#!/usr/bin/perl
use warnings;
use strict;
use Tk;
use Tk::Pane;         
use SDL;
use SDL::Mixer;
use SDL::Music;
    
# a demo for using multi channel sound in Tk 
# by zentara 

$|++;
my $mw = tkinit;
$mw->geometry('600x300+100+100');

####setup mixer 
# See           
# http://aspn.activestate.com/ASPN/CodeDoc/SDL-sdlpl/SDL/Mixer.html 

my $mixer = SDL::Mixer->new(
    -frequency => MIX_DEFAULT_FREQUENCY, # 22050 
    -format    => MIX_DEFAULT_FORMAT,    # AUDIO_S16 
    -channels  => MIX_DEFAULT_CHANNELS,  # 8 
    -size      => 1024    #higher numbers give sloppy reponse 
                          #as buffers continue to empty 
);
# provides 8 channels of 
# 16 bit audio at 22050 Hz. and a single channel of music. 

#background can be mp3,ogg or wav (mp3 needs smpeg libs) 
my $music  = new SDL::Music('1bb.mp3');
                
#sound effects must be wav 
my $sound0 = new SDL::Sound('cannon.wav');
$sound0->volume(128); #max 
               
my $sound1 = new SDL::Sound('explosion.wav');
$sound1->volume(128); #max 
               
$mixer->music_volume(MIX_MAX_VOLUME); #128 
############################################################### 
######setup volume indicators####################### 
my $music_vol = 128;
my $chan0_vol = 128; #cannon 
my $chan1_vol = 128; #explosion 
my $tframe = $mw->Frame(-background =>'black')->pack(-fill=>'x');
                
$tframe->Label(-background =>'black', -foreground => 'lightyellow',
               -text => 'Music Vol: ', )->pack(-side=>'left');
$tframe->Entry(-background =>'black', -foreground => 'lightyellow',
               -textvariable => \$music_vol , -width => 3,
               )->pack(-side=>'left');
$tframe->Label(-background =>'black', -text => ' ',-width=>1,
               )->pack(-side=>'left');
                
$tframe->Label(-background =>'black', -foreground => 'lightgreen',
               -text => 'Cannon Vol: ', )->pack(-side=>'left');
$tframe->Entry(-background =>'black', -foreground => 'lightgreen',
               -textvariable => \$chan0_vol , -width => 3,
               )->pack(-side=>'left');
$tframe->Label(-background =>'black', -text => ' ', -width=>1,
                )->pack(-side=>'left');
           
$tframe->Label(-background =>'black', -foreground => 'lightsteelblue',
               -text => 'Explosion Vol: ', )->pack(-side=>'left');
$tframe->Entry(-background =>'black', -foreground => 'lightsteelblue',
               -textvariable => \$chan1_vol , -width => 3,
               )->pack(-side=>'left');
$tframe->Label(-background =>'black', -text => ' ', -width=>1,
                )->pack(-side=>'left');

my $sound = 1;
$tframe->Checkbutton(
       -text => 'Sound',
       -background => 'lightskyblue',
       -variable => \$sound,
       -command  => \&set_sound,
           )->pack(-side =>'left');

$tframe->Button(-text => 'Exit', -background =>'red',
                -command => sub{ exit })->pack(-side=>'right');


################################################################# 
my $pane = $mw->Scrolled('Pane',
             -background =>'black',
             -scrollbars=>'oe',
             sticky=>'w')->pack(-side => "left", -anchor => "n",
                      -fill=>'both',-expand=>1);

my %keyprs = (
          'm' => {
                text => 'music on/off',
                command => \&music_toggle
                 },
          'e' => {
                text => 'explosion',
                 command => sub{ $mixer->play_channel( 1, $sound1, 0 )  }
                 },

          'c' => {
                text => 'cannon',
                command => sub{ $mixer->play_channel( 0, $sound0, 0 )  }
                },

          'q' => {
                text => 'Exit Program',
                command => sub{ exit }
                },

          'space' => {
                text => 'Pause Music',
                command => \&pause_toggle
                },

          'plus' => {
                text => 'Increase Background Music Volume',
                command => sub{ &music_vol(1) }
                },

          'minus' => {
                text => 'Decrease Background Music Volume',
                command => sub{ &music_vol(-1) }
                },

          'F1' => {
                text => 'Increase Cannon Volume',
                command => sub{
                             $chan0_vol += 1;
                             if($chan0_vol > 128){$chan0_vol = 128}
                             $mixer->channel_volume(0,$chan0_vol);
                        }
                },

                
          'Control-F1' => {
                text => 'Decrease Cannon Volume',
                command => sub{
                             $chan0_vol -= 1;
                             if($chan0_vol < 0){$chan0_vol = 0}
                             $mixer->channel_volume(0,$chan0_vol);
                           }
                },

          'F2' => {
                text => 'Increase Explosion Volume',
                command => sub{
                             $chan1_vol += 1;
                             if($chan1_vol > 128){$chan1_vol = 128}
                             $mixer->channel_volume(1,$chan1_vol);
                           }
                },

          'Control-F2' => {
                text => 'Decrease Explosion Volume',
                command => sub{
                             $chan1_vol -= 1;
                             if($chan1_vol < 0){$chan1_vol = 0}
                             $mixer->channel_volume(1,$chan1_vol);
                            }
                },
    );


#hack to expand pane  
$pane->Label(-text=>'',-background=>'red',-width =>100)
         ->pack(-fill=>'x',-expand=>1 );


my @order = qw(m e c space plus minus F1 Control-F1 F2 Control-F2 q);
foreach(@order){
$pane->Label(-text => "$_ -> $keyprs{$_}{'text'}",
#          -font => 'big', 
          -background => 'cyan',
          -anchor => 'w',
          -borderwidth =>2,
          )->pack( -fill =>'x',-expand=>1);

$mw->bind("<$_>", $keyprs{$_}{'command'});

}

MainLoop;
############################################ 
sub music_toggle{
    if( $mixer->playing_music() ){
           $mixer->halt_music();
     }else{
      $mixer->play_music( $music, 100 );
     }
}
############################################# 
sub music_vol{
      $music_vol += $_[0];
      if($music_vol < 0){$music_vol = 0}
      if($music_vol > 128){$music_vol = 128}
      #return if ! $mixer->playing_music();  
      $mixer->music_volume($music_vol);
}
########################################## 
sub pause_toggle{
    return if ! $mixer->playing_music();

    if( $mixer->music_paused() ){
           $mixer->resume_music();
      }else{ $mixer->pause_music()  }
}
############################################# 
sub set_sound{
  if($sound == 0){
      $mixer->music_volume(0);
      $mixer->channel_volume(0,0);
      $mixer->channel_volume(1,0);
      return;
      }
  if($sound == 1){
      $mixer->music_volume($music_vol);
      $mixer->channel_volume(0,$chan0_vol);
      $mixer->channel_volume(1,$chan1_vol);
      return;
      }
}
__END__