[truetype] Fix font height.

* src/truetype/ttobjs.c (tt_size_reset): The Windows rendering
engine uses rounded values of the ascender and descender to compute
the TrueType font height.

ChangeLog

@@ -1,3 +1,11 @@
+2013-01-22  Werner Lemberg  <wl@gnu.org>
+
+	[truetype] Fix font height.
+
+	* src/truetype/ttobjs.c (tt_size_reset): The Windows rendering
+	engine uses rounded values of the ascender and descender to compute
+	the TrueType font height.
+
 2013-01-16  Behdad Esfahbod  <behdad@behdad.org>
 
 	[sfnt] Fix optimized sbit loader.

src/truetype/ttobjs.c

@@ -4,7 +4,7 @@
 /*                                                                         */
 /*    Objects manager (body).                                              */
 /*                                                                         */
-/*  Copyright 1996-2012                                                    */
+/*  Copyright 1996-2013                                                    */
 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
 /*                                                                         */
 /*  This file is part of the FreeType project, and may only be used,       */
@@ -1177,11 +1177,12 @@
         FT_PIX_ROUND( FT_MulFix( face->root.ascender, metrics->y_scale ) );
       metrics->descender =
         FT_PIX_ROUND( FT_MulFix( face->root.descender, metrics->y_scale ) );
-      metrics->height =
-        FT_PIX_ROUND( FT_MulFix( face->root.height, metrics->y_scale ) );
       metrics->max_advance =
         FT_PIX_ROUND( FT_MulFix( face->root.max_advance_width,
                                  metrics->x_scale ) );
+
+      /* the height is derived from rounded values */
+      metrics->height = metrics->ascender - metrics->descender;
     }
 
     /* compute new transformation */