TestVariations.pas

unit TestVariations;

interface

{$I PT_Compiler.inc}

uses
  System.SysUtils,
  System.Classes,
  TestFramework,
  PascalType.Types,
  PascalType.Classes,
  PascalType.FontFace.SFNT,
  PascalType.Variation,
  PascalType.Tables.Apple;

type
  TTestVariations = class(TTestCase)
  private
    FFontFace: TPascalTypeFontFace;
  public
    procedure SetUp; override;
    procedure TearDown; override;
  published
    procedure TestAxisNormalization;
    procedure TestCoordinateClamping;
    procedure TestAvarMapping;
  end;

implementation

{ TTestVariations }

procedure TTestVariations.SetUp;
begin
  inherited;
  FFontFace := TPascalTypeFontFace.Create;
end;

procedure TTestVariations.TearDown;
begin
  FFontFace.Free;
  inherited;
end;

procedure TTestVariations.TestAxisNormalization;
var
  Stream: TMemoryStream;
  Engine: TPascalTypeVariationEngine;
begin
  Stream := TMemoryStream.Create;
  try
    // Header (16 bytes)
    BigEndianValue.WriteWord(Stream, 1); // major
    BigEndianValue.WriteWord(Stream, 0); // minor
    BigEndianValue.WriteWord(Stream, 16); // axesOffset
    BigEndianValue.WriteWord(Stream, 2); // reserved
    BigEndianValue.WriteWord(Stream, 1); // axisCount
    BigEndianValue.WriteWord(Stream, 20); // axisSize
    BigEndianValue.WriteWord(Stream, 0); // instanceCount
    BigEndianValue.WriteWord(Stream, 8); // instanceSize (2*2 + 1*4)

    // Axis Record (20 bytes)
    Stream.Write(AnsiString('wght')[1], 4);
    BigEndianValue.WriteInteger(Stream, 100 shl 16); // min
    BigEndianValue.WriteInteger(Stream, 400 shl 16); // default
    BigEndianValue.WriteInteger(Stream, 900 shl 16); // max
    BigEndianValue.WriteWord(Stream, 0); // flags
    BigEndianValue.WriteWord(Stream, 256); // nameID

    Stream.Position := 0;
    FFontFace.AddTable('fvar').LoadFromStream(Stream, Stream.Size);
  finally
    Stream.Free;
  end;

  Engine := TPascalTypeVariationEngine.Create(FFontFace);
  try
    // Test min
    Engine.SetAxisValue('wght', 100);
    CheckEquals(Engine.NormalizedCoordinates[0].AsSingle, -1.0, 0.0001, 'Min should normalize to -1');

    // Test default
    Engine.SetAxisValue('wght', 400);
    CheckEquals(Engine.NormalizedCoordinates[0].AsSingle, 0.0, 0.0001, 'Default should normalize to 0');

    // Test max
    Engine.SetAxisValue('wght', 900);
    CheckEquals(Engine.NormalizedCoordinates[0].AsSingle, 1.0, 0.0001, 'Max should normalize to 1');

    // Test middle (linear)
    Engine.SetAxisValue('wght', 650);
    CheckEquals(Engine.NormalizedCoordinates[0].AsSingle, 0.5, 0.0001, '650 should normalize to 0.5');
  finally
    Engine.Free;
  end;
end;

procedure TTestVariations.TestCoordinateClamping;
var
  Stream: TMemoryStream;
  Engine: TPascalTypeVariationEngine;
begin
  Stream := TMemoryStream.Create;
  try
    // Header (16 bytes)
    BigEndianValue.WriteWord(Stream, 1); // major
    BigEndianValue.WriteWord(Stream, 0); // minor
    BigEndianValue.WriteWord(Stream, 16); // axesOffset
    BigEndianValue.WriteWord(Stream, 2); // reserved
    BigEndianValue.WriteWord(Stream, 1); // axisCount
    BigEndianValue.WriteWord(Stream, 20); // axisSize
    BigEndianValue.WriteWord(Stream, 0); // instanceCount
    BigEndianValue.WriteWord(Stream, 8); // instanceSize (2*2 + 1*4)

