public bool UpdateVariables(IList <FileFragment> list, ref int index, ref List <int> changed)
{
//Starting saftey thingy
if (index == 0)
{
(list[index] as GIFFileFragment).SectionType = SectionTypes.Header;
return(false);
}
List <SectionTypes> SectionTypeQueue = new List <SectionTypes>();
bool exists = new PackedGlobalColorTableInfo(BinaryFileInterpreter.ReadFileAs <byte>(list[3].Path)).Exists;
if (index <= (exists ? 6 : 5))
{
SectionTypeQueue.AddRange(new SectionTypes[]
{
SectionTypes.Header,
SectionTypes.Width,
SectionTypes.Height,
SectionTypes.GlobalColorTablePacked,
SectionTypes.ColorIndex,
SectionTypes.PixelAspectRatio
});
if (exists)
{
SectionTypeQueue.Add(SectionTypes.ColorTable);
}
index = 0;
}
else
{
index = FindSectionOfType(list, index, SectionTypes.Sentinal, SectionTypes.Trailer);
switch ((list[index] as GIFFileFragment).SectionType)
{
case (SectionTypes.Trailer):
index++;
goto case (SectionTypes.Sentinal);
case (SectionTypes.Sentinal):
switch (BinaryFileInterpreter.ReadFileAs <byte>(list[index].Path))
{
case ((byte)','):
SectionTypeQueue.AddRange(new SectionTypes[]
{
SectionTypes.Sentinal,
SectionTypes.XOffset,
SectionTypes.YOffset,
SectionTypes.Width,
SectionTypes.Height,
SectionTypes.LocalColorTablePacked
});
bool lctexists = new PackedLocalColorTableInfo(BinaryFileInterpreter.ReadFileAs <byte>(list[index + 5].Path)).Exists;
if (lctexists)
{
SectionTypeQueue.Add(SectionTypes.ColorTable);
}
SectionTypeQueue.Add(SectionTypes.Unknown); //Unencoded length?
//Need to +8 if the local color table exists
SectionTypeQueue.AddRange(LabelDataSections(list, index + (lctexists ? 8 : 7), true));
break;
case ((byte)'!'):
SectionTypeQueue.AddRange(new SectionTypes[]
{
SectionTypes.Sentinal,
SectionTypes.ExtensionType
});
switch (BinaryFileInterpreter.ReadFileAs <byte>(list[index + 1].Path))
{
//Plain Text
case (0x01):
SectionTypeQueue.AddRange(new SectionTypes[]
{
SectionTypes.Length,
SectionTypes.XOffset,
SectionTypes.YOffset,
SectionTypes.Width,
SectionTypes.Height,
SectionTypes.Width,
SectionTypes.Height,
SectionTypes.ColorIndex,
SectionTypes.ColorIndex
});
SectionTypeQueue.AddRange(LabelDataSections(list, index + 11, false));
break;
//Graphics Control
case (0xF9):
SectionTypeQueue.AddRange(new SectionTypes[]
{
SectionTypes.Length,
SectionTypes.GraphicsControlPacked,
SectionTypes.DelayTime,
SectionTypes.ColorIndex
});
break;
//Comment
case (0xFE):
SectionTypeQueue.AddRange(LabelDataSections(list, index + 2, false));
break;
//Application
case (0xFF):
SectionTypeQueue.AddRange(new SectionTypes[]
{
SectionTypes.Length,
SectionTypes.ApplicationIdentifier,
SectionTypes.ApplicationAuthCode
});
SectionTypeQueue.AddRange(LabelDataSections(list, index + 5, false));
break;
//Unknown
default:
SectionTypeQueue.Add(SectionTypes.Unknown);
break;
}
SectionTypeQueue.Add(SectionTypes.Trailer);
break;
case ((byte)';'):
SectionTypeQueue.Add(SectionTypes.EndOfFile);
EndOfFileIndex = index; //TODO check this again
break;
default:
SectionTypeQueue.Add(SectionTypes.Unknown);
break;
}
break;
}
}
bool didWork = false;
for (int i = 0; i < SectionTypeQueue.Count; i++) //TODO is this confusing having i++ all the way up here?
