Bundled position parameters/variables (#607)

* Bundled position parameters in `PasteAction.Paste()`

* In `BaseEditEngine`

* - In `EllipseEngine.CreatePoints()`

* Implemented requested changes

Pinta.Tools/Editable/EditEngines/BaseEditEngine.cs

@@ -1351,15 +1351,22 @@ protected void CalculateModifiedCurrentPoint ()
 		//Don't bother calculating a modified point if there is no selected shape.
 		if (selEngine != null) {
 			if (ShapeType != ShapeTypes.OpenLineCurveSeries && selEngine.ControlPoints.Count == 4) {
+
 				// Constrain to a square / circle.
+
 				var origin = selEngine.ControlPoints[(SelectedPointIndex + 2) % 4].Position;
 
-				var dx = current_point.X - origin.X;
-				var dy = current_point.Y - origin.Y;
-				var length = Math.Max (Math.Abs (dx), Math.Abs (dy));
-				dx = length * Math.Sign (dx);
-				dy = length * Math.Sign (dy);
-				current_point = new PointD (origin.X + dx, origin.Y + dy);
+				PointD d = current_point - origin;
+
+				var length = Math.Max (Math.Abs (d.X), Math.Abs (d.Y));
+
+				d = new PointD (
+					X: length * Math.Sign (d.X),
+					Y: length * Math.Sign (d.Y)
+				);
+
+				current_point = origin + d;
+
 			} else {
 				// Calculate the modified position of currentPoint such that the angle between the adjacent point
 				// (if any) and currentPoint is snapped to the closest angle out of a certain number of angles.

Pinta.Tools/Editable/Shapes/EllipseEngine.cs

@@ -199,20 +199,25 @@ private IEnumerable<GeneratedPoint> CreatePoints ()
 		//that will be calculated and stored into the Polygon collection.
 		double tInterval = .02d;
 
-		double rx = width / 2d; //1/2 of the bounding Rectangle Width.
-		double ry = height / 2d; //1/2 of the bounding Rectangle Height.
-		double cx = topLeft.X + rx; //The middle of the bounding Rectangle, horizontally speaking.
-		double cy = topLeft.Y + ry; //The middle of the bounding Rectangle, vertically speaking.
-		double c1 = 0.5522847498307933984022516322796d; //tan(pi / 8d) * 4d / 3d ~= 0.5522847498307933984022516322796d
+		double r_x = width / 2d; //1/2 of the bounding Rectangle Width.
+		double r_y = height / 2d; //1/2 of the bounding Rectangle Height.
+
+		//The middle of the bounding Rectangle...
+		PointD c = new (
+			X: topLeft.X + r_x, // ...Horizontally speaking
+			Y: topLeft.Y + r_y // ...Vertically speaking
+		);
+
+		const double c_1 = 0.5522847498307933984022516322796d; //tan(pi / 8d) * 4d / 3d ~= 0.5522847498307933984022516322796d
 
 		foreach (
 			var p in
 			calculateCurvePoints (
 				tInterval,
-				cx + rx, cy,
-				cx + rx, cy - c1 * ry,
-				cx + c1 * rx, cy - ry,
-				cx, cy - ry,
+				c.X + r_x, c.Y,
+				c.X + r_x, c.Y - c_1 * r_y,
+				c.X + c_1 * r_x, c.Y - r_y,
+				c.X, c.Y - r_y,
 				3
 			)
 		) yield return p;
@@ -221,10 +226,10 @@ var p in
 			var p in
 			calculateCurvePoints (
 				tInterval,
-				cx, cy - ry,
-				cx - c1 * rx, cy - ry,
-				cx - rx, cy - c1 * ry,
-				cx - rx, cy,
+				c.X, c.Y - r_y,
+				c.X - c_1 * r_x, c.Y - r_y,
+				c.X - r_x, c.Y - c_1 * r_y,
+				c.X - r_x, c.Y,
 				0
 			)
 		) yield return p;
@@ -233,10 +238,10 @@ var p in
 			var p in
 			calculateCurvePoints (
 				tInterval,
-				cx - rx, cy,
-				cx - rx, cy + c1 * ry,
-				cx - c1 * rx, cy + ry,
-				cx, cy + ry,
+				c.X - r_x, c.Y,
+				c.X - r_x, c.Y + c_1 * r_y,
+				c.X - c_1 * r_x, c.Y + r_y,
+				c.X, c.Y + r_y,
 				1
 			)
 		) yield return p;
@@ -245,16 +250,16 @@ var p in
 			var p in
 			calculateCurvePoints (
 				tInterval,
-				cx, cy + ry,
-				cx + c1 * rx, cy + ry,
-				cx + rx, cy + c1 * ry,
-				cx + rx, cy,
+				c.X, c.Y + r_y,
+				c.X + c_1 * r_x, c.Y + r_y,
+				c.X + r_x, c.Y + c_1 * r_y,
+				c.X + r_x, c.Y,
 				2
 			)
 		) yield return p;
 
