Structuring .cpp's and .h's

This is a discussion on Structuring .cpp's and .h's within the Game Programming forums, part of the General Programming Boards category; I'm making a game, or atleast planning, and ran into how I should structure everything. Should I make a separate ...

  1. #1
    For Narnia! Sentral's Avatar
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    Structuring .cpp's and .h's

    I'm making a game, or atleast planning, and ran into how I should structure everything. Should I make a separate .cpp for the main menu, or just put it in with my game.cpp? Should I put graphics and loading functions into a separate file? Also, when I get the menu up, and the user selects new game, how should I go about initializing everything? I'm using SDL and C++ with Windows. Thanks!

  2. #2
    Crazy Fool Perspective's Avatar
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    have a class for each entity in your game (such as a menu). You can also model things like a game configuration with a class (you'd create and populate one based on the users menu input), then your game can use a configuration class to run with the appropriate settings.

    You generally want a separate cpp and h file for each class.

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    Super Moderator VirtualAce's Avatar
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    1 object=1 source file and 1 header file.

    Usually.

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    Supermassive black hole cboard_member's Avatar
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    >> Should I put graphics and loading functions into a separate file?

    For everything like texture loading, window initialisation, timing management etc etc, I create a new Singleton class (derived from the attached singleton base class I borrowed from gamedev.net) and keep the definition in a .h with the implementation in a .cpp. Also, I have one .h that is a sort of inclusion point for all standard headers which gets #include'd in just about every .cpp.

    The project I'm working on right now is something I want to be able to re-use. 80% of what I've written can be used a base for any number of games (and replacing the rendering / windowing code takes about 20 minutes).

    EDIT: Oh yeah the Singleton base:

    Code:
    #pragma once
    
    /*
        Singleton
    
        Base class for all singleton classes.
    */
    #include <assert.h>
    
    template <typename T> class Singleton
    {
        static T*   ms_singleton;
    
    public:
        Singleton()
        {
            #pragma warning(disable :4311)  // Pointer truncation from <class> to 'int'
            #pragma warning(disable :4312)  // Conversion from 'int' to <class> of greater size
    
            assert(! ms_singleton);
            // use a cunning trick to get the singleton pointing to the start of
            // the whole, rather than the start of the Singleton part of the object
            int offset = (int)(T*)1 - (int)(Singleton <T>*)(T*)1;
            ms_singleton = (T*)((int)this + offset);
    
            #pragma warning(default :4312)  // Conversion from 'int' to <class> of greater size
            #pragma warning(default :4311)  // Pointer truncation from <class> to 'int'
        }
    
        ~Singleton()
        {
            assert(ms_singleton);
            ms_singleton = 0;
        }
    
        static T& GetSingleton()
        {
            assert(ms_singleton);
            return *ms_singleton;
        }
    
        static T* GetSingletonPtr()
        {
            assert(ms_singleton);
            return ms_singleton;
        }
    };
    
    template <typename T> T* Singleton<T>::ms_singleton = 0;
    Last edited by cboard_member; 06-04-2006 at 03:38 PM.
    Good class architecture is not like a Swiss Army Knife; it should be more like a well balanced throwing knife.

    - Mike McShaffry

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    When using someone else's code, please give credit to that person. This code is part of a tutorial on GDNet. As for singletons, I would much rather use a namespace than make singleton classes. It's much more simple and cleaner in my opinion. Also, I prefer not to make everything an object. Doing so is just as bad as never using OO. People either abusively use it or never use it, this is wrong, in my opinion.

    As for the OT, I would make a different header / implementation file for each module / sub-module.

  6. #6
    Supermassive black hole cboard_member's Avatar
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    Yeah because I was so looking forward to going surfing around gamedev looking for his name while planning my reply.

    So even though my designs "click together" and expose an interface that is easy to use and maintain, I've been abusing OOP? Looks like I've got to redesign my whole project.

    Good class architecture is not like a Swiss Army Knife; it should be more like a well balanced throwing knife.

    - Mike McShaffry

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    I didn't say you were. I'm just saying that sometimes people go crazy about OOP and will make classes like this one:
    Code:
    class LightBulb {
        public:
            LightBulb() : state(false) { }
            LightBulb(bool s) : state(s) { }
            LightBulb(const LightBulb& lb) : state(lb.state) { }
    
            bool IsOn() { return state; }
            void SetState(bool s) { state = s; }
        private:
            bool state;
    };
    I'm exagerating (sp ?) a bit but I've seen people abusing OOP.

  8. #8
    Super Moderator VirtualAce's Avatar
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    Well your light bulb class would work just fine given a 3D graphics API. You could control the exact state, graphic technique, etc, etc. You could then add the light bulb to an array of allowed light sources to be used by the engine shader.

