From 2e079971838b7c0073bcf38ac0d5df56a5a6dbc5 Mon Sep 17 00:00:00 2001
From: Adrian Cochrane <adrian@openwork.nz>
Date: Fri, 11 Feb 2022 15:58:56 +1300
Subject: [PATCH] Draft pure-functional Harfbuzz API.

---
 ChangeLog.md                 |  5 +++
 Data/Text/Glyphize.hs        | 13 +++++++
 Data/Text/Glyphize/Buffer.hs | 48 ++++++++++++++++++++++++
 Data/Text/Glyphize/Font.hs   | 33 +++++++++++++++++
 LICENSE                      | 20 ++++++++++
 Setup.hs                     |  2 +
 cabal.sandbox.config         | 26 +++++++++++++
 harfbuzz-pure.cabal          | 71 ++++++++++++++++++++++++++++++++++++
 8 files changed, 218 insertions(+)
 create mode 100644 ChangeLog.md
 create mode 100644 Data/Text/Glyphize.hs
 create mode 100644 Data/Text/Glyphize/Buffer.hs
 create mode 100644 Data/Text/Glyphize/Font.hs
 create mode 100644 LICENSE
 create mode 100644 Setup.hs
 create mode 100644 cabal.sandbox.config
 create mode 100644 harfbuzz-pure.cabal

diff --git a/ChangeLog.md b/ChangeLog.md
new file mode 100644
index 0000000..34341ce
--- /dev/null
+++ b/ChangeLog.md
@@ -0,0 +1,5 @@
+# Revision history for harfbuzz-pure
+
+## 0.1.0.0  -- YYYY-mm-dd
+
+* First version. Released on an unsuspecting world.
diff --git a/Data/Text/Glyphize.hs b/Data/Text/Glyphize.hs
new file mode 100644
index 0000000..c86b05b
--- /dev/null
+++ b/Data/Text/Glyphize.hs
@@ -0,0 +1,13 @@
+module Data.Text.Glyphize where
+
+import Data.Text.Glyphize.Buffer
+import Data.Text.Glyphize.Font
+
+-- Don't think I'll implement shapeplans at this stage...
+-- shape :: Font -> Buffer -> [(GlyphInfo, GlyphPos)]
+
+-- Defer implementing font features...
+
+-- version :: (Int, Int, Int)
+-- versionAtLeast :: (Int, Int, Int) -> Bool
+-- versionString :: ShortString
diff --git a/Data/Text/Glyphize/Buffer.hs b/Data/Text/Glyphize/Buffer.hs
new file mode 100644
index 0000000..3c074e6
--- /dev/null
+++ b/Data/Text/Glyphize/Buffer.hs
@@ -0,0 +1,48 @@
+module Data.Text.Glyphize.Buffer where
+
+import Data.Text.Lazy as Lazy
+import Data.ByteString.Lazy as Lazy
+import Data.Text.Short
+
+data Buffer = Buffer {
+    text :: Either Lazy.Text Lazy.ByteString,
+    contentType :: Maybe ContentType,
+    direction :: Maybe Direction,
+    script :: Maybe ShortText,
+    language :: Maybe ShortText,
+    beginsText :: Bool,
+    endsText :: Bool,
+    preserveDefaultIgnorables :: Bool,
+    removeDefaultIgnorables :: Bool,
+    don'tInsertDottedCircle :: Bool,
+    clusterLevel :: ClusterLevel,
+    invisibleGlyph :: Char,
+    notFoundGlyph :: Char,
+    replacementCodepoint :: Char
+}
+
+data ContentType = ContentTypeUnicode | ContentTypeGlyphs deriving (Eq, Show)
+data Direction = DirLTR | DirRTL | DirTTB | DirBTT deriving (Eq, Show)
+data ClusterLevel = ClusterMonotoneGraphemes | ClusterMonotoneChars | ClusterChars deriving (Eq, Show)
+
+data GlyphInfo = GlyphInfo {
+    codepoint :: Int,
+    cluster :: Int
+}
+data GlyphPos = GlyphPos {
+    x_advance :: Int, y_advance :: Int,
+    x_offset :: Int, y_offset :: Int
+}
+
+-- guessSegmentProperties :: Buffer -> Buffer
+-- glyphInfo & glyphPositions to be zipped & return from shape function
+-- scriptHorizontalDir :: ShortText -> Direction
+
+dirReverse DirLTR = DirRTL
+dirReverse DirRTL = DirLTR
+dirReverse DirTTB = DirBTT
+dirReverse DirBTT = DirTTB
+dirBackward dir = dir `Prelude.elem` [DirRTL, DirBTT]
+dirForward dir = dir `Prelude.elem` [DirLTR, DirTTB]
+dirHorizontal dir = dir `Prelude.elem` [DirLTR, DirRTL]
+dirVertical dir = dir `Prelude.elem` [DirTTB, DirBTT]
diff --git a/Data/Text/Glyphize/Font.hs b/Data/Text/Glyphize/Font.hs
new file mode 100644
index 0000000..3bb12b3
--- /dev/null
+++ b/Data/Text/Glyphize/Font.hs
@@ -0,0 +1,33 @@
+module Data.Text.Glyphize.Font where
+
+import Data.ByteString
+import Data.Text.Short
+
+data Face = Face -- TODO Define
+
+-- countFace :: ByteString -> Int
+-- createFace :: ByteString -> Int -> Face
+-- emptyFace :: Face
+-- faceGlyphCount :: Face -> Int
+-- faceIndex :: Face -> Int
+-- faceUpem :: Face -> Int
+-- Defer implementation of other functions
+
+data Font = Font -- TODO Define
+data FontOptions = FontOptions {
+    x_ppem :: Int, y_ppem :: Int,
+    ptem :: Int,
+    x_scale :: Int, y_scale :: Int,
+    slant :: Float
+    -- Support variations? Variation coordinates?
