private void CreateOrUpdateBitmap(bool isPopup, IntPtr buffer, Rect dirtyRect, int width, int height, Image image, ref Size currentSize, ref MemoryMappedFile mappedFile, ref MemoryMappedViewAccessor viewAccessor)
{
bool createNewBitmap = false;
if (image.Dispatcher.HasShutdownStarted)
{
return;
}
lock (lockObject)
{
int pixels = width * height;
int numberOfBytes = pixels * BytesPerPixel;
createNewBitmap = mappedFile == null || currentSize.Height != height || currentSize.Width != width;
if (createNewBitmap)
{
ReleaseMemoryMappedView(ref mappedFile, ref viewAccessor);
mappedFile = MemoryMappedFile.CreateNew(null, numberOfBytes, MemoryMappedFileAccess.ReadWrite);
viewAccessor = mappedFile.CreateViewAccessor();
currentSize.Height = height;
currentSize.Width = width;
}
NativeMethodWrapper.CopyMemoryUsingHandle(viewAccessor.SafeMemoryMappedViewHandle.DangerousGetHandle(), buffer, numberOfBytes);
}
image.Dispatcher.BeginInvoke((Action)(() =>
{
lock (lockObject)
{
if (createNewBitmap)
{
if (image.Source != null)
{
image.Source = null;
GC.Collect(1);
}
image.Source = new WriteableBitmap(width, height, DpiX, DpiY, PixelFormat, null);
}
var backBufferHandle = isPopup ? popupMemoryMappedFile.SafeMemoryMappedFileHandle : viewMemoryMappedFile.SafeMemoryMappedFileHandle;
var stride = width * BytesPerPixel;
var noOfBytes = stride * height;
// Update the dirty region
var sourceRect = new Int32Rect(dirtyRect.X, dirtyRect.Y, dirtyRect.Width, dirtyRect.Height);
var bitmap = (WriteableBitmap)image.Source;
bitmap.WritePixels(sourceRect, backBufferHandle.DangerousGetHandle(), noOfBytes, stride, dirtyRect.X, dirtyRect.Y);
}
}), DispatcherPriority.Render);
}
