Cocos2d best practices Best Practices

 

Cocos2d Best Practices

 

Improving Performance Improvement

 

• Use this wizard: performance tests
• Disable thumb editing in xcode
  • ThumbCodeMuch slower than non-thumb code
• Director:
  • UseFastdirector.FastdirectorVertical synchronization is much faster than normal ctor.

 
// Must be called before any other call to the Director[Director usefastdirector];
 

• • If you useDirectorThere will be a 1/240 wait

// If you are using "normal" director you cocould set a very low Interval[[Director shareddire]Setanimationinterval:1/240.0];
 

• How to use it as follows:
  • UseAtlasspriteReplaceSprite
  • UseBitmapfontatlasOrLabelatlasSubstitutionLabel
  • UseTilemapatlasWhile giving up tiles

This version of Atlas provides faster implementation and reduces code overhead and complexity. In Atlas, atlasmanager is used to save a large image in a frame. Each object in the fram framework is referenced by a large image in the framework. It saves the number of textures and calls for opengles acceleration.

Atlas is a manual or table. In this content, it means that it has a large image that can be read into the OpenGL texture. In fact, it saves a series of small images.

• Use a 4-bit or 16-bit texture if possible
  • 16-bit textures for PNG/GIF/BMP/tiff Images

 
[Texture2d setdefaultalphapixelformat:Ktexture2dpixelformat_rgba4444];// Add this line at the very beginning
 

• • 4-bit or 2-bit texture: Use pvrtc texture.

 
Sprite*Sprite= [Sprite spritewithfile: @"Sprite. PVR"];
 

• • Use 32-bit texture as the final choice

Memory switching memory reduces memory overhead

 

• Use 16-bit or 4-bit textures
• UseTexturemgr
  • TexturemgrCache all images
  • Even when the image is not used anymore, it will remain in memory
  • The following methods can be used to remove data from memory:

 // Textures with retain count 1 will be removed  // Use this method at the end of sence to eliminate useless objects # dealloc Method  [  [ Texturemgr sharedtexturemgr ] Removeunusedtextures ] ; // Since v0.8  // Clear the cache from a specific texture Texture2d * Texture=   [ Sprite texture ] ; [  [ Texturemgr sharedtexturemgr ] Removetexture : Texture ]  ] ; // Available in v0.7 too  // Remove all texture... when receiving a memory warning  [  [ Texturemgr sharedtexturemgr ] Removealltextures ] ; // Available in v0.7 too 

Timers Timer

 

• Try not to useNstimerAnd use the scheduler that comes with cocos2d.
• If you use scheduler, you will have:
  • Automatic pause and recovery.
  • When the layer (scene, Sprite, cocosnode) enters the stage the timer will be automatically activated, and when it leaves the stage it will be automatically deactivated.
  • Your target/selector will be called with a Delta time

 
/*************************************** *******************/// The next step is OK.
 

   /*************************************** *******************/  - (  ID  ) Init {      If  (   ( Self =  [ Super init ]   )   )   {          // Schedule timer          [ Self schedule :   @ Selector  ( Tick :  )  ] ; [ Self schedule :   @ Selector  ( Tick2 :  ) Interval : 0.5 ] ; }  Return Self; }  -  (  Void  ) Tick :   ( Cctime ) DT{      // Bla  }  -  (  Void  ) Tick2 :   ( Cctime ) DT {      // Bla  }  /*************************************** *******************/  // The following is a recommended method 

   /*************************************** *******************/ // Why bad?  // Why Not? Because you cannot make it stop automatically.  -  (  Void  ) Onenter {      [ Super onenter ] ; Timer1 =   [  Nstimer Scheduledtimerwithtimeinterval : 1 / FPS target : Self Selector :  @ Selector  ( Tick1) Userinfo :  Nil Repeats :  Yes  ] ; Timer2 =   [  Nstimer Scheduledtimerwithtimeinterval : 0.5 target : Self Selector :  @ Selector  ( Tick2 ) Userinfo :  Nil Repeats : Yes  ] ; }  -  (  Void  ) Onexit {      [ Timer1 invalidate ] ; [ Timer2 invalidate ] ; [ Super onexit ] ; }  -  (  Void  ) Tick{      // Bla  }  -  (  Void  ) Tick2 {      // Bla  } 

Draw vs update plotting and updating

 

• try not to update any state variable inside the draw selector. Do not update the state of the variable in the draw selector.
• try not to draw anything inside a scheduled selector. Do not draw anything in scheduled selector.
• instead update the state variables inside a scheduled selector. It is best to update the state variable in scheduled selector
• instead draw everything inside the draw selector draw in the draw selector
• If you update state variables inside the draw selector, the pause/resume won't work as expected.
• if you draw something inside a scheduled selector, it can't be transformed. If you draw in scheduled selector, it cannot be converted.
• draw is called every frame
• scheduled selectors can be called with any frame rate, but no more frequently than the application's FPS rate. scheduled selectors can be called by any frame, but no application has a high FPS call rate.

