private static void LockToGrid(CanvasPixelPosition canvasOffset, [NotNull] TileCanvas target, ref double x, ref double y)
{
if (canvasOffset == null)
{
return;
}
var scale = 1.0 / target.CurrentZoom();
var grid = TileCanvas.GridSize * scale;
var bias = (3 * grid) / 5.0;
x = Math.Round((x + bias) / grid) * grid;
x -= (canvasOffset.X * scale) % grid;
y = Math.Round((y + bias) / grid) * grid;
y -= (canvasOffset.Y * scale) % grid;
}
/// <summary>
/// Finish a pen stoke. It should be rendered into the tile store.
/// </summary>
public void CommitTo(TileCanvas tileCanvas)
{
if (tileCanvas == null)
{
return;
}
try
{
lock (_dryLock){
_dryingInk.Add(_stroke.ToArray());
_stroke.Clear(); // ready for next
}
// render and copy on a separate thread
DryWaitingStroke(tileCanvas);
}
catch (Exception ex)
{
Logging.WriteLogMessage(ex.ToString());
}
}
private void DryWaitingStroke([NotNull] TileCanvas tileCanvas)
{
// Try to get a waiting stroke (peek, so we can draw the waiting stroke)
DPoint[][] waitingStrokes;
lock (_dryLock)
{
waitingStrokes = _dryingInk.ToArray();
_dryingInk.Clear();
if (waitingStrokes != null)
{
_renderingInk.UnionWith(waitingStrokes);
}
}
tileCanvas.Invalidate(); // show progress if the render is slow.
_renderTarget.Invalidate();
if (waitingStrokes == null)
{
return;
}
foreach (var strokeToRender in waitingStrokes)
{
if (strokeToRender.Length < 1)
{
continue;
}
// Figure out what part of the screen is covered
var clipRegion = MeasureDrawing(strokeToRender, tileCanvas.CurrentZoom());
var pixelWidth = (int)clipRegion.Width;
var pixelHeight = (int)clipRegion.Height;
// draw to an image
byte[] bytes;
using (var offscreen = new CanvasRenderTarget(CanvasDevice.GetSharedDevice(), pixelWidth, pixelHeight, 96,
DirectXPixelFormat.B8G8R8A8UIntNormalized, CanvasAlphaMode.Premultiplied))
{
using (var ds = offscreen.CreateDrawingSession())
{
ds?.Clear(Colors.Transparent);
DrawToSession(ds, strokeToRender, clipRegion, tileCanvas.CurrentZoom());
}
bytes = offscreen.GetPixelBytes();
}
// render into tile cache
var uncropped = new RawImageInterleaved_UInt8
{
Data = bytes,
Width = pixelWidth,
Height = pixelHeight
};
var visualWidth = (int)Math.Ceiling(pixelWidth / tileCanvas.CurrentZoom());
var visualHeight = (int)Math.Ceiling(pixelHeight / tileCanvas.CurrentZoom());
var visualTop = (int)Math.Floor(clipRegion.Y + 0.5);
var visualLeft = (int)Math.Floor(clipRegion.X + 0.5);
var visualRight = visualLeft + visualWidth;
var visualBottom = visualTop + visualHeight;
ThreadPool.QueueUserWorkItem(canv =>
{
var ok = tileCanvas.ImportBytesScaled(uncropped, visualLeft, visualTop, visualRight, visualBottom);
if (!ok)
{
Logging.WriteLogMessage("Tile byte import failed when drawing strokes");
}
lock (_dryLock)
{
_renderingInk.Remove(strokeToRender);
}
tileCanvas.Invalidate(); // show finished strokes
_renderTarget.Invalidate();
});
}
}
/// <summary>
/// Continue a pen stroke
/// </summary>
public void Stroke(PointerEventArgs penEvent, CanvasPixelPosition canvasOffset, [NotNull] TileCanvas target)
{
try
{
if (penEvent?.CurrentPoint?.Properties == null)
{
return;
}
var x = penEvent.CurrentPoint.Position.X;
var y = penEvent.CurrentPoint.Position.Y;
var isEraser = penEvent.CurrentPoint.Properties.IsEraser || penEvent.CurrentPoint.Properties.IsRightButtonPressed; // treat right-click as erase
if (penEvent.KeyModifiers.HasFlag(VirtualKeyModifiers.Control))
{
// hacky straight line tool:
if (_stroke.Count > 1)
{
_stroke.RemoveAt(_stroke.Count - 1); // replace last point instead of adding a new one
}
}
if (penEvent.KeyModifiers.HasFlag(VirtualKeyModifiers.Menu))// this is actually *ALT*
{
LockToGrid(canvasOffset, target, ref x, ref y);
}
_stroke.Add(new DPoint
{
X = x,
Y = y,
StylusId = GuessPointerId(penEvent.CurrentPoint),
Pressure = penEvent.CurrentPoint.Properties.Pressure,
IsErase = isEraser
});
_renderTarget.Invalidate();
}
catch (Exception ex)
{
Logging.WriteLogMessage(ex.ToString());
}
}