gistfile1.txt

//
//  main.m
//

#import <UIKit/UIKit.h>
#import <pop/POP.h>
#import "AppDelegate.h"

static CGFloat deceleration_for_distance(CGFloat distance, CGFloat velocity)
{
    if(distance == 0.0)
    {
        return 0.0;
    }
    if(velocity == 0.0)
    {
        return 0.0;
    }
    
    CGFloat acceleration = ((velocity * velocity)) / (distance * 2.0);
    CGFloat deceleration = 1.0 / (abs(acceleration) / 1000.0);
    return MIN(0.999, MAX(0.0, deceleration));
}

int main(int argc, char * argv[]) {
    @autoreleasepool {
        CGPoint initialPoint = CGPointMake(0, 0);
        CGPoint finalPoint = CGPointMake(100, 0);
        CGPoint velocity = CGPointMake(50, 0);
        
        CGFloat distance = finalPoint.x - initialPoint.x;
        CGFloat deceleration = deceleration_for_distance(distance, velocity.x);
        
        POPDecayAnimation *decayAnimation = [POPDecayAnimation animation];
        decayAnimation.property = [POPAnimatableProperty propertyWithName:kPOPViewCenter];
        decayAnimation.fromValue = [NSValue valueWithCGPoint:initialPoint];
        decayAnimation.deceleration = deceleration;
        decayAnimation.velocity = [NSValue valueWithCGPoint:velocity];
        
        [decayAnimation toValue];
        
        NSLog(@"decay = %@", decayAnimation);
        
        return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
    }
}