    So that's not abusing OOP. The only abuse I've seen here of object oriented code is not using it when you should be.

    Your light bulb class would be perfect for a game. I don't see the issue. And the singleton class might be from gamedev but ahluka engineered it to fit into his game engine for his purposes, which I see no problem with.

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    You don't see the problem ? The whole class is the problem. You could have a single boolean variable and it would be just as good without all of the hassle that comes with the (useless) LightBulb class. Besides, having Get/Set methods without doing anything more than returning the variable itself and setting the variable without doing any other computation (such as resizing a window or adjusting the value of other variables or whatever) is completely useless. The variable could have been public and it would have done the very same job. If you only needed booleans to know if a LightBulb is on or off a vector or an array would have done the job just as good with much less crap involved.

    My article on the subject.
    http://code-dynasty.net/articles/C_A...Programming/83

    Edit: Added link.

    Edit2: I don't care if he uses the code, he has the right to; however, he didn't even mention that the code wasn't his.
    Last edited by Desolation; 06-04-2006 at 06:21 PM.

  10. #10
    Super Moderator VirtualAce's Avatar
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    It depends on how you are using the class. If a light bulb is more than just a boolean then the class is perfectly fine.

    Perhaps your use of 'light bulb' as an example on a game programming board wasn't the best idea. A light bulb or a light source in a game is a helluva lot more than a boolean.

    Code:
    class LightSource
    {
      LP3DXBUFFER *m_pShader;
      D3DXVECTOR3 m_vecPos;
      D3DXVECTOR3 m_vecDir;
      D3DXCOLOR m_Ambient;
      D3DXCOLOR m_Diffuse;
      D3DXCOLOR m_Specular;
      ...
    };
    
    class LightBulb:public LightSource
    {
       ...
    };
    And his singleton hardly qualifies as a non-object. He is probably going to use it for a texture manager or some other resource manager. He has way more than just a boolean so your example for this post is invalid.

    Perhaps in another post your problem has merit, but for the context of this one, I don't see that it does.

    Your code is fine ahluka.
    Last edited by VirtualAce; 06-04-2006 at 06:33 PM.

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    It's not his.

    http://www.gamedev.net/reference/art...rticle1954.asp
    Look toward the end. The author says himself the code is from a book.

    Are you guys purposely stupid ? It was an example of abuse, I didn't point out anyone and said they were abusing OOP. I was simply stating that going all OOP wasn't the best idea as sometimes you can code something much simpler that will do the same thing. In the case of Singletons, I prefer using namespaces.

  12. #12
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    That is just your opinion. Who are you to say what is right and what is wrong and who is stupid and who is not?

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    Quote Originally Posted by Desolation
    When using someone else's code, please give credit to that person. This code is part of a tutorial on GDNet. As for singletons, I would much rather use a namespace than make singleton classes. It's much more simple and cleaner in my opinion. Also, I prefer not to make everything an object. Doing so is just as bad as never using OO. People either abusively use it or never use it, this is wrong, in my opinion.

    As for the OT, I would make a different header / implementation file for each module / sub-module.
    Did I say I was correct ? No.

  14. #14
    Super Moderator VirtualAce's Avatar
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    We've all posted stuff here from books. Hell most algos in games are from books. That is the general idea of Game Programming Gems, Shader Gems, etc, etc.

    Nothing is original and it is the free sharing of information and code that grows the industry.
    Ahluka not quoting a public site like gamedev IMO is no big deal. It's obvious to me if it's found in several books and sites then the info is probably commonly known as is no longer qualified as original or stealing if you use it. It's obvious the creator of the code did not intend on copyrighting it and was just sharing information.

    We are not writing academic posts here with quotes and references and as well Ahluka has demonstrated research and knowledge in this area as well as the ability to adopt complex concepts and use them in his own design.

    To me that's called a game programmer and he doesn't need ridiculed by someone like you with a beef that's assinine as yours.

    Are you guys purposely stupid ?
    And yet you are the one who has responded to the this thread with an issue that isn't even related to the topic at hand?
    Last edited by VirtualAce; 06-04-2006 at 08:42 PM.

  15. #15

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    I'm not even going to get into 'how you should layout your source code' because my stuff has tons of functionality laid out in a completely disorganized mess.

    I will say, however, that I want to psycopathically murder the inventors of the C++ programming language.

    EDIT:
    >>When using someone else's code, please give credit to that person.

    He replied with this:

    >>derived from the attached singleton base class I borrowed from gamedev.net

    and that's good enough. I really didn't even expect him to say it was from a tutorial on GDNet, because I don't really care. Please stop being a douchebag. I'll defend ahluka with all of my might, and I'm pretty mighty.
    Last edited by BobMcGee123; 06-04-2006 at 08:58 PM.
    I'm not immature, I'm refined in the opposite direction.

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