ridder
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A straightforward game engine for simple data-driven games in JavaScript
266 lines (261 loc) • 8.2 kB
JavaScript
/*
Copyright © 2001 Robert Penner
All rights reserved.
Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:
Redistributions of source code must retain the above copyright notice, this list of
conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list
of conditions and the following disclaimer in the documentation and/or other materials
provided with the distribution.
Neither the name of the author nor the names of contributors may be used to endorse
or promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
OF THE POSSIBILITY OF SUCH DAMAGE.
*/
const easeOutBounce = 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 + 0.75) + b;
}
else if (t < 2.5 / 2.75) {
return c * (7.5625 * (t -= 2.25 / 2.75) * t + 0.9375) + b;
}
else {
return c * (7.5625 * (t -= 2.625 / 2.75) * t + 0.984375) + b;
}
};
const easeInBounce = function (t, b, c, d) {
const v = easeOutBounce(d - t, 0, c, d);
return c - v + b;
};
const easeInOutBounce = function (t, b, c, d) {
if (t < d / 2) {
const v = easeInBounce(t * 2, 0, c, d);
return v * 0.5 + b;
}
else {
const v = easeOutBounce(t * 2 - d, 0, c, d);
return v * 0.5 + c * 0.5 + b;
}
};
export const easings = {
linear: function (t, b, c, d) {
return (c * t) / d + b;
},
easeInQuad: function (t, b, c, d) {
return c * (t /= d) * t + b;
},
easeOutQuad: function (t, b, c, d) {
return -c * (t /= d) * (t - 2) + b;
},
easeInOutQuad: function (t, b, c, d) {
if ((t /= d / 2) < 1) {
return (c / 2) * t * t + b;
}
else {
return (-c / 2) * (--t * (t - 2) - 1) + b;
}
},
easeInCubic: function (t, b, c, d) {
return c * (t /= d) * t * t + b;
},
easeOutCubic: function (t, b, c, d) {
return c * ((t = t / d - 1) * t * t + 1) + b;
},
easeInOutCubic: function (t, b, c, d) {
if ((t /= d / 2) < 1) {
return (c / 2) * t * t * t + b;
}
else {
return (c / 2) * ((t -= 2) * t * t + 2) + b;
}
},
easeInQuart: function (t, b, c, d) {
return c * (t /= d) * t * t * t + b;
},
easeOutQuart: function (t, b, c, d) {
return -c * ((t = t / d - 1) * t * t * t - 1) + b;
},
easeInOutQuart: function (t, b, c, d) {
if ((t /= d / 2) < 1) {
return (c / 2) * t * t * t * t + b;
}
else {
return (-c / 2) * ((t -= 2) * t * t * t - 2) + b;
}
},
easeInQuint: function (t, b, c, d) {
return c * (t /= d) * t * t * t * t + b;
},
easeOutQuint: function (t, b, c, d) {
return c * ((t = t / d - 1) * t * t * t * t + 1) + b;
},
easeInOutQuint: function (t, b, c, d) {
if ((t /= d / 2) < 1) {
return (c / 2) * t * t * t * t * t + b;
}
else {
return (c / 2) * ((t -= 2) * t * t * t * t + 2) + b;
}
},
easeInSine: function (t, b, c, d) {
return -c * Math.cos((t / d) * (Math.PI / 2)) + c + b;
},
easeOutSine: function (t, b, c, d) {
return c * Math.sin((t / d) * (Math.PI / 2)) + b;
},
easeInOutSine: function (t, b, c, d) {
return (-c / 2) * (Math.cos((Math.PI * t) / d) - 1) + b;
},
easeInExpo: function (t, b, c, d) {
if (t === 0) {
return b;
}
else {
return c * Math.pow(2, 10 * (t / d - 1)) + b;
}
},
easeOutExpo: function (t, b, c, d) {
if (t === d) {
return b + c;
}
else {
return c * (-Math.pow(2, (-10 * t) / d) + 1) + b;
}
},
easeInOutExpo: function (t, b, c, d) {
if (t === 0) {
b;
}
if (t === d) {
b + c;
}
if ((t /= d / 2) < 1) {
return (c / 2) * Math.pow(2, 10 * (t - 1)) + b;
}
else {
return (c / 2) * (-Math.pow(2, -10 * --t) + 2) + b;
}
},
easeInCirc: function (t, b, c, d) {
return -c * (Math.sqrt(1 - (t /= d) * t) - 1) + b;
},
easeOutCirc: function (t, b, c, d) {
return c * Math.sqrt(1 - (t = t / d - 1) * t) + b;
},
easeInOutCirc: function (t, b, c, d) {
if ((t /= d / 2) < 1) {
return (-c / 2) * (Math.sqrt(1 - t * t) - 1) + b;
}
else {
return (c / 2) * (Math.sqrt(1 - (t -= 2) * t) + 1) + b;
}
},
easeInElastic: function (t, b, c, d) {
let s = 1.70158;
let p = 0;
let a = c;
if (t === 0) {
b;
}
else if ((t /= d) === 1) {
b + c;
}
if (!p) {
p = d * 0.3;
}
if (a < Math.abs(c)) {
a = c;
s = p / 4;
}
else {
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;
},
easeOutElastic: function (t, b, c, d) {
let s = 1.70158;
let p = 0;
let a = c;
if (t === 0) {
b;
}
else if ((t /= d) === 1) {
b + c;
}
if (!p) {
p = d * 0.3;
}
if (a < Math.abs(c)) {
a = c;
s = p / 4;
}
else {
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;
},
easeInOutElastic: function (t, b, c, d) {
let s = 1.70158;
let p = 0;
let a = c;
if (t === 0) {
b;
}
else if ((t /= d / 2) === 2) {
b + c;
}
if (!p) {
p = d * (0.3 * 1.5);
}
if (a < Math.abs(c)) {
a = c;
s = p / 4;
}
else {
s = (p / (2 * Math.PI)) * Math.asin(c / a);
}
if (t < 1) {
return -0.5 * (a * Math.pow(2, 10 * (t -= 1)) * Math.sin(((t * d - s) * (2 * Math.PI)) / p)) + b;
}
else {
return a * Math.pow(2, -10 * (t -= 1)) * Math.sin(((t * d - s) * (2 * Math.PI)) / p) * 0.5 + c + b;
}
},
easeInBack: function (t, b, c, d, s) {
if (s === undefined) {
s = 1.70158;
}
return c * (t /= d) * t * ((s + 1) * t - s) + b;
},
easeOutBack: 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;
},
easeInOutBack: 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;
}
else {
return (c / 2) * ((t -= 2) * t * (((s *= 1.525) + 1) * t + s) + 2) + b;
}
},
easeInBounce,
easeOutBounce,
easeInOutBounce,
};