Hole - Pro 4

Help take the game out of judgement

Play it over at NEWGROUNDS!
Play it over at KONGREGATE!

Spoiler and a could be contest after…

Hole 18 - under par score! Guess how many shots it took?

Also, create, share and post your custom levels here or here, who knows I might put a small contest for submitted custom levels.

For sponsors/publishers, the game is available for site-locked non-exclusive licenses, contact me.

from the old (left) to the newer (right) designs

Just sharing a couple of renewed designs for the success and select level screen. Also the success screen now has fancy animations upon popping up.

What do you think, an improvement or not? Its not final-final either way.

main menu - yes, its interactive!

Only a few more hard levels to be designed for 99% completion – the remaining 1% is not to be questioned.

Come2Play with LinkedIn Flash Game Developers Group has launched the 2nd multiplayer flash game contest, and this time with prizes totaling $10,000! Last years contest had only a handful of entries, so chances of winning the $5,000 pot for first prize this time is very high. Check out the winners games and other entries of the 1st ‘Games that Challenge the World Contest‘.

• 1st place – $5,000
• 2nd place – $3,000
• 3rd place – $1,250
• 4th place – $750

Flash games developers are welcome to join and take the pot. Create awesome head-to-head turned based multiplayer games, use come2play’s multiplayer API, submit and win! Prizes will be given out to the game which will have the best replayability both for new and return players, game design, concept and execution.

Developers keep all rights to the submitted games and even previously published games can be retrofitted to enter. Game entries does not have to be exclusive, so pre-released games are also welcome.

“So I’m interested, but only have a single player game” – Not a problem, see the developer tips on how to evolve your single player game into an interactive multiplayer game.

For complete contest info check out the official contest page.

Edit: Deadline has been extended to April 15th!

Having a SAVE feature in a project/game is one of the common things that could lead users to be more attracted and increase replay value for potentially recovering what was done in a previous visit. Using the SharedObject class in actionscript project/games is sometimes a requirement or at least a need, may it be AS1 (FP6), 2 or 3. It can be used to store valuable data like progress, settings, statistics, achievements and a lot more without dedicating storage on the server. Basically, SO or shared objects are like the browser cookies for flash, it is used to store some amount of data on the user machine, therefore it also has some limitations on its use (for security purposes really).

By reading the documentations or the livedocs, either for AS2 or AS3 (it’s really the same), you might have a gut start of what key points to remember.

• created shared objects can only be stored/retrieved on the same domain
• shared objects cannot be shared across domains, meaning a shared objects from “examplesite.com” cannot read shared objects created by another domain “mywebsite.com”
• users can disallow local storage per domain or opt-out globaly, then the object would not be saved locally
• data size to be stored is limited by which the user sets it (none, 10kb, 100kb, 1mb, 10mb, unlimited), although a dialog box can request an increase in storage if what is set is exceeded
• if the user sets a limit smaller than the shared object, the shared object would be deleted
• shared objects are stored on the user’s local machine not on the server, something shared over another machine cannot be accessed by another machine

The most essential part when using SharedObject is the SharedObject.getLocal() method, which is what we will be discussing more through out. Basically, AS1/2 and AS3 syntax haven’t really changed (although a few more rules were imposed in as3).

getLocal(name:String, localPath:String = null, secure:Boolean = false):SharedObject
[static] Returns a reference to a locally persistent shared object that is only available to the current client.

var mySo:SharedObject = SharedObject.getLocal( 'mySaveName', localPath, secure );
mySo.data.thingtoSave = myVariable; // your variables
mySo.flush(); // stores data into disk

Avoiding Known Issues

It might seem that using shared objects could be the simplest when you are only storing a couple of variables and objects like statistics or even could be the more complex when saving a game progress/state together with the players preferences. The bigger the system, more likely, the more complex your variables/objects are (same for games), and this is where possible issues during saving/loading/handling the shared objects.

Some common things to remember when using shared objects with your games:

1. Don’t use direct reference to objects and use the game’s data only not the actual game objects.
2. Use a localPath param on the getLocal() method.
3. Taking advantage of unique names for your shared object name.
4. Prompt and request for shared object size limit increase when your game needs it.

