY, distZ ) );
+				int cx = chunk.CentreX >> 4, cy = chunk.CentreY >> 4, cz = chunk.CentreZ >> 4;
+				
+				if( !chunk.Empty ) {
+					Console.WriteLine( chunk.OccludedFlags + " , " + xOffset + " : " + yOffset + " : " + zOffset );
+				}
 				if( distMin == distX ) OccludeX( cx, cy, cz, xOffset, chunk );			
-				if( distMin == distZ ) OccludeZ( cx, cy, cz, zOffset, chunk );
 				if( distMin == distY ) OccludeY( cx, cy, cz, yOffset, chunk );
+				if( distMin == distZ ) OccludeZ( cx, cy, cz, zOffset, chunk );
 				
 				//Console.WriteLine( distMin + " , " + distX + " , " + distY + " , " + distZ );
 				//Console.WriteLine( chunk.DistanceFlags + " : " + chunk.OccludedFlags + " : " + chunk.OcclusionFlags );
@@ -104,22 +108,77 @@ namespace ClassicalSharp {
 				QueueChunk( cx, cy, cz + 1, queue );
 				QueueChunk( cx, cy - 1, cz, queue );
 				QueueChunk( cx, cy + 1, cz, queue );
+				if( !chunk.Empty ) {
+					Console.WriteLine( "{0}     D {1}: V {2}, O {3}, {4}", cx + "," + cy + "," + cz, chunk.DistanceFlags,
+			                  chunk.OccludedFlags, chunk.OcclusionFlags, chunk.Occluded );
+					Console.WriteLine( "    M {0} : X {1}, Y {2}, Z {3} ({4}, {5})", distMin, distX, distY, distZ, dxFront, dxBack );
+				}
 			}
 			Console.WriteLine( "======================" );
 		}
 		const byte flagX = 1, flagZ = 2, flagY = 4;
 		
 		public void DebugPickedPos() {
+			return;
 			if( game.SelectedPos.Valid ) {
 				Vector3I p = game.SelectedPos.BlockPos;
-				int cx = p.X >> 4;
+				int cx = p.X >> 4; int cy = p.Y >> 4; int cz = p.Z >> 4;
-				int cy = p.Y >> 4;
+				Print( "-", cx, cy, cz );
-				int cz = p.Z >> 4;
+				//if( cx > 0 ) Print( "X-", cx - 1, cy, cz );
-				ChunkInfo chunk = unsortedChunks[cx + chunksX * (cy + cz * chunksY)];
+				//if( cy > 0 ) Print( "Y-", cx, cy - 1, cz );
-				//Console.WriteLine( chunk.DistanceFlags + " : " + chunk.OccludedFlags + " : " + chunk.OcclusionFlags + " , " + chunk.Occluded );
+				//if( cz > 0 ) Print( "Z-", cx, cy, cz - 1 );
+				
+				//if( cx < chunksX - 1 ) Print( "X+", cx + 1, cy, cz );
+				//if( cy < chunksY - 1 ) Print( "Y+", cx, cy + 1, cz );
+				if( cz < chunksZ - 1 ) Print( "Z+", cx, cy, cz + 1 );
+				if( cz < chunksZ - 2 ) Print( "Z+2", cx, cy, cz + 2 );
+				if( cz < chunksZ - 3 ) Print( "Z+3", cx, cy, cz + 3 );
 			}
 		}
 		
+		void Print( string prefix, int cx, int cy, int cz ) {
+			ChunkInfo chunk = unsortedChunks[cx + chunksX * (cy + cz * chunksY)];
+			Console.WriteLine( "{0}  D {1}: V {2}, O {3}, {4}", prefix, chunk.DistanceFlags,
+			                  chunk.OccludedFlags, chunk.OcclusionFlags, chunk.Occluded );
+			//	Console.WriteLine( chunk.DistanceFlags + " : " + chunk.OccludedFlags + " : " + chunk.OcclusionFlags + " , " + chunk.Occluded );
+			
+			Vector3I p = chunkPos;
+			int x1 = chunk.CentreX - 8, x2 = chunk.CentreX + 8;
+			int y1 = chunk.CentreY - 8, y2 = chunk.CentreY + 8;
+			int z1 = chunk.CentreZ - 8, z2 = chunk.CentreZ + 8;
+			int dx = Math.Max( x1 - p.X, Math.Max( 0, p.X - x2 ) );
+			int dy = Math.Max( y1 - p.Y, Math.Max( 0, p.Y - y2 ) );
+			int dz = Math.Max( z1 - p.Z, Math.Max( 0, p.Z - z2 ) );
+			int distX, distY, distZ;
+			
+			// X axis collisions
+			int dxLeft = Math.Abs( x1 - p.X ), dxRight = Math.Abs( x2 - p.X );
+			if( dxLeft < dxRight ) {
+				distX = dxLeft * dxLeft + dy * dy + dz * dz;
+			} else {
+				distX = dxRight * dxRight + dy * dy + dz * dz;
+			}
+			
+			// Z axis collisions
+			int dxFront = Math.Abs( z1 - p.Z ), dxBack = Math.Abs( z2 - p.Z );
+			if( dxFront < dxBack ) {
+				distZ = dx * dx + dy * dy + dxFront * dxFront;
+			} else {
+				distZ = dx * dx + dy * dy + dxBack * dxBack;
+			}
+			
+			// Y axis collisions
+			int dxBottom = Math.Abs( y1 - p.Y ), dxTop = Math.Abs( y2 - p.Y );
+			if( dxBottom < dxTop ) {
+				distY = dx * dx + dxBottom * dxBottom + dz * dz;
+			} else {
+				distY = dx * dx + dxTop * dxTop + dz * dz;
+			}
+			
+			int distMin = Math.Min( distX, Math.Min( distY, distZ ) );
+			Console.WriteLine( "    M {0} : X {1}, Y {2}, Z {3} ({4}, {5})", distMin, distX, distY, distZ, dxFront, dxBack );
+		}
+		
 		void OccludeX( int cx, int cy, int cz, int xOffset, ChunkInfo info ) {
 			cx += xOffset;
 			if( cx >= 0 && cx < chunksX ) {
@@ -134,20 +193,6 @@ namespace ClassicalSharp {
 			info.DistanceFlags |= flagX;
 		}
 		
