diff --git a/bind/v4k.lua b/bind/v4k.lua
index 5de4cf7..9b84397 100644
--- a/bind/v4k.lua
+++ b/bind/v4k.lua
@@ -957,6 +957,11 @@ ffi.cdef([[
 //lcpp INF [0000] quat: macro name but used as C declaration in:API void printq( quat q );
 //lcpp INF [0000] quat: macro name but used as C declaration in:STATIC void printq( quat q );
 //lcpp INF [0000] quat: macro name but used as C declaration in: void printq( quat q );
+//lcpp INF [0000] vec3: macro name but used as C declaration in:vec3 v;
+//lcpp INF [0000] vec3: macro name but used as C declaration in:vec3 result;
+//lcpp INF [0000] vec3: macro name but used as C declaration in:API void tween_keyframe_set(tween_t *tw, float t, int easing_mode, vec3 v);
+//lcpp INF [0000] vec3: macro name but used as C declaration in:STATIC void tween_keyframe_set(tween_t *tw, float t, int easing_mode, vec3 v);
+//lcpp INF [0000] vec3: macro name but used as C declaration in: void tween_keyframe_set(tween_t *tw, float t, int easing_mode, vec3 v);
 //lcpp INF [0000] vec3: macro name but used as C declaration in:vec3 position;
 //lcpp INF [0000] vec3: macro name but used as C declaration in:vec3 velocity;
 //lcpp INF [0000] vec3: macro name but used as C declaration in:vec3 acceleration;
@@ -1606,6 +1611,7 @@ typedef float mat44[16];
  float simplex3( vec3 xyz );
  float simplex4( vec4 xyzw );
  float ease_linear(float t);
+ float ease_nearest(float t);
  float ease_out_sine(float t);
  float ease_out_quad(float t);
  float ease_out_cubic(float t);
@@ -1836,6 +1842,23 @@ EASE_OUT = 0,
  void print33( float *m );
  void print34( float *m );
  void print44( float *m );
+typedef struct tween_keyframe_t {
+int easing_mode;
+float t;
+vec3 v;
+} tween_keyframe_t;
+typedef struct tween_t {
+tween_keyframe_t* keyframes;
+vec3 result;
+float time;
+float duration;
+} tween_t;
+ tween_t tween();
+ float     tween_update(tween_t *tw, float dt);
+ void      tween_reset(tween_t *tw);
+ void    tween_destroy(tween_t *tw);
+ void tween_keyframe_set(tween_t *tw, float t, int easing_mode, vec3 v);
+ void tween_keyframe_unset(tween_t *tw, float t);
 typedef enum SWARM_DISTANCE {
 SWARM_DISTANCE_LINEAR,
 SWARM_DISTANCE_INVERSE_LINEAR,
diff --git a/demos/99-dblclick.c b/demos/99-dblclick.c
new file mode 100644
index 0000000..0a82a6d
--- /dev/null
+++ b/demos/99-dblclick.c
@@ -0,0 +1,13 @@
+#include "v4k.h" // Minimal C sample
+int main() {
+    window_create(30.0, WINDOW_SQUARE); // 75% size, no extra flags
+    float t=0.0;
+    while( window_swap() && !input(KEY_ESC) ) { // game loop
+        if (input_repeat(KEY_SPACE, 750)) {
+            printf("250ms repeat after %.02f\n", t);
+            t=0;
+        }
+
+        t += window_delta();
+    }
+}
\ No newline at end of file
diff --git a/engine/joint/v4k.h b/engine/joint/v4k.h
index 54404df..fb1a2e2 100644
--- a/engine/joint/v4k.h
+++ b/engine/joint/v4k.h
@@ -14932,6 +14932,7 @@ API float simplex4( vec4 xyzw );
 // ----------------------------------------------------------------------------
 
 API float ease_linear(float t);
+API float ease_nearest(float t);
 
