3 files changed, 16 insertions(+), 13 deletions(-)

M Graphics/Text/Font/Choose/Pattern.hs
M Graphics/Text/Font/Choose/Strings.hs
M Graphics/Text/Font/Choose/Weight.hs

@@ 33,6 33,7 @@ import Data.Text (unpack, Text)
 import Stylist (PropertyParser(..))
 import Data.Scientific (toRealFloat)
 import Data.List (intercalate)
+import Graphics.Text.Font.Choose.Weight (weightFromOpenType)
 
 -- | An `Pattern`` holds a set of names with associated value lists;
 -- each name refers to a property of a font.


@@ 273,19 274,7 @@ parseFontStretch _ = Nothing
 parseFontWeight :: Token -> Maybe Int
 parseFontWeight (Ident k) | k `elem` ["initial", "normal"] = Just 80
 parseFontWeight (Ident "bold") = Just 200
-parseFontWeight (Number _ (NVInteger 100)) = Just 0
-parseFontWeight (Number _ (NVInteger 200)) = Just 40
-parseFontWeight (Number _ (NVInteger 300)) = Just 50
-parseFontWeight (Number _ (NVInteger 400)) = Just 80
-parseFontWeight (Number _ (NVInteger 500)) = Just 100
-parseFontWeight (Number _ (NVInteger 600)) = Just 180
-parseFontWeight (Number _ (NVInteger 700)) = Just 200
-parseFontWeight (Number _ (NVInteger 800)) = Just 205
-parseFontWeight (Number _ (NVInteger 900)) = Just 210
-parseFontWeight (Number _ (NVInteger 950)) = Just 215
-parseFontWeight (Number _ (NVInteger x))
-    | x > 920 = parseFontWeight $ Number "" $ NVInteger 950
-    | otherwise = parseFontWeight $ Number "" $ NVInteger $ (x `div` 100) * 100
+parseFontWeight (Number _ (NVInteger x)) = Just $ weightFromOpenType $ fromEnum x
 parseFontWeight _ = Nothing
 
 nv2double (NVInteger x) = fromInteger x

@@ 11,6 11,7 @@ import Foreign.C.String (CString, withCString, peekCString)
 import Control.Exception (bracket)
 import Control.Monad (forM)
 
+-- | Set of strings, as exposed by other FreeType APIs.
 type StrSet = Set String
 
 data StrSet'


@@ 44,6 45,7 @@ thawStrSet_ cb = bracket (throwNull <$> cb) fcStrSetDestroy thawStrSet
 
 ------------
 
+-- | Output string lists from FontConfig.
 type StrList = [String]
 
 data StrList'

@@ 1,8 1,20 @@
 module Graphics.Text.Font.Choose.Weight where
 
+-- | Returns an double value to use with "weight", from an double in the
+-- 1..1000 range, resembling the numbers from OpenType specification's OS2
+-- usWeight numbers, which are also similar to CSS font-weight numbers.
+-- If input is negative, zero, or greater than 1000, returns -1.
+-- This function linearly interpolates between various FC_WEIGHT_* constants.
+-- As such, the returned value does not necessarily match any of the predefined
+-- constants.
 foreign import ccall "FcWeightFromOpenTypeDouble" weightFromOpenTypeDouble ::
     Double -> Double
+-- | `weightToOpenTypeDouble` is the inverse of `weightFromOpenType`.
+-- If the input is less than FC_WEIGHT_THIN or greater than FC_WEIGHT_EXTRABLACK,
+-- returns -1. Otherwise returns a number in the range 1 to 1000.
 foreign import ccall "FcWeightToOpenTypeDouble" weightToOpenTypeDouble ::
     Double -> Double
+-- | Variant of `weightFromOpenTypeDouble` taking ints.
 foreign import ccall "FcWeightFromOpenType" weightFromOpenType :: Int -> Int
+-- | Variant of `weightToOpenTypeDouble` taking ints.
 foreign import ccall "FcWeightToOpenType" weightToOpenType :: Int -> Int