push source

1 files changed, 27 insertions, 0 deletions

diff --git a/src/util.h b/src/util.h
new file mode 100644
index 0000000..bc06b42
--- /dev/null
+++ b/src/util.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <time.h>
+#include <math.h>
+#include "typedef.h"
+
+inline F64 t_nows() {
+  struct timespec ts;
+  clock_gettime( CLOCK_MONOTONIC, &ts );
+  return (F64)ts.tv_sec + (F64)ts.tv_nsec * 1e-9;
+}
+
+
+inline F32 fade_alpha( F64 since, F64 now ) {
+  if( since <= 0.0 )
+    return 0.0f;
+  F64 a = ( now - since - 0.30 ) / 0.30;
+  if( a < 0.0 ) a = 0.0;
+  if( a > 1.0 ) a = 1.0;
+  return (F32)a;
+}
+
+inline F32 vec_dist( F32 x1, F32 y1, F32 z1, F32 x2, F32 y2, F32 z2 ) {
+  F32 dx = x1 - x2;
+  F32 dy = y1 - y2;
+  F32 dz = z1 - z2;
+  return sqrtf( dx * dx + dy * dy + dz * dz );
+}