Check collision between certain divs

Question

How can I check for collision between certain divs?

At the moment I\'m using getBoundingClientRect(), but it checks for every div:

if (thi         


        

Answer 1

Pure JavaScript version

var overlaps = (function () {
    function getPositions( elem ) {
        var width = parseFloat(getComputedStyle(elem, null).width.replace("px", ""));
        var height = parseFloat(getComputedStyle(elem, null).height.replace("px", ""));
        return [ [ elem.offsetLeft, elem.offsetLeft + width ], [ elem.offsetTop, elem.offsetTop + height ] ];
    }

    function comparePositions( p1, p2 ) {
        var r1 = p1[0] < p2[0] ? p1 : p2;
        var r2 = p1[0] < p2[0] ? p2 : p1;
        return r1[1] > r2[0] || r1[0] === r2[0];
    }

    return function ( a, b ) {
        var pos1 = getPositions( a ),
            pos2 = getPositions( b );
        return comparePositions( pos1[0], pos2[0] ) && comparePositions( pos1[1], pos2[1] );
    };
})();