Re: [Matplotlib-users] different behaviour in Windows and Linux

[Michael D. <md...@st...>]

There is an explicit offset of one pixel on the left when it sets up a 
clip box in Agg.  I don't know why this is there, but it dates back to 
0.98.0, and earlier versions did something completely different.  I can 
only guess it was to compensate for an earlier bug in the precise 
drawing of the axes rectangle.  I can't explain why it would have 
different behavior on Windows vs. Linux, though.

I have fixed this in SVN r6465 and am including a patch below (which 
unfortunately requires a recompile).

Cheers,
Mike


Modified: trunk/matplotlib/src/_backend_agg.cpp
===================================================================
--- trunk/matplotlib/src/_backend_agg.cpp	2008-12-01 19:35:39 UTC (rev 6465)
+++ trunk/matplotlib/src/_backend_agg.cpp	2008-12-02 15:27:23 UTC (rev 6466)
@@ -312,8 +312,8 @@
 
   double l, b, r, t;
   if (py_convert_bbox(cliprect.ptr(), l, b, r, t)) {
-    rasterizer.clip_box(int(mpl_round(l)) + 1, height - int(mpl_round(b)),
-                        int(mpl_round(r)),     height - int(mpl_round(t)));
+    rasterizer.clip_box(int(mpl_round(l)), height - int(mpl_round(b)),
+                        int(mpl_round(r)), height - int(mpl_round(t)));
   }
 
   _VERBOSE("RendererAgg::set_clipbox done");