#!/usr/bin/perl
use warnings;
use strict;
use Gtk2;
use SDL;
use SDL::App;
use SDL::Surface;
use SDL::Event;
use SDL::OpenGL;

# proof of concept to use SDL OpenGL from Gtk2 or Tk
# SDL opengl code taken from the tutorial included with SDL-Perl
# 1 known problem is there is no command to close an sdl window
# it can be iconified, but ->close or ->destroy dosn't work

my $app;  #sdl window
my $appcontrol = 0;
my $sdl_timer;
my $event;
my $angle;
my $other;
my $cube;
my $white;
my $toggle;

package SDL::OpenGL::Cube;
use SDL;
use SDL::OpenGL;

my $vertex_array = pack "d24", 
    -0.5,-0.5,-0.5, 0.5,-0.5,-0.5, 0.5,0.5,-0.5, -0.5,0.5,-0.5, # back
    -0.5,-0.5,0.5,  0.5,-0.5,0.5,  0.5,0.5,0.5,  -0.5,0.5,0.5 ;  # fro
+nt

my $indicies = pack "C24",     
            4,5,6,7,    # front
            1,2,6,5,    # right
            0,1,5,4,    # bottom
            0,3,2,1,    # back
            0,4,7,3,    # left
            2,3,7,6;    # top

sub new {
    my $proto = shift;
    my $class = ref($proto) || $proto;
    my $self = {};
    bless $self,$class;
    $self;
}

sub draw {
    my ($self) = @_;
    $self->color();
    glEnableClientState(GL_VERTEX_ARRAY());
    glVertexPointer(3,GL_DOUBLE(),0,$vertex_array);
    glDrawElements(GL_QUADS(), 24, GL_UNSIGNED_BYTE(), $indicies);
}

sub color {
    my ($self,@colors) = @_;

    if (@colors) {
        $$self{colored} = 1;
        die "SDL::OpenGL::Cube::color requires 24 floating point color
+ values\n"
            unless (scalar(@colors) == 24);
        $$self{-colors} = pack "f24",@colors;
    }

    if ($$self{colored}) {
        glEnableClientState(GL_COLOR_ARRAY);
        glColorPointer(3,GL_FLOAT,0,$$self{-colors});
    } else {
        glDisableClientState(GL_COLOR_ARRAY);
    }
}

1;
##   end of package        #######################################

package main;

Gtk2->init;
my $gtkwindow = Gtk2::Window->new('toplevel');
$gtkwindow->set_title('Gtk2 Window');

$gtkwindow->signal_connect( delete_event => sub {
                            Gtk2->main_quit;
                            return 1; 
                           });

my $count_gtk = 0;
my $gtk_timer_control = 1;

####setup gtk2 window###################
my $vbox = Gtk2::VBox->new( 0, 6 );
$gtkwindow->add($vbox);

my $frame = Gtk2::Frame->new('Count');
$vbox->pack_start( $frame, 1, 1, 0 );
$frame->set_border_width(3);

my $label = Gtk2::Label->new("Count $count_gtk");
$frame->add( $label);


my $button = Gtk2::Button->new('Stop Count');
$vbox->pack_start( $button, 1, 1, 0 );
$button->signal_connect( clicked => 
           sub { $gtk_timer_control = 0 } );


my $button1 = Gtk2::Button->new('Launch OpenGL');
$vbox->pack_start( $button1, 1, 1, 0 );
$button1->signal_connect( clicked => \&init_SDL );

my $button2 = Gtk2::Button->new('Stop OpenGL');
$vbox->pack_start( $button2, 1, 1, 0 );
$button2->signal_connect( clicked => sub{ $appcontrol = 0;
                                           return 0;
                                        } );

my $button3 = Gtk2::Button->new('Close OpenGL Window');
$vbox->pack_start( $button3, 1, 1, 0 );
$button3->signal_connect( clicked => sub{ $appcontrol = 0;
                                          SDL::FreeSurface($app);
                     } );


my $quit_button = Gtk2::Button->new('_Quit');
$vbox->pack_start( $quit_button, 0, 0, 0 );
$quit_button->signal_connect(
           clicked => sub {
            $gtkwindow->destroy;
        exit;
            }
        );

my $timer1 = Glib::Timeout->add (1000,\&show_loop);

