Fixed issue #129

The matrix multiplication order was incorrect
ChartsOrg · Jun 11, 2015 · 4cbd20f · 4cbd20f
1 parent 9b3c8b7
commit 4cbd20f
Showing 1 changed file with 4 additions and 5 deletions.
diff --git a/Charts/Classes/Utils/ChartViewPortHandler.swift b/Charts/Classes/Utils/ChartViewPortHandler.swift
@@ -186,11 +186,10 @@ public class ChartViewPortHandler: NSObject
     /// Centers the viewport around the specified position (x-index and y-value) in the chart.
     public func centerViewPort(#pt: CGPoint, chart: ChartViewBase)
     {
-        var matrix = CGAffineTransformTranslate(
-            _touchMatrix,
-            -(pt.x - offsetLeft),
-            -(pt.y - offsetTop)
-        );
+        let translateX = pt.x - offsetLeft;
+        let translateY = pt.y - offsetTop;
+
+        var matrix = CGAffineTransformConcat(_touchMatrix, CGAffineTransformMakeTranslation(-translateX, -translateY));
 
         refresh(newMatrix: matrix, chart: chart, invalidate: false);
     }