System/Library/PrivateFrameworks/ChatKit.framework
CKElasticFunction.h
@interface CKElasticFunction : NSObject {
double _elastic;
double _oldForce;
double _velocity;
}
@property (nonatomic) double friction;
@property (nonatomic) double tension;
@property (nonatomic) double input;
@property (readonly, nonatomic) double output;
@property (readonly, nonatomic) double velocity;
+ (id)functionWithTension:(double)a0 friction:(double)a1 initialValue:(double)a2;
- (id)init;
- (void)step;
@end