Merge pull request #15 from Dunkhan/issue14Fix

Fixed #14, prevents crash when resized to zero dimensions

Author: Dunkhan

CHANGELOG.md

@@ -15,3 +15,4 @@ All notable changes to this project will be documented in this file.
 - Image Annotations (#7)
 - MeasureText fixed in cases where string is null or empty
 - Fixed render extent not being set in ArrangeOverride step on WPF (#12)
+- Fixed zero dimensions crashing plot (#14)

Source/OxyPlot.SharpDX.Wpf/PlotImage.cs

@@ -591,8 +591,8 @@ private void InitRendering()
                 dpiScale = hwndTarget.TransformToDevice.M11;
             }
 
-            int surfWidth = (int)(this.viewport.Width < 0 ? 0 : Math.Ceiling(this.viewport.Width * dpiScale));
-            int surfHeight = (int)(this.viewport.Height < 0 ? 0 : Math.Ceiling(this.viewport.Height * dpiScale));
+            int surfWidth = (int)(this.viewport.Width <= 0 ? 1 : Math.Ceiling(this.viewport.Width * dpiScale));
+            int surfHeight = (int)(this.viewport.Height <= 0 ? 1 : Math.Ceiling(this.viewport.Height * dpiScale));
 
             var windowHandle = (new WindowInteropHelper(Window.GetWindow(this))).Handle;