public void AddImage(Bitmap image, float delayTime) {
var gceBlock = new GifGraphicControlExtensionBlock();
gceBlock.DelayTime = delayTime;
_structure.Blocks.Add(gceBlock);
//var temp = new Bitmap(image);
//if (_lastImage != null) {
// generateDifference(_lastImage, image);
//}
//_lastImage = temp;
image = _colorReductor.ReduceColor(image, 254);
// image を GIF に変換し、そこから Image Block を抜き出して移植する
using (var frameGif = new GifStructure(image)) {
var imageBlock = (GifImageBlock)frameGif.Blocks.FirstOrDefault(p => p is GifImageBlock);
if (imageBlock == null) throw new FormatException("Image block not found.");
if (imageBlock.HasLocalColorTable) {
// ローカルカラーテーブルがある場合 → 何もしない
}
else if (frameGif.Descriptor.HasGlobalColorTable) {
// グローバルカラーテーブルがある場合 → ローカルに組み替える
imageBlock.HasLocalColorTable = true;
imageBlock.Raw_LocalColorTable = frameGif.Raw_GlobalColorTable;
imageBlock.SizeOfLocalColorTable = frameGif.Descriptor.SizeOfGlobalColorTable;
}
else {
throw new FormatException("Color table not found.");
}
frameGif.Blocks.Remove(imageBlock);
_structure.Blocks.Add(imageBlock);
}
}
public GifAnimationGenerator(Size size, int loopCount = InfinityLoop) {
var descriptor = new GifLogicalScreenDescriptor();
descriptor.BitsPerColorChannel = 8;
descriptor.GlobalColorTableIsSorted = false;
descriptor.HasGlobalColorTable = false;
descriptor.PixelAspectRatio = 1;
descriptor.SizeOfGlobalColorTable = 2;
descriptor.Raw_Width = (UInt16)size.Width;
descriptor.Raw_Height = (UInt16)size.Height;
_structure = new GifStructure(descriptor);
var appExtBlock = new GifApplicationExtensionBlock();
appExtBlock.Raw_ApplicationIdentifier = "NETSCAPE";
appExtBlock.Raw_ApplicationAuthenticationCode = "2.0";
var loopCountH = (byte)((loopCount >> 8) & 0xff);
var loopCountL = (byte)((loopCount >> 0) & 0xff);
appExtBlock.Raw_Data = new byte[] { 0x01, loopCountL, loopCountH };
_structure.Blocks.Add(appExtBlock);
}