Torque3D/Engine/source/math/mEase.h
2018-03-14 15:45:45 -05:00

491 lines
11 KiB
C++

/*
ROBERT PENNER'S MOST EXCELLENT EASING METHODS - ported to Torque C++ by Paul Dana
Easing Equations v1.5
May 1, 2003
(c) 2003 Robert Penner, all rights reserved.
This work is subject to the terms in http://www.robertpenner.com/easing_terms_of_use.html.
These tweening functions provide different flavors of
math-based motion under a consistent API.
Types of easing:
Linear
Quadratic
Cubic
Quartic
Quintic
Sinusoidal
Exponential
Circular
Elastic
Back
Bounce
Changes:
1.5 - added bounce easing
1.4 - added elastic and back easing
1.3 - tweaked the exponential easing functions to make endpoints exact
1.2 - inline optimizations (changing t and multiplying in one step)--thanks to Tatsuo Kato for the idea
Discussed in Chapter 7 of
Robert Penner's Programming Macromedia Flash MX
(including graphs of the easing equations)
http://www.robertpenner.com/profmx
http://www.amazon.com/exec/obidos/ASIN/0072223561/robertpennerc-20
*/
#ifndef _MEASE_H_
#define _MEASE_H_
// the ease methods below all are static and take atomic types as params
// so they are the most generally useful. for convenience, define here
// a type that can contain all the params needed for below to make
// data structures that use these methods cleaner...
//------------------------------------------------------------------------------
class Ease
{
//-------------------------------------- Public data
public:
enum enumDirection
{
InOut=0,
In,
Out
};
enum enumType
{
Linear=0,
Quadratic,
Cubic,
Quartic,
Quintic,
Sinusoidal,
Exponential,
Circular,
Elastic,
Back,
Bounce,
};
};
class EaseF : public Ease
{
//-------------------------------------- Public data
public:
S32 mDir; // inout, in, out
S32 mType; // linear, etc...
F32 mParam[2]; // optional params
//-------------------------------------- Public interface
public:
EaseF();
EaseF(const EaseF &ease);
EaseF(const S32 dir, const S32 type);
EaseF(const S32 dir, const S32 type, F32 param[2]);
//-------------------------------------- Non-math mutators and misc functions
void set(const S32 dir, const S32 type);
void set(const S32 dir, const S32 type, F32 param[2]);
void set(const S32 dir, const S32 type, F32 param0, F32 param1);
void set(const char *s);
F32 getValue(F32 t, F32 b, F32 c, F32 d) const;
F32 getUnitValue(F32 t, bool noExtrapolation) const
{
F32 v = getValue(t,0.0f,1.0f,1.0f);
if (noExtrapolation)
v = mClampF(v,0.0f,1.0f);
return v;
}
F32 getUnitValue(F32 t) const
{
return getValue(t,0.0f,1.0f,1.0f);
}
};
// simple linear tweening - no easing
// t: current time, b: beginning value, c: change in value, d: duration
inline F32 mLinearTween(F32 t, F32 b, F32 c, F32 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
inline F32 mEaseInQuad(F32 t, F32 b, F32 c, F32 d)
{
t /= d;
return c*t*t + b;
};
// quadratic easing out - decelerating to zero velocity
inline F32 mEaseOutQuad(F32 t, F32 b, F32 c, F32 d)
{
t /= d;
return -c * t*(t-2) + b;
};
// quadratic easing in/out - acceleration until halfway, then deceleration
inline F32 mEaseInOutQuad(F32 t, F32 b, F32 c, F32 d)
{
t /= d/2;
if (t < 1)
return c/2*t*t + b;
t--;
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