 API float ease_out_sine(float t);
 API float ease_out_quad(float t);
@@ -15222,6 +15223,30 @@ API void print34( float *m );
 API void print44( float *m );
 #line 0
 
+#line 1 "engine/split/v4k_tween.h"
+typedef struct tween_keyframe_t {
+	int easing_mode;
+	float t;
+	vec3 v;
+} tween_keyframe_t;
+
+typedef struct tween_t {
+	array(tween_keyframe_t) keyframes;
+
+	vec3 result;
+	float time;
+	float duration;
+} tween_t;
+
+API tween_t tween();
+API float     tween_update(tween_t *tw, float dt);
+API void      tween_reset(tween_t *tw);
+API void    tween_destroy(tween_t *tw);
+
+API void tween_keyframe_set(tween_t *tw, float t, int easing_mode, vec3 v);
+API void tween_keyframe_unset(tween_t *tw, float t);
+#line 0
+
 #line 1 "engine/split/v4k_ai.h"
 typedef enum SWARM_DISTANCE {
     SWARM_DISTANCE_LINEAR,
@@ -340857,7 +340882,7 @@ vec2 input2( int vk ) {
 
 // --- events
 
-const float MS2FRAME = 0.06f; // 60 hz/1000 ms
+const float MS2FRAME = 60.0f; // 60 hz/1000 ms
 
 int event( int vk ) {
     float v = input_frame(vk,0);
@@ -340884,18 +340909,29 @@ int input_up( int vk ) {
 int input_idle( int vk ) {
     return input_diff(vk) == 0 && input_frame(vk,0) <= 0; // input_frame(vk,-1) <= 0 && input_frame(vk,0) <= 0;
 }
-int input_repeat( int vk, int ms ) { // @fixme: broken
-    assert((unsigned)ms <= 1000);
-    return input_frame(vk,-ms * MS2FRAME ) > 0 && input_frame(vk,-ms * MS2FRAME /2) > 0 && input_frame(vk,0) > 0;
+int input_repeat(int vk, int ms) {
+    assert(ms >= 0 && ms <= 1000);
+    float hz = window_fps() ? window_fps() : MS2FRAME;
+    return input_frame(vk, -ms * hz) > 0 && 
+           input_frame(vk, -ms * hz / 2.0) > 0 && 
+           input_frame(vk, 0) > 0;
 }
-int input_click( int vk, int ms ) { // @fixme: broken
-    assert((unsigned)ms <= 1000);
-    return input_frame(vk,-ms * MS2FRAME ) <= 0 && input_frame(vk,-ms * MS2FRAME /2) > 0 && input_frame(vk,0) <= 0;
+int input_click(int vk, int ms) {
+    assert(ms >= 0 && ms <= 1000);
+    float hz = window_fps() ? window_fps() : MS2FRAME;
+    return input_frame(vk, -ms * hz) <= 0 && 
+           input_frame(vk, -ms * hz / 2.0) > 0 && 
+           input_frame(vk, 0) <= 0;
 }
-int input_click2( int vk, int ms ) { // @fixme: broken
-    assert((unsigned)ms <= 1000);
-    return input_frame(vk,-ms * MS2FRAME ) <= 0 && input_frame(vk,-ms * MS2FRAME *3/4) > 0
-    && input_frame(vk,-ms * MS2FRAME *2/4) <= 0 && input_frame(vk,-ms * MS2FRAME *1/4) > 0 && input_frame(vk,0) <= 0;
+
+int input_click2(int vk, int ms) {
+    assert(ms >= 0 && ms <= 1000);
+    float hz = window_fps() ? window_fps() : MS2FRAME;
+    return input_frame(vk, -ms * hz) <= 0 && 
+           input_frame(vk, -ms * hz * 3 / 4.0) > 0 &&
+           input_frame(vk, -ms * hz * 2 / 4.0) <= 0 && 
+           input_frame(vk, -ms * hz * 1 / 4.0) > 0 && 
+           input_frame(vk, 0) <= 0;
 }
 
