public static void ReadRgb16(ImageBinReader reader, Span <byte> destination)
{
Debug.Assert(reader != null);
const ushort fiveBitMask = 31;
var px = (ushort)reader.ReadInt16LE();
int b = px & fiveBitMask;
int g = (px >> 5) & fiveBitMask;
int r = (px >> 10) & fiveBitMask;
destination[2] = (byte)(b * 255 / 31);
destination[1] = (byte)(g * 255 / 31);
destination[0] = (byte)(r * 255 / 31);
}
public static BmpInfo?ParseHeader(ImageBinReader s, ReadState ri)
{
if (s == null)
{
throw new ArgumentNullException(nameof(s));
}
if (ri == null)
{
throw new ArgumentNullException(nameof(ri));
}
Span <byte> tmp = stackalloc byte[HeaderSize];
if (!s.TryReadBytes(tmp))
{
return(null);
}
if (!Test(tmp))
{
throw new StbImageReadException(ErrorCode.UnknownFormat);
}
var info = new BmpInfo();
s.ReadInt32LE();
s.ReadInt16LE();
s.ReadInt16LE();
info.offset = s.ReadInt32LE();
info.headerSize = s.ReadInt32LE();
info.mr = info.mg = info.mb = info.ma = 0;
if (info.headerSize != 12 &&
info.headerSize != 40 &&
info.headerSize != 56 &&
info.headerSize != 108 &&
info.headerSize != 124)
{
throw new StbImageReadException(ErrorCode.UnknownHeader);
}
if (info.headerSize == 12)
{
ri.Width = s.ReadInt16LE();
ri.Height = s.ReadInt16LE();
}
else
{
ri.Width = s.ReadInt32LE();
ri.Height = s.ReadInt32LE();
}
ri.Orientation = ri.Height > 0
? ImageOrientation.BottomLeftOrigin
: ImageOrientation.TopLeftOrigin;
ri.Height = Math.Abs(ri.Height);
if (s.ReadInt16LE() != 1)
{
throw new StbImageReadException(ErrorCode.BadColorPlane);
}
info.bitsPerPixel = s.ReadInt16LE();
if (info.bitsPerPixel == 1)
{
throw new StbImageReadException(ErrorCode.MonochromeNotSupported);
}
if (info.headerSize != 12)
{
int compress = s.ReadInt32LE();
if ((compress == 1) || (compress == 2))
{
throw new StbImageReadException(ErrorCode.RLENotSupported);
}
s.ReadInt32LE();
s.ReadInt32LE();
s.ReadInt32LE();
s.ReadInt32LE();
s.ReadInt32LE();
if (info.headerSize == 40 ||
info.headerSize == 56)
{
if (info.headerSize == 56)
{
s.ReadInt32LE();
s.ReadInt32LE();
s.ReadInt32LE();
s.ReadInt32LE();
}
if ((info.bitsPerPixel == 16) || (info.bitsPerPixel == 32))
{
if (compress == 0)
{
if (info.bitsPerPixel == 32)
{
info.mr = 0xffu << 16;
info.mg = 0xffu << 8;
info.mb = 0xffu << 0;
info.ma = 0xffu << 24;
}
else
{
info.mr = 31 << 10;
info.mg = 31 << 5;
info.mb = 31 << 0;
}
}
else if (compress == 3)
{
info.mr = s.ReadUInt32LE();
info.mg = s.ReadUInt32LE();
info.mb = s.ReadUInt32LE();
if ((info.mr == info.mg) && (info.mg == info.mb))
{
throw new StbImageReadException(ErrorCode.BadMasks);
}
}
else
{
throw new StbImageReadException(ErrorCode.BadCompression);
}
}
}
else
{
if (info.headerSize != 108 &&
info.headerSize != 124)
{
throw new StbImageReadException(ErrorCode.UnknownHeader);
}
info.mr = s.ReadUInt32LE();
info.mg = s.ReadUInt32LE();
info.mb = s.ReadUInt32LE();
info.ma = s.ReadUInt32LE();
s.ReadInt32LE();
for (int i = 0; i < 12; ++i)
{
s.ReadInt32LE();
}
if (info.headerSize == 124)
{
for (int i = 0; i < 4; ++i)
{
s.ReadInt32LE();
}
}
}
}
if (info.bitsPerPixel == 24 &&
info.ma == 0xffu << 24)
{
ri.Components = 3;
}
else
{
ri.Components = info.ma != 0 ? 4 : 3;
}
ri.Depth = info.bitsPerPixel / ri.Components;
return(info);
}
public static TgaInfo ParseHeader(ImageBinReader reader, ReadState state)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
if (state == null)
{
throw new ArgumentNullException(nameof(state));
}
Span <byte> tmp = stackalloc byte[HeaderSize];
if (!reader.TryReadBytes(tmp))
{
throw new EndOfStreamException();
}
bool test = TestCore(tmp, out var info);
if (info.colormap_type == 1)
{
if (info.image_type != 1 &&
info.image_type != 9)
{
throw new StbImageReadException(ErrorCode.BadImageType);
}
info.palette_start = reader.ReadInt16LE();
info.palette_len = reader.ReadInt16LE();
info.palette_bpp = reader.ReadByte();
if (info.palette_bpp != 8 &&
info.palette_bpp != 15 &&
info.palette_bpp != 16 &&
info.palette_bpp != 24 &&
info.palette_bpp != 32)
{
throw new StbImageReadException(ErrorCode.BadPalette);
}
}
else
{
if (info.image_type != 2 &&
info.image_type != 3 &&
info.image_type != 10 &&
info.image_type != 11)
{
throw new StbImageReadException(ErrorCode.BadImageType);
}
reader.Skip(5);
// 16bit: Color Map Origin
// 16bit: Color Map Length
// 8bit: Color Map Entry Size
}
Debug.Assert(test); // Prior checks should throw if test was unsucessful.
info.x_origin = reader.ReadInt16LE();
info.y_origin = reader.ReadInt16LE();
state.Width = reader.ReadUInt16LE();
if (state.Width < 1)
{
throw new StbImageReadException(ErrorCode.ZeroWidth);
}
state.Height = reader.ReadUInt16LE();
if (state.Height < 1)
{
throw new StbImageReadException(ErrorCode.ZeroHeight);
}
info.bits_per_pixel = reader.ReadByte();
info.inverted = reader.ReadByte();
info.inverted = 1 - ((info.inverted >> 5) & 1);
// use the number of bits from the palette if paletted
if (info.palette_bpp != 0)
{
if (info.bits_per_pixel != 8 &&
info.bits_per_pixel != 16)
{
throw new StbImageReadException(ErrorCode.BadBitsPerPixel);
}
state.Components = GetComponentCount(
info.palette_bpp, false, out state.Depth);
}
else
{
state.Components = GetComponentCount(
info.bits_per_pixel, info.image_type == 3, out state.Depth);
}
if (state.Components == 0)
{
throw new StbImageReadException(ErrorCode.BadComponentCount);
}
state.OutComponents = state.Components;
state.OutDepth = state.Depth;
state.Orientation =
ImageOrientation.LeftToRight |
(info.inverted != 0 ? ImageOrientation.BottomToTop : ImageOrientation.TopToBottom);
state.StateReady();
return(info);
}