SDLx::Layer - Storage object for surface and position information
Extension
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
A layer (see SDLx::Layer) is an SDL::Surface, the position of the surface on screen and some additional information, e.g. ingame states.
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.
my $index = $layer->index;
The method index
represents the z-index ot this layer within its layermanager.
my $x = $layer->x;
This is a shortcut for $layer->pos->x.
my $y = $layer->y;
This is a shortcut for $layer->pos->y.
my $w = $layer->w;
This is a shortcut for $layer->clip->w.
my $h = $layer->h;
This is a shortcut for $layer->pos->h.
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 retrive the current or set a new surface.
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 );
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 );
my %data = %{ $layer->data }; my %data = %{ $layer->data( %new_data) };
This method returns the hash %data
. You can set %data
by passing a hash.
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.
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.
$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.
$layer->detach_xy( $x, $y );
detach_xy
detaches the prevously attached layer to the given coords. The upper left corner of this layer will be at $x
and $y
.
$layer->foreground;
This method moves the given layer to the foreground so that it is blittet on top of the other layers.
Report at sdlperl.ath.cx
#sdl irc.perl.org
See AUTHORS in SDL.
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.
perl(1), SDL(2).