Merge pull request #255 from frohlfs/viewBox

Nested svg areas are misplaced or invisible 

Source/DataTypes/SvgViewBox.cs

@@ -131,7 +131,7 @@ namespace Svg
 
             if (this.Equals(SvgViewBox.Empty))
             {
-                renderer.TranslateTransform(x, y);
+                renderer.TranslateTransform(x, y, MatrixOrder.Prepend);
                 return;
             }
 
@@ -199,11 +199,11 @@ namespace Svg
                         break;
                 }
             }
-
+            
             renderer.SetClip(new Region(new RectangleF(x, y, width, height)), CombineMode.Intersect);
-            renderer.ScaleTransform(fScaleX, fScaleY, MatrixOrder.Prepend);
-            renderer.TranslateTransform(x, y);
-            renderer.TranslateTransform(fMinX, fMinY);
+            renderer.TranslateTransform(x, y, MatrixOrder.Prepend);
+            renderer.TranslateTransform(fMinX, fMinY, MatrixOrder.Prepend);
+            renderer.ScaleTransform(fScaleX, fScaleY, MatrixOrder.Prepend);       
         }
     }
 

Tests/W3CTestSuite/svg/__issueViewBox.svg

+<?xml version="1.0" encoding="iso-8859-1" standalone="no" ?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 20010904//EN"
+  "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+<svg x="0" y="0" width="450" height="551" viewBox="0 0 670 820" xmlns="http://www.w3.org/2000/svg"
+  xmlns:xlink="http://www.w3.org/1999/xlink">
+  <rect x="0" y="0" width="670" height="820" style="fill:black" />
+
+  <rect x="100" y="200" width="50" height="100" style="fill:blue" />
+  <svg x="100" y="200" width="50" height="100" viewBox="0 0 75 150">
+    <line x1="0" y1="0" x2="75" y2="0" style="stroke:white;" />
+    <line x1="75" y1="0" x2="75" y2="150" style="stroke:white;" />
+    <line x1="75" y1="150" x2="0" y2="150" style="stroke:white;" />
+    <line x1="0" y1="150" x2="0" y2="0" style="stroke:white;" />
+  </svg>
+
+  <rect x="200" y="200" width="50" height="25" style="fill:blue" />
+  <svg x="200" y="200" width="50" height="100" viewBox="0 0 100 50" preserveAspectRatio="xMaxYMin meet">
+    <line x1="0" y1="0" x2="100" y2="0" style="stroke:white;" />
+    <line x1="100" y1="0" x2="100" y2="50" style="stroke:white;" />
+    <line x1="100" y1="50" x2="0" y2="50" style="stroke:white;" />
+    <line x1="0" y1="50" x2="0" y2="0" style="stroke:white;" />
+  </svg>
+
+  <rect x="300" y="275" width="50" height="25" style="fill:blue" />
+  <svg x="300" y="200" width="50" height="100" viewBox="0 0 100 50" preserveAspectRatio="xMaxYMax meet">
+    <line x1="0" y1="0" x2="100" y2="0" style="stroke:white;" />
+    <line x1="100" y1="0" x2="100" y2="50" style="stroke:white;" />
+    <line x1="100" y1="50" x2="0" y2="50" style="stroke:white;" />
+    <line x1="0" y1="50" x2="0" y2="0" style="stroke:white;" />
+  </svg>
+  
+</svg>
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