{
if ((list[index] as GIFFileFragment).SectionType != SectionTypeQueue[i])
{
(list[index] as GIFFileFragment).SectionType = SectionTypeQueue[i];
changed.Add(index);
didWork = true;
}
index++;
}
return(didWork);
}
//I now have a newfound hatred for .gif after writing this code
public void ParseTo(string filename, ref List <FileFragmentReference> output)
{
using (BinaryReader br = new BinaryReader(new FileStream(filename, FileMode.Open, FileAccess.Read)))
{
//Header
string fileHeader = br.ReadString(6);
output.Add(new GIFFileFragment(0, 6, new string[] { "Header", "Header" },
headerTypes.Contains(fileHeader) ? Validity.Valid : Validity.HardInvalid,
$"File header = {fileHeader}", SectionTypes.Header));
//Logical Screen Descriptor
short LSDwidth = br.ReadInt16();
output.Add(new GIFFileFragment(6, 2, new string[] { "Header", "Logical Screen Descriptor", "Width" },
(LSDwidth >= 0) ? Validity.Valid : Validity.HardInvalid,
$"Width = {LSDwidth}", SectionTypes.Width));
short LSDheight = br.ReadInt16();
output.Add(new GIFFileFragment(8, 2, new string[] { "Header", "Logical Screen Descriptor", "Height" },
(LSDheight >= 0) ? Validity.Valid : Validity.HardInvalid,
$"Height = {LSDheight}", SectionTypes.Height));
PackedGlobalColorTableInfo globalColorTableInfo = new PackedGlobalColorTableInfo(br.ReadByte());
//TODO validate all of these
output.Add(new GIFFileFragment(10, 1, new string[] { "Header", "Packed Byte" },
globalColorTableInfo.ToString(), SectionTypes.GlobalColorTablePacked));
output.Add(new GIFFileFragment(11, 1, new string[] { "Header", "Background Color Index" },
Validity.Unknown, SectionTypes.ColorIndex));
output.Add(new GIFFileFragment(12, 1, new string[] { "Header", "Pixel Aspect Ratio" },
Validity.Unknown, SectionTypes.PixelAspectRatio));
br.BaseStream.Seek(2, SeekOrigin.Current);
int GCTLength = 3 * (1 << (globalColorTableInfo.BitsPerEntry + 1));
if (globalColorTableInfo.Exists)
{
//TODO split more?
output.Add(new GIFFileFragment(13, (ulong)GCTLength,
new string[] { "Header", "Global Color Table" },
SectionTypes.ColorTable));
br.BaseStream.Seek(GCTLength, SeekOrigin.Current);
}
//Loop through sections
//TODO seperate section counts for extensions and images
for (int section = 1; br.BaseStream.Position < br.BaseStream.Length; section++)
{
//Switch off of section header
switch (br.ReadByte())
{
#region Image
case ((byte)','):
output.Add(new GIFFileFragment(br.BaseStream.Position - 1, 1,
new string[] { $"Image {section}", "Sentinal" },
Validity.Valid, SectionTypes.Sentinal)); //I would really hope this is valid if we've made it to this case...
output.AddRange(ReadLeftTopWidthHeight(br, $"Image {section}", LSDwidth, LSDheight));
PackedLocalColorTableInfo localColorTableInfo = new PackedLocalColorTableInfo(br.ReadByte());
//TODO Validate?
output.Add(new GIFFileFragment(br.BaseStream.Position - 1, 1,
new string[] { $"Image {section}", "Packed Byte" },
localColorTableInfo.ToString(), SectionTypes.LocalColorTablePacked));
if (localColorTableInfo.Exists)
{
int LCTLength = 3 * (1 << (localColorTableInfo.BitsPerEntry + 1));
//TODO split more?
output.Add(new GIFFileFragment(br.BaseStream.Position, LCTLength,
new string[] { $"Image {section}", "Local Color Table" }, SectionTypes.ColorTable));
br.BaseStream.Seek(LCTLength, SeekOrigin.Current);
}
//TODO what even is this????????
output.Add(new GIFFileFragment(br.BaseStream.Position, 1, new string[] { $"Image {section}", "Unencoded Length" },
br.ReadByte().ToString(), SectionTypes.Unknown /*TODO uncompressed length?*/));
output.AddRange(ReadDataSections(br, $"Image {section}", "Image Data", false, true, Validity.OutOfScope));
break;
#endregion
#region Extension
case ((byte)'!'):
output.Add(new GIFFileFragment(br.BaseStream.Position - 1, 1,
new string[] { $"Extension {section}", "Sentinal" }, Validity.Valid, SectionTypes.Sentinal));
byte type = br.ReadByte(); //TODO Validate this by making a list of all types
output.Add(new GIFFileFragment(br.BaseStream.Position - 1, 1,
new string[] { $"Extension {section}", "Type" }, Validity.Unchecked, SectionTypes.ExtensionType));
switch (type)
{
#region Plain Text
case (0x01):
byte plainTextSize = br.ReadByte(); //Should always be 0x0Ch
output.Add(new GIFFileFragment(br.BaseStream.Position - 1, 1,
new string[] { $"Extension {section}", "Plain Text Block Length" },
plainTextSize == 0x0C ? Validity.Valid : Validity.HardInvalid, SectionTypes.Length)); //tbh, this value not being 0x0C would be a hard invalid for filephoenix rn
output.AddRange(ReadLeftTopWidthHeight(br, $"Extension {section}", LSDwidth, LSDheight));
//TODO validate one byte
output.Add(new GIFFileFragment(br.BaseStream.Position, 1,
new string[] { $"Extension {section}", "Character Cell Width" }, Validity.Valid,
br.ReadByte().ToString(), SectionTypes.Width));
output.Add(new GIFFileFragment(br.BaseStream.Position, 1,
new string[] { $"Extension {section}", "Character Cell Height" }, Validity.Valid,
br.ReadByte().ToString(), SectionTypes.Height));
//TODO this is flawed since it needs to fall back to the Local Color table if !GCTExists
//Also, if both the GCT and LCT aren't there? Oh boy...
