/// <summary>
/// Loads the pixels of a frame.
/// </summary>
/// <param name="imgPath">The Npk Path of the .img file, with the leading sprite/ if present</param>
/// <param name="frameIndex"></param>
/// <returns></returns>
/// <exception cref="System.IO.FileNotFoundException">The img file does not exist in this .npk file
/// or no frame with the given index exists in the img file.</exception>
/// <exception cref="System.IO.IOException">An I/O error occurred.</exception>
/// <exception cref="Dfo.Npk.NpkException">The .npk file is corrupt or the format changed.</exception>
public Image GetImage(NpkPath imgPath, int frameIndex)
{
imgPath.ThrowIfNull("imgPath");
try
{
PreLoadSpriteMetadata(imgPath);
IList<FrameInfo> imgFrames = m_frames[imgPath];
if (frameIndex >= imgFrames.Count || frameIndex < 0)
{
throw new FileNotFoundException("Cannot get frame index {0} of {1}. It only has {2} frames."
.F(frameIndex, imgPath, imgFrames.Count));
}
FrameInfo frameData = imgFrames[frameIndex];
int realFrameIndex = frameIndex;
// Follow frame links
if (frameData.LinkFrame != null)
{
realFrameIndex = frameData.LinkFrame.Value;
if (realFrameIndex >= imgFrames.Count || realFrameIndex < 0)
{
throw new FileNotFoundException("Cannot get linked frame index {0} of {1}. It only has {2} frames."
.F(realFrameIndex, imgPath, imgFrames.Count));
}
frameData = imgFrames[realFrameIndex];
if (frameData.LinkFrame != null)
{
throw new NpkException(
"There is a link frame to another link frame which is not allowed. {0} frame {1} links to frame {2}."
.F(imgPath, frameIndex, realFrameIndex));
}
}
NpkByteRange pixelDataLocation = m_frameLocations[imgPath][realFrameIndex];
// Seek to the pixel data and read it
Seek(pixelDataLocation.FileOffset, SeekOrigin.Begin);
byte[] pixelData = new byte[pixelDataLocation.Size];
m_npkStream.ReadOrDie(pixelData, pixelData.Length);
if (frameData.IsCompressed)
{
using (MemoryStream pixelDataMemoryStream = new MemoryStream(pixelData))
{
try
{
using (InflaterInputStream decompressStream = new InflaterInputStream(pixelDataMemoryStream))
{
byte[] decompressedPixelData = decompressStream.ReadFully();
pixelData = decompressedPixelData;
}
}
catch (SharpZipBaseException ex)
{
throw new NpkException(string.Format("Inflate error: {0}", ex.Message), ex);
}
}
}
pixelData = ExpandPixelData(pixelData, frameData);
return new Image(pixelData, frameData);
}
catch (EndOfStreamException ex)
{
throw new NpkException("Unexpected end of file.", ex);
}
}
