/// <summary>
/// Constructor which takes an existing APNGChunk object and
/// verifies that its type matches that which is expected
/// </summary>
/// <param name="chunk">The APNGChunk to copy</param>
/// <param name="expectedType">The input APNGChunk expected type</param>
public APNGChunk(APNGChunk chunk, String expectedType)
{
// Copy the existing chunks members
chunkLength = chunk.chunkLength;
chunkType = chunk.chunkType;
chunkData = chunk.chunkData;
chunkCRC = chunk.chunkCRC;
// Verify the chunk type is as expected
if (ChunkType != expectedType)
{
throw new ArgumentException(
String.Format("Specified chunk type is not {0} as expected", expectedType));
}
// Parse the chunk's data
ParseData(chunkData);
}
/// <summary>
/// Attempts to load an APNG from the specified file name
/// </summary>
/// <param name="filename">Name of the APNG file to load</param>
public void Load(string filename)
{
chunks = new List <APNGChunk>();
pngs = new List <PNG>();
// Open the file for reading
Stream stream = File.OpenRead(filename);
// Create a new header (should be 1 per file) and
// read it from the stream
APNGHeader header = new APNGHeader();
try
{
header.Read(stream);
}
catch (Exception)
{
stream.Close();
throw;
}
APNGChunk chunk;
PNG png = null;
// Read chunks from the stream until we reach the MEND chunk
do
{
// Read a generic Chunk
chunk = new APNGChunk();
try
{
chunk.Read(stream);
}
catch (Exception)
{
stream.Close();
throw;
}
// Take a look at the chunk type and decide what derived class to
// use to create a specific chunk
switch (chunk.ChunkType)
{
case acTLChunk.NAME:
if (headerChunk != null)
{
throw new ApplicationException(String.Format(
"Only one chunk of type {0} is allowed", chunk.ChunkType));
}
chunk = headerChunk = new acTLChunk(chunk);
break;
case MENDChunk.NAME:
chunk = new MENDChunk(chunk);
break;
case TERMChunk.NAME:
chunk = new TERMChunk(chunk);
break;
case BACKChunk.NAME:
chunk = new BACKChunk(chunk);
break;
case BKGDChunk.NAME:
chunk = new BKGDChunk(chunk);
break;
case fcTLChunk.NAME:
// This is the beginning of a new embedded PNG
chunk = new fcTLChunk(chunk);
png = new PNG();
png.FCTL = chunk as fcTLChunk;
png.IHDR = ihdrChunk;
pngs.Add(png);
break;
case IHDRChunk.NAME:
chunk = new IHDRChunk(chunk);
ihdrChunk = chunk as IHDRChunk;
break;
case IDATChunk.NAME:
chunk = new IDATChunk(chunk);
if (png != null)
{
png.IDAT = chunk as IDATChunk;
}
break;
case fdATChunk.NAME:
chunk = new fdATChunk(chunk);
if (png != null)
{
chunk.ChunkType = IDATChunk.NAME;
png.IDAT = new IDATChunk(chunk);
}
break;
case IENDChunk.NAME:
chunk = new IENDChunk(chunk);
for (int i = 0; i < pngs.Count; i++)
{
pngs[i].IEND = chunk as IENDChunk;
}
break;
default:
break;
}
// Add the chunk to our list of chunks
chunks.Add(chunk);
}while (chunk.ChunkType != IENDChunk.NAME);
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="chunk">The APNG chunk containing the data for this specific chunk</param>
public fdATChunk(APNGChunk chunk)
: base(chunk, NAME)
{
}
///// <summary>
///// The APNG frame rate
///// </summary>
//private uint ticksPerSecond;
///// <summary>
///// The APNG layer count
///// </summary>
//private uint nominalLayerCount;
///// <summary>
///// The APNG frame count
///// </summary>
//private uint nominalFrameCount;
///// <summary>
///// The APNG play time
///// </summary>
//private uint nominalPlayTime;
///// <summary>
///// The APNG simplicity profile
///// </summary>
//private uint simplicityProfile;
/// <summary>
/// Constructor
/// </summary>
/// <param name="chunk">The APNG chunk containing the data for this specific chunk</param>
public acTLChunk(APNGChunk chunk)
: base(chunk, NAME)
{
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="chunk">The APNG chunk containing the data for this specific chunk</param>
public IENDChunk(APNGChunk chunk)
: base(chunk, NAME)
{
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="chunk">The APNG chunk containing the data for this specific chunk</param>
public IHDRChunk(APNGChunk chunk)
: base(chunk, NAME)
{
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="chunk">The APNG chunk containing the data for this specific chunk</param>
public BACKChunk(APNGChunk chunk)
: base(chunk, NAME)
{
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="chunk">The APNG chunk containing the data for this specific chunk</param>
public BKGDChunk(APNGChunk chunk)
: base(chunk, NAME)
{
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="chunk">The APNG chunk containing the data for this specific chunk</param>
public TERMChunk(APNGChunk chunk)
: base(chunk, NAME)
{
}
