meson: add option and build system plumbing for DirectWrite on Windows

Untested though.

meson.build

@@ -136,6 +136,16 @@ if host_machine.system() == 'windows' and not get_option('uniscribe').disabled()
   endif
 endif
 
+# DirectWrite (windows) - FIXME: untested
+if host_machine.system() == 'windows' and not get_option('directwrite').disabled()
+  if cpp.has_header('dwrite.h')
+    deps += [cpp.find_library('dwrite', required: true)]
+    conf.set('HAVE_DIRECTWRITE', 1)
+  elif get_option('directwrite').enabled()
+    error('DirectWrite was enabled explicitly, but required header is missing.')
+  endif
+endif
+
 # threads
 if host_machine.system() != 'windows'
   thread_dep = dependency('threads', required: false)

meson_options.txt

@@ -17,6 +17,8 @@ option('ucdn', type: 'feature', value: 'auto',
   description: 'Use internal HarfBuzz-provided UCDN library')
 option('uniscribe', type: 'feature', value: 'disabled',
   description: 'Enable Uniscribe shaper backend (Windows only)')
+option('directwrite', type: 'feature', value: 'disabled',
+  description: 'Enable DirectWrite shaper backend on Windows (experimental)')
 
 # Common feature options
 #option('tests', type : 'feature', value : 'auto', yield : true,

src/meson.build

@@ -108,10 +108,6 @@ hb_coretext_sources = [
   'hb-coretext.cc',
 ]
 
-hb_directwrite_sources = [
-  'hb-directwrite.cc',
-]
-
 hb_icu_sources = [
   'hb-icu.cc',
 ]
@@ -180,6 +176,11 @@ if conf.get('HAVE_UNISCRIBE', 0) == 1
   hb_headers += ['hb-uniscribe.h']
 endif
 
+if conf.get('HAVE_DIRECTWRITE', 0) == 1
+  hb_sources += ['hb-directwrite.cc']
+  hb_headers += ['hb-directwrite.h']
+endif
+
 version = '0.' + '0'.join(meson.project_version().split('.')) + '.0'
 
 libharfbuzz = library('harfbuzz', hb_sources,