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{- 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 DataKinds #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE RecordWildCards #-}
-- | Outputs information about a font as text.
module Graphics.Fountainhead.Dumper
( ParseErrorOrDump
, dumpCmap
, dumpTrueType
, dumpOffsetTable
) where
import Data.ByteString (ByteString)
import Data.Int (Int64)
import qualified Data.Text.Encoding as Text
import qualified Data.Text.Lazy as Text.Lazy
import qualified Data.Text.Lazy.Builder as Text.Builder
import qualified Data.Text.Lazy.Builder.Int as Text.Builder
import Data.Void
import GHC.Records (HasField(..))
import Graphics.Fountainhead.TrueType
( CmapTable(..)
, FontDirectory(..)
, OffsetSubtable(..)
, TableDirectory(..)
)
import qualified Text.Megaparsec as Megaparsec
import Graphics.Fountainhead.Parser
( parseTable
, cmapTableP
)
type ParseErrorOrDump
= Either (Megaparsec.ParseErrorBundle ByteString Void) Text.Builder.Builder
paddedHexadecimal :: Integral a => a -> Text.Builder.Builder
paddedHexadecimal = ("0x" <>)
. Text.Builder.fromLazyText
. Text.Lazy.justifyRight 8 '0'
. Text.Builder.toLazyText
. Text.Builder.hexadecimal
justifyNumber :: Integral a => Int64 -> a -> Text.Builder.Builder
justifyNumber count = Text.Builder.fromLazyText
. Text.Lazy.justifyRight count ' '
. Text.Builder.toLazyText
. Text.Builder.decimal
newlineBuilder :: Text.Builder.Builder
newlineBuilder = Text.Builder.singleton '\n'
dumpHead :: String -> Text.Builder.Builder
dumpHead headline = Text.Builder.fromString headline
<> newlineBuilder
<> Text.Builder.fromLazyText (Text.Lazy.replicate headlineLength "-")
<> newlineBuilder
where
headlineLength = fromIntegral $ Prelude.length headline
dumpOffsetTable :: FontDirectory -> Text.Builder.Builder
dumpOffsetTable directory
= dumpHead "Offset Table"
<> " sfnt version: 1.0\n number of tables: "
<> Text.Builder.decimal (numTables $ offsetSubtable directory)
<> newlineBuilder
<> dumpOffsetSummary (tableDirectory directory)
where
dumpOffsetSummary = mconcat . fmap dumpOffsetRow . zip [0..]
dumpOffsetRow (index, table) = justifyNumber 4 index
<> ". '"
<> Text.Builder.fromText (Text.decodeASCII $ tag table)
<> "' - checksum = "
<> paddedHexadecimal (getField @"checkSum" table)
<> ", offset = "
<> paddedHexadecimal (getField @"offset" table)
<> ", len = "
<> justifyNumber 9 (getField @"length" table)
<> newlineBuilder
dumpCmap :: CmapTable -> Text.Builder.Builder
dumpCmap = const $ dumpHead "'cmap' Table - Character to Glyph Index Mapping Table"
dumpTrueType
:: Megaparsec.State ByteString Void
-> FontDirectory
-> ParseErrorOrDump
dumpTrueType processedState directory@FontDirectory{..}
= foldr go (Right $ dumpOffsetTable directory) tableDirectory
where
go :: TableDirectory -> ParseErrorOrDump -> ParseErrorOrDump
go tableEntry (Left accumulator) = Left accumulator
go tableEntry (Right accumulator)
= maybe (Right accumulator) (concatDump accumulator)
$ dumpSubTable tableEntry
concatDump accumulator builderDump = ((accumulator <> newlineBuilder) <>)
<$> builderDump
dumpSubTable tableEntry =
case getField @"tag" tableEntry of
"cmap" -> Just $ dumpCmap <$> parseTable tableEntry cmapTableP processedState
_ -> Nothing
|
