Messages

1

Graphics / Re: Very weird sprite behaviour (white rectangle when attempting to draw sprite)

« on: June 16, 2014, 05:12:00 pm »

Thank you!

I actually just purchased the SFML book. Already started to read through it!

2

Graphics / Re: Very weird sprite behaviour (white rectangle when attempting to draw sprite)

« on: June 16, 2014, 02:58:33 pm »

Thank you, Nexus! 

As a general advice, don't store resources (textures, sound buffers, fonts etc.) along with the game objects that use them. This will only cause trouble. Instead, think about storing resources in a centralized place.

Aha, I see your point. I'll probably end up making some sort of resource manager which sprites can use then

3

Graphics / Re: Very weird sprite behaviour (white rectangle when attempting to draw sprite)

« on: June 16, 2014, 09:33:25 am »

Hey Binary1248!

Thank you so much for the reply I'm quite new to C++ but attempting to learn by simply throwing myself out in a project. Thank you, I did not realize that the syntax I used actually caused any copying! So what you are saying is that when you use syntax such as:

WorldEntity rainCloud = WorldEntity(...)

It will actually construct a worldEntity object and then copy it to the "rainCloud" variable due to the assignment operator? So if I instead use:

WorldEntity rainCloud(...)

Then I construct it "in place" for the rainCloud object? Which will not cause any copying.

Thank you for your time!

4

Graphics / Very weird sprite behaviour (white rectangle when attempting to draw sprite)

« on: June 15, 2014, 07:28:53 pm »

Hey everyone

So, I've come across a very weird type of behaviour that has left me stumped.

First of all, I have successfully managed to draw a rain cloud picture using this code:

main.cpp

int main()
{
        RenderWindow window(VideoMode(800, 500), "Rain Cloud");

        WorldEntity rainCloud = WorldEntity();

        while (window.isOpen())
        {
                Event event;

                while (window.pollEvent(event))
                {
                        if (event.type == Event::Closed)
                        {
                                window.close();
                        }
                }

                window.clear();
                window.draw(rainCloud.getSprite());
                window.display();
        }

        return 0;
}

And here's my simple WorldEntity class:

/*
WorldEntity is a collection of basic properties needed by all objects that needs to exist within the game world
*/
class WorldEntity
{
private:
        Sprite m_sprite;
        Vector2f m_position;
        Texture mahTexture;
public:
        WorldEntity::WorldEntity()
        {
                mahTexture.loadFromFile("RainCloud.png");
                m_sprite = Sprite(mahTexture);
                m_position = Vector2f(0, 0);
        }

        void setPosition(float x, float y);
        void setPosition(Vector2f newPosition);
        Sprite getSprite();
};

#endif

Now, this code works perfectly and the rain cloud sprite is drawn. However... if I do the following change to the WorldEntity class:

        WorldEntity::WorldEntity(Texture test)
        {
                mahTexture.loadFromFile("RainCloud.png");
                m_sprite = Sprite(mahTexture);
                m_position = Vector2f(0, 0);
        }

That is, I now pass a texture called "test" by value (Notice I do NOT use it for anything at all!). And then change the first part of the main.cpp source code to pass a texture instead:

        Texture texture_rainCloud;
       
        if (!texture_rainCloud.loadFromFile("TheActual.png"))
                cout << "Dummy textureTexture failed to load" << endl;

        WorldEntity rainCloud = WorldEntity(texture_rainCloud);

It does not work anymore. That is, now I get a white rectangle drawn instead of the cloud! Notice that all I did was simply pass a texture into the WorldEntity class that I do not even use for anything at all. I changed literally nothing but the fact that a texture is now passed to the constructor, and I don't use that variable for anything.

What exactly is going on there!? Anyone has any ideas?