var dirRegexp = /^([+\-])(.+)/;
/**
* Performs an operation on two paper.Point() objects.
* Returns the result of : ` a operator b`.
* @private
* @method _pointDiff
* @param {Object} a a `paper.Point` object
* @param {Object} b a `paper.Point` object
* @param {String} operator either `+` or `-`
* @return {Object} `{x: (a.x operator b.x), y: (a.y operator b.y)}`
* @for Tween
*/
function _pointDiff(a, b, operator) {
if (['+', '-'].indexOf(operator) === -1) return;
if (typeof a === "undefined" || typeof b === "undefined") return;
var ax, bx, ay, by;
ax = a.x || 0;
bx = b.x || 0;
ay = a.y || 0;
by = b.y || 0;
if( operator === '+' ){
return a.add(b);
}
if( operator === '-' ){
return a.subtract(b);
}
throw new Error('Unknown operator');
}
// inspired by https://github.com/jquery/jquery/blob/10399ddcf8a239acc27bdec9231b996b178224d3/src/effects/Tween.js
/**
* Helpers to get, set and ease properties that behave differently from "normal" properties. e.g. `scale`.
* @class _tweenPropHooks
* @private
* @static
*/
var _tweenPropHooks = {
_default: {
get: function(tween) {
var output;
if (tween.item[tween.prop] != null) {
output = tween.item[tween.prop];
}
return output;
},
set: function(tween) {
var toSet = {};
toSet[tween.prop] = tween.now;
tween.item.set(toSet);
}
},
scale: {
get: function(tween) {
if (!tween.item.data._animatePaperVals) {
tween.item.data._animatePaperVals = {};
}
if (typeof tween.item.data._animatePaperVals.scale === "undefined") {
tween.item.data._animatePaperVals.scale = 1;
}
var output = tween.item.data._animatePaperVals.scale;
return output;
},
set: function(tween) {
var curScaling = tween.item.data._animatePaperVals.scale;
var trueScaling = tween.now / curScaling;
tween.item.data._animatePaperVals.scale = tween.now;
var center = false;
if (typeof tween.A.settings.center !== "undefined") {
center = tween.A.settings.center;
}
if (typeof tween.A.settings.scaleCenter !== "undefined") {
center = tween.A.settings.scaleCenter;
}
if (center !== false) {
tween.item.scale(trueScaling, center);
} else {
tween.item.scale(trueScaling);
}
}
},
rotate: {
get: function(tween) {
if (!tween.item.data._animatePaperVals) {
tween.item.data._animatePaperVals = {};
}
if (typeof tween.item.data._animatePaperVals.rotate === "undefined") {
tween.item.data._animatePaperVals.rotate = -0;
}
var output = tween.item.data._animatePaperVals.rotate;
return output;
},
set: function(tween) {
var curRotate = tween.item.data._animatePaperVals.rotate;
var trueRotate = tween.now - curRotate;
tween.item.data._animatePaperVals.rotate = tween.now;
var center = false;
if (typeof tween.A.settings.center !== "undefined") {
center = tween.A.settings.center;
}
if (typeof tween.A.settings.rotateCenter !== "undefined") {
center = tween.A.settings.rotateCenter;
}
if (center !== false) {
tween.item.rotate(trueRotate, center);
} else {
tween.item.rotate(trueRotate);
}
}
},
translate: {
get: function(tween) {
if (!tween.item.data._animatePaperVals) {
tween.item.data._animatePaperVals = {};
}
if (typeof tween.item.data._animatePaperVals.translate === "undefined") {
tween.item.data._animatePaperVals.translate = new paper.Point(0, 0);
}
var output = tween.item.data._animatePaperVals.translate;
return output;
},
set: function(tween) {
