From 356034e375735ec10ea8e0b0b54698c6a297a756 Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Wed, 4 Apr 2018 13:24:55 +0200
Subject: [PATCH] Implemented book

---
 TODO    | 16 +++++++++++++---
 cmds.cc | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 3 deletions(-)

diff --git a/TODO b/TODO
index a155a81..8d36b9c 100644
--- a/TODO
+++ b/TODO
@@ -3,6 +3,7 @@
 - Better error messages from instantiation
 - page->index: use or remove
 - rename page->bbox to page->image_box?
+- "-f" switch
 
 | # Position bbox on a new paper
 | paper("a4")
@@ -30,9 +31,10 @@
 | margins ... params like expand
 
 cropmarks
-	style=box	# Box around image
-	style=cross	# Crosses in the corners
-	style=halfcross	# Half-crosses in the corners (default)
+	mark=box	# Box around image
+	mark=cross	# Crosses in the corners
+	mark=out	# Out-pointing half-crosses in the corners (default)
+	mark=in		# In-pointing half-crosses
 	pen=1pt		# Line width
 	len=5mm		# Cross arm length
 	dist=5mm	# Distance from border
@@ -44,6 +46,7 @@ book
 crop
 	bleed=5mm	# Allow bleeding over the image box
 
+# Can be written as: mix(cat) { modulo(2){1}, modulo(2){2} }
 duplex
 	long-edge
 
@@ -61,6 +64,7 @@ modulo
 #	- paper size + margins
 #	- scale + margins
 nup(hnum, vnum)
+	by=row/column	# Filling order (default: row)
 	paper / w / h	# Specify paper size, default=copy from 1st image
 	+ fit options (*margin, pos)
 	crop		# Crop to image
@@ -69,3 +73,9 @@ nup(hnum, vnum)
 	tile		# Tile with copies of a single page
 	hspace / vspace / space	# Distance between tiles
 	+ cropmarks?
+
+# Send pages to multiple pipes and merge their results
+mix { ..., ..., ...}
+	cat		# Concatenate results (default is interleave)
+	cycle		# When one pipe ends earlier, cycle it from start
+	pad		# When one pipe ends earlier, add blank pages
diff --git a/cmds.cc b/cmds.cc
index 65a9c41..a0e0548 100644
--- a/cmds.cc
+++ b/cmds.cc
@@ -789,6 +789,52 @@ static const arg_def add_blank_args[] = {
   { NULL,	0 }
 };
 
+/*** book ***/
+
+class book_cmd : public cmd_exec {
+  int n;
+public:
+  book_cmd(cmd *c)
+    {
+      n = c->arg("n")->as_int(0);
+      if (n % 4)
+        die("Number of pages per signature must be divisible by 4");
+    }
+  vector<page *> process(vector<page *> &pages) override;
+};
+
+vector<page *> book_cmd::process(vector<page *> &pages)
+{
+  vector<page *> in, out;
+
+  in = pages;
+  while (in.size() % 4)
+    in.push_back(new empty_page(in[0]->width, in[0]->height));
+
+  int i = 0;
+  while (i < (int) in.size())
+    {
+      int sig = in.size() - i;
+      if (n)
+	sig = min(sig, n);
+      for (int j=0; j<sig/2; j+=2)
+	{
+	  out.push_back(in[i + sig-1-j]);
+	  out.push_back(in[i + j]);
+	  out.push_back(in[i + j+1]);
+	  out.push_back(in[i + sig-2-j]);
+	}
+      i += sig;
+    }
+
+  return out;
+}
+
+static const arg_def book_args[] = {
+  { "n",	AT_INT | AT_POSITIONAL },
+  { NULL,	0 }
+};
+
 /*** Command table ***/
 
 template<typename T> cmd_exec *ctor(cmd *c) { return new T(c); }
@@ -810,5 +856,6 @@ const cmd_def cmd_table[] = {
   { "expand",	expand_args,	0,	&ctor<expand_cmd>	},
   { "margins",	margins_args,	0,	&ctor<margins_cmd>	},
   { "add-blank",add_blank_args,	0,	&ctor<add_blank_cmd>	},
+  { "book",	book_args,	0,	&ctor<book_cmd>		},
   { NULL,	NULL,		0,	NULL	}
 };
-- 
2.39.2