While I only have these that I can explain, you are free to share more if you have one or more. We can discuss and make the lives of other actionscript writers a little better.

Don’t use direct reference to objects and use the game’s data only not the actual game objects.

Why do I say this? Basically it is fine to store various data types such as objects and arrays on SO (shared objects), same goes for strings, numbers (int/uint), booleans and bytearray (as3). If you store references to local game objects on your shared objects, one way or another, your in for a later problem.

var mySo:SharedObject = SharedObject.getLocal( "mySaveName" );
// world.gameObject contains further objects like settings, player, etc
mySo.data.gamedata = world.gameObject;
mySo.flush();
// --

When you do something like the above, instead of storing the needed values only, you are referencing the local game object (w/c also contains references to other local game objects) in which Flash defines this as a copy of the local object but is really just a reference. Any change through out the game values/data would update the local object (which the shared object references) and Flash Player would write that into the shared object file when flush() is called or as soon as the shared object session ends – that is then swf file is closed.

The worst case here is that when you clear, reset or even delete your local game objects, the shared object which references to it will be affected and updated (as session has ended).

Also, even if don’t experience the possibility of issues when you do the above there, a problem might still arise when you load the shared object in later time. This case might not be so common but is possible to experience if loading the shared object is sloppily made. You can have inconsistent object references where the object contained within loaded shared object is conflicting, a duplicate, or not referencing the correct object.

A better and safest way of using shared objects (something like):

mySo.data.gamedata = {
  player:{
    score: world.gameObject.player.score,
    health: world.gameObject.player.health,
    currentLevel: <code>world.gameObject.player.currentLevel
  },
  settings:{
    mute: world.gameObject.settings.mute,
    quality: world.gameObject.settings.quality,
    particles: world.gameObject.settings.particles,
  }
}
/* well this is just a shortcut on containing them into objects,
 * but the point here is that score, health, currentLevel, etc
 * are all basic data types like number/int/uint, string, bool, etc</code>

Now you see that we store each valuable data only. We now transfer only the value of the variable not it’s reference. So while it’s fine to use objects and arrays on your shared objects, keeping be wary of how you do it, be careful.

You probably wouldn’t want to directly store instances of display objects, bitmapdata, functions, etc on share objects.

Use a localPath param on the getLocal() method

While passing the localPath parameter upon calling getLocal() is optional, although I would have to recommend using it by this time. In the case where you are building an independent system, prototypes, does not consider expansion/addons and will never be a part of a larger system, you can probably opt-out the localPath and never mind it.

So whats the issue of using and not using the localPath? By default, if you leave localPath by it’s default (null), it would use the the full path of the swf file (w/c includes the swf file itself) to store your shared objects.

#SharedObjects/<random code>/<domain>/<path>/<swf filename>.swf/<object name>.sol

• Windows XP and Vista:
  • For Web sites: %APPDATA%\Macromedia\Flash Player\#SharedObjects\<random code>\<domain>\<path>\<object name>.sol
  • For AIR Applications, %APPDATA%\<AIR Application Reverse Domain Name>\Local Store\#SharedObjects\<flash filename>.swf\<object name>.sol

• Mac OS X:
  • For Web sites, ~/Library/Preferences/Macromedia/Flash Player/#SharedObjects/<random code>/<domain>/<path from webserver>/<object name>.sol
  • For AIR Applications, ~/Library/Preferences/<AIR Application Name>/Local Store/#SharedObjects/<flash filename>.swf/<object name>.sol
• Linux/Unix:
  • ~/.macromedia/Flash_Player/#SharedObjects/<random id>/<domain>/<path>/<flash filename>.swf/<object name>.sol

-taken from wiki

For example, I have a swf  at http://example.com/games/uploads/supergame.swf, and when it creates a shared object (SharedObject.getLocal("supergameData");), the SO can be found at #SharedObjects/<random code>/example.com/games/uploads/supergame.swf/supergameData.sol.

