.\"	$Id: lowdown_gemini_rndr.3,v 1.5 2021/02/13 22:16:43 kristaps Exp $
.\"
.\" Copyright (c) 2020--2021 Kristaps Dzonsons <kristaps@bsd.lv>
.\"
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.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
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.Dd $Mdocdate: February 13 2021 $
.Dt LOWDOWN_GEMINI_RNDR 3
.Os
.Sh NAME
.Nm lowdown_gemini_rndr
.Nd render Markdown into gemini
.Sh LIBRARY
.Lb liblowdown
.Sh SYNOPSIS
.In sys/queue.h
.In stdio.h
.In lowdown.h
.Ft int
.Fo lowdown_gemini_rndr
.Fa "struct lowdown_buf *out"
.Fa "struct lowdown_metaq *mq"
.Fa "void *arg"
.Fa "const struct lowdown_node *n"
.Fc
.Sh DESCRIPTION
Renders a node tree
.Fa n
created by
.Xr lowdown_doc_parse 3
or
.Xr lowdown_diff 3
using the gemini renderer
.Fa arg
as returned by
.Xr lowdown_gemini_new 3 .
The output is written into
.Fa out ,
which must be initialised and freed by the caller.
.Pp
If
.Fa mq
is not
.Dv NULL ,
it is filled with any metadata as parsed.
It must be initialised and its contents freed with
.Xr lowdown_metaq_free 3 .
.Pp
The caller is expected to have invoked
.Xr setlocale 3
to a
.Qq UTF-8
character encoding prior to using this function, otherwise UTF-8
sequences will not be properly recognised.
This is used when formatting table column widths.
.Sh RETURN VALUES
Returns zero on failure to allocate memory, non-zero on success.
.Sh EXAMPLES
The following assumes the the string
.Va buf
of length
.Va bsz
consists of Markdown content.
.Bd -literal -offset indent
struct lowdown_buf *out;
struct lowdown_doc *doc;
struct lowdown_node *n;
void *rndr;

if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL)
  err(1, NULL);

if ((doc = lowdown_doc_new(NULL)) == NULL)
  err(1, NULL);
if ((n = lowdown_doc_parse(doc, NULL, buf, bsz)) == NULL)
  err(1, NULL);
if ((out = lowdown_buf_new(256)) == NULL)
  err(1, NULL);
if ((rndr = lowdown_gemini_new(NULL)) == NULL)
  err(1, NULL);
if (!lowdown_gemini_rndr(out, NULL, rndr, n))
  err(1, NULL);

fwrite(out->data, 1, out->size, stdout);

lowdown_gemini_free(rndr);
lowdown_buf_free(out);
lowdown_node_free(n);
lowdown_doc_free(doc);
.Ed
.Sh SEE ALSO
.Xr lowdown 3 ,
.Xr lowdown_gemini_free 3 ,
.Xr lowdown_gemini_new 3
.Sh STANDARDS
The gemini format is documented in
.Lk https://gemini.circumlunar.space/docs/specification.html Project Gemini .
The version at the time of writing is 0.14.3.