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Help => Graphics => Topic started by: R23MJ on July 02, 2016, 01:10:26 am

Title: [SOLVED] Resource union throws access violation for Fonts.
Post by: R23MJ on July 02, 2016, 01:10:26 am

    So I am trying to write a Resource loader and manager (Yes I know of Thor, this is just a "learning" project.) and I have started experimenting with unions, not something I use very often. I created a class (as seen in code below) called resource which has a union that contains a texture/font. The texture loads correctly; however the font throws an access violation

Exception thrown at 0x00C5DBE0 in Project.exe: 0xC0000005: Access violation reading location 0x00000004.

The following is my complete and minimal example.

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#include <SFML/Graphics.hpp>

class Resource
{
public:
        union
        {
                sf::Texture t;
                sf::Font    f;
        };

        Resource()
        {        }

        ~Resource()
        {         }
};

int main()
{
        Resource font;
        Resource tex;

        if (!tex.t.loadFromFile("player.png")) {}   //! Works great!
                //doError

        if (!font.f.loadFromFile("blocks.ttf")) {}  //! Throws access violation.
                //doError

        return 0;
}
 

Title: Re: Resource union throws access violation for Fonts.
Post by: R23MJ on July 02, 2016, 02:18:57 am

Evan, over at StackOverflow informed me that only the first element in a union is default constructed. This helped me solve the problem by assuring which ever item I plan to use in constructed properly before I use it.