depends zlib &&
depends bzip2 &&
optional_depends libpng \
                 "--with-png=yes" \
                 "--with-png=no" \
                 "to support png compressed OpenType embedded bitmaps" &&

# freetype2 with harfbuzz requires harfbuzz built against freetype2 first
if spell_ok ${SPELL}; then
  optional_depends  -sub 'FT'  'harfbuzz'                        \
                    '--with-harfbuzz=yes'                        \
                    '--with-harfbuzz=no'                         \
                    'to improve auto-hinting of OpenType fonts'  &&

  # LDFLAGS are taken from /usr/lib/libharfbuzz.la
  if is_depends_enabled $SPELL harfbuzz; then
    if is_depends_enabled harfbuzz glib2; then
      depends glib2 &&
      depends pcre
    fi
  fi
else
  message "${PROBLEM_COLOR}harfbuzz optional dependency disabled until ${DEFAULT_COLOR}${SPELL_COLOR}${SPELL}${DEFAULT_COLOR}${PROBLEM_COLOR} is cast.${DEFAULT_COLOR}" &&
  persistent_add FREETYPE_OPTS &&
  list_add FREETYPE_OPTS "--with-harfbuzz=no"
fi