/** * A time-based controller that operates with a single JavaScript object to * handle multiple simultaneous animation events. * * @author Dan Phiffer * @version 0.02 */ function HB_Animator() { this.framerate = 30; this.members = new Array(); } /** * animate([object]) * * Registers an animation sequence using an object with all the parameters that * define the animation. Each member is handled by a separate interval, which * then gets cleared at the conclusion of the animation sequence. The following * object parameters are recognized: * * target (required) * The DOM element to animate. * * property (optional) * The target property that will be manipulated. * * handler (optional) * A handler function to assign a value. Takes one value parameter. * * end_value (required) * The ending value of the animation target. * * duration (required) * The duration of the animation in milliseconds. * * start_value (optional) * The starting value of the animation target. This is required if * target is a function. Otherwise the animator tries to calculate the * starting value. * * motion (optional) * A function that sets the value on each iteration. A few of Robert * Penner's easing functions are included in this module ('animator' is * just an instance of HB_Animator): * animator.motion.linear (default) * animator.motion.quad_[in|out|both] * animator.motion.cubic_[in|out|both] * animator.motion.quart_[in|out|both] * animator.motion.quint_[in|out|both] * animator.motion.sine_[in|out|both] * animator.motion.expo_[in|out|both] * animator.motion.circ_[in|out|both] * animator.motion.bounce_[in|out|both] * animator.motion.back_[in|out|both] * animator.motion.elastic_[in|out|both] * */ HB_Animator.prototype.animate = function(member) { var period = Math.round(1000 / this.framerate); this.members.push(member); var id = this.members.length - 1; member.interval = window.setInterval('animator.iterate(animator.members[' + id + '])', period); } HB_Animator.prototype.iterate = function(member) { var now = new Date(); var time = now.getTime(); if (!member.is_setup) { member.start_time = time; animator.setup_member(member); } if (member.iterator && typeof(member.iterator) == 'function') { member.iterator(member); } if (time >= member.end_time) { member.value = member.end_value; if (typeof(member.callback) == 'function') { member.callback(member); } clearInterval(member.interval); } else { member.value = member.motion(time - member.start_time, parseFloat(member.start_value), parseFloat(member.end_value) - parseFloat(member.start_value), member.duration); if (typeof(member.handler) == 'function') { member.handler(member); } else if (typeof(member.property) != 'undefined') { eval('member.target.' + member.property + ' = ' + member.prefix + member.value + member.postfix); } } } HB_Animator.prototype.setup_member = function(member) { member.is_setup = true; with (member) { if (typeof(start_value) == 'undefined') { eval('member.start_value = parseFloat(member.target.' + member.property + ');'); } if (typeof(duration) == 'undefined') { member.duration = 0; } if (typeof(motion) != 'function') { member.motion = this.motion.linear; } if (typeof(prefix) == 'undefined') { member.prefix = ''; } if (typeof(postfix) == 'undefined') { member.postfix = ''; } } if (member.start_value == member.end_value) { member.end_time = member.start_time; } else { member.end_time = member.start_time + member.duration; member.value = member.start_value; } } /* * The following was adapted from Robert Penner's Easing Equations, which * were originally written for Flash. * * Available at http://www.robertpenner.com/easing/ * * Easing Equations (c) 2003 Robert Penner, all rights reserved. * This work is subject to the terms in