# warrenm/AHEasing

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2a6cb1a Jun 9, 2011
303 lines (269 sloc) 5.97 KB
 // // easing.c // // Copyright (c) 2011, Auerhaus Development, LLC // // This program is free software. It comes without any warranty, to // the extent permitted by applicable law. You can redistribute it // and/or modify it under the terms of the Do What The Fuck You Want // To Public License, Version 2, as published by Sam Hocevar. See // http://sam.zoy.org/wtfpl/COPYING for more details. // #include #include "easing.h" // Modeled after the line y = x AHFloat LinearInterpolation(AHFloat p) { return p; } // Modeled after the parabola y = x^2 AHFloat QuadraticEaseIn(AHFloat p) { return p * p; } // Modeled after the parabola y = -x^2 + 2x AHFloat QuadraticEaseOut(AHFloat p) { return -(p * (p - 2)); } // Modeled after the piecewise quadratic // y = (1/2)((2x)^2) ; [0, 0.5) // y = -(1/2)((2x-1)*(2x-3) - 1) ; [0.5, 1] AHFloat QuadraticEaseInOut(AHFloat p) { if(p < 0.5) { return 2 * p * p; } else { return (-2 * p * p) + (4 * p) - 1; } } // Modeled after the cubic y = x^3 AHFloat CubicEaseIn(AHFloat p) { return p * p * p; } // Modeled after the cubic y = (x - 1)^3 + 1 AHFloat CubicEaseOut(AHFloat p) { AHFloat f = (p - 1); return f * f * f + 1; } // Modeled after the piecewise cubic // y = (1/2)((2x)^3) ; [0, 0.5) // y = (1/2)((2x-2)^3 + 2) ; [0.5, 1] AHFloat CubicEaseInOut(AHFloat p) { if(p < 0.5) { return 4 * p * p * p; } else { AHFloat f = ((2 * p) - 2); return 0.5 * f * f * f + 1; } } // Modeled after the quartic x^4 AHFloat QuarticEaseIn(AHFloat p) { return p * p * p * p; } // Modeled after the quartic y = 1 - (x - 1)^4 AHFloat QuarticEaseOut(AHFloat p) { AHFloat f = (p - 1); return f * f * f * (1 - p) + 1; } // Modeled after the piecewise quartic // y = (1/2)((2x)^4) ; [0, 0.5) // y = -(1/2)((2x-2)^4 - 2) ; [0.5, 1] AHFloat QuarticEaseInOut(AHFloat p) { if(p < 0.5) { return 8 * p * p * p * p; } else { AHFloat f = (p - 1); return -8 * f * f * f * f + 1; } } // Modeled after the quintic y = x^5 AHFloat QuinticEaseIn(AHFloat p) { return p * p * p * p * p; } // Modeled after the quintic y = (x - 1)^5 + 1 AHFloat QuinticEaseOut(AHFloat p) { AHFloat f = (p - 1); return f * f * f * f * f + 1; } // Modeled after the piecewise quintic // y = (1/2)((2x)^5) ; [0, 0.5) // y = (1/2)((2x-2)^5 + 2) ; [0.5, 1] AHFloat QuinticEaseInOut(AHFloat p) { if(p < 0.5) { return 16 * p * p * p * p * p; } else { AHFloat f = ((2 * p) - 2); return 0.5 * f * f * f * f * f + 1; } } // Modeled after quarter-cycle of sine wave AHFloat SineEaseIn(AHFloat p) { return sin((p - 1) * M_PI_2) + 1; } // Modeled after quarter-cycle of sine wave (different phase) AHFloat SineEaseOut(AHFloat p) { return sin(p * M_PI_2); } // Modeled after half sine wave AHFloat SineEaseInOut(AHFloat p) { return 0.5 * (1 - cos(p * M_PI)); } // Modeled after shifted quadrant IV of unit circle AHFloat CircularEaseIn(AHFloat p) { return 1 - sqrt(1 - (p * p)); } // Modeled after