added hxd.Math.ease

h3d/anim/SmoothTarget.hx

@@ -100,8 +100,7 @@ class SmoothTarget extends Animation {
 		var objects = getSmoothObjects();
 		target.sync(true);
 
-		var bpow = Math.pow(blend, 1 + easing);
-		var blend = bpow / (bpow + Math.pow(1 - blend, easing + 1));
+		var blend = hxd.Math.easeFactor(blend, easing);
 
 		for( o in objects ) {
 			var m = @:privateAccess if( o.targetSkin != null ) o.targetSkin.currentRelPose[o.targetJoint] else if( o.targetObject != null ) o.targetObject.defaultTransform else null;

hxd/Math.hx

@@ -135,6 +135,21 @@ class Math {
 		return a + k * (b - a);
 	}
 
+	/**
+	 	Similar to linear interpolation (k is between [0,1]), but can be controled with easing parameter. When easing is 0 it's linear.
+	**/
+	public inline static function ease(a:Float, b:Float, k:Float, easing:Float) {
+		return lerp(a, b, easeFactor(k, easing));
+	}
+
+	/**
+		ease = lerp(a,b,easeFactor(k,easing))
+	**/
+	public inline static function easeFactor( k : Float, easing : Float ) {
+		var p = Math.pow(k, 1 + easing);
+		return p / (p + Math.pow(1 - k, easing + 1));
+	}
+
 	/**
 		Same as lerp but is scaled based on current FPS, using current elapsed time in seconds.
 	**/