How to identify the type of a struct?

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How to identify the type of a struct? #382755 09/12/11 14:15 09/12/11 14:15
Joined: Sep 2003 Posts: 303 Germany Clemens OP Senior Member
Clemens OP Senior Member Joined: Sep 2003 Posts: 303 Germany	Hi there, I'm looking for a way to find out which struct-type has been passed: Code: function draw_object(... void* Object ...) { if (Object.type==PANEL) // ??? WHAT'S THE CORRECT CODE? // code for PANEL-position change else // code for TEXT((/ViewENTITY))-position change while (...) { draw_obj(Object); wait(1); } }

Re: How to identify the type of a struct? [Re: Clemens] #382769 09/12/11 15:43 09/12/11 15:43
Joined: Feb 2010 Posts: 320 TANA/Madagascar 3dgs_snake Senior Member
3dgs_snake Senior Member Joined: Feb 2010 Posts: 320 TANA/Madagascar	I don't kow if there is a function to what you want to do but I think that overloading draw_object would be a solution. Best regards. Best regards. PhysX 3 Plugin Box2D Plugin

Re: How to identify the type of a struct? [Re: 3dgs_snake] #382770 09/12/11 15:53 09/12/11 15:53
Joined: Feb 2011 Posts: 135 Myrkling Member
Myrkling Member Joined: Feb 2011 Posts: 135	"The handle can be used to identify the type of the object." See here: http://www.conitec.net/beta/ain-handle.htm

Re: How to identify the type of a struct? [Re: Myrkling] #382771 09/12/11 16:11 09/12/11 16:11
Joined: Jul 2008 Posts: 894 T TechMuc User
TechMuc User T Joined: Jul 2008 Posts: 894	though handle does ofc only work for engine objects. dynamic_cast is not available for lite-c (or any other c language ) Last edited by TechMuc; 09/12/11 16:12.

Re: How to identify the type of a struct? [Re: TechMuc] #382791 09/12/11 19:11 09/12/11 19:11
Joined: Sep 2003 Posts: 303 Germany Clemens OP Senior Member
Clemens OP Senior Member Joined: Sep 2003 Posts: 303 Germany	Thanks for the manual hint - didn't know that handle is good for that. But cause I'm far away from beeing a struct/pointer/bit-shifting expert... there are two problems appearing for me: 1) How has the code to look like, when I want to -> [converting the handle to a var that contains the index number,] right shift it by 24, then left shift the resulting int by 10? (something I probably would be able to find out with enough time...) 2) And for my function above I forget the problem of the following compiler error: 'pos_x': is not a member of 'VOID' Object.pos_x = PositionX; (something I don't know where to start finding the solution...)

Re: How to identify the type of a struct? [Re: Clemens] #382798 09/12/11 20:24 09/12/11 20:24
Joined: Apr 2007 Posts: 3,751 Canada WretchedSid Expert
WretchedSid Expert Joined: Apr 2007 Posts: 3,751 Canada	Originally Posted By: Clemens 1) How has the code to look like, when I want to -> [converting the handle to a var that contains the index number,] right shift it by 24, then left shift the resulting int by 10? [/quote] Code: int type = (int)(((var)handle(myObject)) >> 24); type = type << 10; if(type == HBYTE_PANEL) { ... } etc.. Originally Posted By: Clemens 2) And for my function above I forget the problem of the following compiler error: 'pos_x': is not a member of 'VOID' Object.pos_x = PositionX; (something I don't know where to start finding the solution...) Short answer: Typecast it to the appropriate type Long answer: Void is a typeless type without any informations, the compiler doesn't know where the offset to the member with the name .x is. You have to tell the compiler what type you are working with so the compiler knows where the offset is. Shitlord by trade and passion. Graphics programmer at Laminar Research. I write blog posts at feresignum.com

Re: How to identify the type of a struct? [Re: WretchedSid] #382800 09/12/11 21:04 09/12/11 21:04
Joined: Sep 2003 Posts: 303 Germany Clemens OP Senior Member
Clemens OP Senior Member Joined: Sep 2003 Posts: 303 Germany	1) -> Sid, thx for that piece... but when I change my code into: Code: function draw_object(... void* Object ...) { int Object_type = (int)(((var)handle(Object)) >> 24); Object_type = Object_type << 10; if (Object_type==HBYTE_PANEL) printf("panel! with %.2f",(int)Object_type); else if (Object_type==HBYTE_TEXT) printf("text! with %.2f",(int)Object_type); else printf("nothing! with %.2f",(int)Object_type); ... } -> always the "nothing"-message (with 0.00) is appearing even when I pass a PANEL or TEXT object... 2) -> your long answer is the explanation of the error, which I already did understand - the short answer is the really interesting part: a solution. But a too short solution how do I tell the compiler what type I'm using -> how to typecast ? Last edited by Clemens; 09/12/11 21:19.

Re: How to identify the type of a struct? [Re: Clemens] #382805 09/12/11 22:16 09/12/11 22:16
Joined: Apr 2007 Posts: 3,751 Canada WretchedSid Expert
WretchedSid Expert Joined: Apr 2007 Posts: 3,751 Canada	Thats strange, it shifts everything like the manual says. I have nothing to test it here, so maybe someone else can help you. Btw, you do already some, wrong, typecasting in your printing function, the format specifier %f specifies a floating point variable to be printed, you pass an integer. And while we are at typecasting and stuff: http://lmgtfy.com/?q=C+style+typecast Shitlord by trade and passion. Graphics programmer at Laminar Research. I write blog posts at feresignum.com

handle function -> HBYTE-type -> how to?? [Re: WretchedSid] #382813 09/13/11 00:37 09/13/11 00:37
Joined: Sep 2003 Posts: 303 Germany Clemens OP Senior Member
Clemens OP Senior Member Joined: Sep 2003 Posts: 303 Germany	Hehe, it's really time for me to read a c(++) book from begin to end! Type casting is in fact a nice - less simple as it looks in code - thing!! But it surprises me, that it doesn't matter if I use ((TEXT)Object).pos_x = PositionX; or ((PANEL)Object).pos_x = PositionX; in my code above. Both works independet from which type is passed... (?) Problem1 -> getting the right HBYTE-type I couldn't solve it on my own, yet. Has anybody an idea what's wrong with Sid's piece of code?

Re: handle function -> HBYTE-type -> how to?? [Re: Clemens] #382828 09/13/11 08:22 09/13/11 08:22
Joined: Feb 2011 Posts: 135 Myrkling Member
Myrkling Member Joined: Feb 2011 Posts: 135	If I remember well, there was something special about the typecasting bit shifting thing. I can't test it right now, but you could try something like this: int type = (int)(handle(Object) >> 14); Last edited by Myrkling; 09/13/11 08:27. Reason: Striked typecasting.

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