inline F32 mEaseInCubic(F32 t, F32 b, F32 c, F32 d)
{
t /= d;
return c*t*t*t + b;
};
// cubic easing out - decelerating to zero velocity
inline F32 mEaseOutCubic(F32 t, F32 b, F32 c, F32 d)
{
t /= d;
t--;
return c*(t*t*t + 1) + b;
};
// cubic easing in/out - acceleration until halfway, then deceleration
inline F32 mEaseInOutCubic(F32 t, F32 b, F32 c, F32 d)
{
t /= d/2;
if (t < 1)
return c/2*t*t*t + b;
t -= 2;
return c/2*(t*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
inline F32 mEaseInQuart(F32 t, F32 b, F32 c, F32 d)
{
t /= d;
return c*t*t*t*t + b;
};
// quartic easing out - decelerating to zero velocity
inline F32 mEaseOutQuart(F32 t, F32 b, F32 c, F32 d)
{
t /= d;
t--;
return -c * (t*t*t*t - 1) + b;
};
// quartic easing in/out - acceleration until halfway, then deceleration
inline F32 mEaseInOutQuart(F32 t, F32 b, F32 c, F32 d)
{
t /= d/2;
if (t < 1)
return c/2*t*t*t*t + b;
t -= 2;
return -c/2 * (t*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
inline F32 mEaseInQuint(F32 t, F32 b, F32 c, F32 d)
{
t /= d;
return c*t*t*t*t*t + b;
};
// quintic easing out - decelerating to zero velocity
inline F32 mEaseOutQuint(F32 t, F32 b, F32 c, F32 d)
{
t /= d;
t--;
return c*(t*t*t*t*t + 1) + b;
};
// quintic easing in/out - acceleration until halfway, then deceleration
inline F32 mEaseInOutQuint(F32 t, F32 b, F32 c, F32 d)
{
t /= d/2;
if (t < 1)
return c/2*t*t*t*t*t + b;
t -= 2;
return c/2*(t*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
inline F32 mEaseInSine(F32 t, F32 b, F32 c, F32 d)
{
return -c * mCos(t/d * (M_PI_F/2)) + c + b;
};
// sinusoidal easing out - decelerating to zero velocity
inline F32 mEaseOutSine(F32 t, F32 b, F32 c, F32 d)
{
return c * mSin(t/d * (M_PI_F/2)) + b;
};
// sinusoidal easing in/out - accelerating until halfway, then decelerating
inline F32 mEaseInOutSine(F32 t, F32 b, F32 c, F32 d)
{
return -c/2 * (mCos(M_PI_F*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
inline F32 mEaseInExpo(F32 t, F32 b, F32 c, F32 d)
{
return c * mPow( 2, 10 * (t/d - 1) ) + b;
};
// exponential easing out - decelerating to zero velocity
inline F32 mEaseOutExpo(F32 t, F32 b, F32 c, F32 d)
{
return c * ( -mPow( 2, -10 * t/d ) + 1 ) + b;
};
// exponential easing in/out - accelerating until halfway, then decelerating
inline F32 mEaseInOutExpo(F32 t, F32 b, F32 c, F32 d)
{
t /= d/2;
if (t < 1)
return c/2 * mPow( 2, 10 * (t - 1) ) + b;
t--;
return c/2 * ( -mPow( 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
inline F32 mEaseInCirc (F32 t, F32 b, F32 c, F32 d)
{
t/=d;
return -c * (mSqrt(1 - (t)*t) - 1) + b;
};
// circular easing out - decelerating to zero velocity
inline F32 mEaseOutCirc (F32 t, F32 b, F32 c, F32 d)
{
t/=d;
t--;
return c * mSqrt(1 - (t)*t) + b;
};
// circular easing in/out - acceleration until halfway, then deceleration
inline F32 mEaseInOutCirc(F32 t, F32 b, F32 c, F32 d)
{
if ((t/=d/2) < 1)
return -c/2 * (mSqrt(1 - t*t) - 1) + b;
t-=2;
return c/2 * (mSqrt(1 - (t)*t) + 1) + b;
};
/////////// ELASTIC EASING: exponentially decaying sine wave //////////////
// t: current time, b: beginning value, c: change in value, d: duration, a: amplitude (optional), p: period (optional)
// t and d can be in frames or seconds/milliseconds
