From f3ed4edbd21eb6ce2ccfd848dc6e88d0008e5f0c Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Sun, 31 Jul 2016 21:52:35 -0300
Subject: [PATCH] sch2fig/: graphics backend can be selected from the command
 line

---
 sch2fig/cairo.c     |  1 +
 sch2fig/fig.c       |  1 +
 sch2fig/gfx.h       |  1 +
 sch2fig/main.c      | 47 ++++++++++++++++++++++++++++++++-------------
 sch2fig/sch2pdf     |  5 +++--
 sch2fig/test/genpng |  2 +-
 sch2fig/util.h      |  4 ++++
 7 files changed, 45 insertions(+), 16 deletions(-)

diff --git a/sch2fig/cairo.c b/sch2fig/cairo.c
index a6c287d..38a00a2 100644
--- a/sch2fig/cairo.c
+++ b/sch2fig/cairo.c
@@ -232,6 +232,7 @@ static void cr_end(void *ctx)
 
 
 const struct gfx_ops cairo_ops = {
+	.name		= "cairo",
 	// .line	= cr_line,	@@@ later
 	.poly		= cr_poly,
 	.circ		= cr_circ,
diff --git a/sch2fig/fig.c b/sch2fig/fig.c
index 82750fd..ef1e90c 100644
--- a/sch2fig/fig.c
+++ b/sch2fig/fig.c
@@ -268,6 +268,7 @@ static void *fig_init(int argc, char *const *argv)
 
 
 const struct gfx_ops fig_ops = {
+	.name		= "fig",
 	.line		= fig_line,
 	.rect		= fig_rect,
 	.poly		= fig_poly,
diff --git a/sch2fig/gfx.h b/sch2fig/gfx.h
index 62a476e..bdbb124 100644
--- a/sch2fig/gfx.h
+++ b/sch2fig/gfx.h
@@ -20,6 +20,7 @@
 
 
 struct gfx_ops {
+	const char *name;
 	void (*line)(void *ctx, int sx, int sy, int ex, int ey,
 	    int color, unsigned layer);
 	void (*rect)(void *ctx, int sx, int sy, int ex, int ey,
diff --git a/sch2fig/main.c b/sch2fig/main.c
index 8d46445..a8438e4 100644
--- a/sch2fig/main.c
+++ b/sch2fig/main.c
@@ -27,6 +27,12 @@
 #include "main.h"
 
 
+static struct gfx_ops const *ops_list[] = {
+	&fig_ops,
+	&cairo_ops,
+};
+
+
 static bool do_lib_parse(void *user, const char *line)
 {
 	return lib_parse(user, line);
@@ -36,9 +42,11 @@ static bool do_lib_parse(void *user, const char *line)
 void usage(const char *name)
 {
 	fprintf(stderr,
-"usage: %s [-r] [file.lib ...] file.sch -- driver_options\n\n"
-"  FIG driver options:\n"
-"    [-t template.fig] [var=value ...]\n"
+"usage: %s [-r] [file.lib ...] file.sch -- driver_spec\n\n"
+"  FIG driver spec:\n"
+"    fig [-t template.fig] [var=value ...]\n"
+"  Cairo driver spec:\n"
+"    cairo\n"
     , name);
 	exit(1);
 }
@@ -52,6 +60,7 @@ int main(int argc, char *const *argv)
 	int arg, dashdash;
 	int gfx_argc;
 	char **gfx_argv;
+	const struct gfx_ops **ops = ops_list;
 
 	for (dashdash = 1; dashdash != argc; dashdash++)
 		if (!strcmp(argv[dashdash], "--"))
@@ -76,19 +85,31 @@ int main(int argc, char *const *argv)
 		file_read(argv[arg], do_lib_parse, &ctx);
 	}
 
