anim-curve.js revision aca18adfbc860a76fb2e4bee2f2e1d3b89c52b1b
YUI.add('anim-curve', function(Y) {
/**
* Adds support for the <code>curve</code> property for the <code>to</code>
* attribute. A curve is zero or more control points and an end point.
* @module anim
* @submodule anim-curve
*/
Y.Anim.behaviors.curve = {
set: function(anim, att, from, to, elapsed, duration, fn) {
from = from.slice.call(from);
to = to.slice.call(to);
var t = fn(elapsed, 0, 100, duration) / 100;
to.unshift(from);
anim._node.setXY(Y.Anim.getBezier(to, t));
},
get: function(anim, att) {
return anim._node.getXY();
}
};
/**
* Get the current position of the animated element based on t.
* Each point is an array of "x" and "y" values (0 = x, 1 = y)
* At least 2 points are required (start and end).
* First point is start. Last point is end.
* Additional control points are optional.
* @for Anim
* @method getBezier
* @static
* @param {Array} points An array containing Bezier points
* @param {Number} t A number between 0 and 1 which is the basis for determining current position
* @return {Array} An array containing int x and y member data
*/
Y.Anim.getBezier = function(points, t) {
var n = points.length;
var tmp = [];
for (var i = 0; i < n; ++i){
tmp[i] = [points[i][0], points[i][1]]; // save input
}
for (var j = 1; j < n; ++j) {
for (i = 0; i < n - j; ++i) {
tmp[i][0] = (1 - t) * tmp[i][0] + t * tmp[parseInt(i + 1, 10)][0];
tmp[i][1] = (1 - t) * tmp[i][1] + t * tmp[parseInt(i + 1, 10)][1];
}
}
return [ tmp[0][0], tmp[0][1] ];
};
}, '@VERSION@' ,{requires:['anim-xy']});