private static IcoFrame GenerateFrame(CommandLineOptions opts, ParseContext context)
{
var frame = new IcoFrame
{
Encoding = new IcoFrameEncoding(),
};
var sourceFile = File.ReadAllBytes(opts.SourceImagePath);
var reader = new ByteReader(sourceFile, ByteOrder.LittleEndian);
var signature = reader.NextUint64();
var sourceEncoding = PngDecoder.IsProbablyPngFile(ByteOrderConverter.To(ByteOrder.NetworkEndian, signature))
? IcoEncodingType.Png
: IcoEncodingType.Bitmap;
bool canSourceBePreserved = false;
switch (sourceEncoding)
{
case IcoEncodingType.Bitmap:
ReadBmpFile(opts, context, frame, sourceFile);
break;
case IcoEncodingType.Png:
ReadPngFile(opts, context, frame, sourceFile, out canSourceBePreserved);
break;
}
frame.Encoding.ActualHeight = (uint)frame.CookedData.Height;
frame.Encoding.ClaimedHeight = (uint)frame.CookedData.Height;
frame.Encoding.ActualWidth = (uint)frame.CookedData.Width;
frame.Encoding.ClaimedWidth = (uint)frame.CookedData.Width;
var outputEncoding = opts.EncodingOverride ?? sourceEncoding;
if (outputEncoding != IcoEncodingType.Bitmap && opts.BitmapEncodingOverride.HasValue)
{
Reporter.WarnLine(IcoErrorCode.OnlySupportedOnBitmaps, "Ignoring bitmap encoding configuration because we're not emitting a bitmap frame");
}
if (outputEncoding != sourceEncoding)
{
canSourceBePreserved = false;
}
if (canSourceBePreserved || opts.KeepRawFrameData)
{
frame.RawData = sourceFile;
}
else
{
switch (outputEncoding)
{
case IcoEncodingType.Bitmap:
WriteBmpFrame(opts, context, frame);
break;
case IcoEncodingType.Png:
WritePngFrame(opts, context, frame);
break;
}
}
if (opts.BitDepthOverride.HasValue)
{
frame.Encoding.ClaimedBitDepth = (uint)opts.BitDepthOverride.Value;
}
return(frame);
}
private static IcoFrame ProcessIcoFrame(ByteReader reader, ParseContext context)
{
var bWidth = reader.NextUint8();
var bHeight = reader.NextUint8();
var bColorCount = reader.NextUint8();
var bReserved = reader.NextUint8();
var wPlanes = reader.NextUint16();
var wBitCount = reader.NextUint16();
var dwBytesInRes = reader.NextUint32();
var dwImageOffset = reader.NextUint32();
if (bWidth != bHeight)
{
context.Reporter.WarnLine(IcoErrorCode.NotSquare, $"Icon is not square ({bWidth}x{bHeight}).", context.DisplayedPath, context.ImageDirectoryIndex.Value);
}
if (bReserved != FileFormatConstants._iconEntryReserved)
{
throw new InvalidIcoFileException(IcoErrorCode.InvalidFrameHeader_bReserved, $"ICONDIRECTORY.bReserved should be {FileFormatConstants._iconEntryReserved}, was {bReserved}.", context);
}
if (wPlanes > 1)
{
throw new InvalidIcoFileException(IcoErrorCode.InvalidFrameHeader_wPlanes, $"ICONDIRECTORY.wPlanes is {wPlanes}. Only single-plane bitmaps are supported.", context);
}
if (dwBytesInRes > int.MaxValue)
{
throw new InvalidIcoFileException(IcoErrorCode.InvalidFrameHeader_dwBytesInRes, $"ICONDIRECTORY.dwBytesInRes == {dwBytesInRes}, which is unreasonably large.", context);
}
if (dwImageOffset > int.MaxValue)
{
throw new InvalidIcoFileException(IcoErrorCode.InvalidFrameHeader_dwImageOffset, $"ICONDIRECTORY.dwImageOffset == {dwImageOffset}, which is unreasonably large.", context);
}
var source = new IcoFrame
{
TotalDiskUsage = dwBytesInRes + /* sizeof(ICONDIRENTRY) */ 16,
Encoding = new IcoFrameEncoding
{
ClaimedBitDepth = wBitCount,
ClaimedHeight = bHeight > 0 ? bHeight : 256u,
ClaimedWidth = bWidth > 0 ? bWidth : 256u,
},
};
source.RawData = reader.Data.Slice((int)dwImageOffset, (int)dwBytesInRes).ToArray();
var bitmapHeader = new ByteReader(source.RawData, ByteOrder.LittleEndian);
var signature = bitmapHeader.NextUint64();
bitmapHeader.SeekOffset = 0;
if (PngDecoder.IsProbablyPngFile(ByteOrderConverter.To(ByteOrder.NetworkEndian, signature)))
{
PngDecoder.DoPngEntry(bitmapHeader, context, source);
}
else
{
BmpDecoder.DoBitmapEntry(bitmapHeader, context, source);
}
return(source);
}
public static PngFileEncoding GetPngFileEncoding(Memory <byte> data)
{
var reader = new ByteReader(data, ByteOrder.NetworkEndian);
if (FileFormatConstants._pngHeader != reader.NextUint64())
{
throw new InvalidPngFileException(IcoErrorCode.NotPng, $"Data stream does not begin with the PNG magic constant");
}
var chunkLength = reader.NextUint32();
var chunkType = reader.NextUint32();
if (chunkType != _ihdrChunkName)
{
throw new InvalidPngFileException(IcoErrorCode.PngBadIHDR, $"PNG file should begin with IHDR chunk; found {chunkType} instead");
}
if (chunkLength < 13)
{
throw new InvalidPngFileException(IcoErrorCode.PngBadIHDR, $"IHDR chunk is invalid length {chunkLength}; expected at least 13 bytes");
}
var result = new PngFileEncoding
{
Width = reader.NextUint32(),
Height = reader.NextUint32(),
BitsPerChannel = reader.NextUint8(),
ColorType = (PngColorType)reader.NextUint8(),
};
if (result.Width == 0 || result.Height == 0)
{
throw new InvalidPngFileException(IcoErrorCode.PngIllegalInputDimensions, $"Illegal Width x Height of {result.Width} x {result.Height}");
}
switch (result.BitsPerChannel)
{
case 1:
case 2:
case 4:
case 8:
case 16:
break;
default:
throw new InvalidPngFileException(IcoErrorCode.PngIllegalInputDepth, $"Illegal bits per color channel / palette entry of {result.BitsPerChannel}");
}
switch (result.ColorType)
{
case PngColorType.Grayscale:
case PngColorType.RGB:
case PngColorType.Palette:
case PngColorType.GrayscaleAlpha:
case PngColorType.RGBA:
break;
default:
throw new InvalidPngFileException(IcoErrorCode.PngIllegalColorType, $"Illegal color type {result.ColorType}");
}
return(result);
}
