1SDLx::LayerManager(3) User Contributed Perl DocumentationSDLx::LayerManager(3)
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6 SDLx::LayerManager - Extension for managing layers in a 2D world
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9 Extension
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12 use SDLx::Layer;
13 use SDLx::LayerManager;
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15 use SDL::Image;
16 use SDL::Surface;
17 use SDL::Video;
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19 # creating layers
20 my $layer1 = SDLx::Layer->new( SDL::Image::load('image1.png'), {userdata => '7'} );
21 my $layer2 = SDLx::Layer->new( SDL::Image::load('image2.png'), 100, 200, {userdata => '42'} );
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23 # creating the manager that holds the layers
24 my $layermanager = SDLx::LayerManager->new();
25 $layermanager->add( $layer1 );
26 $layermanager->add( $layer2 );
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28 my $display = # create your video surface here
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30 $layermanager->blit( $display );
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32 # accessing the layer at point(x,y)
33 print( $layermanager->by_position( 150, 200 )->data->{userdata} ); # should print '42'
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36 SDLx::LayerManager is a package to handle a bunch of layers. A layer
37 (see SDLx::Layer) is an SDL::Surface, the position of the surface on
38 screen and some additional information.
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40 The layermanager gives you the opportunity to obtain the layer at a
41 given point on screen and get the layers that are ahead or behind a
42 layer.
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44 You will even be able to attach one or more layers to the mouse, e.g.
45 for simulation some drag&drop functionality.
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48 new
49 my $layermanager = SDLx::LayerManager->new();
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51 This creates your layermanager object. It doesn't take any parameters.
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53 add
54 $layermanager->add( $layer );
55 $layermanager->add( SDLx::Layer->new( $surface, $x, $y, $options ) );
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57 Call "add" to push an SDLx::Layer object to the layermanager.
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59 layers
60 my @layers = @{ $layermanager->layers };
61 my $first_layer = $layermanager->layers->[0];
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63 The method "layers" returns all layers that were added before.
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65 layer
66 my $layer = $layermanager->layer( $index );
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68 To obtain only one layer at index $index use this function. $index
69 ranges from 0 to "length - 1".
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71 length
72 my $length = $layermanager->length();
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74 This method returns the count of the added layers.
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76 blit
77 $layermanager->blit( $surface );
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79 This method blits all layers to the surface (e.g. your video surface).
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81 by_position
82 my $layer = $layermanager->by_position( $x, $y );
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84 "by_position" returns the "SDLx::Layer" object at point "$x $y", which
85 is not fully transparent at this pixel.
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87 ahead
88 my @layers = @{ $layermanager->ahead( $index ) };
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90 This method returns all layers that are ahead of the given layer
91 indicated by $index. Ahead means that a layer has a higher z-index and
92 is blitted over the given layer.
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94 Note: This method doesn't check for transparency. This will change in
95 future versions.
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97 behind
98 my @layers = @{ $layermanager->behind( $index ) };
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100 This method returns all layers that are behind of the given layer
101 indicated by $index. Behind means that a layer has a lower z-index and
102 is blitted before the given layer.
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104 Note: This method doesn't check for transparency. This will change in
105 future versions.
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107 attach
108 $layermanager->attach( $layer, $x, $y );
109 $layermanager->attach( @layers, $x, $y );
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111 This function makes the given layer(s) sticky to the mouse. If you move
112 the mouse the layer(s) will follow. The layermanager blits these
113 layers at last, so they will appear on top of all layers.
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115 $x and $y should be set to the coords of the mouse, e.g. the coords of
116 the mouse click. If you omit $x and $y the layermanager obtains them
117 via SDL::Events::get_mouse_state.
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119 Note: The z-index is not changed for the given layers.
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121 detach_xy
122 $layermanager->detach_xy( $x, $y );
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124 "detach_xy" detaches the previously attached layers to the given
125 coords. The upper left corner of the backmost layer will be at $x and
126 $y. The other layers are positioned relative to the backmost layer
127 just like before.
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129 detach_back
130 $layermanager->detach_back( );
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132 "detach_back" detaches the previously attached layers back to the
133 position where they were attached.
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135 foreground
136 $layermanager->foreground( $layer );
137 $layermanager->foreground( @layers );
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139 This method moves the given layer(s) to the foreground so that they are
140 blitted on top of the other layers.
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143 Report at sdlperl.ath.cx
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146 #sdl irc.perl.org
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149 See "AUTHORS" in SDL.
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152 This program is free software; you can redistribute it and/or modify it
153 under the same terms as Perl itself.
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155 The full text of the license can be found in the LICENSE file included
156 with this module.
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159 perl(1), SDL(2).
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163perl v5.28.1 2019-02-02 SDLx::LayerManager(3)