int maxIndex = GCTLength / 3;
byte TextColorIndex = br.ReadByte();
output.Add(new GIFFileFragment(br.BaseStream.Position, 1,
new string[] { $"Extension {section}", "Text Color Index" },
TextColorIndex < maxIndex ? Validity.Valid : Validity.HardInvalid,
TextColorIndex.ToString(), SectionTypes.ColorIndex));
byte BackColorIndex = br.ReadByte();
output.Add(new GIFFileFragment(br.BaseStream.Position, 1,
new string[] { $"Extension {section}", "Text Background Color Index" },
BackColorIndex < maxIndex ? Validity.Valid : Validity.HardInvalid, BackColorIndex.ToString(),
SectionTypes.ColorIndex));
output.AddRange(ReadDataSections(br, $"Extension {section}", "Plain Text", true, false, Validity.Valid));
break;
#endregion
#region Graphics Control
case (0xF9):
byte graphicsControlSize = br.ReadByte(); //Should always be 0x04
output.Add(new GIFFileFragment(br.BaseStream.Position - 1, 1,
new string[] { $"Extension {section}", "Graphics Control Block Length" },
graphicsControlSize == 0x04 ? Validity.Valid : Validity.HardInvalid, SectionTypes.Length));
PackedGraphicsControlInfo graphicsControlInfo = new PackedGraphicsControlInfo(br.ReadByte());
output.Add(new GIFFileFragment(br.BaseStream.Position - 1, 1,
new string[] { $"Extension {section}", "Packed Byte" }, graphicsControlInfo.ToString(),
SectionTypes.GraphicsControlPacked));
//In Centiseconds (hundreths of seconds)
short DelayTime = br.ReadInt16();
output.Add(new GIFFileFragment(br.BaseStream.Position - 2, 2,
new string[] { $"Extension {section}", "Delay Time" },
0 <= DelayTime ? Validity.Valid : Validity.HardInvalid, //TODO check if this is hard or soft
SectionTypes.DelayTime));
output.Add(new GIFFileFragment(br.BaseStream.Position, 1,
new string[] { $"Extension {section}", "Transparent Color Index" },
br.ReadByte() < GCTLength / 3 ? Validity.Valid : Validity.HardInvalid, //TODO < or <=?
SectionTypes.ColorIndex));
break;
#endregion
#region Comment
case (0xFE):
output.AddRange(ReadDataSections(br, $"Extension {section}", "Comment", true, false, Validity.Valid));
break;
#endregion
#region Application
case (0xFF):
//TODO kind of unrealistic to parse all possible application chunks... right?
byte applicationSize = br.ReadByte(); //Should always be 0x0B
output.Add(new GIFFileFragment(br.BaseStream.Position - 1, 1,
new string[] { $"Extension {section}", "Application Extension Length" },
applicationSize == 0x0B ? Validity.Valid : Validity.HardInvalid,
SectionTypes.Length));
output.Add(new GIFFileFragment(br.BaseStream.Position, 8,
new string[] { $"Extension {section}", "Identifier" },
Validity.Valid, br.ReadString(8), SectionTypes.ApplicationIdentifier));
output.Add(new GIFFileFragment(br.BaseStream.Position, 3,
new string[] { $"Extension {section}", "Authentication Code" },
Validity.Valid, string.Join(", ", br.ReadBytes(3)), //This could be human readable, or not, so byte[] jsut to be sure
SectionTypes.ApplicationAuthCode));
output.AddRange(ReadDataSections(br, $"Extension {section}", "Application", false, false, Validity.Valid));
break;
#endregion
#region Unknown
default:
output.Add(FindNextSection(br, true,
new string[] { $"Extension {section}", "Unknown Extension Data" }, Validity.Unknown));
break;
#endregion
}
output.Add(new GIFFileFragment(br.BaseStream.Position, 1,
new string[] { $"Extension {section}", "Extension Block Trailer" },
br.ReadByte() == 0 ? Validity.Valid : Validity.SoftInvalid, SectionTypes.Trailer));
break;
#endregion
#region End of file
case ((byte)';'):
output.Add(new GIFFileFragment(br.BaseStream.Position - 1, 1,
new string[] { $"End Of File Marker {section}" },
(br.BaseStream.Position != br.BaseStream.Length || EndOfFileIndex != null) ? Validity.SoftInvalid : Validity.Valid
, SectionTypes.EndOfFile));
EndOfFileIndex = output.Count - 1;
break;
#endregion
#region Unknown
default:
br.BaseStream.Position--;
output.Add(FindNextSection(br, false, new string[] { $"Unknown Section {section}" }, Validity.HardInvalid));
break;
#endregion
}
}
}
}