/// <summary>
/// Initializes a new instance of the <see cref="T:DesktopSprites.SpriteManagement.AnimatedImage`1"/> class from a given file.
/// </summary>
/// <param name="path">The path to the file which contains the image to be loaded.</param>
/// <param name="staticImageFactory">The method that creates a TFrame object for a non-GIF file.</param>
/// <param name="frameFactory">The method used to construct a TFrame object for each frame in a GIF animation.</param>
/// <param name="allowableDepths">The allowable set of depths for the raw buffer. Use as many as your output format permits. The
/// Indexed8Bpp format is required.</param>
public AnimatedImage(string path, Func <string, T> staticImageFactory,
BufferToImage <T> frameFactory, BitDepths allowableDepths)
{
FilePath = path;
if (Path.GetExtension(path) == ".gif")
{
AnimatedImageFromGif(frameFactory, allowableDepths);
}
else
{
AnimatedImageFromStaticFormat(staticImageFactory);
}
}
/// <summary>
/// Creates an <see cref="T:DesktopSprites.SpriteManagement.AnimatedImage`1"/> from a GIF file.
/// </summary>
/// <param name="frameFactory">The method used to construct a TFrame object for each frame in a GIF animation.</param>
/// <param name="allowableDepths">The allowable set of depths for the raw buffer. Use as many as your output format permits. The
/// Indexed8Bpp format is required.</param>
private void AnimatedImageFromGif(BufferToImage <T> frameFactory, BitDepths allowableDepths)
{
GifImage <T> gifImage;
using (FileStream imageStream = new FileStream(FilePath, FileMode.Open, FileAccess.Read, FileShare.Read))
gifImage = new GifImage <T>(imageStream, frameFactory, allowableDepths);
Size = gifImage.Size;
LoopCount = gifImage.Iterations;
ImageDuration = gifImage.Duration;
int frameCount = gifImage.Frames.Length;
var framesList = new List <T>(frameCount);
var durationsList = new List <int>(frameCount);
var frameIndexesList = new List <int>(frameCount);
var frameHashesList = new List <int>(frameCount);
for (int sourceFrame = 0; sourceFrame < frameCount; sourceFrame++)
{
int frameDuration = gifImage.Frames[sourceFrame].Duration;
// Decoding the GIF may have produced frames of zero duration, we can safely drop these.
// If the file has all-zero durations, we're into the land of undefined behavior for animations.
// If we get to the last frame and we have nothing so far, we'll use that just so there is something to display.
// Alternatively, in an image with only one frame, then only this frame ever need be displayed.
if (frameDuration == 0 && !(ImageDuration == 0 && sourceFrame == frameCount - 1))
{
// Dispose of unused frame.
IDisposable disposable = gifImage.Frames[sourceFrame].Image as IDisposable;
if (disposable != null)
{
disposable.Dispose();
}
continue;
}
durationsList.Add(frameDuration);
// Determine if all frames share the same duration.
if (sourceFrame == 0)
{
commonFrameDuration = frameDuration;
}
else if (commonFrameDuration != frameDuration)
{
commonFrameDuration = -1;
}
// Calculate the frame hash to check if a duplicate frame exists.
// This will update our collection and given hash list appropriately.
AddOrReuseFrame(gifImage.Frames[sourceFrame], framesList, frameIndexesList, frameHashesList);
}
frames = framesList.ToImmutableArray();
if (frames.Length != frameIndexesList.Count)
{
frameIndexes = frameIndexesList.ToImmutableArray();
}
if (commonFrameDuration == -1)
{
durations = durationsList.ToImmutableArray();
}
}