+}
+
+-- createFont :: Face -> FontOptions -> Font
+-- emptyFont :: Font
+-- fontFace :: Font -> Face
+-- fontGlyph :: Font -> Char -> Maybe Char -> Maybe Int
+-- fontString2Glyph :: Font -> ShortText -> Maybe Int
+-- fontGlyph2String :: Font -> Int -> ShortText
+-- Defer implementation of other functions
+
+-- Do we need FontFuncs?
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..1a79030
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,20 @@
+Copyright (c) 2022 Adrian Cochrane
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
index 0000000..9a994af
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/cabal.sandbox.config b/cabal.sandbox.config
new file mode 100644
index 0000000..9571933
--- /dev/null
+++ b/cabal.sandbox.config
@@ -0,0 +1,26 @@
+-- This is a Cabal package environment file.
+-- THIS FILE IS AUTO-GENERATED. DO NOT EDIT DIRECTLY.
+-- Please create a 'cabal.config' file in the same directory
+-- if you want to change the default settings for this sandbox.
+
+
+local-repo: /home/alcinnz/Projects/browser-engine/harfbuzz-pure/.cabal-sandbox/packages
+logs-dir: /home/alcinnz/Projects/browser-engine/harfbuzz-pure/.cabal-sandbox/logs
+world-file: /home/alcinnz/Projects/browser-engine/harfbuzz-pure/.cabal-sandbox/world
+user-install: False
+package-db: /home/alcinnz/Projects/browser-engine/harfbuzz-pure/.cabal-sandbox/x86_64-linux-ghc-8.0.2-packages.conf.d
+build-summary: /home/alcinnz/Projects/browser-engine/harfbuzz-pure/.cabal-sandbox/logs/build.log
+
+install-dirs
+  prefix: /home/alcinnz/Projects/browser-engine/harfbuzz-pure/.cabal-sandbox
+  bindir: $prefix/bin
+  libdir: $prefix/lib
+  libsubdir: $abi/$libname
+  dynlibdir: $libdir/$abi
+  libexecdir: $prefix/libexec
+  datadir: $prefix/share
+  datasubdir: $abi/$pkgid
+  docdir: $datadir/doc/$abi/$pkgid
+  htmldir: $docdir/html
+  haddockdir: $htmldir
+  sysconfdir: $prefix/etc
diff --git a/harfbuzz-pure.cabal b/harfbuzz-pure.cabal
new file mode 100644
index 0000000..584bd26
--- /dev/null
+++ b/harfbuzz-pure.cabal
@@ -0,0 +1,71 @@
+-- Initial harfbuzz-pure.cabal generated by cabal init.  For further 
+-- documentation, see http://haskell.org/cabal/users-guide/
+
+-- The name of the package.
+name:                harfbuzz-pure
+
+-- The package version.  See the Haskell package versioning policy (PVP) 
+-- for standards guiding when and how versions should be incremented.
+-- https://wiki.haskell.org/Package_versioning_policy
+-- PVP summary:      +-+------- breaking API changes
+--                   | | +----- non-breaking API additions
+--                   | | | +--- code changes with no API change
+version:             0.1.0.0
+
+-- A short (one-line) description of the package.
+synopsis:            Pure-functional Harfbuzz language bindings
+
+-- A longer description of the package.
+description:         HarfBuzz is a text shaping library. Using the HarfBuzz library allows programs to convert a sequence of Unicode input into properly formatted and positioned glyph output—for any writing system and language.
+
+-- URL for the project homepage or repository.
+homepage:            https://harfbuzz.github.io/
+
+-- The license under which the package is released.
+license:             MIT
+
+-- The file containing the license text.
+license-file:        LICENSE
+
+-- The package author(s).
+author:              Adrian Cochrane
+
+-- An email address to which users can send suggestions, bug reports, and 
+-- patches.
+maintainer:          opensource@openwork.nz
+
+-- A copyright notice.
+-- copyright:           
+
+category:            Text
+
+build-type:          Simple
+
+-- Extra files to be distributed with the package, such as examples or a 
+-- README.
+extra-source-files:  ChangeLog.md
+
+-- Constraint on the version of Cabal needed to build this package.
+cabal-version:       >=1.10
+
+
+library
+  -- Modules exported by the library.
+  exposed-modules:     Data.Text.Glyphize, Data.Text.Glyphize.Buffer, Data.Text.Glyphize.Font
+  
+  -- Modules included in this library but not exported.
+  -- other-modules:       
+  
+  -- LANGUAGE extensions used by modules in this package.
+  -- other-extensions:    
+  
+  -- Other library packages from which modules are imported.
+  build-depends:       base >=4.9 && <4.10, bytestring, text, text-short
+  extra-libraries:     harfbuzz
+  
+  -- Directories containing source files.
+  -- hs-source-dirs:      
+  
+  -- Base language which the package is written in.
+  default-language:    Haskell2010
+  
-- 
2.30.2