XAML-Map-Control/MapControl/Shared/Map.cs

// XAML Map Control - https://github.com/ClemensFischer/XAML-Map-Control
// © 2020 Clemens Fischer
// Licensed under the Microsoft Public License (Ms-PL)

#if WINDOWS_UWP
using Windows.UI.Xaml;
#else
using System.Windows;
#endif

namespace MapControl
{
    /// <summary>
    /// MapBase with default input event handling.
    /// </summary>
    public partial class Map : MapBase
    {
        public static readonly DependencyProperty MouseWheelZoomDeltaProperty = DependencyProperty.Register(
            nameof(MouseWheelZoomDelta), typeof(double), typeof(Map), new PropertyMetadata(1d));

        /// <summary>
        /// Gets or sets the amount by which the ZoomLevel property changes during a MouseWheel event.
        /// The default value is 1.
        /// </summary>
        public double MouseWheelZoomDelta
        {
            get { return (double)GetValue(MouseWheelZoomDeltaProperty); }
            set { SetValue(MouseWheelZoomDeltaProperty, value); }
        }

        private Vector translation;
        private double rotation;
        private double scale = 1d;
        private bool transformPending;

        private void ResetTransform()
        {
            translation.X = 0d;
            translation.Y = 0d;
            rotation = 0d;
            scale = 1d;
            transformPending = false;
        }
    }
}