C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Second class instance fails          C++Talk.NET Forum Index -> C++ language (comp.lang.c++) View previous topic :: View next topic   Author Message Krice Guest Posted: Sat Jul 30, 2005 7:05 pm    Post subject: Second class instance fails If I make two instances of the class, the second one will fail: map_tiles=new G_Tile("terrain.wst",32,32,3,0); back_tiles=new G_Tile("backtiles.wst",32,32,2,1); The program doesn't crash and the code seems to work, but the tiles are not showing for the second instance. If I switch places then back_tiles can be seen, but not map_tiles. Then I discovered that if I put some code between those calls, then both will work. In this case: map_tiles=new G_Tile("terrain.wst",32,32,3,0); ustr=new Font(8,16,"bfonts.bmp"); back_tiles=new G_Tile("backtiles.wst",32,32,2,1); What could be the reason for that? Back to top red floyd Guest Posted: Sat Jul 30, 2005 7:38 pm    Post subject: Re: Second class instance fails Krice wrote: Quote: If I make two instances of the class, the second one will fail: map_tiles=new G_Tile("terrain.wst",32,32,3,0); back_tiles=new G_Tile("backtiles.wst",32,32,2,1); The program doesn't crash and the code seems to work, but the tiles are not showing for the second instance. If I switch places then back_tiles can be seen, but not map_tiles. Then I discovered that if I put some code between those calls, then both will work. In this case: map_tiles=new G_Tile("terrain.wst",32,32,3,0); ustr=new Font(8,16,"bfonts.bmp"); back_tiles=new G_Tile("backtiles.wst",32,32,2,1); What could be the reason for that? You have an error on line 42 of your code. Back to top Krice Guest Posted: Sun Jul 31, 2005 3:28 pm    Post subject: Re: Second class instance fails red floyd wrote: Quote: You have an error on line 42 of your code. You must be proud of yourself now.. My guess is that something inside the constructor corrupts memory, since those objects are most likely generated one after another in the memory space. But some of the source code was taken from previous project and that didn't had any errors. It's these silent memory errors I hate the most, because they don't even crash the program. Back to top Krice Guest Posted: Sun Jul 31, 2005 6:48 pm    Post subject: Re: Second class instance fails Krice wrote: Quote: My guess is that something inside the constructor corrupts memory First I took SDL_Surface out from the class, but that didn't help. Only when I removed all SDL variables from the class (as member variables) the problem was gone. But why SDL doesn't work in a class? Back to top Krice Guest Posted: Wed Aug 03, 2005 11:28 am    Post subject: Re: Second class instance fails Krice wrote: Quote: But why SDL doesn't work in a class? Speaking to myself, but the reason was a local variable with same name that silently shadowed the class member variable, causing such unpredictable behavior. Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         C++Talk.NET Forum Index -> C++ language (comp.lang.c++) All times are GMT Page 1 of 1   Jump to: Select a forum C/C++----------------C LanguageC Language (Moderated)C++ Language (Moderated)C++ language (comp.lang.c++)C++ language, library and standards Non-English C/C++ Newsgroups----------------C++ (German)C++ (French)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.