[TouchCanvas] Set of fixes:

* Fix azimuth position
* App crashes caused by Apple Pencil touches
* Missed code from ReticleView class

ios9/TouchCanvas/TouchCanvas/CanvasView.cs

@@ -86,7 +86,7 @@ namespace TouchCanvas {
 			if (needsFullRedraw) {
 				SetFrozenImageNeedsUpdate ();
 				FrozenContext.ClearRect (Bounds);
-				foreach (var line in finishedLines) {
+				foreach (var line in finishedLines.Union (lines)) {
 					line.DrawCommitedPointsInContext (context, IsDebuggingEnabled, UsePreciseLocations);
 				}
 
@@ -122,7 +122,7 @@ namespace TouchCanvas {
 					line = AddActiveLineForTouch (touch);
 				updateRect = updateRect.UnionWith (line.RemovePointsWithType (PointType.Predicted));
 
-				var coalescedTouches = evt.GetCoalescedTouches (touch);
+				var coalescedTouches = evt.GetCoalescedTouches (touch) ?? new UITouch[0];
 				var coalescedRect = AddPointsOfType (PointType.Coalesced, coalescedTouches, line, updateRect);
 				updateRect = updateRect.UnionWith (coalescedRect);
 
@@ -132,8 +132,8 @@ namespace TouchCanvas {
 					updateRect = updateRect.UnionWith (predictedRect);
 				}
 			}
-
-			SetNeedsDisplayInRect (updateRect);
+			SetNeedsDisplay ();
+//			SetNeedsDisplayInRect (updateRect);
 		}
 
 		Line AddActiveLineForTouch (UITouch touch)
@@ -166,7 +166,7 @@ namespace TouchCanvas {
 				}
 
 				var touchRect = line.AddPointOfType (type, touch);
-				accumulatedRect.UnionWith (touchRect);
+				accumulatedRect = accumulatedRect.UnionWith (touchRect);
 				CommitLine (line);
 			}
 
@@ -191,7 +191,7 @@ namespace TouchCanvas {
 				if (cancel)
 					updateRect = updateRect.UnionWith (line.Cancel ());
 
-				if (line.IsComplete || !isTouchUpdatingEnabled) {
+				if (line.IsComplete) {
 					FinishLine (line);
 				} else {
 					pendingLines.Add (touch, line);
@@ -216,7 +216,8 @@ namespace TouchCanvas {
 					return;
 
 				var updateResult = possibleLine.UpdateWithTouch (touch);
-				SetNeedsDisplayInRect (updateResult.Value);
+				if (updateResult.Key)
+					SetNeedsDisplayInRect (updateResult.Value);
 
 				// If this update updated the last point requiring an update, move the line to the `frozenImage`.
 				if (isPending && possibleLine.IsComplete) {

ios9/TouchCanvas/TouchCanvas/Extensions.cs

@@ -35,7 +35,7 @@ namespace TouchCanvas {
 			try {
 				return (T)(object)(((int)(object)type & ~(int)(object)value));
 			} catch (Exception ex) {
-				throw new ArgumentException ( string.Format ("Could not remove value from enumerated type '{0}'.", typeof(T).Name), ex);
+				return value;
 			}
 		}
 	}

ios9/TouchCanvas/TouchCanvas/Line.cs

@@ -22,25 +22,22 @@ namespace TouchCanvas {
 
 		public KeyValuePair<bool, CGRect> UpdateWithTouch (UITouch touch)
 		{
-			var emptyResult = new KeyValuePair<bool, CGRect> (false, CGRect.Empty);
-
-			LinePoint point;
-			if (!pointsWaitingForUpdatesByEstimationIndex.TryGetValue (touch.EstimationUpdateIndex, out point))
-				return emptyResult;
-
+			var estimationUpdateIndex = touch.EstimationUpdateIndex;
+			var point = pointsWaitingForUpdatesByEstimationIndex[estimationUpdateIndex];
 			if (point != null) {
 				var rect = UpdateRectForExistingPoint (point);
 				var didUpdate = point.UpdateWithTouch (touch);
 				if (didUpdate)
 					rect = rect.UnionWith (UpdateRectForExistingPoint (point));
 
