internal static DrawingCall[] AppendCommand(DrawingCall[] drawing, DrawingCall draw)
{
if (drawing == null)
{
return new[] { draw }
}
;
else
{
var subCanvas = drawing[drawing.Length - 1].Action.Target as SubCanvas;
if (subCanvas != null)
{
subCanvas = new SubCanvas(subCanvas, draw);
var result = new DrawingCall[drawing.Length];
Array.Copy(drawing, result, drawing.Length - 1);
draw.Action = subCanvas.Draw;
result[drawing.Length - 1] = draw;
return(result);
}
else
{
var result = new DrawingCall[drawing.Length + 1];
Array.Copy(drawing, result, drawing.Length);
result[drawing.Length] = draw;
return(result);
}
}
}
public override IObservable <Canvas> Process(IObservable <Canvas> source)
{
return(Observable.Create <Canvas>(observer =>
{
return source.Select(input =>
{
var rect = RegionOfInterest;
var subCanvas = new SubCanvas(image =>
{
try
{
if (rect.Width > 0 && rect.Height > 0)
{
return image.GetSubRect(rect);
}
return image;
}
catch (Exception ex)
{
observer.OnError(ex);
throw;
}
});
DrawingCall draw;
draw.Action = subCanvas.Draw;
draw.Observer = observer;
return new Canvas(input, draw);
}).SubscribeSafe(observer);
}));
}
public SubCanvas(SubCanvas source, SubCanvas other, bool excludeSource)
{
if (source.generator != other.generator)
{
throw new InvalidOperationException();
}
generator = source.generator;
drawing = MergeCommands(source.drawing, other.drawing, excludeSource);
}
internal Canvas(Canvas source, Canvas other)
{
if (source.generator != other.generator)
{
throw new InvalidOperationException("Unable to merge drawing operators targeting different image sources.");
}
generator = source.generator;
drawing = SubCanvas.MergeCommands(source.drawing, other.drawing);
}
public SubCanvas(SubCanvas canvas, DrawingCall draw)
{
generator = canvas.generator;
drawing = AppendCommand(canvas.drawing, draw);
}
internal Canvas(Canvas canvas, DrawingCall draw)
{
generator = canvas.generator;
drawing = SubCanvas.AppendCommand(canvas.drawing, draw);
}
internal static DrawingCall[] MergeCommands(DrawingCall[] source, DrawingCall[] other, bool excludeSource = false)
{
if (source == other)
{
return(source);
}
else if (source == null)
{
return(other);
}
else if (other == null)
{
return(source);
}
else
{
var commandList = new List <DrawingCall>();
var hashSet = new Dictionary <Action <IplImage>, int>(SubCanvasEqualityComparer.Default);
for (int i = 0; i < source.Length; i++)
{
hashSet.Add(source[i].Action, i);
if (!excludeSource)
{
commandList.Add(source[i]);
}
}
for (int i = 0; i < other.Length; i++)
{
int index;
if (hashSet.TryGetValue(other[i].Action, out index))
{
var sourceDraw = source[index];
if (object.ReferenceEquals(sourceDraw.Action, other[i].Action))
{
continue;
}
var subCanvas = other[i].Action.Target as SubCanvas;
if (subCanvas != null)
{
if (!excludeSource && i == 0 && index == hashSet.Count - 1)
{
// actions are adjacent in command list so we can merge the two subcanvases
subCanvas = new SubCanvas((SubCanvas)sourceDraw.Action.Target, subCanvas, excludeSource: false);
sourceDraw.Action = subCanvas.Draw;
hashSet.Remove(sourceDraw.Action);
hashSet.Add(sourceDraw.Action, index);
commandList[index] = sourceDraw;
}
else
{
// remove redundant actions from other subcanvas
subCanvas = new SubCanvas((SubCanvas)sourceDraw.Action.Target, subCanvas, excludeSource: true);
sourceDraw.Action = subCanvas.Draw;
commandList.Add(sourceDraw);
}
}
}
else
{
commandList.Add(other[i]);
}
}
return(commandList.ToArray());
}
}