While it works well and fine without the localPath parameter, there are certain sites/APIs/services that change the game’s file name by using their automated uploads, feeds, etc as the file name is used in the path. When the developer tries to upload a bug fixed build (v1.0.1), the swf might have another file name hence a problem appears where the previous build’s (v1.0.0) shared object won’t be accessible from the new build due to security reasons.

Although your shared object would be secured against any another swf so it can’t read it, by setting a localPath parameter like “/games” or simply “/”, the shared object can now be read by another swf file within the same domain. Using “/games” would make the SO accessible for any swf within the game directory, while having “/” would make it accessible from any swf within the domain.

Again from the same example but using SharedObject.getLocal("supergameData","/");, makes the SO at #SharedObjects/<random code>/example.com/supergameData.sol. This would make it not dependant on the swf’s file name.

Note: If you set a localPath in which the path doesn’t physically exists as a (sub) directory of the domain the shared object won’t be stored. Luckily with AS3 you’ll be prompted with an Error #2134 when the SharedObject can’t be created, but for AS2, you have to be well aware of this.

Taking advantage of unique names for your shared object name

This is one is something that I have just learned through experimentation and will soon incorporate on my next projects. While setting the localPath parameter to “/” makes the SO accessible to other swfs, there is also a risk that your SO name might be the same with another swf. We wouldn’t want another swf to mess up or overwrite our SO file just because it both uses general and/or generic SO names like “saveData” or “gameData“.

The ultimate tip: Since the SO names allow certain special characters like / (slash), we take advantage of that! Together with the localPath “/”, what I recommend is do a standard setup for your SO names something like:

<company/developer name>/<game name>/<data name>

var mySo:SharedObject = SharedObject.getLocal( "jaycsantos/neolithic/preferences", "/" );
// -- and/or something else like
var mySo:SharedObject = SharedObject.getLocal( "jaycsantos/neolithic/gameData1", "/" );
// --

…will store your SO at something like: #SharedObjects/<random code>/<domain>/#jaycsantos/neolithic/gameData.sol

Although I still have to confirm this with Mac OS and Linux machines. Drop me a line if you find it working with those.

Now ain’t that a little more organized than having all SO on the “/” of the domain!

Prompt and request for shared object size limit increase when your game needs it

There are cases when your shared object has a lot of data in it and it could exceed the default 100kb limit of a user. If this happens, it may cause your shared objects to be written but not read. I have read quite a few times where issues of reading/writing of share objects were resolved by prompting a request to increase local storage limit. This is where the flush() method takes it stand.

Immediately writes a locally persistent shared object to a local file.
AS3
flush(minDiskSpace:int = 0):String

minDiskSpace:int (default = 0) — The minimum disk space, in bytes, that must be allotted for this object.

AS2
flush([minDiskSpace:Number]):Object

minDiskSpace:Number [optional] – An integer specifying the number of bytes that must be allotted for this object. The default value is 0.

With AS3, the flush() method basically does the same thing as with AS2 including their parameters, the only difference made was their return values. AS3 returns a string constant but AS2 returns an object; still their purpose is the same, only the data types have changed.

var mySo:SharedObject = SharedObject.getLocal( 'mySaveName', localPath, secure  );
mySo.data.thingtoSave = myVariable; // your variables
/* stores data into disk and require 10kb of min space
 * if the allocated disk space for local storage is
 * less than 10bk which most probaly be 1kb, then it
 * would prompt a dialog box requesting for an increase
 */
var fushResult:Object = mySo.flush(10000);
trace( fushResult );

So saying simply, if you know your game’s shared object will be greater than a few kbs, you should consider using flush(minDiskSpace) with as your expect maximum size for your data. Why maximum? – think of it as your allowance. Now don’t even consider 2mb or more as an allowance if it’ll never even reach it, play your game at it’s fullest and see what is the size of the shared object using the getSize() method (as2) and the property size (as3) then add around 5-10% of it’s size for an allowance.

