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game crashes when trying to fire a second time.

by Nathan Morton · in Torque Game Builder · 03/29/2011 (6:52 pm) · 11 replies

I have my enemies fire a missile when they spawn, then I want them to fire another on via a schedule.

code is below

//********Drone Spawning********
function spawnDrone()
{
     %enemyDrone = new t2dAnimatedSprite(){
          scenegraph = $sceneGraph;
          class = enemyShip;
          Layer=1;
          imageMap = Defender2ImageMap;
          size = "6.102 5.768";
     };
     %speed = getrandom(3,7);
     %x= getrandom(-40,40);
     %enemyDrone.playAnimation("Defender2Animation");
     %enemyDrone.health=3;
     %enemyDrone.setPosition(%x, -45);
     %enemyDrone.setLinearVelocityY(%speed*2);
     %enemyDrone.setLinearVelocityX(getrandom(-5,5));
     %enemyDrone.setCollisionActive( true, true );
     %enemyDrone.setCollisionPhysics(false, false);
     %enemyDrone.setCollisionCallback(true);
     %enemyDrone.setWorldLimit( kill, "-73.748 -67.575 33.359 76.630" );
     %this = %enemyDrone;
     /*if ($game $= true) - WORKS FINE NOT USDE DURING TESTING
     {
          schedule (getrandom(500,1000),0,spawnDrone);
     }*/
     if ($game $= true)
     {
          %this.fireMissile();
     }
}

function enemyShip::fireMissile(%this)
{
     echo("fireMissile");
     echo(%this);
     %this.enemyMissile = new t2dAnimatedSprite()
     {
          scenegraph = %this.scenegraph;
          class = enemyMissile;
          enemy = %this;
     };
     schedule (getrandom(500,1000),0,%this.fireMissile());
   %this.enemyMissile.fire();
}

the specific line that causes the problem is 

schedule (getrandom(500,1000),0,%this.fireMissile());

when I comment it out, game runs fine, but the enemies only fire once.

when I leave it in, game blows up with an app crash. nothing indicated in the console log.

any help is appreciated
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Employee Michael Perry
ZombieShortbus
#1
03/29/2011 (7:38 pm)
Don't do this:

%this = %enemyDrone;

Just use %drone:

if($game == true)
{
     %drone. fireMissile();
}

Also, I would not use schedule(...). Use %this.schedule(...). Try to make those changes and see what happens. Also, check your console.log for any errors or warnings.

Nathan Morton
Wicked Creationz
#2
03/30/2011 (6:26 pm)
still having a problem. though the game doesn't crash anymore.

if I use
%enemyDrone.schedule(getrandom(500,1000),0,fireMissile);

nothing happens at all - no indication that I even tried to schedule something

if I use

%enemyDrone.schedule(getrandom(500,1000),0,fireMissile());

I get the following message in my console log

game/gameScripts/enemy.cs (50): Unable to find function fireMissile

Employee Michael Perry
ZombieShortbus
#3
03/30/2011 (7:17 pm)
Try this:

%enemyDrone.schedule(getRandom(500,1000), fireMissle);

fireMissle is not a stand alone function. It is scoped to your enemyShip class. Because %enemyDrone has the enemyShip class, it can schedule to call its own functions. That is the difference between schedule() and %someObject.schedule().

Employee Michael Perry
ZombieShortbus
#4
03/30/2011 (8:45 pm)
Also, I don't have the code in front of me, but I do not think this is what you want:

%this.scenegraph;

You need to get the scene graph from your level:

SceneWindow2D.getScenegraph()

Employee Michael Perry
ZombieShortbus
#5
03/30/2011 (8:53 pm)
With my above posts in mind, here is how I would rewrite the function:

function enemyShip::fireMissile(%this)
{
     // This echo will notify that we are in the function
     echo("fireMissile");

     // This echo will tell us the specific object calling the method (id)
     echo(%this);

     // Get the scenegraph
     %sceneGraph =  scenegraph = SceneWindow2D.getScenegraph();

     // This will create a new t2dAnimatedSprite
     // The properties here are somewhat circular, but that should be fine
     %this.enemyMissile = new t2dAnimatedSprite()
     {
         scenegraph = %sceneGraph;
          class = enemyMissile;
          enemy = %this;
     };
     
     // Schedule a call to this function in a random
     // time between 0.5 and 1 second
     %this.schedule(getRandom(500,1000), fireMissile);

    // Call the enemyMissile::fire() routine
     %this.enemyMissile.fire();
}

Employee Michael Perry
ZombieShortbus
#6
03/30/2011 (8:55 pm)
You are definitely on the right track. Your logic is fine. The problem is just learning the right functions to call and what certain inherent variables are used for. Give that a try and let me know how it works.

Nathan Morton
Wicked Creationz
#7
03/30/2011 (9:09 pm)
actually I have

%sceneGraph =  scenegraph = SceneWindow2D.getScenegraph();

set in my game.cs as 

$sceneGraph = sceneWindow2D.getSceneGraph();


under the startGame function - if this isn't best practices let me know.

Are there any good resources on the actual scripting side? What I generally do right now is find a tutorial that is "close" to what I want and go from there.

I'd love some explanations on the collision functions, and custom functions.

I really do appreciate all the help!

Torque Owner Chris Labombard
Premium Preferred
#8
03/31/2011 (5:37 am)
Nathan - In my startgame function I set a global variable to the scenegraph like this:

$global_scenegraph = sceneWindow2D.loadLevel(%level);

Saves you having to call getSceneGraph. So yes, what you are doing is pretty much how a lot of us are doing the same thing. :)

EDIT:

I think Mich made a typo when he posted this:
%sceneGraph =  scenegraph = SceneWindow2D.getScenegraph();

I don't think that will even compile.

Employee Michael Perry
ZombieShortbus
#9
03/31/2011 (7:31 am)
@Nathan - I recently updated the iTorque 2D documentation and added a new section on scripting. The guides are applicable to Torque 2D: iTorque 2D Documentation.

Click on the Scripting section to start reading them.

Nathan Morton
Wicked Creationz
#10
03/31/2011 (6:03 pm)
@Mike, thanks for all the help, it's working correctly now. I probably need to read up on schedule() a bit.

I'll check out that documentation.

@Chris, I was hoping I was using something close, thanks for confirming.

Employee Michael Perry
ZombieShortbus
#11
03/31/2011 (7:54 pm)
@Nathan - Huzzah! Glad you got it working. I hope you like the docs. On a separate note, I've been working my way through the product line to overhaul and fix the documentation. I started with T3D, hit iTorque 2D, so Torque 2D is next in line for a documentation overhaul.

Because of how similar the two engines are, you can probably find both the Torque 2D and iTorque 2D documentation useful for gathering information. The iTorque 2D docs are the most up to date and I cover a lot more details on certain aspects, like building particles in the Rainy Day tutorial and explaining scrollers a bit more. Stuff like that.

Let us know if you need any other help.