inline F32 mEaseInElastic(F32 t, F32 b, F32 c, F32 d, F32 a, F32 p)
{
if (t==0)
return b;
F32 dt = t /= d;
if (dt == 1)
return b+c;
if (p<=0)
p=d*.3f;
F32 s;
if (a < mFabs(c))
{
a=c;
s=p/4;
}
else
s = p/(2*M_PI_F) * mAsin (c/a);
t -= 1;
return -(a*mPow(2,10*t) * mSin( (t*d-s)*(2*M_PI_F)/p )) + b;
};
inline F32 mEaseOutElastic(F32 t, F32 b, F32 c, F32 d, F32 a, F32 p)
{
if (t==0)
return b;
F32 dt = t /= d;
if (dt == 1)
return b+c;
if (p<=0)
p=d*.3f;
F32 s;
if (a < mFabs(c))
{
a=c;
s=p/4;
}
else
s = p/(2*M_PI_F) * mAsin (c/a);
return a*mPow(2,-10*t) * mSin( (t*d-s)*(2*M_PI_F)/p ) + c + b;
};
inline F32 mEaseInOutElastic(F32 t, F32 b, F32 c, F32 d, F32 a, F32 p)
{
if (t==0)
return b;
F32 dt = t /= d / 2;
if (dt == 2)
return b+c;
if (p<=0)
p=d*(.3f*1.5f);
F32 s;
if (a < mFabs(c))
{
a=c;
s=p/4;
}
else
s = p/(2*M_PI_F) * mAsin (c/a);
if (t < 1)
{
t -= 1;
return -.5f*(a*mPow(2, 10 * t) * mSin((t*d - s)*(2 * M_PI_F) / p)) + b;
}
t -= 1;
return a*mPow(2,-10*t) * mSin( (t*d-s)*(2*M_PI_F)/p )*.5f + c + b;
};
/////////// BACK EASING: overshooting cubic easing: (s+1)*t^3 - s*t^2 //////////////
// back easing in - backtracking slightly, then reversing direction and moving to target
// t: current time, b: beginning value, c: change in value, d: duration, s: overshoot amount (optional)
// t and d can be in frames or seconds/milliseconds
// s controls the amount of overshoot: higher s means greater overshoot
// s has a default value of 1.70158, which produces an overshoot of 10 percent
// s==0 produces cubic easing with no overshoot
inline F32 mEaseInBack(F32 t, F32 b, F32 c, F32 d, F32 s)
{
if (s < 0)
s = 1.70158f;
F32 td = t /= d;
return c*td*t*((s + 1)*t - s) + b;
};
// back easing out - moving towards target, overshooting it slightly, then reversing and coming back to target
inline F32 mEaseOutBack(F32 t, F32 b, F32 c, F32 d, F32 s)
{
if (s < 0)
s = 1.70158f;
F32 td = t / d - 1;
t = td;
return c*(td*t*((s + 1)*t + s) + 1) + b;
};
// back easing in/out - backtracking slightly, then reversing direction and moving to target,
// then overshooting target, reversing, and finally coming back to target
inline F32 mEaseInOutBack(F32 t, F32 b, F32 c, F32 d, F32 s)
{
if (s < 0)
s = 1.70158f;
F32 td = t /= d / 2;
if (td < 1)
{
s *= 1.525f;
return c / 2 * (t*t*((s + 1)*t - s)) + b;
}
s *= 1.525f;
t -= 2;
return c/2*(t*t*((s+1)*t + s) + 2) + b;
};
/////////// BOUNCE EASING: exponentially decaying parabolic bounce //////////////
// bounce easing out
inline F32 mEaseOutBounce(F32 t, F32 b, F32 c, F32 d)
{
if ((t/=d) < (1/2.75f))
{
return c*(7.5625f*t*t) + b;
}
else if (t < (2/2.75))
{
t -= 1.5f / 2.75f;
return c*(7.5625f*t*t + .75f) + b;
}
else if (t < (2.5/2.75))
{
t -= 2.25f / 2.75f;
return c*(7.5625f*t*t + .9375f) + b;
}
else
{
t -= 2.625f / 2.75f;
return c*(7.5625f*t*t + .984375f) + b;
}
};
// bounce easing in
// t: current time, b: beginning value, c: change in position, d: duration
inline F32 mEaseInBounce(F32 t, F32 b, F32 c, F32 d)
{
return c - mEaseOutBounce (d-t, 0, c, d) + b;
};
// bounce easing in/out
inline F32 mEaseInOutBounce(F32 t, F32 b, F32 c, F32 d)
{
if (t < d/2)
return mEaseInBounce (t*2, 0, c, d) * .5f + b;
return mEaseOutBounce (t*2-d, 0, c, d) * .5f + c*.5f + b;
};
#endif // _MEASE_H_