Several fixes for wxAffineMatrix2D transformations.

Correct errors in TransformPoint() and TransformDistance().

Change Rotate() to interpret positive angles as rotating clockwise, for
consistency with wxGraphicsContext::Rotate().

Improve the unit test to verify that all the transformations work correctly.

Closes #14334.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71555 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/graphics.h

@@ -1299,7 +1299,10 @@ public:
     virtual bool IsIdentity() const;
 
     /**
-        Rotates this matrix (in radians).
+        Rotates this matrix clockwise (in radians).
+
+        @param radians
+            Rotation angle in radians, clockwise.
     */
     virtual void Rotate(wxDouble angle);