 #undef MS2FRAME
@@ -341301,6 +341337,7 @@ float simplex4( vec4 v ) { return snoise4(v.x,v.y,v.z,v.w); }
 // ----------------------------------------------------------------------------
 
 float ease_linear(float t) { return t; }
+float ease_nearest(float t) { return t >= 0.5f ? 1.0f : 0.0f; }
 
 float ease_out_sine(float t) { return sinf(t*(C_PI*0.5f)); }
 float ease_out_quad(float t) { return -(t*(t-2)); }
@@ -342189,6 +342226,70 @@ AUTORUN {
 }
 #line 0
 
+#line 1 "engine/split/v4k_tween.c"
+tween_t tween() {
+	tween_t tw = {0};
+	return tw;
+}
+
+float tween_update(tween_t *tw, float dt) {
+	if (!array_count(tw->keyframes)) return 0.0f;
+
+	for (size_t i = 0; i < array_count(tw->keyframes) - 1; ++i) {
+        tween_keyframe_t *kf1 = &tw->keyframes[i];
+        tween_keyframe_t *kf2 = &tw->keyframes[i + 1];
+        if (tw->time >= kf1->t && tw->time <= kf2->t) {
+            float localT = (tw->time - kf1->t) / (kf2->t - kf1->t);
+            float easedT = ease(localT, kf1->easing_mode);
+            tw->result = mix3(kf1->v, kf2->v, easedT);
+            break;
+        }
+    }
+
+	float done = (tw->time / tw->duration);
+	tw->time += dt;
+	return clampf(done, 0.0f, 1.0f);
+}
+
+void tween_reset(tween_t *tw) {
+	tw->time = 0.0f;
+}
+
+void tween_destroy(tween_t *tw) {
+	tween_t tw_ = {0};
+	array_free(tw->keyframes);
+	*tw = tw_;
+}
+
+static inline
+int tween_comp_keyframes(const void *a, const void *b) {
+    float t1 = ((const tween_keyframe_t*)a)->t;
+    float t2 = ((const tween_keyframe_t*)b)->t;
+    return (t1 > t2) - (t1 < t2);
+}
+
+void tween_keyframe_set(tween_t *tw, float t, int mode, vec3 v) {
+	tween_keyframe_t keyframe = { mode, t, v };
+	array_push(tw->keyframes, keyframe);
+	array_sort(tw->keyframes, tween_comp_keyframes);
+	tw->duration = array_back(tw->keyframes)->t;
+}
+
+void tween_keyframe_unset(tween_t *tw, float t) { /*@todo: untested*/
+	int id = -1;
+	for (int i = 0; i < array_count(tw->keyframes); i++) {
+		if (tw->keyframes[i].t == t) {
+			id = i;
+			break;
+		}
+	}
+
+	if (id == -1) return;
+	array_erase_slow(tw->keyframes, id);
+	tw->duration = array_back(tw->keyframes)->t;
+}
+#line 0
+
 #line 1 "engine/split/v4k_memory.c"
 size_t dlmalloc_usable_size(void*); // __ANDROID_API__
 
diff --git a/engine/split/v4k.c.inl b/engine/split/v4k.c.inl
index d58201a..18e683a 100644
--- a/engine/split/v4k.c.inl
+++ b/engine/split/v4k.c.inl
@@ -139,6 +139,8 @@ API void *ui_handle();
 
 {{FILE:v4k_math.c}}
 
+{{FILE:v4k_tween.c}}
+
 {{FILE:v4k_memory.c}}
 
 {{FILE:v4k_network.c}}
diff --git a/engine/split/v4k.h.inl b/engine/split/v4k.h.inl
index 1770504..67032ef 100644
--- a/engine/split/v4k.h.inl
+++ b/engine/split/v4k.h.inl
@@ -101,6 +101,8 @@ extern "C" {
 
