ofCamera and inverted texture mapped image

Hi, arturo asked me to open an issue about this here.

original forum post : https://forum.openframeworks.cc/t/ofcamera-and-inverted-texture-mapped-image/26398

I figured out the texture mapped image looks inverted when I use ofCamera.
As you can see the American continent is inverted.

It works correctly when I call ofCamera::setVFlip(true);
But Is this natural to see the image inverted when VFlip is set to false?

Here's a test code below. I used ofEasyCam.

void ofApp::setup(){
    
    ofEnableDepthTest();
    ofDisableArbTex();
    
    img.load("earth.jpg");
    mesh = ofMesh::sphere(300,300);
}

void ofApp::draw(){

    cam.begin();
    img.bind();
    mesh.draw();
    img.unbind();
    cam.end();
}

And Here's a link to the test image
[http://paulbourke.net/geometry/transformationprojection/earth.jpg]

Start by running the supplied ofEasyCam reproduction with ofDisableArbTex(), earth.jpg, and the sphere mesh, then compare the result with ofCamera::setVFlip(true). Trace the texture mapping and camera orientation involved in that example; done means determining whether the inverted continent is expected and documenting or correcting the behavior.