/// <summary>
/// Creates a new <see cref="AsepriteHeader"/> instance.
/// </summary>
/// <param name="reader">
/// The <see cref="AsepriteReader"/> instance being used to read the
/// Aseprite file.
/// </param>
internal AsepriteHeader(AsepriteReader reader)
{
// Get the basestream position of the reader
long headerStart = reader.BaseStream.Position;
// Header is 128 bytes. Calcualte the base stream position that is
// at the end of the header
long headerEnd = headerStart + 128;
// Read but ignore the file size
_ = reader.ReadDWORD();
// Read and validate the magic number
if (reader.ReadWORD() != 0xA5E0)
{
throw new Exception($"File given does not appear to be a valid .ase/.aseprite file!");
}
FrameCount = reader.ReadWORD();
Width = reader.ReadWORD();
Height = reader.ReadWORD();
ColorDepth = (AsepriteColorDepth)(reader.ReadWORD() / 8);
_flags = (AsepriteHeaderFlags)reader.ReadDWORD();
// Per ase file specs, the speed field is deprecated, so we'll
// ignroe it.
_ = reader.ReadWORD();
// Per ase file specs, next two DWORDs are ignored.
_ = reader.ReadDWORD();
_ = reader.ReadDWORD();
TransparentIndex = reader.ReadByte();
// Per ase file specs, next 3 bytes are ignored
reader.Ignore(3);
ColorCount = reader.ReadWORD();
// We're going to ignore the rest of the header as we don't need
// the information. For documentation though, the following is
// what we are skipping
//
// Pixel Width
// Pixel Height
// X position of the grid
// Y position of the grid
// Grid width (zero if there is no grid, grid size is 16x16 on Aseprite default)
// Grid height (zero if there is no grid
// 84 bytes which are reserved for future use.
//
// Since we are skipping all this, we'll just set the reader's basestream to
// the end of the header position we calculated earlier
reader.BaseStream.Position = headerEnd;
}
/// <summary>
/// Creates a new <see cref="AsepriteSliceChunk"/> instance.
/// </summary>
/// <param name="reader">
/// The <see cref="AsepriteReader"/> instance being used to read the
/// Aseprite file.
/// </param>
internal AsepriteSliceChunk(AsepriteReader reader)
{
TotalKeys = (int)reader.ReadDWORD();
Flags = (AsepriteSliceFlags)reader.ReadDWORD();
// Per ase file spec, ignore the next DWORD, it's "reserved"
_ = reader.ReadDWORD();
Name = reader.ReadString();
Keys = new AsepriteSliceKey[TotalKeys];
for (int i = 0; i < TotalKeys; i++)
{
Keys[i] = new AsepriteSliceKey(reader, Flags);
}
}
private void ReadAsNewPalette(AsepriteReader reader)
{
// Read the size value
int size = (int)reader.ReadDWORD();
// Read the first index value.
int firstIndex = (int)reader.ReadDWORD();
// Read the last index value.
int lastIndex = (int)reader.ReadDWORD();
// Per ase file spec, ignore next 8 bytes, they are reserved for future use
reader.Ignore(8);
Colors = new AsepritePaletteColor[size];
for (int i = 0; i < lastIndex - firstIndex + 1; i++)
{
Colors[i] = new AsepritePaletteColor(reader, true);
}
}
/// <summary>
/// Creates a new <see cref="AsepriteSliceKey"/> instance.
/// </summary>
/// <param name="reader">
/// The <see cref="AsepriteReader"/> instance being used to read the
/// Aseprite file.
/// </param>
/// <param name="flags">
/// The <see cref="AsepriteSliceFlags"/> value of the slice this
/// slice key belongs to.
/// </param>
internal AsepriteSliceKey(AsepriteReader reader, AsepriteSliceFlags flags)
{
Frame = (int)reader.ReadDWORD();
X = reader.ReadLONG();
Y = reader.ReadLONG();
Width = (int)reader.ReadDWORD();
Height = (int)reader.ReadDWORD();
if ((flags & AsepriteSliceFlags.HasNinePatch) != 0)
{
CenterX = reader.ReadLONG();
CenterY = reader.ReadLONG();
Width = (int)reader.ReadDWORD();
Height = (int)reader.ReadDWORD();
}
if ((flags & AsepriteSliceFlags.HasPivot) != 0)
{
PivotX = reader.ReadLONG();
PivotY = reader.ReadLONG();
}
}
/// <summary>
/// Reads the userdata values for this chunk from the provided
/// reader.