$gtkwindow->show_all;

###################################################

Gtk2->main;

########################################
sub show_loop{
  $count_gtk++;
  $label->set_text("Count $count_gtk");
  return $gtk_timer_control;  #return FALSE to end gtk2 timer
}

###################################################

sub init_SDL{

$appcontrol = 1;

$app = new SDL::App -w => 800, -h => 600, -d => 16, -gl =>1;

print "Initializing OpenGL settings\n";
printf "%-24s%s\n", "GL_RED_SIZE ", $app->attribute( SDL_GL_RED_SIZE()
+ );
printf "%-24s%s\n", "GL_GREEN_SIZE ", $app->attribute( SDL_GL_GREEN_SI
+ZE());
printf "%-24s%s\n", "GL_BLUE_SIZE ", $app->attribute( SDL_GL_BLUE_SIZE
+() );
printf "%-24s%s\n", "GL_DEPTH_SIZE ", $app->attribute( SDL_GL_DEPTH_SI
+ZE() );
printf "%-24s%s\n", "GL_DOUBLEBUFFER ", $app->attribute( SDL_GL_DOUBLE
+BUFFER() );

$angle = 0;    
$other = 0;
    
my @colors =  (
    1.0,1.0,0.0,    1.0,0.0,0.0,    0.0,1.0,0.0, 0.0,0.0,1.0,    #back
    0.4,0.4,0.4,    0.3,0.3,0.3,    0.2,0.2,0.2, 0.1,0.1,0.1 );    #fr
+ont
    

$cube = new SDL::OpenGL::Cube;
$cube->color(@colors);
$white = new SDL::OpenGL::Cube;
$toggle = 1;
glEnable(GL_CULL_FACE);
glFrontFace(GL_CCW);
glCullFace(GL_BACK);

InitView();
DrawScene();
$app->sync();

$event = new SDL::Event;

$sdl_timer = Glib::Timeout->add (100,\&pump_sdl);

}
#######################################################
sub pump_sdl{

  if ($appcontrol == 0){return 0}  

         for (0 .. 5) { 
                    if ($appcontrol == 0){return 0} 
                    
                $event->pump();    
            $event->poll();
            
            # dosn't work to close sdl window (but should :-) )
            #if ($event->type() == SDL_QUIT()){$app ->destroy }    
                        
            if ($appcontrol == 0){return 0};    

            if (SDL::GetKeyState(SDLK_SPACE()) == SDL_PRESSED()) {
                $toggle = 0;
            } else {
                $toggle = 1;
            }
            
                 
    DrawScene();
     }

return 1;
}
#######################################################
sub DrawScene {

    glClear( GL_DEPTH_BUFFER_BIT() 
        | GL_COLOR_BUFFER_BIT());

    glLoadIdentity();

    glTranslate(0,0,-6.0);
    glRotate($angle % 360,1,1,0);
    glRotate($other % 360,0,1,1);

    $angle += 6;
    $other += $angle % 5;

    glColor(1,1,1);
    $toggle ? $cube->draw() : $white->draw();

    $app->sync();

}

sub InitView {
    glViewport(0,0,800,600);

    glMatrixMode(GL_PROJECTION());
    glLoadIdentity();

    if ( @_ ) {
        gluPerspective(45.0,4/3,0.1,100.0);
    } else {
        glFrustum(-0.1,0.1,-0.075,0.075,0.3,100.0);
    }

    glMatrixMode(GL_MODELVIEW());
    glLoadIdentity();
}
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