Added streaming support to Face

Source/SharpFont/FTStream.cs

@@ -43,14 +43,14 @@ namespace SharpFont
 	/// <returns>The number of bytes effectively read by the stream.</returns>
 	[CLSCompliant(false)]
 	[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
-	public delegate uint StreamIOFunc(NativeReference<FTStream> stream, uint offset, IntPtr buffer, uint count);
+	public delegate uint StreamIOFunc(IntPtr stream, uint offset, IntPtr buffer, uint count);
 
 	/// <summary>
 	/// A function used to close a given input stream.
 	/// </summary>
 	/// <param name="stream">A handle to the target stream.</param>
 	[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
-	public delegate void StreamCloseFunc(NativeReference<FTStream> stream);
+	public delegate void StreamCloseFunc(IntPtr stream);
 
 	/// <summary>
 	/// A handle to an input stream.
@@ -84,7 +84,7 @@ public IntPtr Base
 				return rec.@base;
 			}
 		}
-		
+
 		/// <summary>
 		/// Gets the stream size in bytes.
 		/// </summary>

Source/SharpFont/Face.cs

@@ -24,6 +24,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Runtime.InteropServices;
 
 using SharpFont.Bdf;
@@ -53,6 +54,12 @@ public sealed class Face : NativeObject, IDisposable
 		private Library parentLibrary;
 		private List<FTSize> childSizes;
 
+		GCHandle customStreamHandle;
+		IntPtr customStreamPtr;
+		private IntPtr openArgsPtr;
+		private StreamIOFunc streamIOFunc;
+		private StreamCloseFunc streamCloseFunc;
+
 		#endregion
 
 		#region Constructors
@@ -67,6 +74,8 @@ public Face(Library library, string path)
 		{
 		}
 
+
+
 		/// <summary>
 		/// Initializes a new instance of the <see cref="Face"/> class.
 		/// </summary>
@@ -85,7 +94,85 @@ public Face(Library library, string path, int faceIndex)
 			Reference = reference;
 		}
 
-		//TODO make an overload with a FileStream instead of a byte[]
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="Face"/> class.
+		/// </summary>
+		/// <param name="library">The parent library.</param>
+		/// <param name="stream">The stream of the font file.</param>
+		/// <param name="faceIndex">The index of the face to take from the file.</param>
+		/// <param name="takeStreamOwnership">The stream is automatically disposed with the face.</param>
+		public Face(Library library, Stream stream, int faceIndex, bool takeStreamOwnership)
+			: this(library, new StreamAccessor(stream, takeStreamOwnership), faceIndex)
+		{
+		}
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="Face"/> class.
+		/// </summary>
+		/// <param name="library">The parent library.</param>
+		/// <param name="streamAccessor">Custom object for handling stream access to the font file.</param>
+		/// <param name="faceIndex">The index of the face to take from the file.</param>
+		public Face(Library library, ICustomStreamAccessor streamAccessor, int faceIndex)
+			: this(library)
+		{
+			IntPtr reference;
+
+			streamIOFunc = new StreamIOFunc(StreamIOFunc);
+			streamCloseFunc = new StreamCloseFunc(StreamCloseFunc);
+
+			customStreamHandle = GCHandle.Alloc(streamAccessor);
+
+			StreamRec streamRec = new StreamRec();
+			streamRec.size = (UIntPtr)streamAccessor.Length;
+			streamRec.descriptor.pointer = GCHandle.ToIntPtr(customStreamHandle);
+			streamRec.read = streamIOFunc;
+			streamRec.close = streamCloseFunc;
+
+			customStreamPtr = Marshal.AllocHGlobal(Marshal.SizeOf(streamRec));
+			Marshal.StructureToPtr(streamRec, customStreamPtr, false);
+
+
+			OpenArgsRec openArgs = new OpenArgsRec();
+			openArgs.flags = OpenFlags.Stream;
+			openArgs.stream = customStreamPtr;
+
+			openArgsPtr = Marshal.AllocHGlobal(Marshal.SizeOf(openArgs));
+			Marshal.StructureToPtr(openArgs, openArgsPtr, false);
+
+
+			Error err = FT.FT_Open_Face(library.Reference, openArgsPtr, faceIndex, out reference);
+			if (err != Error.Ok)
+				throw new FreeTypeException(err);
+
+			Reference = reference;
+		}
+
+		private uint StreamIOFunc(IntPtr streamPtr, uint offset, IntPtr buffer, uint count)
+		{
+			FTStream ftStream = new FTStream(streamPtr);
+			ICustomStreamAccessor streamAccessor = ((GCHandle)ftStream.Descriptor.Pointer).Target as ICustomStreamAccessor;
+			if (streamAccessor != null)
+			{
+				streamAccessor.Seek((int)offset);
+				if (count > 0)
+				{
+					byte[] readbuffer = new byte[count];
+					int bytesread = streamAccessor.Read(readbuffer);
+					Marshal.Copy(readbuffer, 0, buffer, (int)count);
+					return (uint)bytesread;
+				}
+			}
+			return 0;
+		}
+
+		private void StreamCloseFunc(IntPtr streamPtr)
+		{
+			FTStream ftStream = new FTStream(streamPtr);
+			ICustomStreamAccessor streamAccessor = ((GCHandle)ftStream.Descriptor.Pointer).Target as ICustomStreamAccessor;
+			if (streamAccessor != null) streamAccessor.Close();
+		}
+
 
