# Implement bounding boxes for SDL::Game::Rect #29

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opened this Issue Jul 26, 2011 · 0 comments

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### kthakore commented Jul 26, 2011

The minimum bounding rectangle (MBR), also known as bounding box or envelope, is an expression of the maximum extents of a 2-dimensional object (e.g. point, line, polygon) within its 2-D (x, y) coordinate system, in other words min(x), max(x), min(y), max(y). The MBR is a 2-dimensional case of the minimum bounding box.

SDL::Game::Rect could have bounding values for coordinates and size. Something like:

\$rect->min_x(0);
\$rect->max_x(100);
\$rect->min_height(3);
\$rect->max_height(7);

they should probably be "paired" methods as well:

\$rect->min_pos(0, 0); # x, y
\$rect->max_pos(102, 109); # x, y

\$rect->min_size(10, 18); # width, height
\$rect->max_size(42, 42); # width, height

# I don't like this API:

\$rect->min_boundbox(2, 2, undef, 7); # x, y, w, h
\$rect->max_boundbox(2, 2, undef, 7); # x, y, w, h

# I like this one better (or something like that):

\$rect->size_boundbox(2, 2, undef, 7); # min_w, min_h, max_w, max_h
\$rect->pos_boundbox (2, 2, undef, 7); # min_x, min_y, max_w, max_h

There should also be a way to do this inside the constructor, something like:

my \$rect = SDL::Game::Rect->new(
-top => 0,
-left => 0,
-width => 10,
-height => 10,
-min_x => 0,
-max_width => 42,
);

or something like that. Since there are several things to be done on SDL Perl before tackling this, just feel free to comment on the suggested API, or suggest your own while we're not there yet.