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Lenght Between A Dot And A Line //JavaScript Function
<a href="http://jsfromhell.com/math/dot-line-length">
Given a dot and a line, it returns the distance between them, the last parameter tells if the line should be considered infinite or if the function should respect its limits.
[UPDATED CODE AND HELP CAN BE FOUND HERE]
</a>
//+ Jonas Raoni Soares Silva
//@ http://jsfromhell.com/math/dot-line-length [v1.0]
dotLineLength = function( x, y, x0, y0, x1, y1, o ){
function lineLength( x, y, x0, y0 ){
return Math.sqrt( ( x -= x0 ) * x + ( y -= y0 ) * y );
}
if( o && !( o = function( x, y, x0, y0, x1, y1 ){
if( !( x1 - x0 ) ) return { x: x0, y: y };
else if( !( y1 - y0 ) ) return { x: x, y: y0 };
var left, tg = -1 / ( ( y1 - y0 ) / ( x1 - x0 ) );
return { x: left = ( x1 * ( x * tg - y + y0 ) + x0 * ( x * - tg + y - y1 ) ) / ( tg * ( x1 - x0 ) + y0 - y1 ), y: tg * left - tg * x + y };
}( x, y, x0, y0, x1, y1 ), o.x >= Math.min( x0, x1 ) && o.x <= Math.max( x0, x1 ) && o.y >= Math.min( y0, y1 ) && o.y <= Math.max( y0, y1 ) ) ){
var l1 = lineLength( x, y, x0, y0 ), l2 = lineLength( x, y, x1, y1 );
return l1 > l2 ? l2 : l1;
}
else {
var a = y0 - y1, b = x1 - x0, c = x0 * y1 - y0 * x1;
return Math.abs( a * x + b * y + c ) / Math.sqrt( a * a + b * b );
}
};
