private static Dictionary <int, Animator.GifPalette> CreatePalettes(GifDataStream metadata)
{
Dictionary <int, Animator.GifPalette> dictionary = new Dictionary <int, Animator.GifPalette>();
Color[] colorArray = (Color[])null;
if (metadata.Header.LogicalScreenDescriptor.HasGlobalColorTable)
{
colorArray = (Color[])Enumerable.ToArray <Color>(Enumerable.Select <GifColor, Color>(metadata.GlobalColorTable, (Func <GifColor, Color>)(gc => Color.FromArgb(byte.MaxValue, gc.R, gc.G, gc.B))));
}
for (int index = 0; index < metadata.Frames.Count; ++index)
{
GifFrame frame = metadata.Frames[index];
Color[] colors = colorArray;
if (frame.Descriptor.HasLocalColorTable)
{
colors = (Color[])Enumerable.ToArray <Color>(Enumerable.Select <GifColor, Color>(frame.LocalColorTable, (Func <GifColor, Color>)(gc => Color.FromArgb(byte.MaxValue, gc.R, gc.G, gc.B))));
}
int?transparencyIndex = new int?();
GifGraphicControlExtension graphicControl = frame.GraphicControl;
if (graphicControl != null && graphicControl.HasTransparency)
{
transparencyIndex = new int?(graphicControl.TransparencyIndex);
}
dictionary[index] = new Animator.GifPalette(transparencyIndex, colors);
}
return(dictionary);
}
private async Task RenderFrameAsync(int frameIndex, CancellationToken cancellationToken)
{
if (frameIndex < 0)
{
return;
}
GifFrame frame = this._metadata.Frames[frameIndex];
GifImageDescriptor desc = frame.Descriptor;
using (Stream indexStreamAsync = await this.GetIndexStreamAsync(frame, cancellationToken))
{
if (frameIndex < this._previousFrameIndex)
{
this.ClearArea((IGifRect)this._metadata.Header.LogicalScreenDescriptor);
}
else
{
this.DisposePreviousFrame(frame);
}
int length = 4 * desc.Width;
byte[] buffer = new byte[desc.Width];
byte[] numArray = new byte[length];
Animator.GifPalette palette = this._palettes[frameIndex];
int num1 = palette.TransparencyIndex ?? -1;
foreach (int num2 in frame.Descriptor.Interlace ? Animator.InterlacedRows(frame.Descriptor.Height) : Animator.NormalRows(frame.Descriptor.Height))
{
if (indexStreamAsync.Read(buffer, 0, desc.Width) != desc.Width)
{
throw new EndOfStreamException();
}
int offset = (desc.Top + num2) * this._stride + desc.Left * 4;
if (num1 >= 0)
{
Animator.CopyFromBitmap(numArray, this._bitmap, offset, length);
}
for (int index = 0; index < desc.Width; ++index)
{
byte num3 = buffer[index];
int startIndex = 4 * index;
if ((int)num3 != num1)
{
Animator.WriteColor(numArray, palette[(int)num3], startIndex);
}
}
Animator.CopyToBitmap(numArray, this._bitmap, offset, length);
}
this._bitmap.Invalidate();
this._previousFrame = frame;
this._previousFrameIndex = frameIndex;
}
}