-		void OccludeZ( int cx, int cy, int cz, int zOffset, ChunkInfo info ) {
-			cz += zOffset;
-			if( cz >= 0 && cz < chunksZ ) {
-				ChunkInfo neighbour = unsortedChunks[cx + chunksX * (cy + cz * chunksY)];
-				if( (neighbour.OccludedFlags & neighbour.DistanceFlags) != neighbour.DistanceFlags )
-					info.Occluded = false;
-				else
-					info.OccludedFlags |= flagZ;
-			} else {
-				info.Occluded = false;
-			}
-			info.DistanceFlags |= flagZ;
-		}
-		
 		void OccludeY( int cx, int cy, int cz, int yOffset, ChunkInfo info ) {
 			cy += yOffset;
 			if( cy >= 0 && cy < chunksY ) {
@@ -162,6 +207,20 @@ namespace ClassicalSharp {
 			info.DistanceFlags |= flagY;
 		}
 		
+		void OccludeZ( int cx, int cy, int cz, int zOffset, ChunkInfo info ) {
+			cz += zOffset;
+			if( cz >= 0 && cz < chunksZ ) {
+				ChunkInfo neighbour = unsortedChunks[cx + chunksX * (cy + cz * chunksY)];
+				if( (neighbour.OccludedFlags & neighbour.DistanceFlags) != neighbour.DistanceFlags )
+					info.Occluded = false;
+				else
+					info.OccludedFlags |= flagZ;
+			} else {
+				info.Occluded = false;
+			}
+			info.DistanceFlags |= flagZ;
+		}
+
 		void QueueChunk( int cx, int cy, int cz, ChunkQueue queue ) {
 			if( cx >= 0 && cy >= 0 && cz >= 0 && cx < chunksX && cy < chunksY && cz < chunksZ ) {
 				ChunkInfo info = unsortedChunks[cx + chunksX * (cy + cz * chunksY)];

ClassicalSharp/Rendering/MapRenderer.cs

@@ -301,7 +301,7 @@ namespace ClassicalSharp {
 			}
 			api.AlphaTest = false;
 			api.Texturing = false;
-			//DebugPickedPos();
+			DebugPickedPos();
 		}
 		
 		// Render translucent(liquid) blocks. These 'blend' into other blocks.

ClassicalSharp/Utils/Utils.cs

@@ -21,16 +21,19 @@ namespace ClassicalSharp {
 		
 		public static string AppName = "ClassicalSharp 0.95";
 		
+		/// <summary> Clamps that specified value such that min ≤ value ≤ max </summary>
 		public static void Clamp( ref float value, float min, float max ) {
 			if( value < min ) value = min;
 			if( value > max ) value = max;
 		}
 		
+		/// <summary> Clamps that specified value such that min ≤ value ≤ max </summary>
 		public static void Clamp( ref int value, int min, int max ) {
 			if( value < min ) value = min;
 			if( value > max ) value = max;
 		}
 		
+		/// <summary> Returns the next highest power of 2 that is ≥ to the given value. </summary>
 		public static int NextPowerOf2( int value ) {
 			int next = 1;
 			while( value > next ) {
@@ -39,14 +42,12 @@ namespace ClassicalSharp {
 			return next;
 		}
 		
+		/// <summary> Returns whether the given value is a power of 2. </summary>
 		public static bool IsPowerOf2( int value ) {
 			return value != 0 && (value & (value - 1)) == 0;
 		}
 		
