private readonly bool ReadOnly;// readonly
internal PngMetadata(ChunksList chunks)
{
chunkList = chunks;
if (chunks is ChunksListForWrite)
{
ReadOnly = false;
}
else
{
ReadOnly = true;
}
}
public string GetHeader(string icon)
{
string ztxt = string.Empty;
PngReader pngr = FileHelper.CreatePngReader(FileName);
width = pngr.ImgInfo.Cols;
height = pngr.ImgInfo.Rows;
ChunksList clist = pngr.GetChunksList();
/*The File should only have one zTxt, this chunk stores our DMI information such as
* sprite width, height, iconstates, directionals and frames among other things.
*/
foreach (PngChunkZTXT desc in clist.GetById("zTXt"))
{
ztxt = desc.GetVal();
break;
}
pngr.ShouldCloseStream = true;
pngr.End();
return(ztxt);
}
/// <summary>
/// Constructs a PNGReader objet from a opened Stream
/// </summary>
/// <remarks>The constructor reads the signature and first chunk (IDHR)<seealso cref="FileHelper.CreatePngReader(string)"/>
/// </remarks>
///
/// <param name="inputStream"></param>
/// <param name="filename">Optional, can be the filename or a description.</param>
public PngReader(Stream inputStream, String filename)
{
this.filename = (filename == null) ? "" : filename;
this.inputStream = inputStream;
this.chunksList = new ChunksList(null);
this.metadata = new PngMetadata(chunksList);
this.offset = 0;
// set default options
this.CurrentChunkGroup = -1;
this.ShouldCloseStream = true;
this.MaxBytesMetadata = 5 * 1024 * 1024;
this.MaxTotalBytesRead = 200 * 1024 * 1024; // 200MB
this.SkipChunkMaxSize = 2 * 1024 * 1024;
this.SkipChunkIds = new string[] { "fdAT" };
this.ChunkLoadBehaviour = Hjg.Pngcs.Chunks.ChunkLoadBehaviour.LOAD_CHUNK_ALWAYS;
// starts reading: signature
byte[] pngid = new byte[8];
PngHelperInternal.ReadBytes(inputStream, pngid, 0, pngid.Length);
offset += pngid.Length;
if (!PngCsUtils.arraysEqual(pngid, PngHelperInternal.PNG_ID_SIGNATURE))
{
throw new PngjInputException("Bad PNG signature");
}
CurrentChunkGroup = ChunksList.CHUNK_GROUP_0_IDHR;
// reads first chunk IDHR
int clen = PngHelperInternal.ReadInt4(inputStream);
offset += 4;
if (clen != 13)
{
throw new Exception("IDHR chunk len != 13 ?? " + clen);
}
byte[] chunkid = new byte[4];
PngHelperInternal.ReadBytes(inputStream, chunkid, 0, 4);
if (!PngCsUtils.arraysEqual4(chunkid, ChunkHelper.b_IHDR))
{
throw new PngjInputException("IHDR not found as first chunk??? ["
+ ChunkHelper.ToString(chunkid) + "]");
}
offset += 4;
PngChunkIHDR ihdr = (PngChunkIHDR)ReadChunk(chunkid, clen, false);
bool alpha = (ihdr.Colormodel & 0x04) != 0;
bool palette = (ihdr.Colormodel & 0x01) != 0;
bool grayscale = (ihdr.Colormodel == 0 || ihdr.Colormodel == 4);
// creates ImgInfo and imgLine, and allocates buffers
ImgInfo = new ImageInfo(ihdr.Cols, ihdr.Rows, ihdr.Bitspc, alpha, grayscale, palette);
rowb = new byte[ImgInfo.BytesPerRow + 1];
rowbprev = new byte[rowb.Length];
rowbfilter = new byte[rowb.Length];
interlaced = ihdr.Interlaced == 1;
deinterlacer = interlaced ? new PngDeinterlacer(ImgInfo) : null;
