Entity pointer to a removed entity

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by 7th_zorro. 05/11/24 09:25

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Entity pointer to a removed entity #334205 07/21/10 19:31 07/21/10 19:31
Joined: Apr 2009 Posts: 138 Germany T Toryno OP Member
Toryno OP Member T Joined: Apr 2009 Posts: 138 Germany	Hi, how can I check if an entity pointer (not me or you) points to an entity which has removed allready? I tried if(handle(ent) = -1) {...} but it doesn't work. Hope there's a very simple way. Thanks for reading, thinking, answering

Re: Entity pointer to a removed entity [Re: Toryno] #334207 07/21/10 19:42 07/21/10 19:42
Joined: May 2007 Posts: 2,043 Germany Lukas Programmer
Lukas Programmer Joined: May 2007 Posts: 2,043 Germany	After removing an entity, set its pointer to NULL. Then you can always check if(ent) {...} Kubetris LBGUI

Re: Entity pointer to a removed entity [Re: Lukas] #334209 07/21/10 20:08 07/21/10 20:08
Joined: Apr 2009 Posts: 138 Germany T Toryno OP Member
Toryno OP Member T Joined: Apr 2009 Posts: 138 Germany	From the manual: "All my and you pointers to that entity are set to NULL in all functions." The pointer I'm using is a self-declarated. This isn't set to NULL and it's not global so I can't set in to NULL myself. Thanks for reading, thinking, answering

Re: Entity pointer to a removed entity [Re: Toryno] #334210 07/21/10 20:19 07/21/10 20:19
Joined: May 2007 Posts: 2,043 Germany Lukas Programmer
Lukas Programmer Joined: May 2007 Posts: 2,043 Germany	Well, then you just have to check if(you) {...} and if you remove an entity in its action, just put a return; after the remove. Kubetris LBGUI

Re: Entity pointer to a removed entity [Re: Lukas] #334216 07/21/10 20:30 07/21/10 20:30
Joined: Apr 2009 Posts: 138 Germany T Toryno OP Member
Toryno OP Member T Joined: Apr 2009 Posts: 138 Germany	It seems that this doesn't work. Ok here's my code. You see: In the second frame, victim points to an entity which has allready been removed so the engine crashes. Code: ENTITY* jet = ent_create(...); function example() { wait(1); ent_remove(jet); } action turret() { ENTITY* victim = jet; ... while(1) if (victim != NULL) { victim.LIFE -= time_step; // crash } } } Last edited by Toryno; 07/21/10 20:45. Reason: i wrote an example to the code to make in more unsterstandable Thanks for reading, thinking, answering

Re: Entity pointer to a removed entity [Re: Toryno] #334219 07/21/10 20:42 07/21/10 20:42
Joined: Apr 2008 Posts: 586 Austria Petra Support
Petra Support Joined: Apr 2008 Posts: 586 Austria	Only the "me" and "you" pointers are automatically set to NULL when an entity is removed. Your "victim" pointer is not set to NULL. So, your "if (victim != NULL)" or "if(victim)" make no sense as they are always true. You must not remove an entity as long as its pointer is still used in another function. Terminate that function first.

Re: Entity pointer to a removed entity [Re: Petra] #334221 07/21/10 20:50 07/21/10 20:50
Joined: May 2007 Posts: 2,043 Germany Lukas Programmer
Lukas Programmer Joined: May 2007 Posts: 2,043 Germany	Or, as I said, set jet and victim to NULL. If you don't always know which other pointers also point to the entity, you could use ENTITY** pointers that all point to one pointer you can set to NULL. Kubetris LBGUI

Re: Entity pointer to a removed entity [Re: Lukas] #334225 07/21/10 21:43 07/21/10 21:43
Joined: Apr 2009 Posts: 138 Germany T Toryno OP Member
Toryno OP Member T Joined: Apr 2009 Posts: 138 Germany	Entity** is a good idea I will make that. thanks Thanks for reading, thinking, answering

Re: Entity pointer to a removed entity [Re: Toryno] #334262 07/22/10 06:36 07/22/10 06:36
Joined: Sep 2007 Posts: 62 Germany B bodden Junior Member
bodden Junior Member B Joined: Sep 2007 Posts: 62 Germany	I'm not in front of my 3dgs-PC, so I'm not sure. But you could try Quote: if (victim == jet) instead of Quote: if (victim != NULL) Or use Quote: if (victim != jet) { victim = null; } insisde the while {}

Re: Entity pointer to a removed entity [Re: bodden] #334290 07/22/10 10:56 07/22/10 10:56
Joined: Feb 2008 Posts: 3,232 Australia EvilSOB Expert
EvilSOB Expert Joined: Feb 2008 Posts: 3,232 Australia	you should also be able to use Code: if(ptr_first(victim) != NULL) Because if 'victim' is no longer pointing to a valid entity, ptr_first will return a NULL... "There is no fate but what WE make." - CEO Cyberdyne Systems Corp. A8.30.5 Commercial

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