use 5.0.12;

use SDL;
use SDLx::App;
use SDL::Events;
use SDL::Event;
use OpenGL qw(:all);

my ($SDLAPP, $WIDTH, $HEIGHT, $SDLEVENT);

$| = 1;
$WIDTH = 700;
$HEIGHT = 500;
$SDLAPP = SDLx::App->new(
    title => "OpenGL App",
    width => $WIDTH,
    height => $HEIGHT,
    gl => 1);

$SDLEVENT = SDL::Event->new;

glEnable(GL_DEPTH_TEST);
glMatrixMode(GL_PROJECTION);
glLoadIdentity;
gluPerspective(60, $WIDTH / $HEIGHT, 1, 1000);
glTranslatef(0, 0, -20);

sub handlepolls {
    SDL::Events::pump_events();

    while (SDL::Events::poll_event($SDLEVENT)) {
        my $type = $SDLEVENT->type();
        if ($type == SDL_QUIT) {
            $cv_finish->send(1);
        }
    }
};

my $refresh_world = sub {
  &handlepolls;
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glRasterPos2i(0, 0);
# ~~~~~~~~~~~~~~~~~~~ - problematic call
  $SDLAPP->sync;
};

$refresh_world->();