var cur = tween.item.data._animatePaperVals.translate;
var actual = _pointDiff(tween.now, cur, "-");
tween.item.data._animatePaperVals.translate = tween.now;
tween.item.translate(actual);
},
ease: function(tween, eased) {
var temp = _pointDiff(tween.end, tween.start, "-");
temp.x = temp.x * eased;
temp.y = temp.y * eased;
tween.now = _pointDiff(temp, tween.start, "+");
return tween.now;
}
},
position: {
get: function(tween) {
return {
x: tween.item.position.x,
y: tween.item.position.y
};
},
set: function(tween) {
tween.item.position.x += tween.now.x;
tween.item.position.y += tween.now.y;
},
ease: function(tween, eased) {
// If the values start with + or -,
// the values are relative to the current pos
var dirX = "";
var dirY = "";
var rX = null;
var rY = null;
// used to store value progess
if(typeof tween._easePositionCache === "undefined") {
tween._easePositionCache = {
x: 0,
y: 0
}
}
var endX = Number(tween.end.x || 0);
var endY = Number(tween.end.y || 0);
if(!!tween.end.x) var rX = (""+tween.end.x).match(dirRegexp);
if(!!tween.end.y) var rY = (""+tween.end.y).match(dirRegexp);
if(!!rX) {
dirX = rX[1];
endX = Number(rX[2]);
}
if(!!rY) {
dirY = rY[1];
endY = Number(rY[2]);
}
var _ease = function(val) {
return ((val || 0) * eased);
};
if(typeof tween.end.x !== "undefined") {
if(dirX==="+") {
tween.now.x = (_ease(endX) - tween._easePositionCache.x);
tween._easePositionCache.x += tween.now.x;
}
else if(dirX==="-") {
tween.now.x = _ease(endX) - tween._easePositionCache.x;
tween._easePositionCache.x += tween.now.x;
tween.now.x = - tween.now.x;
}
else {
// absolute, not relative
tween.now.x = ((endX - tween.start.x) * eased) - tween._easePositionCache.x;
tween._easePositionCache.x += tween.now.x;
}
}
else {
tween.now.x = 0;
}
if(typeof tween.end.y !== "undefined") {
if(dirY==="+") {
tween.now.y = _ease(endY) - tween._easePositionCache.y;
tween._easePositionCache.y += tween.now.y;
}
else if(dirY==="-") {
tween.now.y = _ease(endY) - tween._easePositionCache.y;
tween._easePositionCache.y += tween.now.y;
tween.now.y = - tween.now.y;
}
else {
// absolute, not relative
tween.now.y = ((endY - tween.start.y) * eased) - tween._easePositionCache.y;
tween._easePositionCache.y += tween.now.y;
}
}
else {
tween.now.y = 0;
}
return tween.now;
}
},
pointPosition: {
get: function(tween) {
return {
x: tween.item.x,
y: tween.item.y
};
},
set: function(tween) {
tween.item.x += tween.now.x;
tween.item.y += tween.now.y;
},
ease: function(tween, eased) {
// If the values start with + or -,
// the values are relative to the current pos
var dirX = "";
var dirY = "";
var rX = null;
var rY = null;
// used to store value progess
if(typeof tween._easePositionCache === "undefined") {
tween._easePositionCache = {
x: 0,
y: 0
}
}
var endX = Number(tween.end.x || 0);
var endY = Number(tween.end.y || 0);
if(!!tween.end.x) var rX = (""+tween.end.x).match(dirRegexp);
if(!!tween.end.y) var rY = (""+tween.end.y).match(dirRegexp);
if(!!rX) {
dirX = rX[1];
endX = Number(rX[2]);
}
if(!!rY) {
dirY = rY[1];
endY = Number(rY[2]);
}
var _ease = function(val) {
return ((val || 0) * eased);
};
if(typeof tween.end.x !== "undefined") {
if(dirX==="+") {
tween.now.x = (_ease(endX) - tween._easePositionCache.x);
tween._easePositionCache.x += tween.now.x;
