Create a Metrics module

lib/Graphics/Fountainhead/Dumper.hs

@@ -114,6 +114,7 @@ import Graphics.Fountainhead.Type
     ( Fixed32(..)
     , succIntegral
     , ttfEpoch
+    , newlineBuilder
     , fixed2Double
     )
 import Data.Foldable (Foldable(..), find)
@@ -160,9 +161,6 @@ justifyNumber count = Text.Builder.fromLazyText
     . Text.Builder.toLazyText
     . Text.Builder.decimal
 
-newlineBuilder :: Text.Builder.Builder
-newlineBuilder = Text.Builder.singleton '\n'
-
 dumpCaption :: String -> Text.Builder.Builder
 dumpCaption headline = Text.Builder.fromString headline
     <> newlineBuilder
@@ -288,7 +286,7 @@ longDateTime localTime = Text.Builder.fromLazyText
 dumpCVTable :: CVTable -> Text.Builder.Builder
 dumpCVTable (CVTable cvTable) = dumpCaption "'cvt ' Table - Control Value Table"
     <> "Size = " <> Text.Builder.decimal (tableSize * 2)
-    <> " bytes, " <> Text.Builder.decimal tableSize <> " entries\n"
+    <> " bytes, " <> Text.Builder.decimal tableSize <> " entries" <> newlineBuilder
     <> foldMap (uncurry go) (zip [0..] cvTable)
   where
     tableSize = Prelude.length cvTable

lib/Graphics/Fountainhead/Metrics.hs

@@ -0,0 +1,29 @@
+{- This Source Code Form is subject to the terms of the Mozilla Public License,
+   v. 2.0. If a copy of the MPL was not distributed with this file, You can
+   obtain one at https://mozilla.org/MPL/2.0/. -}
+
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards #-}
+
+module Graphics.Fountainhead.Metrics
+    ( FontMetrics(..)
+    , afmFontMetrics
+    ) where
+
+import qualified Data.Text.Lazy.Builder as Text.Builder
+import Data.Version (Version(..), showVersion)
+import Graphics.Fountainhead.Type (newlineBuilder)
+
+newtype FontMetrics = FontMetrics
+    { version :: Version
+    } deriving (Eq, Show)
+
+afmKeyString :: Text.Builder.Builder -> String -> Text.Builder.Builder
+afmKeyString key value = key <> Text.Builder.singleton '\t'
+    <> Text.Builder.fromString value <> newlineBuilder
+
+afmFontMetrics :: FontMetrics -> Text.Builder.Builder
+afmFontMetrics FontMetrics{..}
+    = afmKeyString "StartFontMetrics" (showVersion version)
+    <> afmKeyString "Comment" "Generated by Fountainhead"
+    <> "EndFontMetrics" <> newlineBuilder

lib/Graphics/Fountainhead/Type.hs

@@ -9,10 +9,12 @@ module Graphics.Fountainhead.Type
     , FWord
     , UFWord
     , fixed2Double
+    , newlineBuilder
     , succIntegral
     , ttfEpoch
     ) where
 
+import qualified Data.Text.Lazy.Builder as Text.Builder
 import Data.Bits ((.>>.), (.&.))
 import Data.Int (Int16)
 import Data.Word (Word16, Word32)
@@ -39,3 +41,6 @@ fixed2Double (F2Dot14 fixed) =
     let mantissa = realToFrac (fixed .>>. 14)
         fraction = realToFrac (fixed .&. 0x3fff) / 16384.0
      in mantissa + fraction
+
+newlineBuilder :: Text.Builder.Builder
+newlineBuilder = Text.Builder.singleton '\n'