Framerate drops when connecting HDMI display on lubuntu 14.04 ->related to ofGetScreenWith()

hi all,

i discovered a strange latency in my app when connecting an hdmi monitor to my laptop.

after a bit of research, it turns out to be related with ofGetScreenWidth and ofGetScreenHeight, when i comment the call to this two function, the problem disapear.

if i make a test app who only calls this two methods and ofGetFrameRate, the problem is still appearing, at the moment i connect the hdmi monitor, framerate drops from 60 FPS (fixed) to 1-6 FPS.
i made those test with a clone from github master on the 1st of june.

main.cpp :

#include "ofMain.h"
#include "ofApp.h"
#include "GuiApp.h"
#include "ofAppGLFWWindow.h"
int main( ){
	ofAppGLFWWindow window;
window.setMultiDisplayFullscreen(true);
ofSetupOpenGL(&window,1024,768,OF_WINDOW);			// <-------- setup the GL context
ofRunApp(new ofApp());
}

ofApp.cpp :

#include "ofApp.h"
#include "ofVideoGrabber.h"
void ofApp::setup(){
    ofSetFrameRate(60);
}
void ofApp::draw(){
	ofDrawBitmapString("FPS: " + ofToString(int(ofGetFrameRate())),20,ofGetHeight()-40);
float screenFactorX = (ofGetWidth()/(float)ofGetScreenWidth());
    float screenFactorY = (ofGetHeight()/(float)ofGetScreenHeight());

}

strange isn’it?

stranger is that ofGetScreenWidth() and ofGetScreenHeight() always return the same value even if my hdmi display is connected (should be 2* 1980*1080).

does anyone have an idea of how i can get this to work?

the problem disapear when using Glut window instead of glfw.

As Arturoc mentioned, this might be related to libglfw on ubuntu 14.04, if an update of libglfw will be available, i will give it a try.

until then, i will be using glut… :slight_smile: