[PATCH] [grotrin] Add post-processor for groff input.

[Lennart Jablonka]

This is useless.  And also not what Alejandro wanted, presumably.

Suggested-By: Alejandro Colomar <alx@kernel.org>
---
I don’t wanna wait for April 1st.

 .gitignore                        |   1 +
 Makefile.am                       |   1 +
 src/devices/grotrin/.gitignore    |   5 ++
 src/devices/grotrin/grotrin.1.man |  82 +++++++++++++++++++
 src/devices/grotrin/grotrin.am    |  14 ++++
 src/devices/grotrin/trin.cpp      | 129 ++++++++++++++++++++++++++++++
 6 files changed, 232 insertions(+)
 create mode 100644 src/devices/grotrin/.gitignore
 create mode 100644 src/devices/grotrin/grotrin.1.man
 create mode 100644 src/devices/grotrin/grotrin.am
 create mode 100644 src/devices/grotrin/trin.cpp

diff --git a/.gitignore b/.gitignore
index 2c749f1aa..8b271e54f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -32,6 +32,7 @@
 /grolj4
 /gropdf
 /grops
+/grotrin
 /grotty
 /gxditview
 /hpftodit
diff --git a/Makefile.am b/Makefile.am
index e15a8ff0f..19c5f6a2c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -653,6 +653,7 @@ include $(top_srcdir)/src/devices/grolbp/grolbp.am
 include $(top_srcdir)/src/devices/grolj4/grolj4.am
 include $(top_srcdir)/src/devices/gropdf/gropdf.am
 include $(top_srcdir)/src/devices/grops/grops.am
+include $(top_srcdir)/src/devices/grotrin/grotrin.am
 include $(top_srcdir)/src/devices/grotty/grotty.am
 include $(top_srcdir)/src/devices/xditview/xditview.am
 include $(top_srcdir)/src/preproc/eqn/eqn.am
diff --git a/src/devices/grotrin/.gitignore b/src/devices/grotrin/.gitignore
new file mode 100644
index 000000000..4bca70d9e
--- /dev/null
+++ b/src/devices/grotrin/.gitignore
@@ -0,0 +1,5 @@
+# build artifacts
+/.deps/
+/.dirstamp
+/grotrin.1
+/trin.o
diff --git a/src/devices/grotrin/grotrin.1.man 
b/src/devices/grotrin/grotrin.1.man
new file mode 100644
index 000000000..21e83856e
--- /dev/null
+++ b/src/devices/grotrin/grotrin.1.man
@@ -0,0 +1,82 @@
+.TH grotrin @MAN1EXT@ "@MDATE@" "groff @VERSION@"
+.SH Name
+grotrin \-
+.I groff
+output driver for
+.I groff
+.
+.
+.\" Save and disable compatibility mode (for, e.g., Solaris 10/11).
+.do nr *groff_gropdf_1_man_C \n[.cp]
+.cp 0
+.
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.nr do-fallback 0
+.if !\n(.f           .nr do-fallback 1 \" mandoc
+.if  \n(.g .if !d MR .nr do-fallback 1 \" older groff
+.if !\n(.g           .nr do-fallback 1 \" non-groff *roff
+.if \n[do-fallback]  \{\
+.  de MR
+.    ie \\n(.$=1 \
+.      I \%\\$1
+.    el \
+.      IR \%\\$1 (\\$2)\\$3
+.  .
+.\}
+.rr do-fallback
+.
+.
+.\" ====================================================================
+.SH Synopsis
+.\" ====================================================================
+.
+.SY grotrin
+.RI [ file\~ .\|.\|.]
+.YS
+.
+.
+.\" ====================================================================
+.SH Description
+.\" ====================================================================
+.
+This GNU
+.I roff
+output driver translates the output of
+.MR @g@troff @MAN1EXT@
+into input suitable for
+.MR @g@troff @MAN1EXT@ .
+.
+.
+.\" ====================================================================
+.SH Bugs
+.\" ====================================================================
+.
+The output is only correct if the input has an
+.B s
+command before the first text or the text size scaling factor is\~1000.
+.
+.P
+The processed output contains a stray blank page at the end.
+.
+.P
+Both the output of
+.I grotrin
+and documents generated from it are likely much larger than the input.
+.