 {{FILE:v4k_math.h}}
 
+{{FILE:v4k_tween.h}}
+
 {{FILE:v4k_ai.h}}
 
 {{FILE:v4k_bt.h}}
diff --git a/engine/split/v4k_input.c b/engine/split/v4k_input.c
index 1610c9d..fdac191 100644
--- a/engine/split/v4k_input.c
+++ b/engine/split/v4k_input.c
@@ -398,7 +398,7 @@ vec2 input2( int vk ) {
 
 // --- events
 
-const float MS2FRAME = 0.06f; // 60 hz/1000 ms
+const float MS2FRAME = 60.0f; // 60 hz/1000 ms
 
 int event( int vk ) {
     float v = input_frame(vk,0);
@@ -425,18 +425,29 @@ int input_up( int vk ) {
 int input_idle( int vk ) {
     return input_diff(vk) == 0 && input_frame(vk,0) <= 0; // input_frame(vk,-1) <= 0 && input_frame(vk,0) <= 0;
 }
-int input_repeat( int vk, int ms ) { // @fixme: broken
-    assert((unsigned)ms <= 1000);
-    return input_frame(vk,-ms * MS2FRAME ) > 0 && input_frame(vk,-ms * MS2FRAME /2) > 0 && input_frame(vk,0) > 0;
+int input_repeat(int vk, int ms) {
+    assert(ms >= 0 && ms <= 1000);
+    float hz = window_fps() ? window_fps() : MS2FRAME;
+    return input_frame(vk, -ms * hz) > 0 && 
+           input_frame(vk, -ms * hz / 2.0) > 0 && 
+           input_frame(vk, 0) > 0;
 }
-int input_click( int vk, int ms ) { // @fixme: broken
-    assert((unsigned)ms <= 1000);
-    return input_frame(vk,-ms * MS2FRAME ) <= 0 && input_frame(vk,-ms * MS2FRAME /2) > 0 && input_frame(vk,0) <= 0;
+int input_click(int vk, int ms) {
+    assert(ms >= 0 && ms <= 1000);
+    float hz = window_fps() ? window_fps() : MS2FRAME;
+    return input_frame(vk, -ms * hz) <= 0 && 
+           input_frame(vk, -ms * hz / 2.0) > 0 && 
+           input_frame(vk, 0) <= 0;
 }
-int input_click2( int vk, int ms ) { // @fixme: broken
-    assert((unsigned)ms <= 1000);
-    return input_frame(vk,-ms * MS2FRAME ) <= 0 && input_frame(vk,-ms * MS2FRAME *3/4) > 0
-    && input_frame(vk,-ms * MS2FRAME *2/4) <= 0 && input_frame(vk,-ms * MS2FRAME *1/4) > 0 && input_frame(vk,0) <= 0;
+
+int input_click2(int vk, int ms) {
+    assert(ms >= 0 && ms <= 1000);
+    float hz = window_fps() ? window_fps() : MS2FRAME;
+    return input_frame(vk, -ms * hz) <= 0 && 
+           input_frame(vk, -ms * hz * 3 / 4.0) > 0 &&
+           input_frame(vk, -ms * hz * 2 / 4.0) <= 0 && 
+           input_frame(vk, -ms * hz * 1 / 4.0) > 0 && 
+           input_frame(vk, 0) <= 0;
 }
 
 #undef MS2FRAME
diff --git a/engine/split/v4k_math.c b/engine/split/v4k_math.c
index 52f2677..c44dc8b 100644
--- a/engine/split/v4k_math.c
+++ b/engine/split/v4k_math.c
@@ -76,6 +76,7 @@ float simplex4( vec4 v ) { return snoise4(v.x,v.y,v.z,v.w); }
 // ----------------------------------------------------------------------------
 
 float ease_linear(float t) { return t; }
+float ease_nearest(float t) { return t >= 0.5f ? 1.0f : 0.0f; }
 
 float ease_out_sine(float t) { return sinf(t*(C_PI*0.5f)); }
 float ease_out_quad(float t) { return -(t*(t-2)); }
diff --git a/engine/split/v4k_math.h b/engine/split/v4k_math.h
index 6ab1d80..d243578 100644
--- a/engine/split/v4k_math.h
+++ b/engine/split/v4k_math.h
@@ -50,6 +50,7 @@ API float simplex4( vec4 xyzw );
 // ----------------------------------------------------------------------------
 
