Cleanup: use .hh extension for C++ headers

Follow documented convention for file naming.

source/blender/io/gpencil/CMakeLists.txt

@@ -48,10 +48,10 @@ set(SRC
   nanosvg/nanosvg.h
 
   gpencil_io.h
-  intern/gpencil_io_base.h
-  intern/gpencil_io_export_base.h
-  intern/gpencil_io_import_base.h
-  intern/gpencil_io_import_svg.h
+  intern/gpencil_io_base.hh
+  intern/gpencil_io_export_base.hh
+  intern/gpencil_io_import_base.hh
+  intern/gpencil_io_import_svg.hh
 )
 
 set(LIB
@@ -64,7 +64,7 @@ if(WITH_PUGIXML)
   list(APPEND SRC
     intern/gpencil_io_export_svg.cc
 
-    intern/gpencil_io_export_svg.h
+    intern/gpencil_io_export_svg.hh
   )
   list(APPEND INC_SYS
     ${PUGIXML_INCLUDE_DIR}
@@ -79,7 +79,7 @@ if(WITH_HARU)
   list(APPEND SRC
     intern/gpencil_io_export_pdf.cc
 
-    intern/gpencil_io_export_pdf.h
+    intern/gpencil_io_export_pdf.hh
   )
   list(APPEND INC_SYS
     ${HARU_INCLUDE_DIRS}

source/blender/io/gpencil/intern/gpencil_io_base.cc

@@ -49,7 +49,7 @@
 #include "DEG_depsgraph.h"
 #include "DEG_depsgraph_query.h"
 
-#include "gpencil_io_base.h"
+#include "gpencil_io_base.hh"
 
 using blender::Span;
 

source/blender/io/gpencil/intern/gpencil_io_capi.cc

@@ -40,14 +40,14 @@
 #include "../gpencil_io.h"
 
 #ifdef WITH_HARU
-#  include "gpencil_io_export_pdf.h"
+#  include "gpencil_io_export_pdf.hh"
 #endif
 
 #ifdef WITH_PUGIXML
-#  include "gpencil_io_export_svg.h"
+#  include "gpencil_io_export_svg.hh"
 #endif
 
-#include "gpencil_io_import_svg.h"
+#include "gpencil_io_import_svg.hh"
 
 #ifdef WITH_HARU
 using blender::io::gpencil::GpencilExporterPDF;

source/blender/io/gpencil/intern/gpencil_io_export_base.hh

@@ -21,7 +21,7 @@
 /** \file
  * \ingroup bgpencil
  */
-#include "gpencil_io_base.h"
+#include "gpencil_io_base.hh"
 
 namespace blender::io::gpencil {
 

source/blender/io/gpencil/intern/gpencil_io_export_pdf.cc

@@ -49,7 +49,7 @@
 #include "UI_view2d.h"
 
 #include "gpencil_io.h"
-#include "gpencil_io_export_pdf.h"
+#include "gpencil_io_export_pdf.hh"
 
 namespace blender ::io ::gpencil {
 

source/blender/io/gpencil/intern/gpencil_io_export_svg.cc

@@ -49,7 +49,7 @@
 #include "UI_view2d.h"
 
 #include "gpencil_io.h"
-#include "gpencil_io_export_svg.h"
+#include "gpencil_io_export_svg.hh"
 
 #include "pugixml.hpp"
 

source/blender/io/gpencil/intern/gpencil_io_export_svg.hh

@@ -23,7 +23,7 @@
  */
 #include "BLI_path_util.h"
 
-#include "gpencil_io_export_base.h"
+#include "gpencil_io_export_base.hh"
 #include "pugixml.hpp"
 
 struct GpencilIOParams;

source/blender/io/gpencil/intern/gpencil_io_import_base.cc

@@ -33,7 +33,7 @@
 
 #include "ED_gpencil.h"
 
-#include "gpencil_io_import_base.h"
+#include "gpencil_io_import_base.hh"
 
 namespace blender::io::gpencil {
 

source/blender/io/gpencil/intern/gpencil_io_import_base.hh

@@ -21,7 +21,7 @@
 /** \file
  * \ingroup bgpencil
  */
-#include "gpencil_io_base.h"
+#include "gpencil_io_base.hh"
 
 namespace blender::io::gpencil {
 

source/blender/io/gpencil/intern/gpencil_io_import_svg.cc

@@ -36,7 +36,7 @@
 #include "ED_gpencil.h"
 
 #include "gpencil_io.h"
-#include "gpencil_io_import_svg.h"
+#include "gpencil_io_import_svg.hh"
 
 /* Custom flags for NanoSVG. */
 #define NANOSVG_ALL_COLOR_KEYWORDS

source/blender/io/gpencil/intern/gpencil_io_import_svg.hh

@@ -21,7 +21,7 @@
 /** \file
  * \ingroup bgpencil
  */
-#include "gpencil_io_import_base.h"
+#include "gpencil_io_import_base.hh"
 
 struct GpencilIOParams;
 struct NSVGshape;