Merge pull request #3706 from lb90/dwrite-dll

Load DirectWrite dynamically

CMakeLists.txt

@@ -308,9 +308,12 @@ if (WIN32 AND HB_HAVE_UNISCRIBE)
 endif ()
 
 if (WIN32 AND HB_HAVE_DIRECTWRITE)
+  check_include_file_cxx(dwrite_1.h, HAVE_DWRITE_1_H)
+  if (NOT ${HAVE_DWRITE_1_H})
+    message(FATAL_ERROR "DirectWrite was enabled explicitly, but required header is missing")
+  endif()
   add_definitions(-DHAVE_DIRECTWRITE)
   list(APPEND project_headers ${PROJECT_SOURCE_DIR}/src/hb-directwrite.h)
-  list(APPEND THIRD_PARTY_LIBS dwrite rpcrt4)
 endif ()
 
 if (HB_HAVE_GOBJECT)

configure.ac

@@ -373,10 +373,6 @@ if test "x$with_directwrite" = "xyes" -a "x$have_directwrite" != "xtrue"; then
 	AC_MSG_ERROR([directwrite support requested but not found])
 fi
 if $have_directwrite; then
-	DIRECTWRITE_CXXFLAGS=
-	DIRECTWRITE_LIBS=-ldwrite
-	AC_SUBST(DIRECTWRITE_CXXFLAGS)
-	AC_SUBST(DIRECTWRITE_LIBS)
 	AC_DEFINE(HAVE_DIRECTWRITE, 1, [Have DirectWrite library])
 fi
 AM_CONDITIONAL(HAVE_DIRECTWRITE, $have_directwrite)

meson.build

@@ -232,17 +232,12 @@ if host_machine.system() == 'windows' and not get_option('gdi').disabled()
 endif
 
 # DirectWrite (Windows)
-directwrite_dep = null_dep
 if host_machine.system() == 'windows' and not get_option('directwrite').disabled()
   if get_option('directwrite').enabled() and not cpp.has_header('dwrite_1.h')
     error('DirectWrite was enabled explicitly, but required header is missing.')
   endif
 
-  directwrite_dep = cpp.find_library('dwrite', required: get_option('directwrite'))
-
-  if directwrite_dep.found()
-    conf.set('HAVE_DIRECTWRITE', 1)
-  endif
+  conf.set('HAVE_DIRECTWRITE', 1)
 endif
 
 # CoreText (macOS)

src/hb-directwrite.cc

@@ -43,6 +43,14 @@
  * Functions for using HarfBuzz with DirectWrite fonts.
  **/
 
+/* Declare object creator for dynamic support of DWRITE */
+typedef HRESULT (WINAPI *t_DWriteCreateFactory)(
+  DWRITE_FACTORY_TYPE factoryType,
+  REFIID              iid,
+  IUnknown            **factory
+);
+
+
 /*
  * DirectWrite font stream helpers
  */
@@ -137,6 +145,7 @@ public:
 
 struct hb_directwrite_face_data_t
 {
+  HMODULE dwrite_dll;
   IDWriteFactory *dwriteFactory;
   IDWriteFontFile *fontFile;
   DWriteFontFileStream *fontFileStream;
@@ -158,12 +167,33 @@ _hb_directwrite_shaper_face_data_create (hb_face_t *face)
     return nullptr; \
   } HB_STMT_END
 
+  data->dwrite_dll = LoadLibrary (TEXT ("DWRITE"));
+  if (unlikely (!data->dwrite_dll))
+    FAIL ("Cannot find DWrite.DLL");
+
+  t_DWriteCreateFactory p_DWriteCreateFactory;
+
+#if defined(__GNUC__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-function-type"
+#endif
+
+  p_DWriteCreateFactory = (t_DWriteCreateFactory)
+			  GetProcAddress (data->dwrite_dll, "DWriteCreateFactory");
+
+#if defined(__GNUC__)
+#pragma GCC diagnostic pop
+#endif
+
+  if (unlikely (!p_DWriteCreateFactory))
+    FAIL ("Cannot find DWriteCreateFactory().");
+
   HRESULT hr;
 
   // TODO: factory and fontFileLoader should be cached separately
   IDWriteFactory* dwriteFactory;
-  hr = DWriteCreateFactory (DWRITE_FACTORY_TYPE_SHARED, __uuidof (IDWriteFactory),
-			    (IUnknown**) &dwriteFactory);
+  hr = p_DWriteCreateFactory (DWRITE_FACTORY_TYPE_SHARED, __uuidof (IDWriteFactory),
+			      (IUnknown**) &dwriteFactory);
 
   if (unlikely (hr != S_OK))
     FAIL ("Failed to run DWriteCreateFactory().");
@@ -227,6 +257,8 @@ _hb_directwrite_shaper_face_data_destroy (hb_directwrite_face_data_t *data)
     delete data->fontFileStream;
   if (data->faceBlob)
     hb_blob_destroy (data->faceBlob);
+  if (data->dwrite_dll)
+    FreeLibrary (data->dwrite_dll);
   if (data)
     delete data;
 }

src/meson.build

@@ -429,7 +429,6 @@ endif
 if conf.get('HAVE_DIRECTWRITE', 0) == 1
   hb_sources += hb_directwrite_sources
   hb_headers += hb_directwrite_headers
-  harfbuzz_deps += directwrite_dep
   # hb-directwrite needs a C++ linker
   libharfbuzz_link_language = 'cpp'
 endif