 		// Close the curve.
-		yield return new GeneratedPoint (new PointD (cx + rx, cy), 3);
+		yield return new GeneratedPoint (new PointD (c.X + r_x, c.Y), 3);
 	}
 
 	/// <summary>

Pinta/Actions/Edit/PasteAction.cs

@@ -58,7 +58,11 @@ private void Activated (object sender, EventArgs e)
 		// Paste into the active document.
 		// The 'false' argument indicates that paste should be
 		// performed into the current (not a new) layer.
-		Paste (doc, false, (int) canvasPos.X, (int) canvasPos.Y);
+		Paste (
+			doc: doc,
+			toNewLayer: false,
+			pastePosition: canvasPos.ToInt ()
+		);
 	}
 
 	/// <summary>
@@ -72,7 +76,7 @@ private void Activated (object sender, EventArgs e)
 	/// <param name="y">Optional. Location within image to paste to.
 	/// Position will be adjusted if pasted image would hang
 	/// over right or bottom edges of canvas.</param>
-	public static async void Paste (Document doc, bool toNewLayer, int x = 0, int y = 0)
+	public static async void Paste (Document doc, bool toNewLayer, PointI pastePosition = new ())
 	{
 		// Create a compound history item for recording several
 		// operations so that they can all be undone/redone together.
@@ -116,8 +120,10 @@ public static async void Paste (Document doc, bool toNewLayer, int x = 0, int y
 
 		// If the pasted image would fall off bottom- or right-
 		// side of image, adjust paste position
-		x = Math.Max (0, Math.Min (x, canvas_size.Width - cb_image.Width));
-		y = Math.Max (0, Math.Min (y, canvas_size.Height - cb_image.Height));
+		pastePosition = new PointI (
+		    X: Math.Clamp (pastePosition.X, 0, canvas_size.Width - cb_image.Width),
+		    Y: Math.Clamp (pastePosition.Y, 0, canvas_size.Height - cb_image.Height)
+		);
 
 		// If requested, create a new layer, make it the current
 		// layer and record it's creation in the history
@@ -137,13 +143,13 @@ public static async void Paste (Document doc, bool toNewLayer, int x = 0, int y
 		g.Paint ();
 
 		doc.Layers.SelectionLayer.Transform.InitIdentity ();
-		doc.Layers.SelectionLayer.Transform.Translate (x, y);
+		doc.Layers.SelectionLayer.Transform.Translate (pastePosition.X, pastePosition.Y);
 
 		PintaCore.Tools.SetCurrentTool ("MoveSelectedTool");
 
 		var old_selection = doc.Selection.Clone ();
 
-		doc.Selection.CreateRectangleSelection (new RectangleD (x, y, cb_image.Width, cb_image.Height));
+		doc.Selection.CreateRectangleSelection (new RectangleD ((PointD) pastePosition, cb_image.Width, cb_image.Height));
 		doc.Selection.Visible = true;
 
 		doc.Workspace.Invalidate ();

Pinta/Actions/Edit/PasteIntoNewLayerAction.cs

@@ -57,6 +57,10 @@ private void Activated (object sender, EventArgs e)
 		// Paste into the active document.
 		// The 'true' argument indicates that paste should be
 		// performed into a new layer.
-		PasteAction.Paste (doc, true, (int) canvasPos.X, (int) canvasPos.Y);
+		PasteAction.Paste (
+			doc: doc,
+			toNewLayer: true,
+			pastePosition: canvasPos.ToInt ()
+		);
 	}
 }