58 lines
No EOL
1.7 KiB
C#
58 lines
No EOL
1.7 KiB
C#
namespace Uwaa.PNG;
|
|
|
|
/// <summary>
|
|
/// The header for a data chunk in a PNG file.
|
|
/// </summary>
|
|
public readonly struct ChunkHeader
|
|
{
|
|
/// <summary>
|
|
/// The position/start of the chunk header within the stream.
|
|
/// </summary>
|
|
public long Position { get; }
|
|
|
|
/// <summary>
|
|
/// The length of the chunk in bytes.
|
|
/// </summary>
|
|
public int Length { get; }
|
|
|
|
/// <summary>
|
|
/// The name of the chunk, uppercase first letter means the chunk is critical (vs. ancillary).
|
|
/// </summary>
|
|
public string Name { get; }
|
|
|
|
/// <summary>
|
|
/// Whether the chunk is critical (must be read by all readers) or ancillary (may be ignored).
|
|
/// </summary>
|
|
public bool IsCritical => char.IsUpper(Name[0]);
|
|
|
|
/// <summary>
|
|
/// A public chunk is one that is defined in the International Standard or is registered in the list of public chunk types maintained by the Registration Authority.
|
|
/// Applications can also define private (unregistered) chunk types for their own purposes.
|
|
/// </summary>
|
|
public bool IsPublic => char.IsUpper(Name[1]);
|
|
|
|
/// <summary>
|
|
/// Whether the (if unrecognized) chunk is safe to copy.
|
|
/// </summary>
|
|
public bool IsSafeToCopy => char.IsUpper(Name[3]);
|
|
|
|
/// <summary>
|
|
/// Create a new <see cref="ChunkHeader"/>.
|
|
/// </summary>
|
|
public ChunkHeader(long position, int length, string name)
|
|
{
|
|
if (length < 0)
|
|
{
|
|
throw new ArgumentException($"Length less than zero ({length}) encountered when reading chunk at position {position}.");
|
|
}
|
|
|
|
Position = position;
|
|
Length = length;
|
|
Name = name;
|
|
}
|
|
|
|
public override string ToString()
|
|
{
|
|
return $"{Name} at {Position} (length: {Length}).";
|
|
}
|
|
} |