From aedd41800e40767aa9c534569e8e551ab2405cb8 Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Sun, 1 Apr 2018 13:36:42 +0200
Subject: [PATCH] Select works

---
 TODO        |  1 +
 cmds.cc     | 50 ++++++++++++++++++++++++++++++++++++++++++++++++--
 jam.h       |  4 ++++
 paperjam.cc | 30 +++++++++++++++++++++---------
 4 files changed, 74 insertions(+), 11 deletions(-)

diff --git a/TODO b/TODO
index c2e744d..29db5d5 100644
--- a/TODO
+++ b/TODO
@@ -1,3 +1,4 @@
 - Integrate pdf-tools.cc with the rest of the code
 - What if an input page specifies /Rotate?
 - Better error messages from instantiation
+- Select should work without commands in the pipeline
diff --git a/cmds.cc b/cmds.cc
index 34fd25a..fa4f615 100644
--- a/cmds.cc
+++ b/cmds.cc
@@ -10,7 +10,7 @@ class null_cmd : public cmd_exec {
   vector<page *> process(vector<page *> &pages) { return pages; }
 };
 
-static const arg_def null_args[] = {
+static const arg_def no_args[] = {
   { NULL,	0 }
 };
 
@@ -156,12 +156,58 @@ static cmd_exec *rotate_ctor(cmd *c)
   return r;
 }
 
+/*** select ***/
+
+class select_cmd : public cmd_exec {
+public:
+  pipeline *pipe;
+  vector<page *> process(vector<page *> &pages);
+};
+
+static int validate_page_index(vector<page *> &pages, int idx)
+{
+  if (idx >= 1 && idx <= (int) pages.size())
+    return idx - 1;
+  if (idx <= -1 && idx >= (int) -pages.size())
+    return idx + pages.size();
+  die("Page index %d out of range", idx);
+}
+
+vector<page *> select_cmd::process(vector<page *> &pages)
+{
+  vector<page *> out;
+  for (auto pb: pipe->branches)
+    for (auto ps: pb->selectors)
+      {
+	int f = validate_page_index(pages, ps.from);
+	int t = validate_page_index(pages, ps.to);
+	int step = (f <= t) ? 1 : -1;
+	for (int i=f; f<=t; f += step)
+	  {
+	    vector<page *> selected;
+	    selected.push_back(pages[i]);
+	    selected = run_command_list(pb->commands, selected);
+	    for (auto p: selected)
+	      out.push_back(p);
+	  }
+      }
+  return out;
+}
+
+static cmd_exec *select_ctor(cmd *c)
+{
+  select_cmd *r = new select_cmd;
+  r->pipe = c->pipe;
+  return r;
+}
+
 /*** Command table ***/
 
 const cmd_def cmd_table[] = {
+  { "null",	no_args,	0,	null_ctor	},
   { "move",	move_args,	0,	move_ctor	},
   { "scale",	scale_args,	0,	scale_ctor	},
   { "rotate",	rotate_args,	0,	rotate_ctor	},
-  { "null",	null_args,	0,	null_ctor	},
+  { "select",	no_args,	1,	select_ctor	},
   { NULL,	NULL,		0,	NULL	}
 };
diff --git a/jam.h b/jam.h
index b384ddd..f4235dd 100644
--- a/jam.h
+++ b/jam.h
@@ -85,6 +85,10 @@ struct pipeline {
   vector<pipeline_branch *> branches;
 };
 
+// paperjam.cc
+
+vector<page *> run_command_list(list<cmd *> &cmds, vector<page *> &pages);
+
 // parse.cc
 
 void parse(const char *in, list<cmd *> &cmds);
diff --git a/paperjam.cc b/paperjam.cc
index f81cc2b..07ae6b4 100644
--- a/paperjam.cc
+++ b/paperjam.cc
@@ -46,13 +46,32 @@ void in_page::render(page_out *out, pdf_matrix xform)
   out->contents += "q " + m.to_string() + " cm " + xobj_res + " Do Q";
 }
 
+static int run_indent;
+
 static void debug_pages(vector<page *> &pages)
 {
   if (!debug_mode)
     return;
 
   for (auto pg: pages)
-    debug("Page #%d: w=%.3f h=%.3f", pg->index, pg->width, pg->height);
+    debug("%*sPage #%d: w=%.3f h=%.3f", run_indent, "", pg->index, pg->width, pg->height);
+}
+
+vector<page *> run_command_list(list<cmd *> &cmds, vector<page *> &pages)
+{
+  debug("%*s# Input", run_indent, "");
+  debug_pages(pages);
+
+  for (auto c: cmds)
+    {
+      debug("%*s# Executing %s", run_indent, "", c->def->name);
+      run_indent += 4;
+      pages = c->exec->process(pages);
+      run_indent -= 4;
+      debug_pages(pages);
+    }
+
+  return pages;
 }
 
 static void process(list<cmd *> &cmds, const char *in_name, const char *out_name)
@@ -69,15 +88,8 @@ static void process(list<cmd *> &cmds, const char *in_name, const char *out_name
   int cnt = 0;
   for (auto inpg: in_pages)
     pages.push_back(new in_page(inpg, ++cnt));
-  debug("# Input document");
-  debug_pages(pages);
 
-  for (auto c: cmds)
-    {
-      debug("# Executing %s", c->def->name);
-      pages = c->exec->process(pages);
-      debug_pages(pages);
-    }
+  pages = run_command_list(cmds, pages);
 
   for (auto pg: pages)
     {
-- 
2.39.2