private static void SetPlainTextExtension(byte[] gifBytes, ref int byteIndex, ref GifData gifData)
{
PlainTextExtension plainTxtEx = new PlainTextExtension();
// Extension Introducer(1 Byte)
// 0x21
plainTxtEx.m_extensionIntroducer = gifBytes[byteIndex];
byteIndex++;
// Plain Text Label(1 Byte)
// 0x01
plainTxtEx.m_plainTextLabel = gifBytes[byteIndex];
byteIndex++;
// Block Size(1 Byte)
// 0x0c
plainTxtEx.m_blockSize = gifBytes[byteIndex];
byteIndex++;
// Text Grid Left Position(2 Bytes)
// Not supported
byteIndex += 2;
// Text Grid Top Position(2 Bytes)
// Not supported
byteIndex += 2;
// Text Grid Width(2 Bytes)
// Not supported
byteIndex += 2;
// Text Grid Height(2 Bytes)
// Not supported
byteIndex += 2;
// Character Cell Width(1 Bytes)
// Not supported
byteIndex++;
// Character Cell Height(1 Bytes)
// Not supported
byteIndex++;
// Text Foreground Color Index(1 Bytes)
// Not supported
byteIndex++;
// Text Background Color Index(1 Bytes)
// Not supported
byteIndex++;
// Block Size & Plain Text Data List
while (true)
{
// Block Size(1 Byte)
byte blockSize = gifBytes[byteIndex];
byteIndex++;
if (blockSize == 0x00)
{
// Block Terminator(1 Byte)
break;
}
var plainTextDataBlock = new PlainTextExtension.PlainTextDataBlock();
plainTextDataBlock.m_blockSize = blockSize;
// Plain Text Data(n Byte)
plainTextDataBlock.m_plainTextData = new byte[plainTextDataBlock.m_blockSize];
for (int i = 0; i < plainTextDataBlock.m_plainTextData.Length; i++)
{
plainTextDataBlock.m_plainTextData[i] = gifBytes[byteIndex];
byteIndex++;
}
if (plainTxtEx.m_plainTextDataList == null)
{
plainTxtEx.m_plainTextDataList = new List <PlainTextExtension.PlainTextDataBlock>();
}
plainTxtEx.m_plainTextDataList.Add(plainTextDataBlock);
}
if (gifData.m_plainTextExList == null)
{
gifData.m_plainTextExList = new List <PlainTextExtension>();
}
gifData.m_plainTextExList.Add(plainTxtEx);
}
static void SetPlainTextExtension (byte[] gifBytes, ref int byteIndex, ref GifData gifData)
{
PlainTextExtension plainTxtEx = new PlainTextExtension ();
// Extension Introducer(1 Byte)
// 0x21
plainTxtEx.extensionIntroducer = gifBytes[byteIndex];
byteIndex++;
// Plain Text Label(1 Byte)
// 0x01
plainTxtEx.plainTextLabel = gifBytes[byteIndex];
byteIndex++;
// Block Size(1 Byte)
// 0x0c
plainTxtEx.blockSize = gifBytes[byteIndex];
byteIndex++;
// Text Grid Left Position(2 Bytes)
// Not supported
byteIndex += 2;
// Text Grid Top Position(2 Bytes)
// Not supported
byteIndex += 2;
// Text Grid Width(2 Bytes)
// Not supported
byteIndex += 2;
// Text Grid Height(2 Bytes)
// Not supported
byteIndex += 2;
// Character Cell Width(1 Bytes)
// Not supported
byteIndex++;
// Character Cell Height(1 Bytes)
// Not supported
byteIndex++;
// Text Foreground Color Index(1 Bytes)
// Not supported
byteIndex++;
// Text Background Color Index(1 Bytes)
// Not supported
byteIndex++;
// Block Size & Plain Text Data List
while (true) {
// Block Size(1 Byte)
byte blockSize = gifBytes[byteIndex];
byteIndex++;
if (blockSize == 0x00) {
// Block Terminator(1 Byte)
break;
}
var plainTextDataBlock = new PlainTextExtension.PlainTextDataBlock ();
plainTextDataBlock.blockSize = blockSize;
// Plain Text Data(n Byte)
plainTextDataBlock.plainTextData = new byte[plainTextDataBlock.blockSize];
for (int i = 0; i < plainTextDataBlock.plainTextData.Length; i++) {
plainTextDataBlock.plainTextData[i] = gifBytes[byteIndex];
byteIndex++;
}
if (plainTxtEx.plainTextDataList == null) {
plainTxtEx.plainTextDataList = new List<PlainTextExtension.PlainTextDataBlock> ();
}
plainTxtEx.plainTextDataList.Add (plainTextDataBlock);
}
if (gifData.plainTextExList == null) {
gifData.plainTextExList = new List<PlainTextExtension> ();
}
gifData.plainTextExList.Add (plainTxtEx);
}
private static List <Block> ReadBlocks(byte[] bytes, ref int startIndex)
{
var blocks = new List <Block>();
var index = startIndex;
while (true)
{
switch (bytes[index])
{
case Block.ExtensionIntroducer:
{
Block extension;
switch (bytes[index + 1])
{
case Block.PlainTextExtensionLabel:
extension = new PlainTextExtension(bytes, ref index);
break;
case Block.GraphicControlExtensionLabel:
extension = new GraphicControlExtension(bytes, ref index);
break;
case Block.CommentExtensionLabel:
extension = new CommentExtension(bytes, ref index);
break;
case Block.ApplicationExtensionLabel:
extension = new ApplicationExtension(bytes, ref index);
break;
default:
throw new NotSupportedException("Unknown extension!");
}
blocks.Add(extension);
break;
}
case Block.ImageDescriptorLabel:
{
var descriptor = new ImageDescriptor(bytes, ref index);
blocks.Add(descriptor);
if (descriptor.LocalColorTableFlag == 1)
{
var localColorTable = new ColorTable(descriptor.LocalColorTableSize, bytes, ref index);
blocks.Add(localColorTable);
}
var data = new TableBasedImageData(bytes, ref index);
blocks.Add(data);
break;
}
case 0x3B: // End
{
return(blocks);
}
default:
throw new NotSupportedException($"Unsupported GIF block: {bytes[index]:X}.");
}
}
}
/// <summary>
/// Returns the length of the parsed data stream byte[].