}
else if(dirX==="-") {
tween.now.x = _ease(endX) - tween._easePositionCache.x;
tween._easePositionCache.x += tween.now.x;
tween.now.x = - tween.now.x;
}
else {
// absolute, not relative
tween.now.x = ((endX - tween.start.x) * eased) - tween._easePositionCache.x;
tween._easePositionCache.x += tween.now.x;
}
}
else {
tween.now.x = 0;
}
if(typeof tween.end.y !== "undefined") {
if(dirY==="+") {
tween.now.y = _ease(endY) - tween._easePositionCache.y;
tween._easePositionCache.y += tween.now.y;
}
else if(dirY==="-") {
tween.now.y = _ease(endY) - tween._easePositionCache.y;
tween._easePositionCache.y += tween.now.y;
tween.now.y = - tween.now.y;
}
else {
// absolute, not relative
tween.now.y = ((endY - tween.start.y) * eased) - tween._easePositionCache.y;
tween._easePositionCache.y += tween.now.y;
}
}
else {
tween.now.y = 0;
}
return tween.now;
}
},
Color: {
get: function(tween) {
if (typeof (tween.end[ "lightness" ] !== "undefined")) {
return {
hue: tween.item[tween.prop].hue,
lightness: tween.item[tween.prop].lightness,
saturation: tween.item[tween.prop].saturation
};
} else {
return {
hue: tween.item[tween.prop].hue,
brightness: tween.item[tween.prop].brightness,
saturation: tween.item[tween.prop].saturation
};
}
},
set: function(tween) {
tween.item[tween.prop].hue += tween.now.hue;
if (typeof tween.end[ "lightness" ] !== "undefined") {
tween.item[tween.prop].lightness += tween.now.lightness;
} else {
tween.item[tween.prop].brightness += tween.now.brightness;
}
tween.item[tween.prop].saturation += tween.now.saturation;
},
ease: function(tween, eased) {
var props = [];
if (typeof tween.end[ "lightness" ] !== "undefined") {
props = [ "hue", "saturation", "lightness" ];
} else {
props = [ "hue", "brightness", "saturation" ];
}
var _ease = function(val) {
return (val || 0) * eased;
};
for (var i = 0, l = props.length; i < l; i++) {
var curProp = props[i];
var dir = "";
var r = "";
if (typeof tween._easeColorCache === "undefined") {
tween._easeColorCache = {};
}
if (typeof tween._easeColorCache[curProp] === "undefined") {
tween._easeColorCache[curProp] = 0;
}
var end = Number(tween.end[curProp] || 0);
if (!!tween.end[curProp]) var r = ("" + tween.end[curProp]).match(dirRegexp);
if (!!r) {
dir = r[1];
end = Number(r[2]);
}
if (typeof tween.end[curProp] !== "undefined") {
if (dir === "+") {
tween.now[curProp] = _ease(end) - tween._easeColorCache[curProp];
tween._easeColorCache[curProp] += tween.now[curProp];
} else if (dir === "-") {
tween.now[curProp] = _ease(end) - tween._easeColorCache[curProp];
tween._easeColorCache[curProp] += tween.now[curProp];
tween.now[curProp] = -tween.now[curProp];
} else {
tween.now[curProp] = (end - tween.start[curProp]) * eased - tween._easeColorCache[curProp];
tween._easeColorCache[curProp] += tween.now[curProp];
}
} else {
tween.now[curProp] = 0;
}
}
return tween.now;
}
}
};
var _colorProperties = [ "fill", "stroke" ];
for (var i = 0, l = _colorProperties.length; i < l; i++) {
_tweenPropHooks[_colorProperties[i] + "Color"] = _tweenPropHooks.Color;
}
module.exports = {
_tweenPropHooks: _tweenPropHooks,
_pointDiff: _pointDiff,
extendPropHooks: function(customHooks) {
for (var i in customHooks) {
if (customHooks.hasOwnProperty(i)) {
_tweenPropHooks[i] = customHooks[i];
}
}
}
};
