topical media & game development
lib-flex-animation-code-10-caurina-transitions-properties-CurveModifiers.ax
lib-flex-animation-code-10-caurina-transitions-properties-CurveModifiers.ax
(swf
)
[ flash
]
flex
package caurina.transitions.properties {
properties.@ax-lib-flex-animation-code-10-caurina-transitions-properties-CurveModifiers
List of default special properties modifiers for the Tweener class
The function names are strange/inverted because it makes for easier debugging (alphabetic order). They're only for internal use (on this class) anyways.
@author Zeh Fernando, Nate Chatellier, Arthur Debert
@version 1.0.0
import caurina.transitions.Tweener;
public class @ax-lib-flex-animation-code-10-caurina-transitions-properties-CurveModifiers {
There's no constructor.
public function @ax-lib-flex-animation-code-10-caurina-transitions-properties-CurveModifiers () {
trace ("This is an static class and should not be instantiated.")
}
Registers all the special properties to the Tweener class, so the Tweener knows what to do with them.
public static function init(): void {
// Bezier modifiers
Tweener.registerSpecialPropertyModifier("_bezier", _bezier_modifier, _bezier_get);
}
// ==================================================================================================================================
// SPECIAL PROPERTY MODIFIER functions ----------------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------------------------------------------------
// _bezier
Given the parameter object passed to this special property, return an array listing the properties that should be modified, and their parameters
@param p_obj Object Parameter passed to this property
@return Array Array listing name and parameter of each property
public static function _bezier_modifier (p_obj:*):Array {
var mList:Array = []; // List of properties to be modified
var pList:Array; // List of parameters passed, normalized as an array
if (p_obj is Array) {
// Complex
pList = p_obj;
} else {
pList = [p_obj];
}
var i:uint;
var istr:String;
var mListObj:Object = {}; // Object describing each property name and parameter
for (i = 0; i < pList.length; i++) {
for (istr in pList[i]) {
if (mListObj[istr] == undefined) mListObj[istr] = [];
mListObj[istr].push(pList[i][istr]);
}
}
for (istr in mListObj) {
mList.push({name:istr, parameters:mListObj[istr]});
}
return mList;
}
Given tweening specifications (beging, end, t), applies the property parameter to it, returning new t
@param b Number Beginning value of the property
@param e Number Ending (desired) value of the property
@param t Number Current t of this tweening (0-1), after applying the easing equation
@param p Array Array of parameters passed to this specific property
@return Number New t, with the p parameters applied to it
public static function _bezier_get (b:Number, e:Number, t:Number, p:Array):Number {
// This is based on Robert Penner's code
if (p.length == 1) {
// Simple curve with just one bezier control point
return b + t*(2*(1-t)*(p[0]-b) + t*(e - b));
} else {
// Array of bezier control points, must find the point between each pair of bezier points
var ip:uint = Math.floor(t * p.length); // Position on the bezier list
var it:Number = (t - (ip * (1 / p.length))) * p.length; // t inside this ip
var p1:Number, p2:Number;
if (ip == 0) {
// First part: belongs to the first control point, find second midpoint
p1 = b;
p2 = (p[0]+p[1])/2;
} else if (ip == p.length - 1) {
// Last part: belongs to the last control point, find first midpoint
p1 = (p[ip-1]+p[ip])/2;
p2 = e;
} else {
// Any middle part: find both midpoints
p1 = (p[ip-1]+p[ip])/2;
p2 = (p[ip]+p[ip+1])/2;
}
return p1+it*(2*(1-it)*(p[ip]-p1) + it*(p2 - p1));
}
}
}
}
(C) Æliens
18/6/2009
You may not copy or print any of this material without explicit permission of the author or the publisher.
In case of other copyright issues, contact the author.