+.P
+.I grotrin
+does not support drawing commands.
+.
+.P
+There is no reason to use
+.I grotrin.
+.
+.
+.\" ====================================================================
+.SH "See also"
+.\" ====================================================================
+.
+.MR groff @MAN1EXT@ ,
+.MR @g@troff @MAN1EXT@ ,
+.MR groff_out @MAN5EXT@ ,
+.MR groff @MAN7EXT@
diff --git a/src/devices/grotrin/grotrin.am b/src/devices/grotrin/grotrin.am
new file mode 100644
index 000000000..db012985e
--- /dev/null
+++ b/src/devices/grotrin/grotrin.am
@@ -0,0 +1,14 @@
+bin_PROGRAMS += grotrin
+grotrin_SOURCES = src/devices/grotrin/trin.cpp
+grotrin_LDADD = libdriver.a \
+  libgroff.a \
+  lib/libgnu.a
+man1_MANS += src/devices/grotrin/grotrin.1
+EXTRA_DIST += \
+  src/devices/grotrin/grotrin.1.man
+
+# Local Variables:
+# fill-column: 72
+# mode: makefile-automake
+# End:
+# vim: set autoindent filetype=automake textwidth=72:
diff --git a/src/devices/grotrin/trin.cpp b/src/devices/grotrin/trin.cpp
new file mode 100644
index 000000000..5fa84cbc1
--- /dev/null
+++ b/src/devices/grotrin/trin.cpp
@@ -0,0 +1,129 @@
+#include "driver.h"
+
+#if __cplusplus < 201103L
+# define override
+#endif
+
+static void usage(FILE *stream);
+
+class trin_printer : public printer {
+  font *current_font;
+  // in scaled points
+  int current_size;
+  // next output byte is at the beginning of a line
+  bool at_newline;
+public:
+  trin_printer();
+  void begin_page(int) override;
+  void end_page(int) override;
+private:
+  void set_char(glyph *, font *, const environment *, int,
+                       const char *) override;
+  void newline();
+};
+
+trin_printer::trin_printer()
+{
+  current_font = NULL;
+  // TODO: don’t depend on a certain scale factor
+  current_size = 10000;
+  at_newline = true;
+
+  puts(
+       ".po 0\n"
+       ".nf\n"
+       ".hy 0\n"
+       ".lg 0\n"
+       ".vs 0");
+}
+
+void trin_printer::begin_page(int)
+{
+}
+
+void trin_printer::end_page(int)
+{
+  newline();
+  puts(".bp");
+}
+
+void trin_printer::set_char(glyph *g, font *f, const environment *env, int w, 
const char *)
+{
+  if (current_font != f) {
+    newline();
+    printf(".ft %s\n", f->get_name());
+    current_font = f;
+  }
+
+  if (current_size != env->size) {
+    newline();
+    printf(
+       ".nr s %ds\n"
+       ".ps \\nsu\n",
+       env->size);
+    current_size = env->size;
+  }
+
+  printf("\\v'|%du'\\h'%du-\\n(.ku'", env->vpos, env->hpos);
+
+  int no;
+  const char *name;
+  if ((no = glyph_to_number(g)) != -1)
+    printf("\\N'%d'", no);
+  else if ((name = glyph_to_name(g)) != nullptr) {
+    if (name[0] == '\\')
+      name++;
+    printf("\\[%s]", name);
+  }
+  at_newline = false;
+
+  newline();
+  puts(".br");
+}
+
+/*
+ * Ensure the next byte printed is at the start of a line.
+ */
+void trin_printer::newline()
+{
+  if (!at_newline) {
+    at_newline = true;
+    putchar('\n');
+  }
+}
+
+printer *make_printer()
+{
+  return new trin_printer();
+}
+
+int main(int argc, char **argv)
+{
+  program_name = argv[0];
+  setlocale(LC_CTYPE, "");
+  int c;
+  while ((c = getopt(argc, argv, "")) != -1)
+    switch (c) {
+    case '?':
+      usage(stderr);
+      exit(EXIT_FAILURE);
+    }
+  if (optind == argc)
+    do_file("-");
+  else
+    for (int i = optind; i < argc; i++)
+      do_file(argv[i]);
+}
+
+static void usage(FILE *stream)
+{
+  fprintf(stream,
+"usage: %s [file ...]\n",
+         program_name);
+}
+
+// Local Variables:
+// fill-column: 72
+// mode: C++
+// End:
+// vim: set cindent noexpandtab shiftwidth=2 textwidth=72:
-- 
2.44.0