#!/usr/bin/env perl

use SDL;
use SDLx::App;
use SDL::Surface;
use SDL::Event;
use SDL::OpenGL;
use SDL::OpenGL::Constants;

#for ( keys %main:: ) {
#	print "$_\n";
#}

print "Starting $0\n";

my $app = SDLx::App->new( -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() );

sub DrawScene {

	glClear( GL_DEPTH_BUFFER_BIT() | GL_COLOR_BUFFER_BIT() );

	glLoadIdentity();

	glTranslate( -1.5, 0, -6 );

	glColor( 1, 1, 1 );

	glBegin( GL_TRIANGLES() );
	glColor( 1, 0, 0 ) if (@_);
	glVertex( 0, 1, 0 );
	glColor( 0, 1, 0 ) if (@_);
	glVertex( -1, -1, 0 );
	glColor( 0, 0, 1 ) if (@_);
	glVertex( 1, -1, 0 );
	glEnd();

	glTranslate( 3, 0, 0 );

	glBegin( GL_QUADS() );
	glColor( 1, 0, 0 ) if (@_);
	glVertex( -1, 1, 0 );
	glColor( 0, 1, 0 ) if (@_);
	glVertex( 1, 1, 0 );
	glColor( 0, 0, 1 ) if (@_);
	glVertex( 1, -1, 0 );
	glColor( 1, 1, 0 ) if (@_);
	glVertex( -1, -1, 0 );
	glEnd();
}

sub DrawColorScene {
	DrawScene 'with color';
}

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, 0.175, 100.0 );
	}

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

InitView();

DrawScene();

$app->sync();

$toggle = 1;

$app->loop(
	{   SDL_QUIT()    => sub { exit(0); },
		SDL_KEYDOWN() => sub {
			$toggle = ($toggle) ? 0 : 1;
			($toggle) ? DrawScene() : DrawColorScene();
			$app->sync();
		},
	}
);