Re: GtkGLExt

[zentara <zentara1 sbcglobal net>]

On Wed, 7 Feb 2007 15:02:08 -0500
zentara <zentara1 sbcglobal net> wrote:

>On Wed, 7 Feb 2007 16:50:04 +0100
>"Jeffrey Ratcliffe" <jeffrey ratcliffe gmail com> wrote:
>
>>On 07/02/07, Jeffrey Ratcliffe <jeffrey ratcliffe gmail com> wrote:
>>> According to their website (http://www.k-3d.org/gtkglext/Main_Page),
>>> there are Gtk2 OpenGL bindings for Python.
>>>
>>> Is there anything equivalent for Perl?
>
>>make then fails with
>>
>>/usr/bin/perl: symbol lookup error:
>>blib/arch/auto/Gtk2/GLExt/GLExt.so: undefined symbol:
>>gdk_gl_config_get_type
>>
>>Any ideas?
>>Jeff
>
>Well Perl - SDL  has working OpenGL. You could probably
>use that.  There are some nice tutorial examples in the
>SDL_Perl-2.1.3/test  subdir.

>You probably could do the same thing with SDL's mainloop.
>You would run the Gtk2 Mainloop as the controller, the have it 
>run a timer, that does a do_one_sdl_loop. 

>zentara

Well just to see if it was possible, I made a Gtk2 mainloop
to control an SDL OpenGL window.  This is just a quick
hack.....
-- I use alot of  Gtk2->main_iteration while Gtk2->events_pending; 
   in the SDL loop, and it would be preferable to "pump" the SDL
   loop with a GLib timer.

-- I couldn't find any way to destroy the SDL window. I'm sure
   there is one, but that seems to be a small problem, you can
   iconify it.

Anyways for a proof of concept.  The OpenGL code
is taken from the tutorial that comes with SDL-Perl.

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

my $app;  #sdl window
my $appcontrol = 0;

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 ;  # front

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;
$delay = 5;
$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_SIZE());
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_SIZE() );
printf "%-24s%s\n", "GL_DOUBLEBUFFER ", $app->attribute( SDL_GL_DOUBLEBUFFER() );

$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 );	#front
	

$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();

my $event = new SDL::Event;

  while (1) {
       if ($appcontrol == 0){return}  
	Gtk2->main_iteration while Gtk2->events_pending;	
         for (0 .. 5) { 
	                if ($appcontrol == 0){return} 
                    	Gtk2->main_iteration while Gtk2->events_pending;
			$event->pump();	
			$event->poll();
			exit(0) if ($event->type() == SDL_QUIT());	
                        
			if ($appcontrol == 0){return};	

			if (SDL::GetKeyState(SDLK_SPACE()) == SDL_PRESSED()) {
				$toggle = 0;
			} else {
				$toggle = 1;
			}
			
			Gtk2->main_iteration while Gtk2->events_pending;
			$app->delay($delay);
		     }
	DrawScene();
   }

}

#######################################################
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();
}

__END__




-- 
I'm not really a human, but I play one on earth.
http://zentara.net/japh.html