/// </summary>
/// <returns></returns>
public int GetLength()
{
int length = 0;
length += Header.TotalBlockLength + LogicalScreenDescriptor.TotalBlockLength + Trailer.TotalBlockLength;
if (LogicalScreen.GlobalColorTable != null)
{
length += LogicalScreen.GlobalColorTable.TotalBlockLength;
}
foreach (DataBlock db in DataBlocks)
{
if (db is GraphicBlock)
{
GraphicBlock gb = (GraphicBlock)db;
if (gb.GraphicControlExtension != null)
{
length += GraphicControlExtension.TotalBlockLength;
}
if (gb.GraphicRenderingBlock is PlainTextExtension)
{
PlainTextExtension pte = (PlainTextExtension)gb.GraphicRenderingBlock;
length += pte.TotalBlockLength;
}
else if (gb.GraphicRenderingBlock is TableBasedImage)
{
TableBasedImage tbi = (TableBasedImage)gb.GraphicRenderingBlock;
length += tbi.ImageData.TotalBlockLength + ImageDescriptor.TotalBlockLength;
if (tbi.LocalColorTable != null)
{
length += tbi.LocalColorTable.TotalBlockLength;
}
}
}
else if (db is SpecialPurposeBlock)
{
SpecialPurposeBlock spb = (SpecialPurposeBlock)db;
if (spb is ApplicationExtension)
{
ApplicationExtension ae = (ApplicationExtension)spb;
length += ae.TotalBlockLength;
}
else if (spb is CommentExtension)
{
CommentExtension ce = (CommentExtension)spb;
length += ce.TotalBlockLength;
}
}
}
return(length);
}
/// <summary>
/// Compiles the parsed tokens/components back into a byte array.
/// </summary>
public void CompileByteArray()
{
List <byte> output = new List <byte>();
output.AddRange(DataStream.Header.Bytes);
output.AddRange(DataStream.LogicalScreen.LogicalScreenDescriptor.Bytes);
if (DataStream.LogicalScreen.GlobalColorTable != null)
{
output.AddRange(DataStream.LogicalScreen.GlobalColorTable.Bytes);
}
foreach (DataBlock db in DataStream.DataBlocks)
{
if (db is GraphicBlock)
{
GraphicBlock gb = (GraphicBlock)db;
if (gb.GraphicControlExtension != null)
{
output.AddRange(gb.GraphicControlExtension.Bytes);
}
if (gb.GraphicRenderingBlock is PlainTextExtension)
{
PlainTextExtension pte = (PlainTextExtension)gb.GraphicRenderingBlock;
output.AddRange(pte.Bytes);
}
else if (gb.GraphicRenderingBlock is TableBasedImage)
{
TableBasedImage tbi = (TableBasedImage)gb.GraphicRenderingBlock;
output.AddRange(tbi.ImageDescriptor.Bytes);
if (tbi.LocalColorTable != null)
{
output.AddRange(tbi.LocalColorTable.Bytes);
}
output.AddRange(tbi.ImageData.Bytes);
}
}
else if (db is SpecialPurposeBlock)
{
SpecialPurposeBlock spb = (SpecialPurposeBlock)db;
if (spb is ApplicationExtension)
{
ApplicationExtension ae = (ApplicationExtension)spb;
output.AddRange(ae.Bytes);
}
else if (spb is CommentExtension)
{
CommentExtension ce = (CommentExtension)spb;
output.AddRange(ce.Bytes);
}
}
}
output.AddRange(DataStream.Trailer.Bytes);
DataStream.Bytes = output.ToArray();
}
