GameEngine2D

[nautilusnsk]

Hi!

I'm new in C# and in Playstation Mobile. I know that i can add physic object to world like this:

sceneBodies[numBody] = new PhysicsBody(sceneShapes[0], 1.0f);

numBody++;

But how can I remove an object from the physic world?

[tsuneyan]

Hello,

I think that frequent insertion and deletion of object may decrease the simulation performance.

( It requires re-order of objects including joints)

Object is ignored when it is put outside of the simulation area until the scene is changed.

TutorialScene/SimulationAreaScene.cs shows how the simulation area works.

When you change the scene,  you can construct your scene again from the scratch.

Thanks,

[AlexMcDev · Accepted solution]

Hi:

Use sceneBodies[numBody].clear(); and then sceneBodies[numBody] = null; The GC will take care of memory.

cheers,

[nautilusnsk]

Thank you for the answers.

But my game uses physics engine and supposes deletion of object. When some object connected by joint is removed it should have adequate behaviour.

I tried to use a solution from AlexMcDev.  It works, but as I understand I should watch that PhysicsBody elements in the sceneBodies array were located one by one. I mean there shouldn't be null in the 2-nd index if we have 1-st and 3-rd.

[sophie_89_2]

If you're removing a body from the middle of the array, do as AlexMcDev says, but then shift the following ones down by one each

sceneBodies[numBody].clear();
sceneBodies[numBody] = null;

for ( var body= numBody; body < totalNumberOfBodies; body++)
{
	if( (body+ 1) < totalNumberOfBodies)
{
		sceneBodies[ body ] = sceneBodies[ body + 1 ];
	}
	else
	{
		sceneBodies[ body].Clear();
		sceneBodies[body] = null;
	}
} 

[AlexMcDev]

Hi:

Sophie_89_2 it's right if you want to maintain the coherence in the array you must reorder it. I'm not sure because I'm not using the PhysicsEngine but you could try some kind of List node structure to avoid reordering it but the access time is slower than index array.

Cheers,