til_args: introduce --print-module-contexts

Some rudimentary instrumentation for monitoring the active module
contexts alongside the pipes

You probably want to redirect stderr to a file when using
--print-pipes and/or --print-module-contexts...

e.g.
```
rototiller --defaults --go --print-pipes --print-module-contexts 2>/dev/null
```

or, if you still want to monitor FPS or log_channels=on in rtv,
2>/file/to/tail then tail -F /file/to/tail in another terminal.

3 files changed, 20 insertions, 8 deletions

diff --git a/src/main.c b/src/main.c
index de26001..8306b64 100644
--- a/src/main.c
+++ b/src/main.c
@@ -338,9 +338,15 @@ static void * rototiller_thread(void *_rt)
 		til_module_render(rt->module_context, rt->stream, ticks, &fragment);
 		til_fb_fragment_submit(fragment);
 
-		if (rt->args.print_pipes) { /* render threads are idle at this point */
+		if (rt->args.print_module_contexts || rt->args.print_pipes) {
+			/* render threads are idle at this point */
 			printf("\x1b[2J\x1b[;H"); /* ANSI codes for clear screen and move cursor to top left */
-			til_stream_fprint_pipes(rt->stream, stdout);
+
+			if (rt->args.print_module_contexts)
+				til_stream_fprint_module_contexts(rt->stream, stdout);
+
+			if (rt->args.print_pipes)
+				til_stream_fprint_pipes(rt->stream, stdout);
 		}
 	}
 
diff --git a/src/til_args.c b/src/til_args.c
index 11f2487..7e4c7e6 100644
--- a/src/til_args.c
+++ b/src/til_args.c
@@ -13,6 +13,7 @@
  * ./rototiller --go			// don't show args and wait for user input before proceeding
  * ./rototiller --seed=0xdeadbeef	// explicitly set global random seed instead of generating one
  * ./rototiller --print-pipes		// print values for the pipes every frame
+ * ./rototiller --print-module-contexts // print information about registered module contexts every frame
  *
  * unrecognized arguments trigger an -EINVAL error, unless res_{argc,argv} are non-NULL
  * where a new argv will be allocated and populated with the otherwise invalid arguments
@@ -55,6 +56,8 @@ static int args_parse(int argc, const char *argv[], til_args_t *res_args, int *r
 			res_args->help = 1;
 		} else if (!strcasecmp("--go", argv[i])) {
 			res_args->gogogo = 1;
+		} else if (!strcasecmp("--print-module-contexts", argv[i])) {
+			res_args->print_module_contexts = 1;
 		} else if (!strcasecmp("--print-pipes", argv[i])) {
 			res_args->print_pipes = 1;
 		} else {
@@ -87,11 +90,13 @@ int til_args_parse(int argc, const char *argv[], til_args_t *res_args)
 int til_args_help(FILE *out)
 {
 	return fprintf(out,
-		"  --defaults	use defaults for unspecified settings\n"
-		"  --go		start rendering immediately upon fulfilling all required settings\n"
-		"  --help	this help\n"
-		"  --module=	module settings\n"
-		"  --seed=	seed to use for all PRNG in hexadecimal (e.g. 0xdeadbeef)\n"
-		"  --video=	video settings\n"
+		"  --defaults              use defaults for unspecified settings\n"
+		"  --go                    start rendering immediately upon fulfilling all required settings\n"
+		"  --help                  this help\n"
+		"  --module=               module settings\n"
+		"  --print-module-contexts print active contexts on-stream to stdout\n"
+		"  --print-pipes           print active pipes on-stream to stdout\n"
+		"  --seed=                 seed to use for all PRNG in hexadecimal (e.g. 0xdeadbeef)\n"
+		"  --video=                video settings\n"
 		);
 }
diff --git a/src/til_args.h b/src/til_args.h
index 85d4d7b..7c21668 100644
--- a/src/til_args.h
+++ b/src/til_args.h
@@ -11,6 +11,7 @@ typedef struct til_args_t {
 	unsigned	use_defaults:1;
 	unsigned	help:1;
 	unsigned	gogogo:1;
+	unsigned	print_module_contexts:1;
 	unsigned	print_pipes:1;
 } til_args_t;