unit GAF_Format;

interface

Const
  // The standard version for all GAFs and TAFs
  GafVersionStandard = $00010100;
// NOTE: Most of the content in this file was derived from the document
//       ta-gaf-fmt.txt by Joe D.
{$MINENUMSIZE 1}
type
  // The header at the beginning of ever GAF or TAF
  PGafHeader = ^TGafHeader;
  TGafHeader = packed record
    // Version is always $00010100 for both TA and Kingdoms
    Version : Longword;
    // Specifies the number of entries contained in this file
    NumberOfEntries : longword;
    // Presumably padding, its always $00000000
    Padding : longword;
    // Immediately following this header is an array of pointers to each
    // entry in this file.
    // EntryPointers : array [0 .. NumberOfEntries-1] of Longword;
  end; {TGafHeader}

  TGafName = Packed array [1..32] of char;
  // Each entry pointer points to a structure of this type.
  PGafEntry = ^TGafEntry;
  TGafEntry = packed record
    // Scecifies the number of graphical frames for this entry item
    NumberOfFrames : Word;
    // This is always $0001
    UnKnown_1 : Word;
    // This is always $0000
    UnKnown_2 : longword;
    // The unique name of this entry, always padded to 32 characters long with 0
    Name : TGafName;
    // Immediately following an entry is an array of frame entries
    // FrameEntries : array [ 0..NumberOfFrames-1 ] of TGafFrameEntry;
  end; {TGafEntry}

  // This structure provides an offset to the frame data
  PGafFrameEntry = ^TGafFrameEntry;
  TGafFrameEntry = packed record
    // The offset into the file at which the frame's data resides
    OffsetToFrameData : Longword;
    // This value seems to vary by a huge margin, perhaps it contains
    // bit flags used by CAVEDOG.
    Unknown_1 : longword;
  end; {TGafFrameEntry}

  PGafFrameData = ^TGafFrameData;
  TGafFrameData = packed record
    // The final width and height of the frame in pixels
    Width : word;
    Height : word;
    // The X and Y offset of the frame when displayed. Used for centering the
    // frame or other various purposes. Sometimes just ignored.
    XOffset : SmallInt;
    YOffset : SmallInt;
    // This is always $09 in TA, for TA:K .taf files it is $00
    Unknown_1 : Byte;
    // The compression flag for this frame
    CompressionMethod : byte;
    // Specifies the amount of subframes associated with this frame
    NumberOfSubFrames : word;
    // This is always $00000000
    Unknown_2 : Longword;
    // If there are no sub frames, this points to the pixel data.
    // If there are sub frames, this points to an array of offsets to
    // the sb frame data structures.
    OffsetToFrameData : Longword;
    // This seems to be another value that holds bit flags
    Unknown_3 : Longword;
  end; {TGafFrameData}

const
  // This flag indicates that the frame is uncompressed. OffsetToFrameData points
  // to an array of Width x Height bytes.
  GafFrameNotCompressed = 0;

  // This flag inndicates that the frame is compressed using the compression
  // scheme used for TA and Kingdoms
  GafFrameCompressed_TA = 1;

  // This flag indicates that the frame is compressed using the compression
  // scheme used for Kingdoms TAF files ending in "*_4444.TAF"
  GafFrameCompressed_TAK1 = 4;

  // This flag indicates that the frame is compressed using the compression
  // scheme used for Kingdoms TAF files ending in "*_1555.TAF"
  GafFrameCompressed_TAK2 = 5;

implementation

end.