Conclusion

After all I have read about using SharedObject is as simple as it could be, in reality it can be a whole lot more than spinning circles for all of what you would need. Well yes, storing a string and recovering it is a piece of icing but storing a complete game state/progress is a new kind of cake to bake. Basically what I have written here are tips and suggestions that I have experienced and with what I have experimented. Either it be accurate or I know not, using SharedObjects has its own work around and is not as simple as most people have said like building a chair, while yes it is not the most complicated but it could be a big question mark on the head for someone new or not familiar to its purpose. I might even consider making a SaveManager or the like but that would be when I get to it. Well, that’s it, this one is quite long but I know it’ll help!

Other Keywords

• Working with Flash Actionscript Shared objects.
• Issues and techniques with Flash Actionscript shared objects.
• Saving data with action script using shared objects.
• Actionscript tips and tricks, shared objects.
• Shared object help, actionscript 2 & actionscript 3.
• Flash actionscript saving & loading locally.
• Flash Actionscript proper way of use when Shared Object does not work.

Some common but usually neglected things you might not want but your game might have:

• The everlasting suggestion of “avoid directly referencing _root“.
• Yellow boxes appear (on buttons/movieclips) when pressing Tab.
• Cheating by pressing Space when the yellow boxes focus on buttons/movieclips.
• Cheating by right clicking (shows the context menu, a cheat for some game genres).
• Cheating/altering game play/screens by pressing forward, back, etc from the context menu.

_root or no _root

_root ?

As you might have read a dozen or countless times, it is highly recommended to not directly call _root within the project, although using _root is not necessarily wrong. These developers come to use _root as a hack way of referencing an absolute path to their objects. If you are building an independent system, prototypes, does not consider expansion/addons and will never be a part of a larger system then it would be fine to use _root as a hacky way. But if your work is part of a larger system or the like consider having to add in various (most of the time, 3rd party) extensions, plugins, services, APIs (application programming interfaces), SDKs (software development kits), or anything similar in it’s purpose then you’ll be in for some serious headaches. Most notable of these are those that wrap your game within another swf file. You might be able to face serious issues and problems varying from sounds not playing/missing, disposition world objects, localtoGlobal/globaltoLocal miscalculations, undefined object property, sprites (movieclips) not following the expected position and behavior, wrongly positioned custom cursors and a lot more.

// somewhere in the timeline...
_root.mySuperFunction = function(){
  // doing some super things
  return 'my super function worked!';
}
 
// somewhere else in the game...
trace( _root.mySuperFunction() );
// before
  // outputs: my super  function worked!
// after some integration and browser testing...
  // outputs:         (its really has no output)
// nooooo!!! it isn't working now! but it used to work before,
// maybe this thing wrecks my game when I use it!? I didn't do anything else.

Although I won’t be discussing fixes for the issues mentioned above, we can start by doing what is recommended, to not directly reference from the _root. The most starter’s way from first look at the documentations and other sources, is using _lockroot. Basically it could prove to be a good way to fix and keep things the same but for some cases it might not be enough. For more assurance and better practice I would recommend referencing _root from a global variable or static variable from a class (most recommended).

Why do I have to use a variable? So what we reference can be dynamic – there are some cases where the _root is not technically the parent most, where it can be a specific game container or something similar, this way you don’t have to shift through using _root and updating all your codes when needed. And the sole reason is for code reusability.

// probably on frame1 before your preloader code
this._lockroot = true; // where this = root actually
this.mySuperFunction = function(){
  // doing some super things
  return 'my super function worked!';
}

// for those who do timeline coding or the like
_global.gameroot = this; // where this = root actually
 
// somewhere else through the game...
trace( _global.gameroot.mySuperFunction() ); // output: my super function worked!
// hoorah! its working well!

// and for those who use classes (highly recommended),
// simply pass it on your main class during instantiation
// to be referenced on a static variable
var maingame = new MainGame( this ); // where this = root actually
 
// on your MainGame class or the like
class MainGame{
  public static var GameRoot:MovieClip;
  // constructor
  public function MainGame( root:MovieClip) {
    GameRoot = root; // stores the root mc in static var
  }
}
 
// somewhere else through the game...
// now simply reference from static variable MainGame.GameRoot instead of _root
trace( MainGame.GameRoot.mySuperFunction() );  // output: my super function worked!

