add bounce animation

UICountingLabel.h

@@ -5,7 +5,9 @@ typedef NS_ENUM(NSInteger, UILabelCountingMethod) {
     UILabelCountingMethodEaseInOut,
     UILabelCountingMethodEaseIn,
     UILabelCountingMethodEaseOut,
-    UILabelCountingMethodLinear
+    UILabelCountingMethodLinear,
+    UILabelCountingMethodEaseInBounce,
+    UILabelCountingMethodEaseOutBounce
 };
 
 typedef NSString* (^UICountingLabelFormatBlock)(CGFloat value);

UICountingLabel.m

@@ -34,6 +34,14 @@ @interface UILabelCounterEaseInOut : NSObject<UILabelCounter>
 
 @end
 
+@interface UILabelCounterEaseInBounce : NSObject<UILabelCounter>
+
+@end
+
+@interface UILabelCounterEaseOutBounce : NSObject<UILabelCounter>
+
+@end
+
 @implementation UILabelCounterLinear
 
 -(CGFloat)update:(CGFloat)t
@@ -73,6 +81,50 @@ -(CGFloat) update: (CGFloat) t
 
 @end
 
+@implementation UILabelCounterEaseInBounce
+
+-(CGFloat) update: (CGFloat) t {
+
+    if (t < 4.0 / 11.0) {
+        return 1.0 - (powf(11.0 / 4.0, 2) * powf(t, 2)) - t;
+    }
+
+    if (t < 8.0 / 11.0) {
+        return 1.0 - (3.0 / 4.0 + powf(11.0 / 4.0, 2) * powf(t - 6.0 / 11.0, 2)) - t;
+    }
+
+    if (t < 10.0 / 11.0) {
+        return 1.0 - (15.0 /16.0 + powf(11.0 / 4.0, 2) * powf(t - 9.0 / 11.0, 2)) - t;
+    }
+
+    return 1.0 - (63.0 / 64.0 + powf(11.0 / 4.0, 2) * powf(t - 21.0 / 22.0, 2)) - t;
+
+}
+
+@end
+
+@implementation UILabelCounterEaseOutBounce
+
+-(CGFloat) update: (CGFloat) t {
+
+    if (t < 4.0 / 11.0) {
+        return powf(11.0 / 4.0, 2) * powf(t, 2);
+    }
+
+    if (t < 8.0 / 11.0) {
+        return 3.0 / 4.0 + powf(11.0 / 4.0, 2) * powf(t - 6.0 / 11.0, 2);
+    }
+
+    if (t < 10.0 / 11.0) {
+        return 15.0 /16.0 + powf(11.0 / 4.0, 2) * powf(t - 9.0 / 11.0, 2);
+    }
+
+    return 63.0 / 64.0 + powf(11.0 / 4.0, 2) * powf(t - 21.0 / 22.0, 2);
+
+}
+
+@end
+
 #pragma mark - UICountingLabel
 
 @interface UICountingLabel ()
@@ -138,6 +190,12 @@ -(void)countFrom:(CGFloat)startValue to:(CGFloat)endValue withDuration:(NSTimeIn
         case UILabelCountingMethodEaseInOut:
             self.counter = [[UILabelCounterEaseInOut alloc] init];
             break;
+        case UILabelCountingMethodEaseOutBounce:
+            self.counter = [[UILabelCounterEaseOutBounce alloc] init];
+            break;
+        case UILabelCountingMethodEaseInBounce:
+            self.counter = [[UILabelCounterEaseInBounce alloc] init];
+            break;
     }
 
     CADisplayLink *timer = [CADisplayLink displayLinkWithTarget:self selector:@selector(updateValue:)];