fps: move FPS printing to stderr

With --print-pipes there will be a potential shitload of stuff
getting printed out, and it'd be nice to easily distinguish that
content from the FPS counter.

Since stderr is normally less buffered than stdout (line
buffered) not lose debugging information, just put the
low-bandwidth periodic FPS print there instead.  This leaves
stdout for --print-pipes output which occurs every frame *and*
may have a lot of content per print.

3 files changed, 6 insertions, 4 deletions

diff --git a/src/fps.c b/src/fps.c
index 30b65cf..bb4107c 100644
--- a/src/fps.c
+++ b/src/fps.c
@@ -36,7 +36,7 @@ int fps_setup(void)
 }
 
 
-void fps_print(til_fb_t *fb)
+void fps_fprint(til_fb_t *fb, FILE *out)
 {
 #ifdef __WIN32__
 
@@ -47,7 +47,7 @@ void fps_print(til_fb_t *fb)
 		return;
 
 	til_fb_get_put_pages_count(fb, &n);
-	printf("FPS: %u\n", n);
+	fprintf(out, "FPS: %u\n", n);
 
 	print_fps = 0;
 #endif
diff --git a/src/fps.h b/src/fps.h
index 1afb566..ede9efb 100644
--- a/src/fps.h
+++ b/src/fps.h
@@ -1,9 +1,11 @@
 #ifndef _FPS_H
 #define _FPS_H
 
+#include <stdio.h>
+
 #include "til_fb.h"
 
 int fps_setup(void);
-void fps_print(til_fb_t *fb);
+void fps_fprint(til_fb_t *fb, FILE *out);
 
 #endif
diff --git a/src/main.c b/src/main.c
index 943a8ff..0718bfd 100644
--- a/src/main.c
+++ b/src/main.c
@@ -398,7 +398,7 @@ int main(int argc, const char *argv[])
 		if (til_fb_flip(rototiller.fb) < 0)
 			break;
 
-		fps_print(rototiller.fb);
+		fps_fprint(rototiller.fb, stderr);
 	}
 
 	pthread_cancel(rototiller.thread);