private void writeFrame(BufferFrame src)
{
using var quant = new OctreeQuantizer();
using var buffI = new FrameBufferSource(ctx.Source.Width, ctx.Source.Height, PixelFormat.Indexed8Bpp);
var buffC = EncodeFrame.Source;
quant.CreateHistorgram(buffC.Span, buffC.Width, buffC.Height, buffC.Stride);
quant.Quantize(buffC.Span, buffI.Span, buffC.Width, buffC.Height, buffC.Stride, buffI.Stride);
var palette = quant.Palette;
using var pal = default(ComPtr <IWICPalette>);
HRESULT.Check(Wic.Factory->CreatePalette(pal.GetAddressOf()));
fixed(uint *ppal = palette)
HRESULT.Check(pal.Get()->InitializeCustom(ppal, (uint)palette.Length));
ctx.WicContext.DestPalette = pal;
ctx.Source = buffI;
using var frm = new WicImageEncoderFrame(ctx, encoder, src.Area);
using var frmmeta = default(ComPtr <IWICMetadataQueryWriter>);
HRESULT.Check(frm.WicEncoderFrame->GetMetadataQueryWriter(frmmeta.GetAddressOf()));
frmmeta.SetValue(Wic.Metadata.Gif.FrameDisposal, (byte)src.Disposal);
frmmeta.SetValue(Wic.Metadata.Gif.FrameDelay, (ushort)src.Delay);
if (src.Area.X != 0)
{
frmmeta.SetValue(Wic.Metadata.Gif.FrameLeft, (ushort)src.Area.X);
}
if (src.Area.Y != 0)
{
frmmeta.SetValue(Wic.Metadata.Gif.FrameTop, (ushort)src.Area.Y);
}
frmmeta.SetValue(Wic.Metadata.Gif.TransparencyFlag, true);
frmmeta.SetValue(Wic.Metadata.Gif.TransparentColorIndex, (byte)(palette.Length - 1));
frm.WriteSource(ctx, src.Area);
ctx.WicContext.DestPalette = null;
}
private void writeFrame(BufferFrame src)
{
var curFormat = ctx.Source.Format;
var newFormat = PixelFormat.Indexed8Bpp;
bool alpha = src.Trans || src.Disposal != GifDisposalMethod.RestoreBackground;
using var pal = ComHandle.Wrap(Wic.Factory.CreatePalette());
pal.ComObject.InitializeFromBitmap(wicSource, 256u, alpha);
ctx.WicContext.DestPalette = pal.ComObject;
using var conv = ComHandle.Wrap(Wic.Factory.CreateFormatConverter());
conv.ComObject.Initialize(wicSource, newFormat.FormatGuid, WICBitmapDitherType.WICBitmapDitherTypeErrorDiffusion, pal.ComObject, 25.0, WICBitmapPaletteType.WICBitmapPaletteTypeCustom);
ctx.Source = conv.ComObject.AsPixelSource($"{nameof(IWICFormatConverter)}: {curFormat.Name}->{newFormat.Name}", false);
using var frm = new WicImageEncoderFrame(ctx, encoder, src.Area);
using var frmmeta = ComHandle.Wrap(frm.WicEncoderFrame.GetMetadataQueryWriter());
var fm = frmmeta.ComObject;
fm.SetMetadataByName(Wic.Metadata.Gif.FrameDisposal, new PropVariant((byte)src.Disposal));
fm.SetMetadataByName(Wic.Metadata.Gif.FrameDelay, new PropVariant((ushort)src.Delay));
if (src.Area.X != 0)
{
fm.SetMetadataByName(Wic.Metadata.Gif.FrameLeft, new PropVariant((ushort)src.Area.X));
}
if (src.Area.Y != 0)
{
fm.SetMetadataByName(Wic.Metadata.Gif.FrameTop, new PropVariant((ushort)src.Area.Y));
}
if (alpha)
{
fm.SetMetadataByName(Wic.Metadata.Gif.TransparencyFlag, new PropVariant(true));
fm.SetMetadataByName(Wic.Metadata.Gif.TransparentColorIndex, new PropVariant((byte)(pal.ComObject.GetColorCount() - 1)));
}
frm.WriteSource(ctx, src.Area);
}