    // Axis Record (20 bytes)
    Stream.Write(AnsiString('wght')[1], 4);
    BigEndianValue.WriteInteger(Stream, 100 shl 16); // min
    BigEndianValue.WriteInteger(Stream, 400 shl 16); // default
    BigEndianValue.WriteInteger(Stream, 900 shl 16); // max
    BigEndianValue.WriteWord(Stream, 0); // flags
    BigEndianValue.WriteWord(Stream, 256); // nameID

    Stream.Position := 0;
    FFontFace.AddTable('fvar').LoadFromStream(Stream, Stream.Size);
  finally
    Stream.Free;
  end;

  Engine := TPascalTypeVariationEngine.Create(FFontFace);
  try
    // Test clamping to min
    Engine.SetAxisValue('wght', 50);
    CheckEquals(100.0, Engine.UserCoordinates[0].AsSingle, 'Should clamp to 100');
    CheckEquals(-1.0, Engine.NormalizedCoordinates[0].AsSingle, 'Should normalize to -1');

    // Test clamping to max
    Engine.SetAxisValue('wght', 1000);
    CheckEquals(900.0, Engine.UserCoordinates[0].AsSingle, 'Should clamp to 900');
    CheckEquals(1.0, Engine.NormalizedCoordinates[0].AsSingle, 'Should normalize to 1');
  finally
    Engine.Free;
  end;
end;

procedure TTestVariations.TestAvarMapping;
var
  fvarStream, avarStream: TMemoryStream;
  Engine: TPascalTypeVariationEngine;
begin
  fvarStream := TMemoryStream.Create;
  try
    // fvar Header
    BigEndianValue.WriteWord(fvarStream, 1);
    BigEndianValue.WriteWord(fvarStream, 0);
    BigEndianValue.WriteWord(fvarStream, 16);
    BigEndianValue.WriteWord(fvarStream, 2);
    BigEndianValue.WriteWord(fvarStream, 1);
    BigEndianValue.WriteWord(fvarStream, 20);
    BigEndianValue.WriteWord(fvarStream, 0);
    BigEndianValue.WriteWord(fvarStream, 8);
    // fvar Axis
    fvarStream.Write(AnsiString('wght')[1], 4);
    BigEndianValue.WriteInteger(fvarStream, 100 shl 16);
    BigEndianValue.WriteInteger(fvarStream, 400 shl 16);
    BigEndianValue.WriteInteger(fvarStream, 900 shl 16);
    BigEndianValue.WriteWord(fvarStream, 0);
    BigEndianValue.WriteWord(fvarStream, 256);

    fvarStream.Position := 0;
    FFontFace.AddTable('fvar').LoadFromStream(fvarStream, fvarStream.Size);
  finally
    fvarStream.Free;
  end;

  avarStream := TMemoryStream.Create;
  try
    // avar Header (8 bytes)
    BigEndianValue.WriteWord(avarStream, 1); // major
    BigEndianValue.WriteWord(avarStream, 0); // minor
    BigEndianValue.WriteWord(avarStream, 0); // reserved
    BigEndianValue.WriteWord(avarStream, 1); // axisCount

    // Segment (axis 0)
    BigEndianValue.WriteWord(avarStream, 3);
    // pair 0: -1.0 -> -1.0
    BigEndianValue.WriteSmallInt(avarStream, -16384);
    BigEndianValue.WriteSmallInt(avarStream, -16384);
    // pair 1: 0.0 -> 0.5 (mapping linear 0 to 0.5)
    BigEndianValue.WriteSmallInt(avarStream, 0);
    BigEndianValue.WriteSmallInt(avarStream, 8192); // 0.5 in F2DOT14
    // pair 2: 1.0 -> 1.0
    BigEndianValue.WriteSmallInt(avarStream, 16384);
    BigEndianValue.WriteSmallInt(avarStream, 16384);

    avarStream.Position := 0;
    FFontFace.AddTable('avar').LoadFromStream(avarStream, avarStream.Size);
  finally
    avarStream.Free;
  end;

  Engine := TPascalTypeVariationEngine.Create(FFontFace);
  try
    // Default value (400) normalizes linearly to 0.
    // avar maps 0 to 0.5.
    Engine.SetAxisValue('wght', 400);
    CheckEquals(Engine.NormalizedCoordinates[0].AsSingle, 0.5, 0.0001, 'avar should map linear 0 to 0.5');
  finally
    Engine.Free;
  end;
end;

initialization
  RegisterTest(TTestVariations.Suite);
end.