Magical Weirdness of Yellow Boxes

Yellow Box

Some games that incorporate interactive buttons (or movieclips that acts as buttons) are not wary of this feature. Basically flash has the ability to take use of tabbing on GUI, but since we are game developers there are high chances we would not want this as it might look ugly. While most games might not be affected by this feature there are certain circumstances that the game play can be cheated one way or another. Good examples are those games that use mouse interactivity using mouse over and mouse click events, where as the player can cheat things by combining tabbing, pressing space (to select) and the use of mouse. When a yellow box appears over a button its rollOver event is triggered, and when space is pressed its onPress event is, and that is where some cheating may occur on some combinations and timing. It is fairly a simple piece of code you have to declare at the beginning to disable all of the magical yellow boxes.

// probably on frame1 before your preloader code
this.tabEnabled = false; // disable tabs for the whole movieclip
this.tabChildren = false; // disables tabs for the rest movieclip's childrens

Right clicks and Context Menus

Which frame to move?

While the context menus from right clicks (control-click for Macs) on flash can’t be removed, we can modify the menus and also strip down unnecessary movie controls like forward, back, play, etc. If your game/project is AS2 powered and is not really well structured (timeline coding and uses gotoAndStop() methods ) then you might encounter glitches and frame skips once the player right clicks and select any movie controls. They could end up skipping levels to scoring indefinitely and would make things less fun and more cheating for them.

If all you want is to simplify the menu:

// probably on frame1 before your preloader code
Stage.showMenu = false;

But if you also would like to customize and add your own menus then:

// probably on frame1 before your preloader code
// instantiate a new contextmenu
var my_cm:ContextMenu = new ContextMenu();
my_cm.hideBuiltInItems(); // hides the built in items, duh
my_cm.customItems.push( new ContextMenuItem("(c) Jayc Santos", gotoJayc) ); // creates a new menu
function gotoJayc(obj, item){ getURL("http://jaycsantos.com/"); }
this.menu = my_cm; // overwrites the default menu and where this = _root (most of the time)

There are also some cases where simply right clicking would create issues for the game play and/or cheat things. A good way to determine is to use the onSelect event. You can also use the onSelect event for more customizations of your context menus (see livedocs sample).

var my_cm:ContextMenu = new ContextMenu();
function menuHandler(obj:Object, menu:ContextMenu) {
  trace( "right click context menu was invoked" );
  // do awesome things
}
my_cm.onSelect = menuHandler;
this.menu = my_cm;

Conclusion

So overall you might probably want to have something like:

// probably on frame1 before your preloader code
Stage.showMenu = false; // hides the built in items on context menu
this._lockroot = true; // locks the root, duh
this.tabEnabled = false; // disables tabs
this.tabChildren = false; // disables tabs for it's children

for timeline coders

_global.gameroot = this; // where this = root actually
//  when "this" is traced it ouputs "_level0" most of the time unless altered

and for those who use a little more OOP approach

var maingame = new MainGame( this ); // where this = root actually
 
// on your MainGame class or the like
class MainGame{
  public static var GameRoot:MovieClip;
  // constructor
  public function MainGame( root:MovieClip) {
    GameRoot = root; // stores the root mc in static var
  }
}

Now, your actionscript 2 coding life will be a little better with these in mind.

Other Keywords

• Starting flash with actionscript 2 (AS2).
• Frame 1 of actionscript 2 project/game.
• Preloader code actionscript 2 (AS2).
• Why to avoid or why not use _root/root with actionscript.
• Getting rid of yellow boxes when tabbed.
• Flash actionscript tabs.
• Flash actionscript context menus.
• Flash actionscript important points especially for games.

Plan your behavior

So I have introduced how to plan out simple AI behavior from my previous post – Cheating AI from Hardcourt – Plan it out – if you haven’t, read that one first before this.

