setMode(OF_PRIMITIVE_POINTS) Not working

Im new to openframeworks and im learning mesh by following the tutorials on openframeworks.cc. But setMode(OF_PRIMITIVE_POINTS) seems not working. There is no point after running it…the code is just as same as the tutorial like:

void testApp::setup() {
mesh.setMode(OF_PRIMITIVE_POINTS);

ofVec3f top(100.0, 50.0, 0.0);
ofVec3f left(50.0, 150.0, 0.0);
ofVec3f right(150.0, 150.0, 0.0);

mesh.addVertex(top);
mesh.addVertex(left);
mesh.addVertex(right);
}
void testApp::draw() {
ofBackground(0);
mesh.draw();
}

Try moving ofBackground(0) to the setup function. and changing the draw function to

void testApp::setup() {
     ofBackground(0)
     mesh.setMode(OF_PRIMITIVE_POINTS);
     ....
}

void testApp::draw() {
     ofSetColor( 255, 0, 255);
     mesh.draw();
}

thx for answering me. it doesn`t work still.

In the draw function, can you try adding

cout << "mesh verts: " << mesh.getNumVertices() << endl;

And see what that prints out to make sure there are vertices in the mesh.

i found the resolve. i add glPointSize() before the ofMesh.draw() and i can see the point.Still thx for answering!