Loading SFML Textures in Opengl

[Bogdan]

Hello there,
I've encountered a new problem with sfml/opengl loading of textures. There is much outdated info on the net about opengl and sfml...
As the example below uses a different library, I wanted to ask: How to do the texture loading part just with SFML and Opengl. If I try using sf::Texture, it always says that it's incompatible wit Gluint type.

unsigned int texture;
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
// set the texture wrapping/filtering options (on the currently bound texture object)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);  
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// load and generate the texture
int width, height, nrChannels;
unsigned char *data = stbi_load("container.jpg", &width, &height, &nrChannels, 0);
if (data)
{
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
    glGenerateMipmap(GL_TEXTURE_2D);
}
else
{
    std::cout << "Failed to load texture" << std::endl;
}
stbi_image_free(data);

[Bogdan]

I've found a modern example.
It seems to be done with "sf::Image".

main.cpp
https://gist.github.com/alexmercerind/a1d9115d9944fa1e82f8c2abcd1c9b5d

shader_compiler.cpp
https://gist.github.com/alexmercerind/6b15e7eb3872d5a284f25a93fab7c625

But why does the square still stay white in the code example? (no texture is shown, no visible errors)

[Hapax]

Do you have those shader files (that that code attempts to load) as well and are they in the correct location?

Are you using SFML 2 or SFML 3?

Does this work:
https://github.com/SFML/SFML/blob/master/examples/opengl/OpenGL.cpp

[Bogdan]

Unfortunately I don't have those shader files.
I'm using SFML 2 as SFML 3 is still experimental.
The given code example doesn't work (Visual Studio 2022), because it doesn't recognize GLAD.
Esp. one function: gladLoadGL(sf::Context::getFunction);
Is there a way to circumvent those additional libraries and just do it with sfml, GLM and opengl?

At least I've found a working example from a different site (made with SFML 2.5):
https://gist.github.com/gamepopper/1931ca297f3decdee90e785f12762192

Is this good enough as modern example?

[Hapax]

It looks like that original "modern" example you gave uses sf::Image to load the image data in but then uploads it to the graphics card using GL commands (sf::Image is basically just an array of pixels). Without the shaders that that code uses, it won't be able to show those textures.

SFML 3 is currently on its second Release Candidate so it's borderline being released.

I think I may have misunderstood your original question. Are you trying to use raw OpenGL calls and pass an SFML texture to use in it? If so, would it not be simpler to also use raw OpenGL calls to set up the texture?

With that said, the official example (the one that you said requires GLAD) shows how to use an sf::Texture within OpenGL.
The one I linked was the example for SFML 3. Does this work?
https://github.com/SFML/SFML/blob/2.6.x/examples/opengl/OpenGL.cpp

Anyway, in that example, this part binds the texture:
https://github.com/SFML/SFML/blob/2.6.x/examples/opengl/OpenGL.cpp#L115-L117

For some more information, you can see sf::Texture's documentation about "bind":
https://www.sfml-dev.org/documentation/2.6.2/classsf_1_1Texture.php#ae9a4274e7b95ebf7244d09c7445833b0

[Bogdan]

Yes, I'm trying to use raw Opengl without unnecessary dependencies, with the exemption
of sfml (input events,textures,window....) and GLM for the 3d camera/view as SFML won't allow me to do it.

[Hapax]

I see.
And where you able to bind the texture as I mentioned?