Our next step would be writing the data charts into codes. It might look quite easy when you see the simple flow charts but remember that the AI must process this through out the game with a character’s lifespan.

What I’m about to share is simply a psuedo codish (partly actionscript syntax) of the AI’s logic. Eventually you can port it into which ever approach you are comfortable with, like OOP or the old school timeline.

Remember that this is my first published game where as I still used AS2 using prototypes and functions but I’ll discuss this in a little of close objective approach. First of we prepare a few world declarations & preparation in a quick manner.

Prepare the world

In the game world object or whichever the game’s entities reside, we’ll be having a calculateDistance method that pre-calculates distances of each of the characters then stores each of their enemies distance on an enemyDist container object.

// from the game world
 // called within the main loop
function calculateDistances() {
  // pre-calculate distances of:
  //   ball to char - store distance to the character's ballDist variable
  //   char to char - store all other character's (enemy's) distance to character's enemyDist container variable
}

The code below acts as base methods for all characters. This is primarily an advantage from inheritance whereas properties and methods of the base class is inherited by the class that extends it. Basically all the characters will be capable of methods such as moving (moveChar), getting the ball (getBall), shooting it (shoot) and punching their enemies (punch).

  // used to store the ball object also do determine if the we have the ball; set to null if we not
var myBall:Ball;
  // the distance of the ball from character in Vector2D (x, y)
var ballDist:Vector2D;
  // contains enemies distances
var enemyDist:Object;
  // assuming that 25 is the range where the character can punch it's enemies
var punchRange:Number = 25;
 
 // moves the character
function moveChar( xdir, ydir ) {
  //  xdir - move left (-1) or right (1)
  //  ydir - move up (-1) or down (1)
}
 
 // determines if we have the ball else if the ball is close & not owned (by enemy) then get it
function getBall():Object {
  //  use ballDist for the calculated distance;
  //  returns: ball object - if our char already has it
  // 	      null - if the ball is nowhere near
}
 
 // shoots the ball
function shoot() {
  // release the ball towards the ring
  // set myBall to null
}
 
 // attacks the enemy
 //  params: enemy:Object - the enemy instance to punch
function punch( enemy:BaseChar ):Boolean {
  //  returns: true - if successful hit
  //           false - else not
}

Note: for the Vector2D, some might be wondering what it is, well it is a class whose purpose is to calculate Vector operations in two dimensions.

Now we have prepared the initial methods, let’s go with the proposed coding of the flow charts.

Basic Behaviors

The AI controlled character behavior:

  // runs with the main loop for each AI character
function thinkAI(){
  var xdir = 0;
  var ydir = 0;
 
    // if we have the ball
  if ( getBall() ) {
      // then shoot it!!
    shoot();
    // if not
  }else {
      // get the direction of the ball
    xdir = ballDist.x ? ballDist.x / Math.abs( ballDist.x ) : 0;
    ydir = ballDist.y ? ballDist.y / Math.abs( ballDist.y ) : 0;
      // and move towards it
    moveChar( xdir, ydir );
  }
}

Basic Chart - Get & shoot

We used the method getBall() to determine if we have the ball or not, if so shoot it. Else, we get the distance from ballDist (which contains the distance in x & y values), have it’s polarity from it’s the absolute value and move towards it.

This is only the first chart (Basic Chart), our AI only considers that in the game world there is only the character himself and the ball, so whenever he gets the ball he shoots it immediately and repeats the process.

Expanding for more Interactions

What we do next is implement the second chart (Interactive Chart) and consider situations with the enemy and interact with it.