http://www.robertpenner.com/easing_terms_of_use.html. */ HB_Animator.prototype.motion = new Object; // simple linear tweening - no easing // t: current time, b: beginning value, c: change in value, d: duration HB_Animator.prototype.motion.linear = function (t, b, c, d) { return c * t / d + b; } ///////////// QUADRATIC EASING: t^2 /////////////////// // quadratic easing in - accelerating from zero velocity // t: current time, b: beginning value, c: change in value, d: duration // t and d can be in frames or seconds/milliseconds HB_Animator.prototype.motion.quad_in = function (t, b, c, d) { return c*(t/=d)*t + b; } // quadratic easing out - decelerating to zero velocity HB_Animator.prototype.motion.quad_out = function (t, b, c, d) { return -c *(t/=d)*(t-2) + b; } // quadratic easing in/out - acceleration until halfway, then deceleration HB_Animator.prototype.motion.quad_both = function (t, b, c, d) { if ((t/=d/2) < 1) return c/2*t*t + b; return -c/2 * ((--t)*(t-2) - 1) + b; } ///////////// CUBIC EASING: t^3 /////////////////////// // cubic easing in - accelerating from zero velocity // t: current time, b: beginning value, c: change in value, d: duration // t and d can be frames or seconds/milliseconds HB_Animator.prototype.motion.cubic_in = function (t, b, c, d) { return c*(t/=d)*t*t + b; } // cubic easing out - decelerating to zero velocity HB_Animator.prototype.motion.cubic_out = function (t, b, c, d) { return c*((t=t/d-1)*t*t + 1) + b; } // cubic easing in/out - acceleration until halfway, then deceleration HB_Animator.prototype.motion.cubic_both = function (t, b, c, d) { if ((t/=d/2) < 1) return c/2*t*t*t + b; return c/2*((t-=2)*t*t + 2) + b; } ///////////// QUARTIC EASING: t^4 ///////////////////// // quartic easing in - accelerating from zero velocity // t: current time, b: beginning value, c: change in value, d: duration // t and d can be frames or seconds/milliseconds HB_Animator.prototype.motion.quart_in = function (t, b, c, d) { return c*(t/=d)*t*t*t + b; } // quartic easing out - decelerating to zero velocity HB_Animator.prototype.motion.quart_out = function (t, b, c, d) { return -c * ((t=t/d-1)*t*t*t - 1) + b; } // quartic easing in/out - acceleration until halfway, then deceleration HB_Animator.prototype.motion.quart_both = function (t, b, c, d) { if ((t/=d/2) < 1) return c/2*t*t*t*t + b; return -c/2 * ((t-=2)*t*t*t - 2) + b; } ///////////// QUINTIC EASING: t^5 //////////////////// // quintic easing in - accelerating from zero velocity // t: current time, b: beginning value, c: change in value, d: duration // t and d can be frames or seconds/milliseconds HB_Animator.prototype.motion.quint_in = function (t, b, c, d) { return c*(t/=d)*t*t*t*t + b; } // quintic easing out - decelerating to zero velocity HB_Animator.prototype.motion.quint_out = function (t, b, c, d) { return c*((t=t/d-1)*t*t*t*t + 1) + b; } // quintic easing in/out - acceleration until halfway, then deceleration HB_Animator.prototype.motion.quint_both = function (t, b, c, d) { if ((t/=d/2) < 1) return c/2*t*t*t*t*t + b; return c/2*((t-=2)*t*t*t*t + 2) + b; } ///////////// SINUSOIDAL EASING: sin(t) /////////////// // sinusoidal easing in - accelerating from zero velocity // t: current time, b: beginning value, c: change in position, d: duration HB_Animator.prototype.motion.sine_in = function (t, b, c, d) { return -c * Math.cos(t/d * (Math.PI/2)) + c + b; } // sinusoidal easing out - decelerating to zero velocity HB_Animator.prototype.motion.sine_out = function (t, b, c, d) { return c * Math.sin(t/d * (Math.PI/2)) + b; } // sinusoidal easing in/out - accelerating until halfway, then decelerating HB_Animator.prototype.motion.sine_both = function (t, b, c, d) { return -c/2 * (Math.cos(Math.PI*t/d) - 