Find the place of a cursor in rectangle
I don't know how to find the place part (one of 4 triangles) of a cursor in a rectangle.
This image is more efficient than my explic开发者_C百科ation :s
Im in javascript (so the rectangle is a DIV, 0,0 placed) I have those varaibles :
var cursor_x = e.clientX + $(document).scrollLeft()
var cursor_y = e.clientY + $(document).scrollTop()
var rect_w = $( rectangle ).width()
var rect_h = $( rectangle ).height()
I just want to know mathematically where is the cursor, in the triangle 1, 2, 3 or 4
What I think is the easiest way is to first normalize y
so the computation is the same as for a square and then check for on which side of the diagonals you are...
var ynorm = y * w / h;
var s1 = x > ynorm ? 0 : 1;
var s2 = (w - x) > ynorm ? 0 : 1;
var area = s1*2 + s2;
the final area
variable is a number between 0 and 3 telling in which of the four parts you are.
@6502: Thk you, its very helpful.
For more info, im working on an experimental light sortable jquery plugin, that can work with floating placement (top, left, right, bottom)
the code :
simply use $( ..selector.. ).sortable({ items: ..selector.. })
-
$.fn.sortable = function( o ) {
o.self = this;
o.helper = null;
$(document).bind('mouseup.sortable', function(e) {
if( o.sortable ) {
o.sortable.css({ opacity: ''});
if( o.target ) {
if( o.area == 's' ) {
o.sortable.css({ float: '' })
}
else if( o.area == 'n' ) {
o.sortable.css({ float: '' })
o.target.css({ float: '' })
}
else if( o.area == 'w' ) {
o.target.css({ float: 'left' })
o.sortable.css({ float: 'left' })
}
else if( o.area == 'e' ) {
o.target.css({ float: 'left' })
o.sortable.css({ float: 'left' })
}
o.target[ o.area == 's' || o.area == 'e' ? 'before':'after']( o.sortable );
o.target[0].style.setProperty( 'cursor', false , false);
o.target = null;
}
o.helper.remove();
o.sortable = null;
}
}).bind('mousemove.sortable', function(e) {
if( o.sortable ) {
o.ex = e.clientX + $(document).scrollLeft() + 10
o.ey = e.clientY + $(document).scrollTop() - o.sortable[0]._height - 10
o.helper.css({ left: o.ex, top: o.ey });
}
});
return $( this.selector ).delegate( o.items, 'mousemove.sortable', function(e) {
if( o.sortable && o.sortable[0] != this ) {
var self = $(this)
var x = e.clientX + $(document).scrollLeft() - self.offset().left
var y = e.clientY + $(document).scrollTop() - self.offset().top
var w = self.width()
var h = self.height()
var ynorm = y * w / h;
o.area = (w - x) > ynorm ? ( x > ynorm ? 's':'e' ) : ( x > ynorm ? 'w':'n' );
this.style.setProperty( 'cursor', o.area+'-resize', 'important');
o.target = self;
}
}).delegate( o.items, 'mousedown.sortable', function( e ) {
o.sortable = $(this).css({ opacity: 0.4 });
this._width = o.sortable.width();
this._height = o.sortable.height();
o.helper = o.sortable.clone().css({ position: 'absolute', left: -99999, top: 0 })
$('body').append( o.helper )
return false;
});
}
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