On Wed, Aug 31, 2011 at 10:52 AM, David Geary <[email protected]> wrote: > In a previous email titled ‘Should Paths be First Class Citizens’, I briefly > discussed this code snippet: > > context.canvas.onmousedown = function (e) { > var loc = windowToCanvas(context.canvas, e); > > polygons.forEach( function (polygon) { // polygons is an array of > polygon objects > polygon.createPath(); // my polygons have a createPath() method > > if (context.isPointInPath(loc.x, loc.y)) { > alert('mouse clicked in polygon'); > } > }); > } > > I implemented the windowToCanvas() myself. That methods’s not too difficult > to implement after you know how to do it properly, but it’s not very > straightforward to implement if you are new to web development. > > Would it make sense to add such a method to the Canvas specification?
I assume this just translates window-relative coordinates to element-relative coordinates. Yes, that sort of thing is useful, but it's nothing to do with canvas specifically - it would be useful for every element if it were easier to do that sort of thing. ~TJ
