fountainhead/lib/Graphics/Fountainhead/Metrics.hs

{- 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 #-}

module Graphics.Fountainhead.Metrics
    ( FontBBox(..)
    , FontDescriptor(..)
    , Number
    , FontDescriptorFlag(..)
    ) where

import Data.Text (Text)

type Number = Double

data FontDescriptorFlag
    = FixedPitch
    | Serif
    | Symbolic
    | Script
    | Nonsymbolic
    | Italic
    | AllCap
    | SmallCap
    | ForceBold
    deriving (Eq, Show)

instance Enum FontDescriptorFlag
  where
    toEnum 1 = FixedPitch
    toEnum 2 = Serif
    toEnum 3 = Symbolic
    toEnum 4 = Script
    toEnum 6 = Nonsymbolic
    toEnum 7 = Italic
    toEnum 17 = AllCap
    toEnum 18 = SmallCap
    toEnum 19 = ForceBold
    toEnum _ = error "Font description flag is not supported."
    fromEnum FixedPitch = 1
    fromEnum Serif = 2
    fromEnum Symbolic = 3
    fromEnum Script = 4
    fromEnum Nonsymbolic = 6
    fromEnum Italic = 7
    fromEnum AllCap = 17
    fromEnum SmallCap = 18
    fromEnum ForceBold = 19

data FontBBox = FontBBox Number Number Number Number
    deriving (Eq, Show)

data FontDescriptor = FontDescriptor
    { fontName :: Text
    , flags :: [FontDescriptorFlag]
    , fullName :: Text
    , familyName :: Text
    , weight :: Text
    , fontBBox :: FontBBox
    , version :: Text
    , notice :: Text
    , encodingScheme :: Text
    , isFixedPitch :: Bool
    , ascender :: Number
    , descender :: Number
    } deriving (Eq, Show)