 API float ease_linear(float t);
+API float ease_nearest(float t);
 
 API float ease_out_sine(float t);
 API float ease_out_quad(float t);
diff --git a/engine/split/v4k_tween.c b/engine/split/v4k_tween.c
new file mode 100644
index 0000000..edf1461
--- /dev/null
+++ b/engine/split/v4k_tween.c
@@ -0,0 +1,61 @@
+tween_t tween() {
+	tween_t tw = {0};
+	return tw;
+}
+
+float tween_update(tween_t *tw, float dt) {
+	if (!array_count(tw->keyframes)) return 0.0f;
+
+	for (size_t i = 0; i < array_count(tw->keyframes) - 1; ++i) {
+        tween_keyframe_t *kf1 = &tw->keyframes[i];
+        tween_keyframe_t *kf2 = &tw->keyframes[i + 1];
+        if (tw->time >= kf1->t && tw->time <= kf2->t) {
+            float localT = (tw->time - kf1->t) / (kf2->t - kf1->t);
+            float easedT = ease(localT, kf1->easing_mode);
+            tw->result = mix3(kf1->v, kf2->v, easedT);
+            break;
+        }
+    }
+
+	float done = (tw->time / tw->duration);
+	tw->time += dt;
+	return clampf(done, 0.0f, 1.0f);
+}
+
+void tween_reset(tween_t *tw) {
+	tw->time = 0.0f;
+}
+
+void tween_destroy(tween_t *tw) {
+	tween_t tw_ = {0};
+	array_free(tw->keyframes);
+	*tw = tw_;
+}
+
+static inline
+int tween_comp_keyframes(const void *a, const void *b) {
+    float t1 = ((const tween_keyframe_t*)a)->t;
+    float t2 = ((const tween_keyframe_t*)b)->t;
+    return (t1 > t2) - (t1 < t2);
+}
+
+void tween_keyframe_set(tween_t *tw, float t, int mode, vec3 v) {
+	tween_keyframe_t keyframe = { mode, t, v };
+	array_push(tw->keyframes, keyframe);
+	array_sort(tw->keyframes, tween_comp_keyframes);
+	tw->duration = array_back(tw->keyframes)->t;
+}
+
+void tween_keyframe_unset(tween_t *tw, float t) { /*@todo: untested*/
+	int id = -1;
+	for (int i = 0; i < array_count(tw->keyframes); i++) {
+		if (tw->keyframes[i].t == t) {
+			id = i;
+			break;
+		}
+	}
+
+	if (id == -1) return;
+	array_erase_slow(tw->keyframes, id);
+	tw->duration = array_back(tw->keyframes)->t;
+}
diff --git a/engine/split/v4k_tween.h b/engine/split/v4k_tween.h
new file mode 100644
index 0000000..802da0e
--- /dev/null
+++ b/engine/split/v4k_tween.h
@@ -0,0 +1,21 @@
+typedef struct tween_keyframe_t {
+	int easing_mode;
+	float t;
+	vec3 v;
+} tween_keyframe_t;
+
+typedef struct tween_t {
+	array(tween_keyframe_t) keyframes;
+
+	vec3 result;
+	float time;
+	float duration;
+} tween_t;
+
+API tween_t tween();
+API float     tween_update(tween_t *tw, float dt);
+API void      tween_reset(tween_t *tw);
+API void    tween_destroy(tween_t *tw);
+
+API void tween_keyframe_set(tween_t *tw, float t, int easing_mode, vec3 v);
+API void tween_keyframe_unset(tween_t *tw, float t);
diff --git a/engine/v4k.c b/engine/v4k.c
index 33c82d7..0c6fe3c 100644
--- a/engine/v4k.c
+++ b/engine/v4k.c
@@ -8881,7 +8881,7 @@ vec2 input2( int vk ) {
 