-				if (point.EstimatedPropertiesExpectingUpdates == 0)
-					pointsWaitingForUpdatesByEstimationIndex.Remove (touch.EstimationUpdateIndex);
+				if (point.EstimatedPropertiesExpectingUpdates == 0) {
+					pointsWaitingForUpdatesByEstimationIndex.Remove (estimationUpdateIndex);
+				}
 
 				return new KeyValuePair<bool, CGRect> (didUpdate, rect);
 			}
 
-			return emptyResult;
+			return new KeyValuePair<bool, CGRect> (false, CGRect.Empty);
 		}
 
 		public CGRect AddPointOfType (PointType pointType, UITouch touch)
@@ -70,10 +67,11 @@ namespace TouchCanvas {
 					if (priorPoint != null)
 						rect = rect.UnionWith (UpdateRectForLinePoint (priorPoint));
 					updateRect = updateRect.UnionWith (rect);
+				} else {
+					keepPoints.Add (point);
 				}
 
 				priorPoint = point;
-				keepPoints.Add (point);
 			}
 
 			Points = keepPoints;
@@ -119,7 +117,7 @@ namespace TouchCanvas {
 						color = UIColor.Blue;
 				} else {
 					if (pointType.Has (PointType.Cancelled))
-						color = UIColor.Clear;
+						color = UIColor.Red;
 					else if (pointType.Has (PointType.Finger))
 						color = UIColor.Purple;
 					
@@ -240,10 +238,10 @@ namespace TouchCanvas {
 			var rect = UpdateRectForLinePoint (point);
 			var arrayIndex = point.SequenceNumber - Points.First ().SequenceNumber;
 
-			if (arrayIndex > 0)
+			if (arrayIndex > 0 && arrayIndex + 1 < Points.Count)
 				rect = rect.UnionWith (UpdateRectForLinePoint (point, Points[arrayIndex - 1]));
 
-			if (arrayIndex + 1 < Points.Count)
+			if (arrayIndex + 1 < Points.Count && arrayIndex + 1 > 0)
 				rect = rect.UnionWith (UpdateRectForLinePoint (point, Points[arrayIndex + 1]));
 
 			return rect;

ios9/TouchCanvas/TouchCanvas/MainViewController.cs

@@ -108,7 +108,7 @@ namespace TouchCanvas {
 
 		public override UIInterfaceOrientationMask GetSupportedInterfaceOrientations ()
 		{
-			return UIInterfaceOrientationMask.LandscapeRight | UIInterfaceOrientationMask.LandscapeRight;
+			return UIInterfaceOrientationMask.LandscapeRight | UIInterfaceOrientationMask.LandscapeLeft;
 		}
 
 		partial void ClearView (UIBarButtonItem sender)
@@ -136,26 +136,26 @@ namespace TouchCanvas {
 
 		void UpdateReticleView (UITouch touch, bool predicated = false)
 		{
-			if (touch.Type != UITouchType.Stylus)
+			if (touch == null || touch.Type != UITouchType.Stylus)
 				return;
 
 			ReticleView.PredictedDotLayer.Hidden = !predicated;
 			ReticleView.PredictedLineLayer.Hidden = !predicated;
 
-			var azimuthAngle = touch.GetAzimuthAngle (touch.View);
-			var azimuthUnitVector = touch.GetAzimuthUnitVector (touch.View);
+			var azimuthAngle = touch.GetAzimuthAngle (View);
+			var azimuthUnitVector = touch.GetAzimuthUnitVector (View);
 			var altitudeAngle = touch.AltitudeAngle;
 
 			if (predicated) {
 				ReticleView.PredictedAzimuthAngle = azimuthAngle;
 				ReticleView.PredictedAzimuthUnitVector = azimuthUnitVector;
-				ReticleView.PredictedAzimuthAngle = altitudeAngle;
+				ReticleView.PredictedAltitudeAngle = altitudeAngle;
 			} else {
 				var location = touch.PreviousLocationInView (View);
 				ReticleView.Center = location;
 				ReticleView.ActualAzimuthAngle = azimuthAngle;
 				ReticleView.ActualAzimuthUnitVector = azimuthUnitVector;
-				ReticleView.ActualAzimuthAngle = altitudeAngle;
+				ReticleView.ActualAltitudeAngle = altitudeAngle;
 			}
 		}
 	}

ios9/TouchCanvas/TouchCanvas/ReticleView.cs

@@ -20,6 +20,12 @@ namespace TouchCanvas {
 		CALayer lineLayer = new CALayer ();
 		UIColor indicatorColor = UIColor.Red;
 
