From 3b54c94538b8f090be52dfbf4e912125d75ce911 Mon Sep 17 00:00:00 2001
From: John Whitington <john@coherentgraphics.co.uk>
Date: Thu, 18 Nov 2021 11:09:09 -0800
Subject: [PATCH] Beginning typesetter

---
 cpdftype.ml  | 66 ++++++++++++++++++++++++++++++++++++++++++----------
 cpdftype.mli | 25 +++++++++++---------
 2 files changed, 68 insertions(+), 23 deletions(-)

diff --git a/cpdftype.ml b/cpdftype.ml
index 6f0509e..c807caf 100644
--- a/cpdftype.ml
+++ b/cpdftype.ml
@@ -1,15 +1,57 @@
-(* cpdftype.ml *)
-type box =
-  Text of string
-| Glue of float
-| Newline
-| Font of string
-| BoldOn
-| BoldOff
-| ItalicOn
-| ItalicOff
+(* A typesetter for cpdf. A list of elements is manipulated zero or more times
+   to lay it out, paginate it, and so on. It is then typeset to produce a list
+   of pages *)
 
-type t = box list
+(* Text is represented as a list of unicode code points *)
+type text = int list
 
-let typeset papersize boxes =
+(* Glue *)
+type glue =
+  {glen : float;
+   stretch : float}
+
+(* Main type *)
+type code =
+  Text of text
+| HGlue of glue
+| VGlue of glue
+| NewLine
+| NewPage
+| Font of Pdftext.font
+
+let indent x = HGlue {glen = x; stretch = 0.}
+let newpara x = HGlue {glen = x; stretch = 0.}
+
+type t = code list
+
+let of_utf8 = Pdftext.codepoints_of_utf8
+
+let example =
+  [Text (of_utf8 "Jackdaws love my Sphinx of Quartz. And this, this is the second sentence to provoke a line-break.");
+   newpara 10.;
+   indent 72.;
+   Text (of_utf8 "The second paragraph");
+   NewPage]
+
+(* Typesetter state. Origin at top left of page *)
+type state =
+  {mutable font : Pdftext.font;
+   mutable xpos : float;
+   mutable ypos : float}
+
+let initial_state () =
+  {font = Pdftext.StandardFont (Pdftext.TimesRoman, Pdftext.WinAnsiEncoding);
+   xpos = 0.;
+   ypos = 0.}
+
+(* Split text into lines, resolve all hglue stretches to 0, remove Newlines. *)
+let layout lmargin rmargin papersize i =
+  i
+
+(* Resolve all hglue stretches, insert NewPage as needed. *)
+let paginate tmargin bmargin papersize i = i
+
+(* Split on NewPages, typeset each page, add font dictionaries *)
+let typeset papersize i =
   [Pdfpage.blankpage papersize]
+
diff --git a/cpdftype.mli b/cpdftype.mli
index 6ff1fb9..ac5d6f3 100644
--- a/cpdftype.mli
+++ b/cpdftype.mli
@@ -1,14 +1,17 @@
-(* Simple typesetter *)
-type box =
-  Text of string
-| Glue of float
-| Newline
-| Font of string
-| BoldOn
-| BoldOff
-| ItalicOn
-| ItalicOff
+type text = int list
 
-type t = box list
+type glue =
+  {glen : float;
+   stretch : float}
+
+type code =
+  Text of text
+| HGlue of glue
+| VGlue of glue
+| NewLine
+| NewPage
+| Font of Pdftext.font
+
+type t = code list
 
 val typeset : Pdfpaper.t -> t -> Pdfpage.t list