diff --git a/src/easings.h b/src/easings.h new file mode 100644 index 00000000..55dce0df --- /dev/null +++ b/src/easings.h @@ -0,0 +1,219 @@ +/******************************************************************************************* +* +* raylib Easings - Useful easing functions for values animation +* +* A port of Robert Penner's easing equations to C (http://robertpenner.com/easing/) +* +* Robert Penner License +* --------------------------------------------------------------------------------- +* Open source under the BSD License. +* +* Copyright (c) 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. +* --------------------------------------------------------------------------------- +* +* Copyright (c) 2015 Ramon Santamaria +* +* This software is provided "as-is", without any express or implied warranty. In no event +* will the authors be held liable for any damages arising from the use of this software. +* +* Permission is granted to anyone to use this software for any purpose, including commercial +* applications, and to alter it and redistribute it freely, subject to the following restrictions: +* +* 1. The origin of this software must not be misrepresented; you must not claim that you +* wrote the original software. If you use this software in a product, an acknowledgment +* in the product documentation would be appreciated but is not required. +* +* 2. Altered source versions must be plainly marked as such, and must not be misrepresented +* as being the original software. +* +* 3. This notice may not be removed or altered from any source distribution. +* +**********************************************************************************************/ + +#ifndef EASINGS_H +#define EASINGS_H + +#include + +#ifdef __cplusplus +extern "C" { // Prevents name mangling of functions +#endif + +// Linear Easing functions +float EaseLinearNone(float t, float b, float c, float d) { return (c*t/d + b); } +float EaseLinearIn(float t, float b, float c, float d) { return (c*t/d + b); } +float EaseLinearOut(float t, float b, float c, float d) { return (c*t/d + b); } +float EaseLinearInOut(float t,float b, float c, float d) { return (c*t/d + b); } + +// Sine Easing functions +float EaseSineIn(float t, float b, float c, float d) { return (-c*cos(t/d*(PI/2)) + c + b); } +float EaseSineOut(float t, float b, float c, float d) { return (c*sin(t/d*(PI/2)) + b); } +float EaseSineInOut(float t, float b, float c, float d) { return (-c/2*(cos(PI*t/d) - 1) + b); } + +// Circular Easing functions +float EaseCircIn(float t, float b, float c, float d) { return (-c*(sqrt(1 - (t/=d)*t) - 1) + b); } +float EaseCircOut(float t, float b, float c, float d) { return (c*sqrt(1 - (t=t/d-1)*t) + b); } +float EaseCircInOut(float t, float b, float c, float d) +{ + if ((t/=d/2) < 1) return (-c/2*(sqrt(1 - t*t) - 1) + b); + return (c/2*(sqrt(1 - t*(t-=2)) + 1) + b); +} + +// Cubic Easing functions +float EaseCubicIn(float t, float b, float c, float d) { return (c*(t/=d)*t*t + b); } +float EaseCubicOut(float t, float b, float c, float d) { return (c*((t=t/d-1)*t*t + 1) + b); } +float EaseCubicInOut(float t, float b, float c, float d) +{ + if ((t/=d/2) < 1) return (c/2*t*t*t + b); + return (c/2*((t-=2)*t*t + 2) + b); +} + +// Quadratic Easing functions +float EaseQuadIn(float t, float b, float c, float d) { return (c*(t/=d)*t + b); } +float EaseQuadOut(float t, float b, float c, float d) { return (-c*(t/=d)*(t-2) + b); } +float EaseQuadInOut(float t, float b, float c, float d) +{ + if ((t/=d/2) < 1) return (((c/2)*(t*t)) + b); + return (-c/2*(((t-2)*(--t)) - 1) + b); +} + +// Exponential Easing functions +float EaseExpoIn(float t, float b, float c, float d) { return (t == 0) ? b : (c*pow(2, 10*(t/d - 1)) + b); } +float EaseExpoOut(float t, float b, float c, float d) { return (t == d) ? (b + c) : (c*(-pow(2, -10*t/d) + 1) + b); } +float EaseExpoInOut(float t, float b, float c, float d) +{ + if (t == 0) return b; + if (t == d) return (b + c); + if ((t/=d/2) < 1) return (c/2*pow(2, 10*(t - 1)) + b); + + return (c/2*(-pow(2, -10*--t) + 2) + b); +} + +// Back Easing functions +float EaseBackIn(float t, float b, float c, float d) +{ + float s = 1.70158f; + float postFix = t/=d; + return (c*(postFix)*t*((s + 1)*t - s) + b); +} + +float EaseBackOut(float t, float b, float c, float d) +{ + float s = 1.70158f; + return (c*((t=t/d-1)*t*((s + 1)*t + s) + 1) + b); +} + +float EaseBackInOut(float t, float b, float c, float d) +{ + float s = 1.70158f; + if ((t/=d/2) < 1) return (c/2*(t*t*(((s*=(1.525f)) + 1)*t - s)) + b); + + float postFix = t-=2; + return (c/2*((postFix)*t*(((s*=(1.525f)) + 1)*t + s) + 2) + b); +} + +// Bounce Easing functions +float EaseBounceIn(float t, float b, float c, float d) { return (c - EaseBounceOut(d-t, 0, c, d) + b); } +float EaseBounceOut(float t, float b, float c, float d) +{ + if ((t/=d) < (1/2.75f)) + { + return (c*(7.5625f*t*t) + b); + } + else if (t < (2/2.75f)) + { + float postFix = t-=(1.5f/2.75f); + return (c*(7.5625f*(postFix)*t + 0.75f) + b); + } + else if (t < (2.5/2.75)) + { + float postFix = t-=(2.25f/2.75f); + return (c*(7.5625f*(postFix)*t + 0.9375f) + b); + } + else + { + float postFix = t-=(2.625f/2.75f); + return (c*(7.5625f*(postFix)*t + 0.984375f) + b); + } +} + +float EaseBounceInOut(float t, float b, float c, float d) +{ + if (t < d/2) return (EaseBounceIn(t*2, 0, c, d)*0.5f + b); + else return (EaseBounceOut(t*2-d, 0, c, d)*0.5f + c*0.5f + b); +} + +// Elastic Easing functions +float EaseElasticIn(float t, float b, float c, float d) +{ + if (t == 0) return b; + if ((t/=d) == 1) return (b + c); + + float p = d*0.3f; + float a = c; + float s = p/4; + float postFix = a*pow(2, 10*(t-=1)); + + return (-(postFix*sin((t*d-s)*(2*PI)/p )) + b); +} + +float EaseElasticOut(float t, float b, float c, float d) +{ + if (t == 0) return b; + if ((t/=d) == 1) return (b + c); + + float p = d*0.3f; + float a = c; + float s = p/4; + + return (a*pow(2,-10*t)*sin((t*d-s)*(2*PI)/p) + c + b); +} + +float EaseElasticInOut(float t, float b, float c, float d) +{ + if (t == 0) return b; + if ((t/=d/2) == 2) return (b + c); + + float p = d*(0.3f*1.5f); + float a = c; + float s = p/4; + + if (t < 1) + { + float postFix = a*pow(2, 10*(t-=1)); + return -0.5f*(postFix*sin((t*d-s)*(2*PI)/p)) + b; + } + + float postFix = a*pow(2, -10*(t-=1)); + + return (postFix*sin((t*d-s)*(2*PI)/p)*0.5f + c + b); +} + +#ifdef __cplusplus +} +#endif + +#endif // EASINGS_H \ No newline at end of file