 // --- events
 
-const float MS2FRAME = 0.06f; // 60 hz/1000 ms
+const float MS2FRAME = 60.0f; // 60 hz/1000 ms
 
 int event( int vk ) {
     float v = input_frame(vk,0);
@@ -8908,18 +8908,29 @@ int input_up( int vk ) {
 int input_idle( int vk ) {
     return input_diff(vk) == 0 && input_frame(vk,0) <= 0; // input_frame(vk,-1) <= 0 && input_frame(vk,0) <= 0;
 }
-int input_repeat( int vk, int ms ) { // @fixme: broken
-    assert((unsigned)ms <= 1000);
-    return input_frame(vk,-ms * MS2FRAME ) > 0 && input_frame(vk,-ms * MS2FRAME /2) > 0 && input_frame(vk,0) > 0;
+int input_repeat(int vk, int ms) {
+    assert(ms >= 0 && ms <= 1000);
+    float hz = window_fps() ? window_fps() : MS2FRAME;
+    return input_frame(vk, -ms * hz) > 0 && 
+           input_frame(vk, -ms * hz / 2.0) > 0 && 
+           input_frame(vk, 0) > 0;
 }
-int input_click( int vk, int ms ) { // @fixme: broken
-    assert((unsigned)ms <= 1000);
-    return input_frame(vk,-ms * MS2FRAME ) <= 0 && input_frame(vk,-ms * MS2FRAME /2) > 0 && input_frame(vk,0) <= 0;
+int input_click(int vk, int ms) {
+    assert(ms >= 0 && ms <= 1000);
+    float hz = window_fps() ? window_fps() : MS2FRAME;
+    return input_frame(vk, -ms * hz) <= 0 && 
+           input_frame(vk, -ms * hz / 2.0) > 0 && 
+           input_frame(vk, 0) <= 0;
 }
-int input_click2( int vk, int ms ) { // @fixme: broken
-    assert((unsigned)ms <= 1000);
-    return input_frame(vk,-ms * MS2FRAME ) <= 0 && input_frame(vk,-ms * MS2FRAME *3/4) > 0
-    && input_frame(vk,-ms * MS2FRAME *2/4) <= 0 && input_frame(vk,-ms * MS2FRAME *1/4) > 0 && input_frame(vk,0) <= 0;
+
+int input_click2(int vk, int ms) {
+    assert(ms >= 0 && ms <= 1000);
+    float hz = window_fps() ? window_fps() : MS2FRAME;
+    return input_frame(vk, -ms * hz) <= 0 && 
+           input_frame(vk, -ms * hz * 3 / 4.0) > 0 &&
+           input_frame(vk, -ms * hz * 2 / 4.0) <= 0 && 
+           input_frame(vk, -ms * hz * 1 / 4.0) > 0 && 
+           input_frame(vk, 0) <= 0;
 }
 
 #undef MS2FRAME
@@ -9325,6 +9336,7 @@ float simplex4( vec4 v ) { return snoise4(v.x,v.y,v.z,v.w); }
 // ----------------------------------------------------------------------------
 
 float ease_linear(float t) { return t; }
+float ease_nearest(float t) { return t >= 0.5f ? 1.0f : 0.0f; }
 
 float ease_out_sine(float t) { return sinf(t*(C_PI*0.5f)); }
 float ease_out_quad(float t) { return -(t*(t-2)); }
@@ -10213,6 +10225,70 @@ AUTORUN {
 }
 #line 0
 