// some checks
if (ihdr.Filmeth != 0 || ihdr.Compmeth != 0 || (ihdr.Interlaced & 0xFFFE) != 0)
{
throw new PngjInputException("compmethod or filtermethod or interlaced unrecognized");
}
if (ihdr.Colormodel < 0 || ihdr.Colormodel > 6 || ihdr.Colormodel == 1 ||
ihdr.Colormodel == 5)
{
throw new PngjInputException("Invalid colormodel " + ihdr.Colormodel);
}
if (ihdr.Bitspc != 1 && ihdr.Bitspc != 2 && ihdr.Bitspc != 4 && ihdr.Bitspc != 8 &&
ihdr.Bitspc != 16)
{
throw new PngjInputException("Invalid bit depth " + ihdr.Bitspc);
}
}
public PngReader(Stream inputStream, string filename)
{
this.filename = ((filename == null) ? "" : filename);
this.inputStream = inputStream;
chunksList = new ChunksList(null);
metadata = new PngMetadata(chunksList);
offset = 0L;
CurrentChunkGroup = -1;
ShouldCloseStream = true;
MaxBytesMetadata = 5242880L;
MaxTotalBytesRead = 209715200L;
SkipChunkMaxSize = 2097152;
SkipChunkIds = new string[1]
{
"fdAT"
};
ChunkLoadBehaviour = ChunkLoadBehaviour.LOAD_CHUNK_ALWAYS;
byte[] array = new byte[8];
PngHelperInternal.ReadBytes(inputStream, array, 0, array.Length);
offset += array.Length;
if (!PngCsUtils.arraysEqual(array, PngHelperInternal.PNG_ID_SIGNATURE))
{
throw new PngjInputException("Bad PNG signature");
}
CurrentChunkGroup = 0;
int num = PngHelperInternal.ReadInt4(inputStream);
offset += 4L;
if (num != 13)
{
throw new Exception("IDHR chunk len != 13 ?? " + num.ToString());
}
byte[] array2 = new byte[4];
PngHelperInternal.ReadBytes(inputStream, array2, 0, 4);
if (!PngCsUtils.arraysEqual4(array2, ChunkHelper.b_IHDR))
{
throw new PngjInputException("IHDR not found as first chunk??? [" + ChunkHelper.ToString(array2) + "]");
}
offset += 4L;
PngChunkIHDR pngChunkIHDR = (PngChunkIHDR)ReadChunk(array2, num, skipforced: false);
bool alpha = (pngChunkIHDR.Colormodel & 4) != 0;
bool palette = (pngChunkIHDR.Colormodel & 1) != 0;
bool grayscale = pngChunkIHDR.Colormodel == 0 || pngChunkIHDR.Colormodel == 4;
ImgInfo = new ImageInfo(pngChunkIHDR.Cols, pngChunkIHDR.Rows, pngChunkIHDR.Bitspc, alpha, grayscale, palette);
rowb = new byte[ImgInfo.BytesPerRow + 1];
rowbprev = new byte[rowb.Length];
rowbfilter = new byte[rowb.Length];
interlaced = (pngChunkIHDR.Interlaced == 1);
deinterlacer = (interlaced ? new PngDeinterlacer(ImgInfo) : null);
if (pngChunkIHDR.Filmeth != 0 || pngChunkIHDR.Compmeth != 0 || (pngChunkIHDR.Interlaced & 0xFFFE) != 0)
{
throw new PngjInputException("compmethod or filtermethod or interlaced unrecognized");
}
if (pngChunkIHDR.Colormodel < 0 || pngChunkIHDR.Colormodel > 6 || pngChunkIHDR.Colormodel == 1 || pngChunkIHDR.Colormodel == 5)
{
throw new PngjInputException("Invalid colormodel " + pngChunkIHDR.Colormodel.ToString());
}
if (pngChunkIHDR.Bitspc != 1 && pngChunkIHDR.Bitspc != 2 && pngChunkIHDR.Bitspc != 4 && pngChunkIHDR.Bitspc != 8 && pngChunkIHDR.Bitspc != 16)
{
throw new PngjInputException("Invalid bit depth " + pngChunkIHDR.Bitspc.ToString());
}
}