+		public override CGSize IntrinsicContentSize {
+			get {
+				return reticleImage.Size;
+			}
+		}
+
 		readonly CALayer predictedDotLayer = new CALayer ();
 		public CALayer PredictedDotLayer {
 			get {
@@ -102,6 +108,8 @@ namespace TouchCanvas {
 
 		public ReticleView (CGRect frame) : base (frame)
 		{
+			ContentScaleFactor = UIScreen.MainScreen.Scale;
+
 			reticleLayer.ContentsGravity = CALayer.GravityCenter;
 			reticleLayer.Position = Layer.Position;
 			Layer.AddSublayer (reticleLayer);
@@ -151,7 +159,7 @@ namespace TouchCanvas {
 			var transform = CGAffineTransform.MakeIdentity ();
 
 			for (int i = 0; i < 4; i++) {
-				path.MoveToPoint (transform, radius * 0.5f, 0f);
+				path.MoveToPoint (transform, radius * .5f, 0f);
 				path.AddLineToPoint (transform, radius * 1.15f, 0);
 				transform.Rotate (NMath.PI / 2f);
 			}
@@ -176,7 +184,7 @@ namespace TouchCanvas {
 			LayoutIndicatorForAzimuthAngle (actualAzimuthAngle, actualAzimuthUnitVector, actualAltitudeAngle, lineLayer, dotLayer);
 		}
 
-		void LayoutIndicatorForAzimuthAngle (nfloat azimuthAngle, CGVector azimuthUnitVector, nfloat altitudeAngle, CALayer lineLayer, CALayer dotLayer)
+		void LayoutIndicatorForAzimuthAngle (nfloat azimuthAngle, CGVector azimuthUnitVector, nfloat altitudeAngle, CALayer targetLineLayer, CALayer targetDotLayer)
 		{
 			var reticleBounds = reticleLayer.Bounds;
 			var centeringTransform = CGAffineTransform.MakeTranslation (reticleBounds.Width / 2f, reticleBounds.Height / 2f);
@@ -185,16 +193,16 @@ namespace TouchCanvas {
 
 			// Draw the indicator opposite the azimuth by rotating pi radians, for easy visualization.
 			rotationTransform = CGAffineTransform.Rotate (rotationTransform, NMath.PI);
-			var altitudeRadius = (1f - altitudeAngle / (NMath.PI / 2f) * radius);
+			var altitudeRadius = (1f - altitudeAngle / NMath.PI / 2f) * radius;
 			var lineTransform = CGAffineTransform.MakeScale (altitudeRadius, 1);
 
-			lineTransform.Multiply (rotationTransform);
-			lineTransform.Multiply (centeringTransform);
-			lineLayer.AffineTransform = lineTransform;
+			lineTransform = CGAffineTransform.Multiply (lineTransform, rotationTransform);
+			lineTransform = CGAffineTransform.Multiply (lineTransform, centeringTransform);
+			targetLineLayer.AffineTransform = lineTransform;
 
 			var dotTransform = CGAffineTransform.MakeTranslation (-azimuthUnitVector.dx * altitudeRadius, -azimuthUnitVector.dy * altitudeRadius);
-			dotTransform.Multiply (centeringTransform);
-			dotLayer.AffineTransform = dotTransform;
+			dotTransform = CGAffineTransform.Multiply (dotTransform, centeringTransform);
+			targetDotLayer.AffineTransform = dotTransform;
 		}
 
 		static void ConfigureDotLayer (CALayer targetLayer, UIColor color)