shifted quadrant II of unit circle AHFloat CircularEaseOut(AHFloat p) { return sqrt((2 - p) * p); } // Modeled after the piecewise circular function // y = (1/2)(1 - sqrt(1 - 4x^2)) ; [0, 0.5) // y = (1/2)(sqrt(-(2x - 3)*(2x - 1)) + 1) ; [0.5, 1] AHFloat CircularEaseInOut(AHFloat p) { if(p < 0.5) { return 0.5 * (1 - sqrt(1 - 4 * (p * p))); } else { return 0.5 * (sqrt(-((2 * p) - 3) * ((2 * p) - 1)) + 1); } } // Modeled after the exponential function y = 2^(10(x - 1)) AHFloat ExponentialEaseIn(AHFloat p) { return (p == 0.0) ? p : pow(2, 10 * (p - 1)); } // Modeled after the exponential function y = -2^(-10x) + 1 AHFloat ExponentialEaseOut(AHFloat p) { return (p == 1.0) ? p : 1 - pow(2, -10 * p); } // Modeled after the piecewise exponential // y = (1/2)2^(10(2x - 1)) ; [0,0.5) // y = -(1/2)*2^(-10(2x - 1))) + 1 ; [0.5,1] AHFloat ExponentialEaseInOut(AHFloat p) { if(p == 0.0 || p == 1.0) return p; if(p < 0.5) { return 0.5 * pow(2, (20 * p) - 10); } else { return -0.5 * pow(2, (-20 * p) + 10) + 1; } } // Modeled after the damped sine wave y = sin(13pi/2*x)*pow(2, 10 * (x - 1)) AHFloat ElasticEaseIn(AHFloat p) { return sin(13 * M_PI_2 * p) * pow(2, 10 * (p - 1)); } // Modeled after the damped sine wave y = sin(-13pi/2*(x + 1))*pow(2, -10x) + 1 AHFloat ElasticEaseOut(AHFloat p) { return sin(-13 * M_PI_2 * (p + 1)) * pow(2, -10 * p) + 1; } // Modeled after the piecewise exponentially-damped sine wave: // y = (1/2)*sin(13pi/2*(2*x))*pow(2, 10 * ((2*x) - 1)) ; [0,0.5) // y = (1/2)*(sin(-13pi/2*((2x-1)+1))*pow(2,-10(2*x-1)) + 2) ; [0.5, 1] AHFloat ElasticEaseInOut(AHFloat p) { if(p < 0.5) { return 0.5 * sin(13 * M_PI_2 * (2 * p)) * pow(2, 10 * ((2 * p) - 1)); } else { return 0.5 * (sin(-13 * M_PI_2 * ((2 * p - 1) + 1)) * pow(2, -10 * (2 * p - 1)) + 2); } } // Modeled after the overshooting cubic y = x^3-x*sin(x*pi) AHFloat BackEaseIn(AHFloat p) { return p * p * p - p * sin(p * M_PI); } // Modeled after overshooting cubic y = 1-((1-x)^3-(1-x)*sin((1-x)*pi)) AHFloat BackEaseOut(AHFloat p) { AHFloat f = (1 - p); return 1 - (f * f * f - f * sin(f * M_PI)); } // Modeled after the piecewise overshooting cubic function: // y = (1/2)*((2x)^3-(2x)*sin(2*x*pi)) ; [0, 0.5) // y = (1/2)*(1-((1-x)^3-(1-x)*sin((1-x)*pi))+1) ; [0.5, 1] AHFloat BackEaseInOut(AHFloat p) { if(p < 0.5) { AHFloat f = 2 * p; return 0.5 * (f * f * f - f * sin(f * M_PI)); } else { AHFloat f = (1 - (2*p - 1)); return 0.5 * (1 - (f * f * f - f * sin(f * M_PI))) + 0.5; } } AHFloat BounceEaseIn(AHFloat p) { return 1 - BounceEaseOut(1 - p); } AHFloat BounceEaseOut(AHFloat p) { if(p < 4/11.0) { return (121 * p * p)/16.0; } else if(p < 8/11.0) { return (363/40.0 * p * p) - (99/10.0 * p) + 17/5.0; } else if(p < 9/10.0) { return (4356/361.0 * p * p) - (35442/1805.0 * p) + 16061/1805.0; } else { return (54/5.0 * p * p) - (513/25.0 * p) + 268/25.0; } } AHFloat BounceEaseInOut(AHFloat p) { if(p < 0.5) { return 0.5 * BounceEaseIn(p*2); } else { return 0.5 * BounceEaseOut(p * 2 - 1) + 0.5; } }