Getting EGL_BAD_DISPLAY while firing eglquerystring() from application

If I understand the problem correctly, :

• you'd like to query the available EGL extensions before trying to call eglGetPlatformDisplayEXT
• you need to call eglQueryString(EGLDisplay, EGLint) for that purpose
• eglQueryString needs an initialised display to work correctly

And therefore you have a circular dependencies problem.

One basic way to check if eglGetPlatformDisplayEXT is available on some platforms is to use dlsym. Something akin to :

EGLDisplay display;
if (dlsym(NULL, "eglGetPlatformDisplayEXT")) {
  display = eglGetPlatformDisplayEXT(...);
  ...
}
else {
  display = eglGetDisplay(your_own_getNativeDisplay_procedure());
  ...
}

dlsym(NULL, "symbolName") will search for symbolName in the current program and all the shared libraries dependencies declared in the current program executable file.

If I understand the problem correctly, :

• you'd like to query the available EGL extensions before trying to call eglGetPlatformDisplayEXT
• you need to call eglQueryString(EGLDisplay, EGLint) for that purpose
• eglQueryString needs an initialised display to work correctly

And therefore you have a circular dependencies problem.

One basic way to check if eglGetPlatformDisplayEXT is available on some platforms is to use dlsym. Something akin to :

EGLDisplay display;
if (dlsym(NULL, "eglGetPlatformDisplayEXT")) {
  display = eglGetPlatformDisplayEXT(...);
  ...
}
else {
  display = eglGetDisplay(your_own_getNativeDisplay_procedure());
  ...
}

dlsym(NULL, "symbolName") will search for symbolName in the current program and all the shared libraries dependencies declared in the current program executable file.

Exactly. Its circular dependency problem .

I will try out one above basic way and come back with results.

Thanks,

VK