private GdkPixBufBitmapSource LoadSourceFromMemory(IntPtr sourceBuffer, int sourceBufferSize)
{
IntPtr gdkStream = LibGdkPixBuf.g_memory_input_stream_new_from_data(sourceBuffer, sourceBufferSize, IntPtr.Zero);
try
{
return(LoadSourceFromGdkStream(gdkStream));
}
finally
{
LibGdkPixBuf.g_object_unref(gdkStream);
}
}
public static GdkPixBufBitmapSource Create(IntPtr pixbuf)
{
var colorSpace = LibGdkPixBuf.gdk_pixbuf_get_colorspace(pixbuf);
if (colorSpace != GdkColorspace.GDK_COLORSPACE_RGB)
{
throw new IOException($"Unsupported color space: {colorSpace}.");
}
var nChannels = LibGdkPixBuf.gdk_pixbuf_get_n_channels(pixbuf);
bool hasAlpha = LibGdkPixBuf.gdk_pixbuf_get_has_alpha(pixbuf);
PixelFormat pixelFormat;
if (nChannels == 4 && hasAlpha)
{
pixelFormat = PixelFormat.RGBA_32;
}
else if (nChannels == 3 && !hasAlpha)
{
pixelFormat = PixelFormat.RGB_24;
}
else
{
throw new IOException($"Unsupported number of channels: {nChannels} (has alpha: {hasAlpha}).");
}
int bitsPerChanel = LibGdkPixBuf.gdk_pixbuf_get_bits_per_sample(pixbuf);
if (bitsPerChanel != 8)
{
throw new IOException($"Unsupported number of bits per chanel: {bitsPerChanel}.");
}
int width = LibGdkPixBuf.gdk_pixbuf_get_width(pixbuf);
int height = LibGdkPixBuf.gdk_pixbuf_get_height(pixbuf);
int stride = LibGdkPixBuf.gdk_pixbuf_get_rowstride(pixbuf);
if (stride < width * nChannels)
{
throw new IOException(
$"Unexpected row stride. Channels: {nChannels}. Bits per chanel: {bitsPerChanel}. Width: {width}. Stride: {stride}."
);
}
IntPtr dataPtr = LibGdkPixBuf.gdk_pixbuf_get_pixels(pixbuf);
return(new GdkPixBufBitmapSource(pixbuf, dataPtr, width, height, stride, pixelFormat));
}
private GdkPixBufBitmapSource LoadSourceFromGdkStream(IntPtr gdkStream)
{
IntPtr pixbuf = LibGdkPixBuf.gdk_pixbuf_new_from_stream(gdkStream, IntPtr.Zero, out IntPtr errorPtr);
try
{
if (pixbuf == IntPtr.Zero)
{
string gdkErrorMessage;
if (errorPtr != IntPtr.Zero)
{
GError error = Marshal.PtrToStructure <GError>(errorPtr);
gdkErrorMessage = error.message;
}
else
{
gdkErrorMessage = "Unknown error.";
}
throw new IOException($"{nameof(LibGdkPixBuf.gdk_pixbuf_new_from_stream)} error: {gdkErrorMessage}");
}
var source = GdkPixBufBitmapSource.Create(pixbuf);
pixbuf = IntPtr.Zero;
return(source);
}
finally
{
if (pixbuf != IntPtr.Zero)
{
LibGdkPixBuf.g_object_unref(pixbuf);
}
if (errorPtr != IntPtr.Zero)
{
LibGdkPixBuf.g_error_free(errorPtr);
}
}
}
public void Dispose()
{
LibGdkPixBuf.g_object_unref(pixbuf);
}