 		/// <summary>
 		/// Initializes a new instance of the <see cref="Face"/> class from a file that's already loaded into memory.
@@ -2401,6 +2488,10 @@ private void Dispose(bool disposing)
 				if (memoryFaceHandle.IsAllocated)
 					memoryFaceHandle.Free();
 
+				if (openArgsPtr != IntPtr.Zero) Marshal.FreeHGlobal(openArgsPtr);
+				if (customStreamPtr != IntPtr.Zero) Marshal.FreeHGlobal(customStreamPtr);
+				if (customStreamHandle.IsAllocated) customStreamHandle.Free();
+
 				EventHandler handler = Disposed;
 				if (handler != null)
 					handler(this, EventArgs.Empty);

Source/SharpFont/ICustomStreamAccessor.cs

@@ -0,0 +1,56 @@
+#region MIT License
+/*Copyright (c) 2015-2016 Robert Rouhani <[email protected]>
+
+SharpFont based on Tao.FreeType, Copyright (c) 2003-2007 Tao Framework Team
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.*/
+#endregion
+
+namespace SharpFont
+{
+	/// <summary>
+	/// Interface for providing access to a custom stream representing a font file.
+	/// </summary>
+	public interface ICustomStreamAccessor
+	{
+		/// <summary>
+		/// Seeks to a specified position within a stream.
+		/// </summary>
+		/// <param name="position">Position from the beginning of the stream to seek to.</param>
+		/// <returns>The new position within the stream.</returns>
+		int Seek(int position);
+
+		/// <summary>
+		/// Reads bytes from the stream. The maximum number of bytes to read is specified by the buffer length.
+		/// </summary>
+		/// <param name="buffer">Buffer to receive read bytes.</param>
+		/// <returns>The actual number of bytes read from the stream.</returns>
+		int Read(byte[] buffer);
+
+		/// <summary>
+		/// Closes the stream. Called by freetype once the font face is destroyed.
+		/// </summary>
+		void Close();
+
+		/// <summary>
+		/// Returns total length of the stream in bytes.
+		/// </summary>
+		int Length { get; }
+	}
+}

Source/SharpFont/SharpFont.csproj

@@ -119,6 +119,7 @@
     <Compile Include="GlyphMetrics.cs" />
     <Compile Include="GlyphSlot.cs" />
     <Compile Include="GlyphToScriptMapProperty.cs" />
+    <Compile Include="ICustomStreamAccessor.cs" />
     <Compile Include="IncreaseXHeightProperty.cs" />
     <Compile Include="Internal\BitmapGlyphRec.cs" />
     <Compile Include="Internal\BitmapRec.cs" />
@@ -205,6 +206,7 @@
     <Compile Include="SizeRequest.cs" />
     <Compile Include="SizeRequestType.cs" />
     <Compile Include="Span.cs" />
+    <Compile Include="StreamAccessor.cs" />
     <Compile Include="StreamDesc.cs" />
     <Compile Include="Stroker.cs" />
     <Compile Include="StrokerBorder.cs" />

Source/SharpFont/StreamAccessor.cs

@@ -0,0 +1,76 @@
+#region MIT License
+/*Copyright (c) 2015-2016 Robert Rouhani <[email protected]>
+
+SharpFont based on Tao.FreeType, Copyright (c) 2003-2007 Tao Framework Team
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.*/
+#endregion
+
+using System;
+using System.IO;
+
+namespace SharpFont
+{
+	/// <summary>
+	/// Custom font stream accessor based on a generic Stream object.
+	/// </summary>
+	internal class StreamAccessor : ICustomStreamAccessor
+	{
+		private Stream _stream;
+		private bool _takeStreamOwnership;
+
+		public StreamAccessor(Stream stream, bool takeStreamOwnership)
+		{
+			if (stream == null)
+				throw new ArgumentException("Stream cannot be null", "stream");
+
+			if (!stream.CanRead || !stream.CanSeek)
+				throw new ArgumentException("Stream must support reading and seeking", "stream");
+
+			_stream = stream;
+			_takeStreamOwnership = takeStreamOwnership;
+		}
+
+		public void Close()
+		{
+			if (_takeStreamOwnership)
+			{
+				_stream.Dispose();
+			}
+		}
+
+		public int Read(byte[] buffer)
+		{
+			return _stream.Read(buffer, 0, buffer.Length);
+		}
+
+		public int Seek(int position)
+		{
+			return (int)_stream.Seek(position, SeekOrigin.Begin);
+		}
+
+		public int Length
+		{
+			get
+			{
+				return (int)_stream.Length;
+			}
+		}
+	}
+}