FT_Open_Face() private method

private FT_Open_Face ( IntPtr library, IntPtr args, int face_index, IntPtr &aface ) : System.Error
library System.IntPtr
args System.IntPtr
face_index int
aface System.IntPtr
return System.Error
FT Class Documentation
Example #1
0
        /// <summary>
        /// Create a <see cref="Face"/> object from a given resource described by <see cref="OpenArgs"/>.
        /// </summary>
        /// <remarks><para>
        /// Unlike FreeType 1.x, this function automatically creates a glyph slot for the face object which can be
        /// accessed directly through <see cref="Face.Glyph"/>.
        /// </para><para>
        /// OpenFace can be used to quickly check whether the font format of a given font resource is supported by
        /// FreeType. If the ‘faceIndex’ field is negative, the function's return value is 0 if the font format is
        /// recognized, or non-zero otherwise; the function returns a more or less empty face handle in ‘*aface’ (if
        /// ‘aface’ isn't NULL). The only useful field in this special case is <see cref="Face.FaceCount"/> which gives
        /// the number of faces within the font file. After examination, the returned <see cref="Face"/> structure
        /// should be deallocated with a call to <see cref="Face.Dispose()"/>.
        /// </para><para>
        /// Each new face object created with this function also owns a default <see cref="FTSize"/> object, accessible
        /// as <see cref="Face.Size"/>.
        /// </para><para>
        /// See the discussion of reference counters in the description of FT_Reference_Face.
        /// </para></remarks>
        /// <param name="args">
        /// A pointer to an <see cref="OpenArgs"/> structure which must be filled by the caller.
        /// </param>
        /// <param name="faceIndex">The index of the face within the font. The first face has index 0.</param>
        /// <returns>
        /// A handle to a new face object. If ‘faceIndex’ is greater than or equal to zero, it must be non-NULL.
        /// </returns>
        public Face OpenFace(OpenArgs args, int faceIndex)
        {
            if (disposed)
            {
                throw new ObjectDisposedException("Library", "Cannot access a disposed object.");
            }

            IntPtr faceRef;

            Error err = FT.FT_Open_Face(Reference, args.Reference, faceIndex, out faceRef);

            if (err != Error.Ok)
            {
                throw new FreeTypeException(err);
            }

            return(new Face(faceRef, this));
        }