/// </summary>
/// <param name="reader">
/// The <see cref="AsepriteReader"/> instance being used to read the
/// Aseprite file.
/// </param>
internal void ReadUserData(AsepriteReader reader)
{
AsepriteUserDataFlags flags = (AsepriteUserDataFlags)reader.ReadDWORD();
if ((flags & AsepriteUserDataFlags.HasText) != 0)
{
UserDataText = reader.ReadString();
}
if ((flags & AsepriteUserDataFlags.HasColor) != 0)
{
UserDataColor = new byte[4];
UserDataColor[0] = reader.ReadByte();
UserDataColor[1] = reader.ReadByte();
UserDataColor[2] = reader.ReadByte();
UserDataColor[3] = reader.ReadByte();
}
}
/// <summary>
/// Creates a new <see cref="AsepriteFrame"/> instance.
/// </summary>
/// <param name="file">
/// The <see cref="AsepriteDocument"/> instance this frame belongs to.
/// </param>
/// <param name="reader">
/// The <see cref="AsepriteReader"/> instance being used to read the
/// Aseprite file.
/// </param>
internal AsepriteFrame(AsepriteDocument file, AsepriteReader reader)
{
Cels = new List <AsepriteCelChunk>();
File = file;
// Ignore the total bytes in frame value, we don't need it
_ = reader.ReadDWORD();
// Read and validate the magic number
if (reader.ReadWORD() != 0xF1FA)
{
throw new Exception($"Invalid frame header, please ensure the .ase/.aseprite file is valid");
}
// The next field contains the chunk count, but this is the old chunk count field
int oldChunkCount = reader.ReadWORD();
// Aseprite stores the frame duration value as milliseconds
Duration = reader.ReadWORD();
// Per ase file spec, the next two bytes are reserved for future use
reader.Ignore(2);
// This field contains the chunk count, but is the new chunk count field.
uint newChunkCount = reader.ReadDWORD();
// Per ase file spec, if the new chunk count filed is 0, then we use the old field
// value instad.
int totalChunks = newChunkCount == 0 ? oldChunkCount : (int)newChunkCount;
// A value indicating if the new palette chunk was found. When it is found
// then we can skip reading the old palette chunk.
bool newPaletteChunkFound = false;
for (int i = 0; i < totalChunks; i++)
{
long chunkStart = reader.BaseStream.Position;
uint chunkSize = reader.ReadDWORD();
long chunkEnd = chunkStart + chunkSize;
AsepriteChunkType chunkType = (AsepriteChunkType)reader.ReadWORD();
System.Diagnostics.Debug.WriteLine($"Chunk Type: {chunkType}");
switch (chunkType)
{
case AsepriteChunkType.Layer:
ReadLayerChunk(reader);
break;
case AsepriteChunkType.Cel:
ReadCelChunk(reader, (int)chunkSize - 6);
break;
case AsepriteChunkType.Tags:
ReadTagChunk(reader);
break;
case AsepriteChunkType.OldPaletteA:
if (newPaletteChunkFound)
{
reader.BaseStream.Position = chunkEnd;
}
else
{
ReadOldPalleteAChunk(reader);
}
break;
case AsepriteChunkType.Palette:
ReadPaletteChunk(reader);
newPaletteChunkFound = true;
break;
case AsepriteChunkType.UserData:
ReadUserDataChunk(reader);
break;
case AsepriteChunkType.Slice:
ReadSliceChunk(reader);
break;
case AsepriteChunkType.OldPaletteB: // Ignore
case AsepriteChunkType.CelExtra: // Ignore
case AsepriteChunkType.ColorProfile: // Ignore
case AsepriteChunkType.Mask: // Ignore
case AsepriteChunkType.Path: // Ignore
// Since we are ignoreing these chunk types, we need to ensure that the
// reader's basestream position is set to where the end of the ignored
// chunk would be.
reader.BaseStream.Position = chunkEnd;
break;
default:
throw new Exception("Invalid chunk type detected");
}
}
}
