private async void Image_MouseUp(object sender, MouseButtonEventArgs e)
{
if (!DrawSelectionBox)
{
return;
}
// Release the mouse capture and stop tracking it.
DrawSelectionBox = false;
OuterGrid.ReleaseMouseCapture();
// Hide the drag selection box.
SelectionBox.Visibility = Visibility.Collapsed;
var l = RenderImage.TranslatePoint(new Point(0, 0), OuterGrid);
var mouseUpPos = e.GetPosition(OuterGrid);
if (mouseUpPos.X < l.X || mouseUpPos.X > l.X + RenderImage.ActualWidth)
{
return;
}
if (!(DataContext is MandelbrotViewModel dc) || !dc.CanRender())
{
return;
}
var topLeft = SelectionBox.TranslatePoint(new Point(0, 0), RenderImage);
var downRight = topLeft;
downRight.X += SelectionBox.Width;
downRight.Y += SelectionBox.Height;
var oldL = dc.LeftEdge;
var oldR = dc.RightEdge;
var oldD = dc.BottomEdge;
var oldU = dc.UpperEdge;
var newL = oldL + (oldR - oldL) * topLeft.X / dc.CurrentBitmap.PixelWidth *
MandelbrotViewModel.DpiScale;
var newR = oldL + (oldR - oldL) * downRight.X / dc.CurrentBitmap.PixelWidth *
MandelbrotViewModel.DpiScale;
var newU = oldU - (oldU - oldD) * topLeft.Y / dc.CurrentBitmap.PixelHeight *
MandelbrotViewModel.DpiScale;
var newD = oldU - (oldU - oldD) * downRight.Y / dc.CurrentBitmap.PixelHeight *
MandelbrotViewModel.DpiScale;
dc.LeftEdge = newL;
dc.RightEdge = newR;
dc.UpperEdge = newU;
dc.BottomEdge = newD;
await dc.ExecuteRender();
}