+#line 1 "engine/split/v4k_tween.c"
+tween_t tween() {
+	tween_t tw = {0};
+	return tw;
+}
+
+float tween_update(tween_t *tw, float dt) {
+	if (!array_count(tw->keyframes)) return 0.0f;
+
+	for (size_t i = 0; i < array_count(tw->keyframes) - 1; ++i) {
+        tween_keyframe_t *kf1 = &tw->keyframes[i];
+        tween_keyframe_t *kf2 = &tw->keyframes[i + 1];
+        if (tw->time >= kf1->t && tw->time <= kf2->t) {
+            float localT = (tw->time - kf1->t) / (kf2->t - kf1->t);
+            float easedT = ease(localT, kf1->easing_mode);
+            tw->result = mix3(kf1->v, kf2->v, easedT);
+            break;
+        }
+    }
+
+	float done = (tw->time / tw->duration);
+	tw->time += dt;
+	return clampf(done, 0.0f, 1.0f);
+}
+
+void tween_reset(tween_t *tw) {
+	tw->time = 0.0f;
+}
+
+void tween_destroy(tween_t *tw) {
+	tween_t tw_ = {0};
+	array_free(tw->keyframes);
+	*tw = tw_;
+}
+
+static inline
+int tween_comp_keyframes(const void *a, const void *b) {
+    float t1 = ((const tween_keyframe_t*)a)->t;
+    float t2 = ((const tween_keyframe_t*)b)->t;
+    return (t1 > t2) - (t1 < t2);
+}
+
+void tween_keyframe_set(tween_t *tw, float t, int mode, vec3 v) {
+	tween_keyframe_t keyframe = { mode, t, v };
+	array_push(tw->keyframes, keyframe);
+	array_sort(tw->keyframes, tween_comp_keyframes);
+	tw->duration = array_back(tw->keyframes)->t;
+}
+
+void tween_keyframe_unset(tween_t *tw, float t) { /*@todo: untested*/
+	int id = -1;
+	for (int i = 0; i < array_count(tw->keyframes); i++) {
+		if (tw->keyframes[i].t == t) {
+			id = i;
+			break;
+		}
+	}
+
+	if (id == -1) return;
+	array_erase_slow(tw->keyframes, id);
+	tw->duration = array_back(tw->keyframes)->t;
+}
+#line 0
+
 #line 1 "engine/split/v4k_memory.c"
 size_t dlmalloc_usable_size(void*); // __ANDROID_API__
 
diff --git a/engine/v4k.h b/engine/v4k.h
index 7b8af17..fe1e258 100644
--- a/engine/v4k.h
+++ b/engine/v4k.h
@@ -999,6 +999,7 @@ API float simplex4( vec4 xyzw );
 // ----------------------------------------------------------------------------
 
 API float ease_linear(float t);
+API float ease_nearest(float t);
 
 API float ease_out_sine(float t);
 API float ease_out_quad(float t);
@@ -1289,6 +1290,30 @@ API void print34( float *m );
 API void print44( float *m );
 #line 0
 
+#line 1 "engine/split/v4k_tween.h"
+typedef struct tween_keyframe_t {
+	int easing_mode;
+	float t;
+	vec3 v;
+} tween_keyframe_t;
+
+typedef struct tween_t {
+	array(tween_keyframe_t) keyframes;
+
+	vec3 result;
+	float time;
+	float duration;
+} tween_t;
+
+API tween_t tween();
+API float     tween_update(tween_t *tw, float dt);
+API void      tween_reset(tween_t *tw);
+API void    tween_destroy(tween_t *tw);
+
+API void tween_keyframe_set(tween_t *tw, float t, int easing_mode, vec3 v);
+API void tween_keyframe_unset(tween_t *tw, float t);
+#line 0
+
 #line 1 "engine/split/v4k_ai.h"
 typedef enum SWARM_DISTANCE {
     SWARM_DISTANCE_LINEAR,