Introduction to Actions in Cocos2d for iPhone game development

IPhone gamesUnder developmentCocos2dOfActionsThis topic describes the content of this article,ActionIt is like a command for a cocosNode object. These actions are usually used to change the attributes of an object, such as position, rotation, and scaling. If these attributes can only be modified for a period of time, they are called IntervalActionAction. Otherwise, they are called InstantAction actions.

For example, a MoveBy Action changes the position attribute within a period of time, that is, it is an IntervalAction Action.

 
 

  
  
# Move a sprite 50 pixels to the right, and 10 pixels to the top over 2 seconds.  
  
  
sprite runAction: [MoveBy actionWithDuration:2 position:ccp(50,10)]];  
 
 

IntervalAction has some interesting attributes.

They can be accelerated by time changes

 
 

  
  
EaseIn   
  
  
EaseOut   
  
  
EaseInOut   
  
  
Speed   
  
  
Etc. (See the EaseActionsTest.m example for more info)  
 
 

All relative actions end with By) and some absolute actions end with To) have a flip action and execute an operation in the opposite direction. You can use pause/resume to stop and restore actions.

 
 

  
  
 # Pause actions  
  
  
[[ActionManager sharedManager ] pauseAllActionsForTarget:sprite ] ;  
  
  
 
  
  
# resume actions  
  
  
[[ActionManager sharedManager ] resumeAllActionsForTarget:sprite ] ;  
 
 

Each of the following actions is extremely simple. I will add a simple example and describe what will happen. After all, it's hard to figure out what happened when moving objects and simple slices. Especially the jump function.

Simple Application: perform a mobile test on a box genie:

 
 

  
  
-(Id) init {
  
  
Self = [super init];
  
  
If (nil! = Self ){
  
  
IsTouchEnabled = YES;
  
  
BoxSprite = [Sprite spriteWithFile: @ "box.png"];
  
  
[BoxSprite setPosition: CGPointMake (25, 25)];
  
  
[Self addChild: boxSprite];
  
  
}
  
  
 
  
  
Return self;
  
  
}
  
  
 
  
  
-(BOOL) ccTouchesBegan :( NSSet *) touches withEvent :( UIEvent *) event
  
  
{
  
  
UITouch * touch = [touches anyObject];
  
  
CGPoint point = [touch locationInView: [touch view];
  
  
// Action definition
  
  
// Position
  
  
// MoveBy
  
  
Id moveByAction = [MoveBy actionWithDuration: 2 position: ccp (30, 50)];
  
  
// Action execution
  
  
[BoxSprite runAction: rotateByAction];
  
  
Return YES;
  
  
}
 
 

Basic Actions

Location

 
 

  
  
MoveBy   
  
  
MoveTo   
  
  
JumpBy   
  
  
JumpTo   
  
  
BezierBy   
  
  
Place  
 
 

Zoom in and out

 
 

  
  
ScaleBy   
  
  
ScaleTo  
 
 

Rotate

 
 

  
  
RotateBy   
  
  
RotateTo  
 
 

Display status

 
 

  
  
Show   
  
  
Hide   
  
  
Blink   
  
  
ToggleVisibility  
 
 

Transparency

 
 

  
  
FadeIn   
  
  
FadeOut   
  
  
FadeTo   
  
  
RGB  
  
  
TintBy   
  
  
TintTo  
 
 

Example

Some actions need to be implemented by yourself to know how the function means. For e-text APIs, it is not as smooth as the ordinary one. Most of them are less used in C. Some strangers.

 
 

  
  
//MoveBy  
  
  
d moveByAction = [MoveBy actionWithDuration:2 position:ccp(30,50)];  
 
 

For each execution, the corresponding genie positions x, y increase by 30, and 50. The time is within 2 seconds. The moving mode is slow.

 
 

  
  
//MoveTo  
  
  
id moveToAction = [MoveTo actionWithDuration:3 position:[[Director sharedDirector]convertCoordinate:point]];  
 
 

Each execution, the corresponding genie moves to the touch location, and moves in 3 seconds

 
 

  
  
//JumpBy  
  
  
d jumpByAction = [JumpBy actionWithDuration:3 position:ccp(100,100) height:20 jumps:20];  
 
 

In each execution, 100,100 is relatively moved within 3 seconds. In the moving mode, 20 is used as the jump height, and 20 hops are made within 3 seconds.

 
 

  
  
//JumpTo  
  
  
d jumpToAction = [JumpTo actionWithDuration:3 position:ccp(100,100) height:20 jumps:20];  
 
 

The usage method is the same as above. The difference is that

 
 

  
  
//BezierBy  
  
  
d bezierByAction = [BezierBy actionWithSize:2];   
  
  
//ScaleBy  
  
  
d scaleByAction = [ScaleBy actionWithDuration:3 scaleX:0.5 scaleY:0.5];  
 
 

After each execution, the genie gradually becomes half of the original length and width within 3 seconds.

 
 

  
  
//ScaleTo  
  
  
d scaleToAction = [ScaleTo actionWithDuration:3 scaleX:0.4 scaleY:0.5];   
  
  
//RotateBy  
  
  
d rotateByAction = [RotateBy actionWithDuration:3 angle:30.0];  
 
 

Within 3 seconds, gradually rotate to the right 30 degrees.

 
 

  
  
     //RotateTo  
  
  
id rotateToAction = [RotateTo actionWithDuration:3 angle:30.0];   
  
  
 
  
  
CGSize s = [[Director sharedDirector] winSize];  
  
  
 
  
  
id actionTo = [MoveTo actionWithDuration: 2 position:ccp(s.width-40, s.height-40)];  
  
  
id actionBy = [MoveBy actionWithDuration:2  position: ccp(80,80)];  
  
  
 
  
  
[sprite1 runAction: actionTo];  
  
  
[sprite2 runAction:actionBy];  
 
 

Roll back Actions

It basically starts with "reverse. Is to implement the opposite Action of an Action.

 
 

  
  
id move = [MoveBy actionWithDuration:2  position: ccp(80,80)];  
  
  
id move_reverse = [move reverse]; 
 
 

The above move_reverse Action refers to moving the MoveBy Action to the ccp (-80,-80) position in 2 seconds.

Summary:IPhone gamesDevelopmentCocos2dMediumActionsThe introduction is complete. I hope this article will help you!