SDL::Game::Rect(3) User Contributed Perl Documentation SDL::Game::Rect(3)NAMESDL::Game::Rect - SDL::Game object for storing and manipulating
rectangular coordinates
SYNOPSIS
my $rect = SDL::Game::Rect->new( 10, 20, 5, 5 ); # top, left, width, height
my $another_rect = SDL::Game::Rect->new( 10, 30, 5, 8);
if ( $rect->collide_rect ($another_rect) ) {
print "collision!!!\n";
$rect->move($new_x, $new_y);
}
WARNING
This module is ***EXPERIMENTAL***
It is being designed for the new SDL Perl API, so things may change at
any given time. In particular, pay attention to the caveat below:
that'll definitely go away in the future and will require changes on
your account.
USAGE CAVEAT
SDL Perl uses some intricate XS magic that doesn't allow us to just use
base 'SDL::Rect'. So, even though we provide the very same accessors
(and more! see below), other SDL modules that take a SDL::Rect object
as argument won't accept passing an SDL::Game::Rect (yet). To work
around this we provide the "rect()" method, which returns a vanilla
"SDL::Rect" object with the appropriate dimensions. So, for example, if
$gamerect is a "SDL::Game::Rect" object, then instead of doing
something like this will trigger a fatal error:
$app->update( $gamerect ); # this will fail!
instead, you should do this (for now):
$app->update( $gamerect->rect ); # ok!
The SDL Perl development team is working to fix this. If you want to
help, please join us in the mailing list or in #sdl on irc.perl.org.
DESCRIPTION
"SDL::Game::Rect" object are used to store and manipulate rectangular
areas. Rect objects are created from a combination of left (or x), top
(or y), width (or w) and height (or h) values, just like raw "SDL::Rect
objects".
All "SDL::Game::Rect" methods that change either position or size of a
Rect are "in-place". This means they change the Rect whose method was
called and return nothing.
ATTRIBUTES
All Rect attributes are acessors, meaning you can get them by name, and
set them by passing a value:
$rect->left(15);
$rect->left; # 15
The Rect object has several attributes which can be used to resize,
move and align the Rect.
· width, w - gets/sets object's width
· height, h - gets/sets object's height
· left, x - moves the object left position to match the given
coordinate
· top, y - moves the object top position to match the given
coordinate
· bottom - moves the object bottom position to match the given
coordinate
· right - moves the object right position to match the given
coordinate
· center_x - moves the object's horizontal center to match the given
coordinate
· center_y - moves the object's vertical center to match the given
coordinate
Some of the attributes above can be fetched or set in pairs:
$rect->top_left(10, 15); # top is now 10, left is now 15
my ($width, $height) = $rect->size;
· size - gets/sets object's size (width, height)
· top_left - gets/sets object's top and left positions
· mid_left - gets/sets object's vertical center and left positions
· bottom_left - gets/sets object's bottom and left positions
· center - gets/sets object's center (horizontal(x), vertical(y))
· top_right - gets/sets object's top and right positions
· mid_right - gets/sets object's vertical center and right positions
· bottom_right - gets/sets object's bottom and right positions
· mid_top - gets/sets object's horizontal center and top positions
· mid_bottom - gets/sets object's horizontal center and bottom
positions
METHODS
Methods denoted as receiving Rect objects can receive either
"<SDL::Game::Rect"> or raw "<SDL::Rect"> objects.
new ($left, $top, $width, $height)
Returns a new Rect object with the given coordinates. If any value is
omitted (by passing undef), 0 is used instead.
copy
duplicate
Returns a new Rect object having the same position and size as the
original
move(x, y)
Moves current Rect by the given offset. The x and y arguments can be
any integer value, positive or negative.
inflate(x, y)
Grows or shrinks the rectangle. Rect's size is changed by the given
offset. The rectangle remains centered around its current center.
Negative values make ita shrinked rectangle instead.
clamp($rect)
Moves original Rect to be completely inside the Rect object passed as
an argument. If the current Rect is too large to fit inside the passed
Rect, it is centered inside it, but its size is not changed.
clip($rect)
Turns the original Rect into the intersection between it and the Rect
object passed as an argument. That is, the original Rect gets cropped
to be completely inside the Rect object passed as an argument. If the
two rectangles do not overlap to begin with, the Rect bcomes zero-
sized, retaining its the original (x,y) coordinates.
union($rect)
union( $rect1, $rect2, ... )
Makes the original Rect big enough to completely cover the area of
itself and all other Rects passed as an argument. As the Rects can have
any given dimensions and positions, there may be area inside the new
Rect that is not covered by the originals.
fit($rect)
Moves and resizes the original Rect to fit the Rect object passed as an
argument. The aspect ratio of the original Rect is preserved, so it may
be smaller than the target in either width or height.
normalize
Corrects negative sizes, flipping width/height of the Rect if they have
a negative size. No repositioning is made so the rectangle will remain
in the same place, but the negative sides will be swapped.
contains($rect)
Returns true (non-zero) when the argument is completely inside the
Rect. Otherwise returns undef.
collide_point(x, y)
Returns true (non-zero) if the given point is inside the Rect,
otherwise returns undef. A point along the right or bottom edge is not
considered to be inside the rectangle.
collide_rect($rect)
Returns true (non-zero) if any portion of either rectangles overlap
(except for the top+bottom or left+right edges).
collide_list( [$rect1, $rect2, ...] )
Test whether the rectangle collides with any in a sequence of
rectangles, passed as an ARRAY REF. The index of the first collision
found is returned. Returns undef if no collisions are found.
collide_list_all( [$rect1, $rect2, ...] )
Returns an ARRAY REF of all the indices that contain rectangles that
collide with the Rect. If no intersecting rectangles are found, an
empty list ref is returned.
collide_hash( {key1 => $rect1, key2 => $rect2, ...} )
Receives a HASH REF and returns the a (key, value) list with the key
and value of the first hash item that collides with the Rect. If no
collisions are found, returns (undef, undef).
collide_hash_all( {key1 => $rect1, key2 => $rect2, ...} )
Returns a HASH REF of all the key and value pairs that intersect with
the Rect. If no collisions are found an empty hash ref is returned.
AUTHOR
Breno G. de Oliveira, "<garu at cpan.org>"
BUGS
Please report any bugs or feature requests to the bug tracker. I will
be notified, and then you'll automatically be notified of progress on
your bug as we make changes.
SUPPORT
You can find documentation for this module with the perldoc command.
perldoc SDL::Game::RectACKNOWLEDGEMENTS
Many thanks to all SDL_Perl contributors, and to the authors of
pygame.rect, in which this particular module is heavily based.
COPYRIGHT & LICENSE
Copyright 2009 The SDL Perl Development Team, all rights reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
SEE ALSO
perl, SDL, SDL::Rect
perl v5.14.1 2011-07-18 SDL::Game::Rect(3)
