Empty image semantics

[Nexus]

Although this is rather a theoretical problem, I want to inform you about some observations I've made. The following code fails with a STL debug assertion (VS 2010):

Code: [Select]

#include <SFML/Graphics/Image.hpp>
int main()
{
sf::Image image;
image.SaveToFile("image.bmp");
}
The problem is the statement &pixels[0] in ImageLoader.cpp. As far as I know, if you access the 0th element of an empty std::vector, you evoke undefined behaviour.

There are a few other places (also in Image.cpp) where the access is unchecked. In some of them, you could handle it like in Image::CreateMaskFromColor():

Code: [Select]

if (myPixels.empty())
        return;
But I don't know if there is a convention how to represent empty image files. Anyway, you should probably make the semantics clearer or explicitly forbid some operations on singular sf::Image instances.

[Laurent]

This is absolutely true. It's a shame that I left so many undefined behaviours in sf::Image

I reviewed all the functions and made sure that the behaviour is always well-defined and robust.

Thanks

[Nexus]

Thank you