So improving the thinkAI() method:

function thinkAI() {
  var xdir = 0;
  var ydir = 0;
 
    // if we have the ball
  if ( getBall() ) {
      // then shoot it!!
    shoot();
    // if not,
  }else {
    var ball = GameWorld.ball;
    var dist:Vector2D;
      // check if another char has the ball, since definitely it isn't this char
    if ( ball.owner ) {
        // store the enemy who has the ball in a local var
      var targetEnemy = enemyDist[ ball.owner.id ];
        // this is the distance of the enemy char with respect to this char
      dist = targetEnemy.dist;
        // if this enemy is within punching range
      if ( dist.len < punchRange ) {
        punch( ball.owner );
          // no need to do the processes below...
        return;
      }
    } else {
      dist = ballDist;
    }
      // get the direction
    xdir = dist.x ? dist.x / Math.abs( dist.x ) : 0;
    ydir = dist.y ? dist.y / Math.abs( dist.y ) : 0;
      // and move towards it
    moveChar( xdir, ydir );
  }
}

Interactive Chart - Steal the ball

After determining that the ball is not in our character’s possession, we check if the ball is owned by another character. As it is owned, it certainly is not our character who has it as we already tested. So from the enemyDist container object (this has the pre-calculated distances of the character’s enemies) we get the enemies distance. See if the enemy is within stealing (ok, punching) range and punch if so, else move towards the enemy.

Now we have considered enemies too, if they have possession of the ball, our AI char simply goes after him and if he is within range we steal/punch.

Take note that when a character is punched he losses the ball so I also call punching stealing the ball.

Then we take this into the 2nd chart.

function thinkAI() {
  var xdir = 0;
  var ydir = 0;
 
    // if we have the ball
  if ( getBall() ) {
      // then shoot it!!
    shoot();
      // if not,
  } else {
    var ball = GameWorld.ball;
    var dist:Vector2D;
      // check if another char has the ball, since definitely it isn't this char
    if ( ball.owner ) {
        // store the enemy who has the ball in a local var
      var targetEnemy = enemyDist[ ball.owner.id ];
        // targetEnemy.dist is the distance of the enemy char with respect to this char
      dist = targetEnemy.dist;
        // if this enemy is within punching range
      if ( dist.len < punchRange ) {
        punch( ball.owner );
          // no need to do the processes below...
        return;
      }
    } else {
        // default the distance from the ball
      var dist = ballDist;
      var ds;
        // loop through enemies
      for ( c in enemyDist ) {
        ds = enemyDist[ c ].dist;
          // see if they are closer
        if ( ds.len < dist.len )
          dist = ds;
          // it seems that this enemy is already in range, no need to check the others
        if ( ds.len < punchRange )
          break;
      }
        // if this is not the ball distance then it could only be the enemy
      if ( dist != ballDist ) {
          // if this enemy is within punching range
        if ( dist.len < punchRange ) {
            // attack!!
          punch( ball.owner );
            // no need to do the processes below...
          return;
        }
      }
    }
      // get the direction
    xdir = dist.x ? dist.x / Math.abs( dist.x ) : 0;
    ydir = dist.y ? dist.y / Math.abs( dist.y ) : 0;
      // and move towards it
    moveChar( xdir, ydir );
  }
}

Interactive Chart 2 - Go offensive, attack!

What I added here is for our AI character to consider not only the ball itself and it’s possible owner, but also nearby enemies. Checking through all enemies and determining if they are close enough or within range, therefore stopping them with a punch.

You can also see clearly the advantage of pre-calculating the distances, as I used the enemy and ball distances enough to avoid recalculating them again and again when needed.

Now we have our competitive AI ready! Or not. Feeling like something is missing? Yes, its “difficulty!” Basically as you might have suspected that this AI behavior has the perfect reflex (well not so perfect really). It does what it has to depending on exact situations at the exact time on the next loop.

Example this:

Just at the same moment you grab the ball the enemy would instantly steal the ball or, simply saying, you can’t even run away, your character’s very change in position and angle is updated and read by the AI at the same time or yet exactly at the next frame therefore it knows where exactly you are same way the moment you move anywhere.

And another problem with the perfect reflex is same way we planned it, the moment the AI character grabs the ball he just shoots it at once.

For this problem, a good fix I did was based around with numbers. Yes, “numbers” will help with everything, you can imagine setting a level of intelligence for the AI and how much well it executes it’s task depends on the numbers assigned. But I’ll leave that to another post to discuss about it more…

What do you think? Play hardcourt now! to experience the AI in action.