/******************************************************************************************* * * raylib easings (header only file) * * Useful easing functions for values animation * * This header uses: * #define EASINGS_STATIC_INLINE // Inlines all functions code, so it runs faster. * // This requires lots of memory on system. * How to use: * The four inputs t,b,c,d are defined as follows: * t = current time (in any unit measure, but same unit as duration) * b = starting value to interpolate * c = the total change in value of b that needs to occur * d = total time it should take to complete (duration) * * Example: * * int currentTime = 0; * int duration = 100; * float startPositionX = 0.0f; * float finalPositionX = 30.0f; * float currentPositionX = startPositionX; * * while (currentPositionX < finalPositionX) * { * currentPositionX = EaseSineIn(currentTime, startPositionX, finalPositionX - startPositionX, duration); * currentTime++; * } * * 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 #define EASINGS_STATIC_INLINE // NOTE: By default, compile functions as static inline #if defined(EASINGS_STATIC_INLINE) #define EASEDEF static inline #else #define EASEDEF extern #endif #include <math.h> // Required for: sin(), cos(), sqrt(), pow() #ifdef __cplusplus extern "C" { // Prevents name mangling of functions #endif // Linear Easing functions EASEDEF float EaseLinearNone(float t, float b, float c, float d) { return (c*t/d + b); } EASEDEF float EaseLinearIn(float t, float b, float c, float d) { return (c*t/d + b); } EASEDEF float EaseLinearOut(float t, float b, float c, float d) { return (c*t/d + b); } EASEDEF float EaseLinearInOut(float t,float b, float c, float d) { return (c*t/d + b); } // Sine Easing functions EASEDEF float EaseSineIn(float t, float b, float c, float d) { return (-c*cos(t/d*(PI/2)) + c + b); } EASEDEF float EaseSineOut(float t, float b, float c, float d) { return (c*sin(t/d*(PI/2)) + b); } EASEDEF float EaseSineInOut(float t, float b, float c, float d) { return (-c/2*(cos(PI*t/d) - 1) + b); } // Circular Easing functions EASEDEF float EaseCircIn(float t, float b, float c, float d) { return (-c*(sqrt(1 - (t/=d)*t) - 1) + b); } EASEDEF float EaseCircOut(float t, float b, float c, float d) { return (c*sqrt(1 - (t=t/d-1)*t) + b); } EASEDEF 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 EASEDEF float EaseCubicIn(float t, float b, float c, float d) { return (c*(t/=d)*t*t + b); } EASEDEF float EaseCubicOut(float t, float b, float c, float d) { return (c*((t=t/d-1)*t*t + 1) + b); } EASEDEF 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 EASEDEF float EaseQuadIn(float t, float b, float c, float d) { return (c*(t/=d)*t + b); } EASEDEF float EaseQuadOut(float t, float b, float c, float d) { return (-c*(t/=d)*(t-2) + b); } EASEDEF 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 EASEDEF float EaseExpoIn(float t, float b, float c, float d) { return (t == 0) ? b : (c*pow(2, 10*(t/d - 1)) + b); } EASEDEF float EaseExpoOut(float t, float b, float c, float d) { return (t == d) ? (b + c) : (c*(-pow(2, -10*t/d) + 1) + b); } EASEDEF 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 EASEDEF 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); } EASEDEF 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); } EASEDEF 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 EASEDEF 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); } } EASEDEF float EaseBounceIn(float t, float b, float c, float d) { return (c - EaseBounceOut(d-t, 0, c, d) + b); } EASEDEF 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 EASEDEF 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); } EASEDEF 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); } EASEDEF 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