-	/*
-	 * Special case: if we have no --, we don't subtract it and argc
-	 * becomes 1 (and no 0).
-	 */
-	gfx_argc = argc == dashdash ? 1 : argc - dashdash;
-	gfx_argv = alloc_size(sizeof(const char *) * (gfx_argc + 1));
-	gfx_argv[0] = argv[0];
-	memcpy(gfx_argv + 1, argv + dashdash + 1,
-	    sizeof(const char *) * gfx_argc);
+	if (dashdash == argc) {
+		gfx_argc = 1;
+		gfx_argv = alloc_size(sizeof(const char *) * 2);
+		gfx_argv[0] = (char *) (*ops)->name;
+		gfx_argv[1] = NULL;
+	} else {
+		gfx_argc = argc - dashdash - 1;
+		gfx_argv = alloc_size(sizeof(const char *) * (gfx_argc + 1));
+		memcpy(gfx_argv, argv + dashdash + 1,
+		    sizeof(const char *) * (gfx_argc + 1));
 
+		for (ops = ops_list; ops != ARRAY_END(ops_list); ops++)
+			if (!strcmp((*ops)->name, *gfx_argv))
+				goto found;
+		fprintf(stderr, "graphics backend \"%s\" not found\n",
+		    *gfx_argv);
+		exit(1);
+found:
+		;
+	}
+		
+	
 	sch_init(&sch_ctx, recurse);
 	sch_parse(&sch_ctx, argv[dashdash - 1]);
-	gfx_init(&fig_ops, gfx_argc, gfx_argv);
+	gfx_init(*ops, gfx_argc, gfx_argv);
 	if (recurse) {
 		const struct sheet *sheet;
 
diff --git a/sch2fig/sch2pdf b/sch2fig/sch2pdf
index 58716e7..823ab7e 100755
--- a/sch2fig/sch2pdf
+++ b/sch2fig/sch2pdf
@@ -56,7 +56,8 @@ while [ "$2" ]; do
 	shift
 done
 
-./sch2fig $libs "$1" -- $template "TITLE=`basename \"$1\" .sch`" NUMBER=$num |
+./sch2fig $libs "$1" \
+    -- fig $template "TITLE=`basename \"$1\" .sch`" NUMBER=$num |
     fig2dev -L pdf >"$out"
 
 sheet=false
@@ -83,7 +84,7 @@ while read line; do
 
 	$quiet || echo "$file" 1>&2
 	./sch2fig $libs `dirname "$1"`/$file \
-	     -- $template "TITLE=$name" NUMBER=$num |
+	     -- fig $template "TITLE=$name" NUMBER=$num |
 	    fig2dev -L pdf >_tmp.pdf
 	pdfunite "$out" _tmp.pdf _tmp2.pdf
 	mv _tmp2.pdf "$out"
diff --git a/sch2fig/test/genpng b/sch2fig/test/genpng
index 956ac71..77275b9 100755
--- a/sch2fig/test/genpng
+++ b/sch2fig/test/genpng
@@ -30,7 +30,7 @@ while [ $sheet -le 38 ]; do
 	file=$dir/$prefix$sn.png
 	$dir/../sch2fig $dir/neo900-ee/hw/neo900.lib \
 	    $dir/kicad-libs/components/powered.lib "$in" \
-	    -- -t $dir/frame.fig SHEET=$sn |
+	    -- fig -t $dir/frame.fig SHEET=$sn |
 	    fig2dev -L png -m 2 >$file
 	sheet=`expr $sheet + 1`
 done
diff --git a/sch2fig/util.h b/sch2fig/util.h
index 8849421..ea40ce5 100644
--- a/sch2fig/util.h
+++ b/sch2fig/util.h
@@ -38,6 +38,10 @@
 	stralloc_tmp; })
 
 
+#define	ARRAY_ELEMENTS(a)	(sizeof(a) / sizeof(a[0]))
+#define	ARRAY_END(a)		((a) + ARRAY_ELEMENTS(a))
+
+
 #define	swap(a, b) \
     ({ typeof(a) _tmp = (a); a = (b); b = _tmp; })