Create README.md

README.md

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+# VirtualJoystickAndroid
+This library provides a very simple and ready-to-use custom view which emulates a joystick for Xamarin.Android. 
+
+
+**This repository is just a transfer of the library (https://github.com/controlwear/virtual-joystick-android) from Java to Xamarin.Android(C#).
+  aka .aar -> .dll**
+
+just add .dll in your project.
+
+### Using 
+
+In .axml:
+```xml
+<io.github.controlwear.virtual.joystick.android.JoystickView
+  android:id="@+id/joystickView"
+  android:layout_width="300dp"
+  android:layout_height="300dp"
+  app:JV_buttonColor="#FF6E40"
+  app:JV_buttonSizeRatio="15%"
+  app:JV_borderColor="#00796B"
+  app:JV_backgroundColor="#009688"
+  app:JV_borderWidth="4dp"
+  app:JV_fixedCenter="false"/>
+```
+
+In activity, example in `OnCreate()`:
+```csharp
+protected override void OnCreate(Bundle savedInstanceState)
+{
+  base.OnCreate(savedInstanceState);
+
+  SetContentView(Resource.Layout.activity_main);
+
+  var joystick = FindViewById<JoystickView>(Resource.Id.joystickView);
+  joystick.Move += JoystickOnMove;
+}
+
+private void JoystickOnMove(object sender, JoystickView.MoveEventArgs e)
+{
+  Log.Info("JoystickView",
+  $"Angle: {e.P0}; " +
+  $"Power: {e.P1}");
+}
+```
+
+### Some additions
+
+Initially, the library provides only the angle and power values.
+But using the code from [here](https://stackoverflow.com/questions/24917804/how-to-translate-joystick-angle-power-to-the-view-x-y-i-want-to-move), you can translate into coordinates(x,y)
+
+**Values may be inaccurate!**
+
+Let's do it as an extension method:
+
+JoystickExtensions.cs:
+```csharp
+public static class JoystickExtensions
+{
+  public static Point GetPoint(this JoystickView.MoveEventArgs e)
+  {
+    var angle = e.P0;
+    var power = e.P1;
+
+    var radians = angle.ToRadians();
+    var x = Math.Cos(radians);
+    var y = Math.Sin(radians);
+
+    var length = Math.Sqrt( (x*x) + (y*y) );
+    x /= length;
+    y /= length;
+
+    x *= power;
+    y *= power;
+
+    return new Point((int) x,(int) y);
+  }
+}
+```
+
+then, in listener:
+```csharp
+private void JoystickOnMove(object sender, JoystickView.MoveEventArgs e)
+{
+  var point = e.GetPoint();
+
+  Log.Info("JoystickView",
+  $"X: {point.X}; " +
+  $"Y: {point.Y}");
+}
+```