CCActionEase.m

/*
 * cocos2d for iPhone: http://www.cocos2d-iphone.org
 *
 * Copyright (c) 2008-2009 Jason Booth
 * Copyright (c) 2013 Nader Eloshaiker
 * Copyright (c) 2013-2014 Cocos2D Authors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 */


/*
 * Elastic, Back and Bounce actions based on code from:
 * http://github.com/NikhilK/silverlightfx/
 *
 * by http://github.com/NikhilK
 */

#import "CCActionEase.h"

#ifndef M_PI_X_2
#define M_PI_X_2 M_PI * 2.0
#endif

#pragma mark EaseAction


@implementation CCActionEase

@synthesize inner=_inner;

+(instancetype) actionWithAction: (CCActionInterval*) action
{
	return [[self alloc] initWithAction: action];
}

-(id) initWithAction: (CCActionInterval*) action
{
	NSAssert( action!=nil, @"Ease: arguments must be non-nil");

	if( (self=[super initWithDuration: action.duration]) )
		_inner = action;

	return self;
}

-(id) copyWithZone: (NSZone*) zone
{
	CCAction *copy = [[[self class] allocWithZone:zone] initWithAction:[_inner copy]];
	return copy;
}

-(void) startWithTarget:(id)aTarget
{
	[super startWithTarget:aTarget];
	[_inner startWithTarget:_target];
}

-(void) stop
{
	[_inner stop];
	[super stop];
}

-(void) update: (CCTime) t
{
	[_inner update: t];
}

-(CCActionInterval*) reverse
{
	return [[self class] actionWithAction: [_inner reverse]];
}
@end


#pragma mark - Ease Sine Actions
//
// EaseSineIn
//
@implementation CCActionEaseSineIn
-(void) update: (CCTime) t
{
	[_inner update:-1*cosf(t * M_PI_2) +1];
}

- (CCActionInterval*) reverse
{
	return [CCActionEaseSineOut actionWithAction: [_inner reverse]];
}
@end

//
// EaseSineOut
//
@implementation CCActionEaseSineOut
-(void) update: (CCTime) t
{
	[_inner update:sinf(t * M_PI_2)];
}

- (CCActionInterval*) reverse
{
	return [CCActionEaseSineIn actionWithAction: [_inner reverse]];
}
@end

//
// EaseSineInOut
//
@implementation CCActionEaseSineInOut
-(void) update: (CCTime) t
{
	[_inner update:-0.5*(cosf( M_PI*t) - 1)];
}
@end

#pragma mark -
#pragma mark EaseRate


@implementation CCActionEaseRate
@synthesize rate=_rate;
+(instancetype) actionWithAction: (CCActionInterval*) action rate:(CGFloat)rate
{
	return [[self alloc] initWithAction: action rate:rate];
}

-(id) initWithAction: (CCActionInterval*) action rate:(CGFloat)rate
{
	if( (self=[super initWithAction:action ]) )
		self.rate = rate;

	return self;
}

-(id) copyWithZone: (NSZone*) zone
{
	CCAction *copy = [[[self class] allocWithZone:zone] initWithAction:[_inner copy] rate:_rate];
	return copy;
}


-(CCActionInterval*) reverse
{
	return [[self class] actionWithAction: [_inner reverse] rate:1/_rate];
}
@end


@implementation CCActionEaseIn
-(void) update: (CCTime) t
{
	[_inner update: powf(t,_rate)];
}
@end


@implementation CCActionEaseOut
-(void) update: (CCTime) t
{
    [_inner update: 1.0 - powf(1.0 - t, _rate)];
}
@end


@implementation CCActionEaseInOut
-(void) update: (CCTime) t
{
	t *= 2;
	if (t < 1) {
		[_inner update: 0.5 * powf (t, _rate)];
    }
	else {
		[_inner update: 1.0 - 0.5 * powf(2-t, _rate)];
    }
}

// InOut and OutIn are symmetrical
-(CCActionInterval*) reverse
{
	return [[self class] actionWithAction: [_inner reverse] rate:_rate];
}

@end

#pragma mark -
#pragma mark EaseElastic actions


@implementation CCActionEaseElastic

@synthesize period = _period;

+(instancetype) actionWithAction: (CCActionInterval*) action
{
	return [[self alloc] initWithAction:action period:0.3];
}

+(instancetype) actionWithAction: (CCActionInterval*) action period:(CGFloat)period
{
	return [[self alloc] initWithAction:action period:period];
}

-(id) initWithAction: (CCActionInterval*) action
{
	return [self initWithAction:action period:0.3];
}

-(id) initWithAction: (CCActionInterval*) action period:(CGFloat)period
{
	if( (self=[super initWithAction:action]) )
		_period = period;

	return self;
}

-(id) copyWithZone: (NSZone*) zone
{
	CCAction *copy = [[[self class] allocWithZone:zone] initWithAction:[_inner copy] period:_period];
	return copy;
}