-		public static bool IsUrl( string value ) {
+		/// <summary> Returns a string with all the colour codes stripped from it. </summary>
-			return value.StartsWith( "http://" ) || value.StartsWith( "https://" );
-		}
-		
 		public static string StripColours( string value ) {
 			if( value.IndexOf( '&' ) == -1 ) {
 				return value;
@@ -79,15 +80,18 @@ namespace ClassicalSharp {
 			char[] hexadecimal = new char[len * 2];
 			for( int i = 0; i < array.Length; i++ ) {
 				int value = array[i];
-				int index = i << 1;
+				int upper = value >> 4;
-				int upperNibble = value >> 4;
+				int lower = value & 0x0F;
-				int lowerNibble = value & 0x0F;
+				
-				hexadecimal[index] = upperNibble < 10 ? (char)( upperNibble + 48 ) : (char)( upperNibble + 55 ); // 48 = index of 0, 55 = index of (A - 10).
+				// 48 = index of 0, 55 = index of (A - 10).
-				hexadecimal[index + 1] = lowerNibble < 10 ? (char)( lowerNibble + 48 ) : (char)( lowerNibble + 55 );
+				hexadecimal[i * 2] = upper < 10 ? (char)(upper + 48) : (char)(upper + 55);
+				hexadecimal[i * 2 + 1] = lower < 10 ? (char)(lower + 48) : (char)(lower + 55);
 			}
 			return new String( hexadecimal );
 		}
 		
+		/// <summary> Returns the hex code represented by the given character.
+		/// Throws FormatException if the input character isn't a hex code. </summary>
 		public static int ParseHex( char value ) {
 			if( value >= '0' && value <= '9' ) {
 				return (int)( value - '0' );
@@ -100,7 +104,9 @@ namespace ClassicalSharp {
 			}
 		}
 		
+		/// <summary> Multiply a value in degrees by this to get its value in radians. </summary>
 		public const float Deg2Rad = (float)(Math.PI / 180);
+		/// <summary> Multiply a value in radians by this to get its value in degrees. </summary>
 		public const float Rad2Deg = (float)(180 / Math.PI);
 		
 		public static int DegreesToPacked( double degrees, int period ) {
@@ -147,6 +153,7 @@ namespace ClassicalSharp {
 			return new Vector3( cosA * x + sinA * y, -sinA * x + cosA * y, z );
 		}
 		
+		/// <summary> Returns the square of the euclidean distance between two points. </summary>
 		public static float DistanceSquared( Vector3 p1, Vector3 p2 ) {
 			float dx = p2.X - p1.X;
 			float dy = p2.Y - p1.Y;
@@ -154,6 +161,7 @@ namespace ClassicalSharp {
 			return dx * dx + dy * dy + dz * dz;
 		}
 		
+		/// <summary> Returns the square of the euclidean distance between two points. </summary>
 		public static float DistanceSquared( float x1, float y1, float z1, float x2, float y2, float z2 ) {
 			float dx = x2 - x1;
 			float dy = y2 - y1;
@@ -161,6 +169,7 @@ namespace ClassicalSharp {
 			return dx * dx + dy * dy + dz * dz;
 		}
 		
+		/// <summary> Returns the square of the euclidean distance between two points. </summary>
 		public static int DistanceSquared( int x1, int y1, int z1, int x2, int y2, int z2 ) {
 			int dx = x2 - x1;
 			int dy = y2 - y1;
@@ -221,19 +230,23 @@ namespace ClassicalSharp {
 			return value >= 0 ? (int)value : (int)value - 1;
 		}
 		
-		public static float Lerp( float a, float b, float t ) {
+		/// <summary> Returns the number of vertices needed to subdivide a quad. </summary>
-			return a + (b - a) * t;
-		}
-		
 		internal static int CountVertices( int axis1Len, int axis2Len, int axisSize ) {
 			return CeilDiv( axis1Len, axisSize ) * CeilDiv( axis2Len, axisSize ) * 4;
 		}
 		
+		/// <summary> Performs rounding upwards integer division. </summary>
 		public static int CeilDiv( int a, int b ) {
 			return a / b + (a % b != 0 ? 1 : 0);
 		}
 		
-		public static float InterpAngle( float leftAngle, float rightAngle, float t ) {
+		/// <summary> Performs linear interpolation between two values. </summary>
+		public static float Lerp( float a, float b, float t ) {
+			return a + (b - a) * t;
+		}
+		
+		/// <summary> Linearly interpolates between a given angle range, adjusting if necessary. </summary>
+		public static float LerpAngle( float leftAngle, float rightAngle, float t ) {
 			// we have to cheat a bit for angles here.
 			// Consider 350* --> 0*, we only want to travel 10*,
 			// but without adjusting for this case, we would interpolate back the whole 350* degrees.
@@ -245,6 +258,7 @@ namespace ClassicalSharp {
 			return Lerp( leftAngle, rightAngle, t );
 		}
 		
+		/// <summary> Determines the skin type of the specified bitmap. </summary>
 		public static SkinType GetSkinType( Bitmap bmp ) {
 			if( bmp.Width == bmp.Height * 2 ) {
 				return SkinType.Type64x32;
@@ -260,5 +274,9 @@ namespace ClassicalSharp {
 				throw new NotSupportedException( "unsupported skin dimensions: " + bmp.Width + ", " + bmp.Height );
 			}
 		}
+		
+		public static bool IsUrl( string value ) {
+			return value.StartsWith( "http://" ) || value.StartsWith( "https://" );
+		}
 	}
 }