callbacks,main: set subpixel antialiasing

...instead of the default one. Might yield some quality improvements.

Closes #245

Author: bk138

src/callbacks.c

@@ -187,7 +187,7 @@ void on_composited_changed ( GdkScreen *screen,
   while (g_hash_table_iter_next (&it, NULL, &value)) 
     {
       GromitPaintContext *context = value;
-      cairo_set_antialias(context->paint_ctx, data->composited ? CAIRO_ANTIALIAS_DEFAULT : CAIRO_ANTIALIAS_NONE);
+      cairo_set_antialias(context->paint_ctx, data->composited ? CAIRO_ANTIALIAS_SUBPIXEL : CAIRO_ANTIALIAS_NONE);
     }
 
 

src/main.c

@@ -70,6 +70,8 @@ GromitPaintContext *paint_context_new (GromitData *data,
   gdk_cairo_set_source_rgba(context->paint_ctx, paint_color);
   if(!data->composited)
     cairo_set_antialias(context->paint_ctx, CAIRO_ANTIALIAS_NONE);
+  else
+    cairo_set_antialias(context->paint_ctx, CAIRO_ANTIALIAS_SUBPIXEL);
   cairo_set_line_width(context->paint_ctx, width);
   cairo_set_line_cap(context->paint_ctx, CAIRO_LINE_CAP_ROUND);
   cairo_set_line_join(context->paint_ctx, CAIRO_LINE_JOIN_ROUND);