-(CCActionInterval*) reverse
{
	NSAssert(NO,@"Override me");
	return nil;
}

@end


@implementation CCActionEaseElasticIn
-(void) update: (CCTime) t
{
	CCTime newT = 0;
	if (t == 0 || t == 1)
		newT = t;

	else {
		CGFloat s = _period / 4;
		t = t - 1;
		newT = -powf(2, 10 * t) * sinf( (t-s) *M_PI_X_2 / _period);
	}
	[_inner update:newT];
}

- (CCActionInterval*) reverse
{
	return [CCActionEaseElasticOut actionWithAction: [_inner reverse] period:_period];
}

@end


@implementation CCActionEaseElasticOut

-(void) update: (CCTime) t
{
	CCTime newT = 0;
	if (t == 0 || t == 1) {
		newT = t;

	} else {
		CGFloat s = _period / 4;
		newT = powf(2, -10 * t) * sinf( (t-s) *M_PI_X_2 / _period) + 1;
	}
	[_inner update:newT];
}

- (CCActionInterval*) reverse
{
	return [CCActionEaseElasticIn actionWithAction: [_inner reverse] period:_period];
}

@end


@implementation CCActionEaseElasticInOut
-(void) update: (CCTime) t
{
	CCTime newT = 0;

	if( t == 0 || t == 1 )
		newT = t;
	else {
		t = t * 2;
		if(! _period )
			_period = 0.3 * 1.5;
		CCTime s = _period / 4;

		t = t -1;
		if( t < 0 )
			newT = -0.5 * powf(2, 10 * t) * sinf((t - s) * M_PI_X_2 / _period);
		else
			newT = powf(2, -10 * t) * sinf((t - s) * M_PI_X_2 / _period) * 0.5 + 1;
	}
	[_inner update:newT];
}

- (CCActionInterval*) reverse
{
	return [CCActionEaseElasticInOut actionWithAction: [_inner reverse] period:_period];
}

@end

#pragma mark -
#pragma mark EaseBounce actions


@implementation CCActionEaseBounce
-(CCTime) bounceTime:(CCTime) t
{
	if (t < 1 / 2.75) {
		return 7.5625 * t * t;
	}
	else if (t < 2 / 2.75) {
		t -= 1.5 / 2.75;
		return 7.5625 * t * t + 0.75;
	}
	else if (t < 2.5 / 2.75) {
		t -= 2.25 / 2.75;
		return 7.5625 * t * t + 0.9375;
	}

	t -= 2.625 / 2.75;
	return 7.5625 * t * t + 0.984375;
}
@end


@implementation CCActionEaseBounceIn

-(void) update: (CCTime) t
{
	CCTime newT = t;
	// prevents rounding errors
	if( t !=0 && t!=1)
		newT = 1 - [self bounceTime:1-t];

	[_inner update:newT];
}

- (CCActionInterval*) reverse
{
	return [CCActionEaseBounceOut actionWithAction: [_inner reverse]];
}

@end


@implementation CCActionEaseBounceOut

-(void) update: (CCTime) t
{
	CCTime newT = t;
	// prevents rounding errors
	if( t !=0 && t!=1)
		newT = [self bounceTime:t];

	[_inner update:newT];
}

- (CCActionInterval*) reverse
{
	return [CCActionEaseBounceIn actionWithAction: [_inner reverse]];
}

@end


@implementation CCActionEaseBounceInOut

-(void) update: (CCTime) t
{
	CCTime newT;
	// prevents possible rounding errors
	if( t ==0 || t==1)
		newT = t;
	else if (t < 0.5) {
		t = t * 2;
		newT = (1 - [self bounceTime:1-t] ) * 0.5;
	} else
		newT = [self bounceTime:t * 2 - 1] * 0.5 + 0.5;

	[_inner update:newT];
}
@end

#pragma mark -
#pragma mark Ease Back actions


@implementation CCActionEaseBackIn

-(void) update: (CCTime) t
{
	CCTime overshoot = 1.70158;
	[_inner update: t * t * ((overshoot + 1) * t - overshoot)];
}

- (CCActionInterval*) reverse
{
	return [CCActionEaseBackOut actionWithAction: [_inner reverse]];
}
@end


@implementation CCActionEaseBackOut
-(void) update: (CCTime) t
{
	CCTime overshoot = 1.70158;

	t = t - 1;
	[_inner update: t * t * ((overshoot + 1) * t + overshoot) + 1];
}

- (CCActionInterval*) reverse
{
	return [CCActionEaseBackIn actionWithAction: [_inner reverse]];
}
@end


@implementation CCActionEaseBackInOut

-(void) update: (CCTime) t
{
	CCTime overshoot = 1.70158 * 1.525;

	t = t * 2;
	if (t < 1)
		[_inner update: (t * t * ((overshoot + 1) * t - overshoot)) / 2];
	else {
		t = t - 2;
		[_inner update: (t * t * ((overshoot + 1) * t + overshoot)) / 2 + 1];
	}
}
@end


@implementation CCActionEaseInstant
-(void) update: (CCTime) t
{
    if (t < 0)
    {
        [self.inner update:0];
    }
    else
    {
        [self.inner update:1];
    }
}
@end