84 lines
2.9 KiB
JavaScript
84 lines
2.9 KiB
JavaScript
/*jslint plusplus: true, vars: true, indent: 2 */
|
|
/* convertPointFromPageToNode.js from
|
|
<script src="https://gist.github.com/Yaffle/1145197.js"></script>
|
|
|
|
convertPointFromPageToNode(element, event.pageX, event.pageY) -> {x, y}
|
|
returns coordinate in element's local coordinate system (works properly
|
|
with css transforms without perspective projection)
|
|
convertPointFromNodeToPage(element, offsetX, offsetY) -> {x, y}
|
|
returns coordinate in window's coordinate system (works properly with
|
|
css transforms without perspective projection)
|
|
*/
|
|
|
|
(function () {
|
|
'use strict'
|
|
|
|
var I = (typeof(WebKitCSSMatrix) == 'undefined') ? new DOMMatrix() : new WebKitCSSMatrix()
|
|
|
|
function Point(x, y, z) {
|
|
this.x = x
|
|
this.y = y
|
|
this.z = z
|
|
}
|
|
|
|
Point.prototype.transformBy = function (matrix) {
|
|
var tmp = matrix.multiply(I.translate(this.x, this.y, this.z))
|
|
return new Point(tmp.m41, tmp.m42, tmp.m43)
|
|
}
|
|
|
|
function createMatrix(transform) {
|
|
try {
|
|
return (typeof(WebKitCSSMatrix) == 'undefined') ? new DOMMatrix(transform) : new WebKitCSSMatrix(transform)
|
|
} catch(e) {
|
|
console.warn(transform)
|
|
console.warn(e.toString())
|
|
return I
|
|
}
|
|
}
|
|
|
|
function getTransformationMatrix(element) {
|
|
var transformationMatrix = I
|
|
var x = element
|
|
|
|
while (x != undefined && x !== x.ownerDocument.documentElement) {
|
|
var computedStyle = window.getComputedStyle(x, undefined)
|
|
var transform = computedStyle.transform || 'none'
|
|
var c = transform === 'none' ? I : createMatrix(transform)
|
|
transformationMatrix = c.multiply(transformationMatrix)
|
|
x = x.parentNode
|
|
}
|
|
|
|
var w = element.offsetWidth
|
|
var h = element.offsetHeight
|
|
var i = 4
|
|
var left = +Infinity
|
|
var top = +Infinity
|
|
while (--i >= 0) {
|
|
var p = new Point(i === 0 || i === 1 ? 0 : w, i === 0 || i === 3 ? 0 : h,
|
|
0).transformBy(transformationMatrix)
|
|
if (p.x < left) {
|
|
left = p.x
|
|
}
|
|
if (p.y < top) {
|
|
top = p.y
|
|
}
|
|
}
|
|
var rect = element.getBoundingClientRect()
|
|
transformationMatrix = I.translate(window.pageXOffset + rect.left - left,
|
|
window.pageYOffset + rect.top - top, 0)
|
|
.multiply(transformationMatrix)
|
|
return transformationMatrix
|
|
}
|
|
|
|
window.convertPointFromPageToNode = function (element, pageX, pageY) {
|
|
return new Point(pageX, pageY, 0).transformBy(
|
|
getTransformationMatrix(element).inverse())
|
|
}
|
|
|
|
window.convertPointFromNodeToPage = function (element, offsetX, offsetY) {
|
|
return new Point(offsetX, offsetY, 0).transformBy(
|
|
getTransformationMatrix(element))
|
|
}
|
|
|
|
}())
|