From 8d304ef7f9094a71fabc3efd87b37a030c437adf Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Tue, 16 Oct 2018 19:04:48 -0700
Subject: [PATCH] [utf] Add UTF16-BE and UTF32-BE

---
 src/hb-buffer.cc |  4 +--
 src/hb-utf.hh    | 80 ++++++++++++++++++++++++++++++++------------------------
 2 files changed, 48 insertions(+), 36 deletions(-)

diff --git a/src/hb-buffer.cc b/src/hb-buffer.cc
index ce9b053..f905c63 100644
--- a/src/hb-buffer.cc
+++ b/src/hb-buffer.cc
@@ -1665,7 +1665,7 @@ hb_buffer_add_utf32 (hb_buffer_t    *buffer,
 		     unsigned int    item_offset,
 		     int             item_length)
 {
-  hb_buffer_add_utf<hb_utf32_t<> > (buffer, text, text_length, item_offset, item_length);
+  hb_buffer_add_utf<hb_utf32_t> (buffer, text, text_length, item_offset, item_length);
 }
 
 /**
@@ -1726,7 +1726,7 @@ hb_buffer_add_codepoints (hb_buffer_t          *buffer,
 			  unsigned int          item_offset,
 			  int                   item_length)
 {
-  hb_buffer_add_utf<hb_utf32_t<false> > (buffer, text, text_length, item_offset, item_length);
+  hb_buffer_add_utf<hb_utf32_novalidate_t> (buffer, text, text_length, item_offset, item_length);
 }
 
 
diff --git a/src/hb-utf.hh b/src/hb-utf.hh
index eccb632..d8b7114 100644
--- a/src/hb-utf.hh
+++ b/src/hb-utf.hh
@@ -29,14 +29,16 @@
 
 #include "hb.hh"
 
+#include "hb-open-type.hh"
+
 
 struct hb_utf8_t
 {
   typedef uint8_t codepoint_t;
 
-  static inline const uint8_t *
-  next (const uint8_t *text,
-	const uint8_t *end,
+  static inline const codepoint_t *
+  next (const codepoint_t *text,
+	const codepoint_t *end,
 	hb_codepoint_t *unicode,
 	hb_codepoint_t replacement)
   {
@@ -103,13 +105,13 @@ struct hb_utf8_t
     return text;
   }
 
-  static inline const uint8_t *
-  prev (const uint8_t *text,
-	const uint8_t *start,
+  static inline const codepoint_t *
+  prev (const codepoint_t *text,
+	const codepoint_t *start,
 	hb_codepoint_t *unicode,
 	hb_codepoint_t replacement)
   {
-    const uint8_t *end = text--;
+    const codepoint_t *end = text--;
     while (start < text && (*text & 0xc0) == 0x80 && end - text < 4)
       text--;
 
@@ -121,20 +123,22 @@ struct hb_utf8_t
   }
 
   static inline unsigned int
-  strlen (const uint8_t *text)
+  strlen (const codepoint_t *text)
   {
     return ::strlen ((const char *) text);
   }
 };
 
 
-struct hb_utf16_t
+template <typename TCodepoint>
+struct hb_utf16_xe_t
 {
-  typedef uint16_t codepoint_t;
+  static_assert (sizeof (TCodepoint) == 2, "");
+  typedef TCodepoint codepoint_t;
 
-  static inline const uint16_t *
-  next (const uint16_t *text,
-	const uint16_t *end,
+  static inline const codepoint_t *
+  next (const codepoint_t *text,
+	const codepoint_t *end,
 	hb_codepoint_t *unicode,
 	hb_codepoint_t replacement)
   {
@@ -164,9 +168,9 @@ struct hb_utf16_t
     return text;
   }
 
-  static inline const uint16_t *
-  prev (const uint16_t *text,
-	const uint16_t *start,
+  static inline const codepoint_t *
+  prev (const codepoint_t *text,
+	const codepoint_t *start,
 	hb_codepoint_t *unicode,
 	hb_codepoint_t replacement)
   {
@@ -198,7 +202,7 @@ struct hb_utf16_t
 
 
   static inline unsigned int
-  strlen (const uint16_t *text)
+  strlen (const codepoint_t *text)
   {
     unsigned int l = 0;
     while (*text++) l++;
@@ -206,15 +210,19 @@ struct hb_utf16_t
   }
 };
 
+typedef hb_utf16_xe_t<uint16_t> hb_utf16_t;
+typedef hb_utf16_xe_t<OT::HBUINT16> hb_utf16_be_t;
+
 
-template <bool validate=true>
-struct hb_utf32_t
+template <typename TCodepoint, bool validate=true>
+struct hb_utf32_xe_t
 {
-  typedef uint32_t codepoint_t;
+  static_assert (sizeof (TCodepoint) == 4, "");
+  typedef TCodepoint codepoint_t;
 
-  static inline const uint32_t *
-  next (const uint32_t *text,
-	const uint32_t *end HB_UNUSED,
+  static inline const TCodepoint *
+  next (const TCodepoint *text,
+	const TCodepoint *end HB_UNUSED,
 	hb_codepoint_t *unicode,
 	hb_codepoint_t replacement)
   {
@@ -224,9 +232,9 @@ struct hb_utf32_t
     return text;
   }
 
-  static inline const uint32_t *
-  prev (const uint32_t *text,
-	const uint32_t *start HB_UNUSED,
+  static inline const TCodepoint *
+  prev (const TCodepoint *text,
+	const TCodepoint *start HB_UNUSED,
 	hb_codepoint_t *unicode,
 	hb_codepoint_t replacement)
   {
@@ -237,7 +245,7 @@ struct hb_utf32_t
   }
 
   static inline unsigned int
-  strlen (const uint32_t *text)
+  strlen (const TCodepoint *text)
   {
     unsigned int l = 0;
     while (*text++) l++;
@@ -245,14 +253,18 @@ struct hb_utf32_t
   }
 };
 
+typedef hb_utf32_xe_t<uint32_t> hb_utf32_t;
+typedef hb_utf32_xe_t<uint32_t, false> hb_utf32_novalidate_t;
+typedef hb_utf32_xe_t<OT::HBUINT32> hb_utf32_be_t;
+
 
 struct hb_latin1_t
 {
   typedef uint8_t codepoint_t;
 
-  static inline const uint8_t *
-  next (const uint8_t *text,
-	const uint8_t *end HB_UNUSED,
+  static inline const codepoint_t *
+  next (const codepoint_t *text,
+	const codepoint_t *end HB_UNUSED,
 	hb_codepoint_t *unicode,
 	hb_codepoint_t replacement HB_UNUSED)
   {
@@ -260,9 +272,9 @@ struct hb_latin1_t
     return text;
   }
 
-  static inline const uint8_t *
-  prev (const uint8_t *text,
-	const uint8_t *start HB_UNUSED,
+  static inline const codepoint_t *
+  prev (const codepoint_t *text,
+	const codepoint_t *start HB_UNUSED,
 	hb_codepoint_t *unicode,
 	hb_codepoint_t replacement)
   {
@@ -271,7 +283,7 @@ struct hb_latin1_t
   }
 
   static inline unsigned int
-  strlen (const uint8_t *text)
+  strlen (const codepoint_t *text)
   {
     unsigned int l = 0;
     while (*text++) l++;
-- 
2.7.4