From 3cd34a9be1fce965016122cad0644a2ab3b7ffdd Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Tue, 3 Apr 2018 22:51:10 +0200
Subject: [PATCH] Implemented expand, margins

---
 TODO     | 42 ++++++++++++++++++------------------
 cmds.cc  | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++---
 parse.cc |  9 +++++++-
 3 files changed, 91 insertions(+), 25 deletions(-)

diff --git a/TODO b/TODO
index 5874a01..289e387 100644
--- a/TODO
+++ b/TODO
@@ -4,30 +4,30 @@
 - page->index: use or remove
 - rename page->bbox to page->image_box?
 
-# Position bbox on a new paper
-paper("a4")
-paper(w=210mm,h=297mm,pos=(t|b|c)(l|r|c))
+| # Position bbox on a new paper
+| paper("a4")
+| paper(w=210mm,h=297mm,pos=(t|b|c)(l|r|c))
 
-# Scale paper to a new size
-scaleto("a4")
-scaleto(w=210mm,h=297mm,pos=tl)
+| # Scale paper to a new size
+| scaleto("a4")
+| scaleto(w=210mm,h=297mm,pos=tl)
 
-# Fit image to a paper
-# If paper is given: scale image
-# If no paper is given: adjust paper to image + margins
-fit("a4")
-fit(w=, h=)
-margin= hmargin= vmargin=
-lmargin= rmargin= tmargin= bmargin=
-pos=
+| # Fit image to a paper
+| # If paper is given: scale image
+| # If no paper is given: adjust paper to image + margins
+| fit("a4")
+| fit(w=, h=)
+| margin= hmargin= vmargin=
+| lmargin= rmargin= tmargin= bmargin=
+| pos=
 
-# Adjust paper size
-expand(10mm)
-expand(h=10mm, v=20mm)
-expand(l=10mm, r=10mm, t=10mm, b=10mm)
+| # Adjust paper size
+| expand(10mm)
+| expand(h=10mm, v=20mm)
+| expand(l=10mm, r=10mm, t=10mm, b=10mm)
 
-# Adjust image size (in terms of margins around)
-margins ... params like expand
+| # Adjust image size (in terms of margins around)
+| margins ... params like expand
 
 cropmarks
 	style=box	# Box around image
@@ -47,7 +47,7 @@ crop
 duplex
 	long-edge
 
-merge
+| merge
 
 modulo
 	half
diff --git a/cmds.cc b/cmds.cc
index 3dcf02b..6acb19c 100644
--- a/cmds.cc
+++ b/cmds.cc
@@ -209,8 +209,13 @@ public:
     }
 };
 
-#define MARGIN_ARGS(basic, sx) 		\
-  { basic,	AT_DIMEN },		\
+#define MARGIN_ARGS1_NAMED(name)	\
+  { name,	AT_DIMEN }
+
+#define MARGIN_ARGS1_POSNL(name)	\
+  { name,	AT_DIMEN | AT_POSITIONAL }
+
+#define MARGIN_ARGS2(sx)		\
   { "h" sx,	AT_DIMEN },		\
   { "v" sx,	AT_DIMEN },		\
   { "l" sx,	AT_DIMEN },		\
@@ -690,7 +695,59 @@ public:
 static const arg_def fit_args[] = {
   PAPER_ARGS,
   POS_ARGS,
-  MARGIN_ARGS("margin", "margin"),
+  MARGIN_ARGS1_NAMED("margin"),
+  MARGIN_ARGS2("margin"),
+  { NULL,	0 }
+};
+
+/*** expand ***/
+
+class expand_cmd : public cmd_exec_simple {
+  margin_spec marg;
+public:
+  expand_cmd(cmd *c) : marg(c, "by", "") { }
+  page *process_page(page *p) override
+    {
+      pdf_matrix xf;
+      xf.shift(marg.l, marg.b);
+      page *q = new xform_page(p, xf);
+      q->width = p->width + marg.l + marg.r;
+      q->height = p->height + marg.t + marg.b;
+      if (q->width < 0.001 || q->height < 0.001)
+	die("Expansion must result in positive page dimensions");
+      return q;
+    }
+};
+
+static const arg_def expand_args[] = {
+  MARGIN_ARGS1_POSNL("by"),
+  MARGIN_ARGS2(""),
+  { NULL,	0 }
+};
+
+/*** margins ***/
+
+class margins_cmd : public cmd_exec_simple {
+  margin_spec marg;
+public:
+  margins_cmd(cmd *c) : marg(c, "size", "") { }
+  page *process_page(page *p) override
+    {
+      pdf_matrix xf;
+      xf.shift(-p->bbox.x_min, -p->bbox.y_min);
+      xf.shift(marg.l, marg.b);
+      page *q = new xform_page(p, xf);
+      q->width = p->bbox.width() + marg.l + marg.r;
+      q->height = p->bbox.height() + marg.t + marg.b;
+      if (q->width < 0.001 || q->height < 0.001)
+	die("Margins must result in positive page dimensions");
+      return q;
+    }
+};
+
+static const arg_def margins_args[] = {
+  MARGIN_ARGS1_POSNL("size"),
+  MARGIN_ARGS2(""),
   { NULL,	0 }
 };
 
@@ -712,5 +769,7 @@ const cmd_def cmd_table[] = {
   { "paper",	paper_args,	0,	&ctor<paper_cmd>	},
   { "scaleto",	scaleto_args,	0,	&ctor<scaleto_cmd>	},
   { "fit",	fit_args,	0,	&ctor<fit_cmd>		},
+  { "expand",	expand_args,	0,	&ctor<expand_cmd>	},
+  { "margins",	margins_args,	0,	&ctor<margins_cmd>	},
   { NULL,	NULL,		0,	NULL	}
 };
diff --git a/parse.cc b/parse.cc
index cc0a582..5158eeb 100644
--- a/parse.cc
+++ b/parse.cc
@@ -218,7 +218,14 @@ static double parse_dimen(const arg_def *adef)
 
   t = next_token();
   if (t != TOK_IDENT)
-    parse_error("Parameter %s must have a unit", adef->name);
+    {
+      if (is_zero(tmp))
+	{
+	  return_token();
+	  return 0;
+	}
+      parse_error("Parameter %s must have a unit", adef->name);
+    }
   for (uint i=0; units[i].name; i++)
     if (token == units[i].name)
       return tmp * units[i].multiplier;
-- 
2.39.2