computeshader

1 files changed, 25 insertions, 0 deletions

diff --git a/samples/OpenGL/compute_shader/stats.c b/samples/OpenGL/compute_shader/stats.c
new file mode 100644
index 0000000..1cf7fcb
--- /dev/null
+++ b/samples/OpenGL/compute_shader/stats.c
@@ -0,0 +1,25 @@
+#include "stats.h"
+
+void stats_running_reset(struct stats_running *s)
+{
+	if( s ) {
+		s->n = 0;
+		s->S = NAN;
+		s->m = NAN;
+	}
+}
+
+void stats_running_push(struct stats_running *s, double value)
+{
+	if( s && isfinite(value) ) {
+		double   const m_prev = 0 < s->n ? s->m : 0.;
+		double   const S_prev = 1 < s->n ? s->S : 0.;
+		unsigned const n      = (s->n += 1);
+
+		s->m = m_prev + (value - m_prev) / n;
+		if( 1 < n ) {
+			/* variance is defined only for n > 1 */
+			s->S = S_prev + (value - s->m) * (value - m_prev);
+		}
+	}
+}