gentoo-overlay/sci-libs/vtk/files/vtk-8.2.0-freetype-2.10.3-provide-FT_CALLBACK_DEF.patch

--- VTK-8.2.0/ThirdParty/freetype/vtk_freetype.h.in.orig	2019-01-30 18:15:13.000000000 +0100
+++ VTK-8.2.0/ThirdParty/freetype/vtk_freetype.h.in	2020-10-17 00:03:32.730820908 +0200
@@ -20,6 +20,15 @@
 
 #ifdef VTK_USE_SYSTEM_FREETYPE
 # include <ft2build.h>
+/* FT_CALLBACK_DEF no longer exported since freetype-2.10.3 */
+/* has been moved to <freetype/internal/compiler-macros.h> */
+# ifndef FT_CALLBACK_DEF
+#  ifdef __cplusplus
+#   define FT_CALLBACK_DEF( x )  extern "C"  x
+#  else
+#   define FT_CALLBACK_DEF( x )  static  x
+#  endif
+# endif /* FT_CALLBACK_DEF */
 #else
 # include <vtkfreetype/include/ft2build.h>
 #endif