Collision and Raycasting?

[Andr3wHur5t]

HI,

can someone tell me how they get what object collided with another?

[Joh]

EntityCollisionCallback

C: void _stdcall EntityCollisionCallback( TEntity entity0, TEntity entity1, byte* position, byte* normal, byte* force, flt speed )

BlitzMax: EntityCollisionCallback(entity0:TEntity,entity1:TEntity,position:Byte Ptr,normal:Byte Ptr,force:Byte Ptr,speed:Float)

This will be called when entity0 collides with another entity. The first entity is always the one which the callback was specified for. Note that the function can have any name. See the examples page for more info.

[Examples]

http://www.leadwerks.com/wiki/index.php?title=Entities

[Andr3wHur5t]

alright, also could you tell me how to share the data between the collision callback and my main loop i have tried some of my methods without success.

 

 

thanks.

[Joh]

What do you mean exactly?

You could use a public variable in your main loop..

[Andr3wHur5t]

I need to know what entity1 and entity0 are so I can compare them to see if one of them is a trigger body and the other is the environment or player inside my main loop.

 

also: when you say public variable you mean created outside of created main loop and callback then initialized in one of them?

[Pixel Perfect]

when you say public variable you mean created outside of created main loop and callback then initialized in one of them?

Exactly, the public variable will be visible to both so can be set by the callback and read by the main loop.

 

Conversely, you could encapsulate your main loop within a 'game' class and have it reference a member variable. The member variable could be set by a public member function in the class which is called from the callback passing the value as a parameter. In this case the pointer to the 'game' class would be a public variable ensuring it's scoped to the callback function.

[Joh]

Also don't forget that you could set key and retrieve it in this way you don't need many public variable..

As for example:

You create 5 trigger trap, you set a key like this "Type of entity" = 1 (1 trap, 2 ai, 3 player, 4..) , when 2 entity collide you can get the key, also you could set other value to them as for example the "effect" you need to reproduce.

[Andr3wHur5t]

Pixel Perfect could you post an example for me of this?

[Rick]

If you are using C++ then it's a nice feature to use SetEntityData and GetEntityData, where you assign your class to the entity so you can retrieve it in the collision method.