public AnimatedGifFrame[] ReadAnimatedGif(Stream stream, out int x, out int y, out int comp, int req_comp)
{
try
{
x = y = comp = 0;
var res = new List <AnimatedGifFrame>();
_stream = stream;
var context = new Stb.stbi__context();
Stb.stbi__start_callbacks(context, _callbacks, null);
if (Stb.stbi__gif_test(context) == 0)
{
throw new Exception("Input stream is not GIF file.");
}
var g = new Stb.stbi__gif();
do
{
int ccomp;
var result = Stb.stbi__gif_load_next(context, g, &ccomp, req_comp);
if (result == null)
{
break;
}
comp = ccomp;
var c = req_comp != 0 ? req_comp : comp;
var data = new byte[g.w * g.h * c];
Marshal.Copy(new IntPtr(result), data, 0, data.Length);
Operations.Free(result);
var frame = new AnimatedGifFrame
{
Data = data,
Delay = g.delay
};
res.Add(frame);
} while (true);
Operations.Free(g._out_);
if (res.Count > 0)
{
x = g.w;
y = g.h;
}
return(res.ToArray());
}
finally
{
_stream = null;
}
}
public void Write(Image image, ImageWriterFormat format, Stream dest)
{
if (image?.Data == null)
{
throw new ArgumentNullException(nameof(image));
}
try
{
_stream = dest;
fixed(byte *b = &image.Data[0])
{
switch (format)
{
case ImageWriterFormat.Bmp:
Stb.stbi_write_bmp_to_func(WriteCallback, null, image.Width, image.Height, image.Comp, b);
break;
case ImageWriterFormat.Tga:
Stb.stbi_write_tga_to_func(WriteCallback, null, image.Width, image.Height, image.Comp, b);
break;
case ImageWriterFormat.Hdr:
{
var f = new float[image.Data.Length];
for (var i = 0; i < image.Data.Length; ++i)
{
f[i] = image.Data[i] / 255.0f;
}
fixed(float *fptr = f)
{
Stb.stbi_write_hdr_to_func(WriteCallback, null, image.Width, image.Height, image.Comp, fptr);
}
}
break;
case ImageWriterFormat.Png:
Stb.stbi_write_png_to_func(WriteCallback, null, image.Width, image.Height, image.Comp, b, image.Width * image.Comp);
break;
default:
throw new ArgumentOutOfRangeException(nameof(format), format, null);
}
}
}
finally
{
_stream = null;
}
}
public Image Read(Stream stream, int req_comp = Stb.STBI_default)
{
_stream = stream;
try
{
int x, y, comp;
var result = Stb.stbi_load_from_callbacks(_callbacks, null, &x, &y, &comp, req_comp);
var image = new Image
{
Width = x,
Height = y,
SourceComp = comp,
Comp = req_comp == Stb.STBI_default ? comp : req_comp
};
if (result == null)
{
throw new Exception(Stb.LastError);
}
// Convert to array
var data = new byte[x * y * image.Comp];
Marshal.Copy(new IntPtr(result), data, 0, data.Length);
Operations.Free(result);
image.Data = data;
return(image);
}
finally
{
_stream = null;
}
}