  /********************** ***********************************/  // the following code is very OK   /*********** **************************************** * ******/ -  (  void  )  draw {  [ item draw ] ;  // OK: draw Inside draw  } -  (  void  )  tick :   ( cctime )  dt { item. position = dt  *  finalposition;  // OK, update state in scheduled selector  }: it is best to call draw in the draw method 

Use update in scheduled Selector
 

 
 /*************************************** *******************/// Check the following code for bad 1:/*************************************** *******************/-(Void)Draw{DT= [Self calculatedelta];// Dont update state in draw.Item. Position=DT*Finalposition;// Pause won't work[Item draw];}Translator's conclusion: Do not call update in draw
 

 
And stops working.
 

 /*************************************** *******************/// Another piece of bad code 2/*************************************** *******************/-(Void)Tick:(Cctime)DT{Item. Position=DT*Finalposition;[Item draw];// & Lt; --- don't draw in scheduled Selector// Because transformations won't alter your image}
 

 
Do not use the draw method in scheduled selector.
 

Because transformations does not change the image
 

Director Flow Control

 

• UseReplacesceneInsteadPushscene
• PushsceneVery convenient, but it will push scene to the memory. The memory in the iPhone is too valuable.

 
// Reduce the number of times that scenes is pushed to the memory Stack
 

   -  (  Void  ) Mainmenu (  )  {      // Etc      [  [ Director shareddire ] Pushscene : Gamescene ] ; }  // Stack:  //. Game & lt; -- running scene  //. Mainmenu  -  (  Void  ) Game {      [  [ Director shareddire ] Pushscene : Gameoverscene ] ;}  // Stack:  //. Gameover & lt; -- running scene  //. Game  //. Mainmenu  -  (  Void  ) Showgameover {      [  [ Director shareddire ] Pushscene : Hiscorescene ] ; }  // Stack: //. Scores & lt; -- running scene (4 pushed scenes... expensive)  //. Gameover  //. Game  //. Mainmenu 

Creating nodes (sprites, labels, Etc ..) Create nodes (genie, tags, etc)

 

• If possible, create a cocosnode object (genie, Tag, layer, etc.) or any other object in the selector, and try not to initialize it in the draw function or in it.
• Creating a node has a high overhead. Try to pre-create the node as much as possible.
• On the other hand, be careful with memory operations and do not cause many unnecessary objects in it.

 /*************************************** *******************/  // OK. This is often used in many cases.  /*************************************** *******************/  - (  ID  ) Init {      // Etc... Sprite1 =   [ Sprite1 create ] ; // & Lt; -- usually this is the case  // Etc...  }  -  (  Void  ) Tick :   ( Cctime ) DT{      // Etc...      If  ( Something )   {          [ Sprite1 show ] ; // & Lt; --- if you do not use it frequently, the memory will be wasted.      }  }  /*************************************** *******************/  // Bad. This is not good.  /*************************************** *******************/  -  (  Void ) Tick :   ( Cctime ) DT {      // Etc...      If  ( Something )   { Sprite =   [ Sprite1 create ] ; // & Lt; --- our expensive memory overhead          [ Sprite1 show ] ; //...  [ Sprite1 release ] ; // & Lt;-at least the memory is released      }  } 

Hierarchy of layers class

 

• Never create a layer with many levels. Try to create as few layers as possible.

Actions

 

• It is expensive to create certain actions, since it might require a lotMalloc (). For example:SequenceOfSpawnWithRotatebyWith a anotherSequence, Etc... Is very expensive.
• So try to reuse actions.
• Once the action is used, save it for later if you know you will execute that type of action again. Then, instead of allocing a new action, you can just initialize it.

Put this at the end: the province's crawlers have no source.

Translator: alexliu (Alex DOTNET learning)
: Http://alexliu.cnblogs.com/