1) + b; } ///////////// EXPONENTIAL EASING: 2^t ///////////////// // exponential easing in - accelerating from zero velocity // t: current time, b: beginning value, c: change in position, d: duration HB_Animator.prototype.motion.expo_in = function (t, b, c, d) { return (t==0) ? b : c * Math.pow(2, 10 * (t/d - 1)) + b; } // exponential easing out - decelerating to zero velocity HB_Animator.prototype.motion.expo_out = function (t, b, c, d) { return (t==d) ? b+c : c * (-Math.pow(2, -10 * t/d) + 1) + b; } // exponential easing in/out - accelerating until halfway, then decelerating HB_Animator.prototype.motion.expo_both = function (t, b, c, d) { if (t==0) return b; if (t==d) return b+c; if ((t/=d/2) < 1) return c/2 * Math.pow(2, 10 * (t - 1)) + b; return c/2 * (-Math.pow(2, -10 * --t) + 2) + b; } /////////// CIRCULAR EASING: sqrt(1-t^2) ////////////// // circular easing in - accelerating from zero velocity // t: current time, b: beginning value, c: change in position, d: duration HB_Animator.prototype.motion.circ_in = function (t, b, c, d) { return -c * (Math.sqrt(1 - (t/=d)*t) - 1) + b; } // circular easing out - decelerating to zero velocity HB_Animator.prototype.motion.circ_out = function (t, b, c, d) { return c * Math.sqrt(1 - (t=t/d-1)*t) + b; } // circular easing in/out - acceleration until halfway, then deceleration HB_Animator.prototype.motion.circ_both = function (t, b, c, d) { if ((t/=d/2) < 1) return -c/2 * (Math.sqrt(1 - t*t) - 1) + b; return c/2 * (Math.sqrt(1 - (t-=2)*t) + 1) + b; } HB_Animator.prototype.motion.bounce_out = function (t, b, c, d) { if ((t/=d) < (1/2.75)) { return c*(7.5625*t*t) + b; } else if (t < (2/2.75)) { return c*(7.5625*(t-=(1.5/2.75))*t + .75) + b; } else if (t < (2.5/2.75)) { return c*(7.5625*(t-=(2.25/2.75))*t + .9375) + b; } else { return c*(7.5625*(t-=(2.625/2.75))*t + .984375) + b; } } HB_Animator.prototype.motion.bounce_in = function (t, b, c, d) { return c - HB_Animator.prototype.motion.bounce_out(d-t, 0, c, d) + b; } HB_Animator.prototype.motion.bounce_both = function (t, b, c, d) { if (t < d/2) return HB_Animator.prototype.motion.bounce_in(t*2, 0, c, d) * .5 + b; else return HB_Animator.prototype.motion.bounce_out(t*2-d, 0, c, d) * .5 + c*.5 + b; } HB_Animator.prototype.motion.back_in = function (t, b, c, d, s) { if (s == undefined) s = 1.70158; return c*(t/=d)*t*((s+1)*t - s) + b; } HB_Animator.prototype.motion.back_out = function (t, b, c, d, s) { if (s == undefined) s = 1.70158; return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b; } HB_Animator.prototype.motion.back_both = function (t, b, c, d, s) { if (s == undefined) s = 1.70158; if ((t/=d/2) < 1) return c/2*(t*t*(((s*=(1.525))+1)*t - s)) + b; return c/2*((t-=2)*t*(((s*=(1.525))+1)*t + s) + 2) + b; } HB_Animator.prototype.motion.elastic_in = function (t, b, c, d, a, p) { if (t==0) return b; if ((t/=d)==1) return b+c; if (!p) p=d*.3; if (!a || a < Math.abs(c)) { a=c; var s=p/4; } else var s = p/(2*Math.PI) * Math.asin (c/a); return -(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b; } HB_Animator.prototype.motion.elastic_out = function (t, b, c, d, a, p) { if (t==0) return b; if ((t/=d)==1) return b+c; if (!p) p=d*.3; if (!a || a < Math.abs(c)) { a=c; var s=p/4; } else var s = p/(2*Math.PI) * Math.asin (c/a); return (a*Math.pow(2,-10*t) * Math.sin( (t*d-s)*(2*Math.PI)/p ) + c + b); } HB_Animator.prototype.motion.elastic_both = function (t, b, c, d, a, p) { if (t==0) return b; if ((t/=d/2)==2) return b+c; if (!p) p=d*(.3*1.5); if (!a || a < Math.abs(c)) { a=c; var s=p/4; } else var s = p/(2*Math.PI) * Math.asin (c/a); if (t < 1) return -.5*(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b; return a*Math.pow(2,-10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )*.5 + c + b; }