1 files changed, 27 insertions, 0 deletions
diff --git a/src/util/anim.h b/src/util/anim.h
new file mode 100644
index 0000000..dbc2c11
--- /dev/null
+++ b/src/util/anim.h
@@ -0,0 +1,27 @@
+#include "typedef.h"
+
+#include <SDL.h>
+
+template < typename T >
+inline T lerp( T a, T b, F32 t ) {
+  return a + ( b - a ) * t;
+}
+
+template < typename t >
+inline t clamp( t a, t min, t max ) {
+  if ( a < min ) return min;
+  if ( a > max ) return max;
+  return a;
+}
+
+inline F32 ease_in( F32 t, F32 pow = 2.f ) {
+  return powf( t, pow );
+}
+
+inline F32 ease_out( F32 t, F32 pow = 2.f ) {
+  return 1.f - powf( 1.f - t, pow );
+}
+
+inline F32 ease_in_out( F32 t, F32 pow = 2.f ) {
+  return t < 0.5f ? ease_in( t * 2.f, pow ) / 2.f : ease_out( t * 2.f - 1.f, pow ) / 2.f + 0.5f;
+}