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

namespace SixLabors.Fonts.Tables.General.Colr {
  /// <summary>
  /// Represents a variation-aware 2x3 affine transformation matrix used by COLR v1 PaintVarTransform operations.
  /// Values are stored as Fixed 16.16 numbers with an associated variation index base for font variations.
  /// <see href="https://learn.microsoft.com/en-us/typography/opentype/spec/colr#formats-12-and-13-painttransform-paintvartransform"/>
  /// </summary>
  internal readonly struct VarAffine2x3
  {
      /// <summary>
      /// The x-component of the x-basis vector.
      /// </summary>
      public readonly float Xx;

      /// <summary>
      /// The y-component of the x-basis vector.
      /// </summary>
      public readonly float Yx;

      /// <summary>
      /// The x-component of the y-basis vector.
      /// </summary>
      public readonly float Xy;

      /// <summary>
      /// The y-component of the y-basis vector.
      /// </summary>
      public readonly float Yy;

      /// <summary>
      /// The x-translation component.
      /// </summary>
      public readonly float Dx;

      /// <summary>
      /// The y-translation component.
      /// </summary>
      public readonly float Dy;

      /// <summary>
      /// The base index into the ItemVariationStore delta sets for this transform's variation data.
      /// </summary>
      public readonly uint VarIndexBase;

      /// <summary>
      /// Initializes a new instance of the <see cref="VarAffine2x3"/> struct.
      /// </summary>
      /// <param name="xx">The x-component of the x-basis vector.</param>
      /// <param name="yx">The y-component of the x-basis vector.</param>
      /// <param name="xy">The x-component of the y-basis vector.</param>
      /// <param name="yy">The y-component of the y-basis vector.</param>
      /// <param name="dx">The x-translation component.</param>
      /// <param name="dy">The y-translation component.</param>
      /// <param name="varIndexBase">The base index into the ItemVariationStore delta sets.</param>
      public VarAffine2x3(float xx, float yx, float xy, float yy, float dx, float dy, uint varIndexBase)
      {
          this.Xx = xx;
          this.Yx = yx;
          this.Xy = xy;
          this.Yy = yy;
          this.Dx = dx;
          this.Dy = dy;
          this.VarIndexBase = varIndexBase;
      }
  }
}