// Copyright (c) Six Labors.
// Licensed under the Six Labors Split License.

using SixLabors.Fonts.Tables.TrueType.Glyphs;

namespace SixLabors.Fonts.Tables.Woff {
  /// <summary>
  /// A glyph loader for WOFF2 fonts that wraps a pre-parsed <see cref="GlyphVector"/>
  /// from the transformed glyph data stream.
  /// See: <see href="https://www.w3.org/TR/WOFF2/#glyf_table_format"/>.
  /// </summary>
  internal sealed class Woff2GlyphLoader : GlyphLoader
  {
      /// <summary>
      /// The glyph vector containing the decoded outline data.
      /// </summary>
      private GlyphVector glyphVector;

      /// <summary>
      /// Initializes a new instance of the <see cref="Woff2GlyphLoader"/> class.
      /// </summary>
      /// <param name="glyphVector">The pre-parsed glyph vector from the WOFF2 transformed glyph stream.</param>
      public Woff2GlyphLoader(GlyphVector glyphVector) => this.glyphVector = glyphVector;

      /// <summary>
      /// Creates a glyph vector, computing bounding box on demand if not already set.
      /// </summary>
      /// <param name="table">The glyph table.</param>
      /// <returns>The <see cref="GlyphVector"/>.</returns>
      public override GlyphVector CreateGlyph(GlyphTable table)
      {
          if (this.glyphVector.Bounds == default)
          {
              this.glyphVector.Bounds = Bounds.Load(this.glyphVector.ControlPoints);
          }

          return this.glyphVector;
      }
  }
}