From 90e99e3130bd382b65c26f6f539ba86bbb2836b9 Mon Sep 17 00:00:00 2001
From: Adrian Cochrane <adrian@openwork.nz>
Date: Sun, 13 Feb 2022 08:20:43 +1300
Subject: [PATCH] Expose util functions on scripts & buffers.

---
 Data/Text/Glyphize/Buffer.hs | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/Data/Text/Glyphize/Buffer.hs b/Data/Text/Glyphize/Buffer.hs
index d4b9c17..bbf6368 100644
--- a/Data/Text/Glyphize/Buffer.hs
+++ b/Data/Text/Glyphize/Buffer.hs
@@ -142,9 +142,16 @@ instance Storable GlyphPos where
         pokeElemOff q 2 xoff
         pokeElemOff q 3 yoff
 
--- guessSegmentProperties :: Buffer -> Buffer
--- glyphInfo & glyphPositions to be zipped & return from shape function
--- scriptHorizontalDir :: ShortText -> Direction
+guessSegmentProperties :: Buffer -> Buffer
+guessSegmentProperties = thaw . freeze
+scriptHorizontalDir :: ShortText -> Maybe Direction
+scriptHorizontalDir script =
+    case hb_script_get_horizontal_direction $ hb_script_from_txt script of
+        4 -> Just DirLTR
+        5 -> Just DirRTL
+        6 -> Just DirTTB
+        7 -> Just DirBTT
+        _ -> Nothing
 
 dirReverse DirLTR = DirRTL
 dirReverse DirRTL = DirLTR
@@ -306,6 +313,8 @@ hb_script_from_string str = hb_tag_from_string $ case titlecase str of
 hb_script_from_txt txt = hb_script_from_string $ Short.toString txt
 foreign import ccall "hb_buffer_set_script" hb_buffer_set_script
     :: Ptr Buffer'' -> Word32 -> IO ()
+foreign import ccall "hb_script_get_horizontal_direction" hb_script_get_horizontal_direction
+    :: Word32 -> Int
 foreign import ccall "hb_language_from_string" hb_language_from_string
     :: Ptr Word8 -> Int -> Int
 hb_language_from_txt txt = let Strict.PS ptr offset size = toByteString txt
-- 
2.30.2