SDLx::Layer - Storage object for surface and position information

Authors

       See "AUTHORS" in SDL.

Bugs

       Report at sdlperl.ath.cx

Copyright

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl
       itself.

       The full text of the license can be found in the LICENSE file included with this module.

Description

       A layer (see SDLx::Layer) is an SDL::Surface, the position of the surface on screen and some additional
       information, e.g. ingame states.

Methods

new
         my $layer = SDLx::Layer->new( $surface );
         my $layer = SDLx::Layer->new( $surface,                                   %data );
         my $layer = SDLx::Layer->new( $surface, $pos_x,                           %data );
         my $layer = SDLx::Layer->new( $surface, $pos_x, $pos_y,                   %data );
         my $layer = SDLx::Layer->new( $surface, $pos_x, $pos_y, $clip_w,          %data );
         my $layer = SDLx::Layer->new( $surface, $pos_x, $pos_y, $clip_w, $clip_h, %data );

       This constructs the layer object. See how you can omit the position and dimension of the layer. The hash
       %data is for your use only.  The layer object just pass it through.

   index
         my $index = $layer->index;

       The method "index" represents the z-index of this layer within its layermanager.

   x
         my $x = $layer->x;

       This is a shortcut for $layer->pos->x.

   y
         my $y = $layer->y;

       This is a shortcut for $layer->pos->y.

   w
         my $w = $layer->w;

       This is a shortcut for $layer->clip->w.

   h
         my $h = $layer->h;

       This is a shortcut for $layer->pos->h.

   surface
         my $surface = $layer->surface;
         my $surface = $layer->surface( $new_surface );

       Example:

         SDL::Video::blit_surface( $layer->surface, $layer->clip, $destination_surface, $layer->pos );

       This method let you retrieve the current or set a new surface.

   pos
         my $rect = $layer->pos;

       The method "pos" returns an SDL::Rect object. The pos x and y are stored there.

       Example:

         SDL::Video::blit_surface( $layer->surface, $layer->clip, $destination_surface, $layer->pos );

   clip
         my $rect = $layer->clip;

       The method "clip" returns an SDL::Rect object. The clip width and height are stored there.

       Example:

         SDL::Video::blit_surface( $layer->surface, $layer->clip, $destination_surface, $layer->pos );

   data
         my %data = %{ $layer->data };
         my %data = %{ $layer->data( %new_data) };

       This method returns the hash %data. You can set %data by passing a hash.

   ahead
         my @layers = $layer->ahead;

       This method returns all layers that are ahead of the given layer.  Ahead means that a layer has a higher
       z-index and is blitted over the given layer.

       Note: This method doesn't check for transparency. This will change in future versions.

   behind
         my @layers = $layer->behind;

       This method returns all layers that are behind of the given layer.  Behind means that a layer has a lower
       z-index and is blitted over the given layer.

       Note: This method doesn't check for transparency. This will change in future versions.

   attach
         $layer->attach( $x, $y );

       This function makes the given layer sticky to the mouse. If you move the mouse the layer will follow.
       The layermanager blits this layer at last, so they will appear on top of all layers.

       $x and $y should be set to the coords of the mouse, e.g. the coords of the mouse click.  If you omit $x
       and $y the layer obtains them via SDL::Events::get_mouse_state.

       Note: The z-index is not changed for the given layer.

   detach_xy
         $layer->detach_xy( $x, $y );

       "detach_xy" detaches the previously attached layer to the given coords. The upper left corner of this
       layer will be at $x and $y.

   foreground
         $layer->foreground;

       This method moves the given layer to the foreground so that it is blitted on top of the other layers.

Name

       SDLx::Layer - Storage object for surface and position information

Support

       #sdl irc.perl.org

Synopsis

         use SDLx::Layer;
         use SDLx::LayerManager;

         use SDL::Image;
         use SDL::Surface;
         use SDL::Video;

         # creating layers
         my $layer1 = SDLx::Layer->new( SDL::Image::load('image1.png'), {userdata => '7'} );
         my $layer2 = SDLx::Layer->new( SDL::Image::load('image2.png'), 100, 200, {userdata => '42'} );

         # creating the manager that holds the layers
         my $layermanager = SDLx::LayerManager->new();
         $layermanager->add( $layer1 );
         $layermanager->add( $layer2 );

         my $display = # create your video surface here

         $layer1->foreground;
         printf( "%s\n", $layer1->behind->[0]->data->{userdata} ); # prints 42