Example #1
0
    /// <summary>
    /// Returns a value between 0 and 1 (inclusive) based on the elapsed time and ease selected
    /// </summary>
    public static float Evaluate(Ease easeType, EaseFunction customEase, float time, float duration, float overshootOrAmplitude, float period)
    {
        switch (easeType)
        {
        case Ease.Linear:
            return(time / duration);

        case Ease.InSine:
            return(-(float)Math.Cos(time / duration * _PiOver2) + 1);

        case Ease.OutSine:
            return((float)Math.Sin(time / duration * _PiOver2));

        case Ease.InOutSine:
            return(-0.5f * ((float)Math.Cos(Mathf.PI * time / duration) - 1));

        case Ease.InQuad:
            return((time /= duration) * time);

        case Ease.OutQuad:
            return(-(time /= duration) * (time - 2));

        case Ease.InOutQuad:
            if ((time /= duration * 0.5f) < 1)
            {
                return(0.5f * time * time);
            }
            return(-0.5f * ((--time) * (time - 2) - 1));

        case Ease.InCubic:
            return((time /= duration) * time * time);

        case Ease.OutCubic:
            return((time = time / duration - 1) * time * time + 1);

        case Ease.InOutCubic:
            if ((time /= duration * 0.5f) < 1)
            {
                return(0.5f * time * time * time);
            }
            return(0.5f * ((time -= 2) * time * time + 2));

        case Ease.InQuart:
            return((time /= duration) * time * time * time);

        case Ease.OutQuart:
            return(-((time = time / duration - 1) * time * time * time - 1));

        case Ease.InOutQuart:
            if ((time /= duration * 0.5f) < 1)
            {
                return(0.5f * time * time * time * time);
            }
            return(-0.5f * ((time -= 2) * time * time * time - 2));

        case Ease.InQuint:
            return((time /= duration) * time * time * time * time);

        case Ease.OutQuint:
            return((time = time / duration - 1) * time * time * time * time + 1);

        case Ease.InOutQuint:
            if ((time /= duration * 0.5f) < 1)
            {
                return(0.5f * time * time * time * time * time);
            }
            return(0.5f * ((time -= 2) * time * time * time * time + 2));

        case Ease.InExpo:
            return((time == 0) ? 0 : (float)Math.Pow(2, 10 * (time / duration - 1)));

        case Ease.OutExpo:
            if (time == duration)
            {
                return(1);
            }
            return(-(float)Math.Pow(2, -10 * time / duration) + 1);

        case Ease.InOutExpo:
            if (time == 0)
            {
                return(0);
            }
            if (time == duration)
            {
                return(1);
            }
            if ((time /= duration * 0.5f) < 1)
            {
                return(0.5f * (float)Math.Pow(2, 10 * (time - 1)));
            }
            return(0.5f * (-(float)Math.Pow(2, -10 * --time) + 2));

        case Ease.InCirc:
            return(-((float)Math.Sqrt(1 - (time /= duration) * time) - 1));

        case Ease.OutCirc:
            return((float)Math.Sqrt(1 - (time = time / duration - 1) * time));

        case Ease.InOutCirc:
            if ((time /= duration * 0.5f) < 1)
            {
                return(-0.5f * ((float)Math.Sqrt(1 - time * time) - 1));
            }
            return(0.5f * ((float)Math.Sqrt(1 - (time -= 2) * time) + 1));

        case Ease.InElastic:
            float s0;
            if (time == 0)
            {
                return(0);
            }
            if ((time /= duration) == 1)
            {
                return(1);
            }
            if (period == 0)
            {
                period = duration * 0.3f;
            }
            if (overshootOrAmplitude < 1)
            {
                overshootOrAmplitude = 1;
                s0 = period / 4;
            }
            else
            {
                s0 = period / _TwoPi * (float)Math.Asin(1 / overshootOrAmplitude);
            }
            return(-(overshootOrAmplitude * (float)Math.Pow(2, 10 * (time -= 1)) * (float)Math.Sin((time * duration - s0) * _TwoPi / period)));

        case Ease.OutElastic:
            float s1;
            if (time == 0)
            {
                return(0);
            }
            if ((time /= duration) == 1)
            {
                return(1);
            }
            if (period == 0)
            {
                period = duration * 0.3f;
            }
            if (overshootOrAmplitude < 1)
            {
                overshootOrAmplitude = 1;
                s1 = period / 4;
            }
            else
            {
                s1 = period / _TwoPi * (float)Math.Asin(1 / overshootOrAmplitude);
            }
            return(overshootOrAmplitude * (float)Math.Pow(2, -10 * time) * (float)Math.Sin((time * duration - s1) * _TwoPi / period) + 1);

        case Ease.InOutElastic:
            float s;
            if (time == 0)
            {
                return(0);
            }
            if ((time /= duration * 0.5f) == 2)
            {
                return(1);
            }
            if (period == 0)
            {
                period = duration * (0.3f * 1.5f);
            }
            if (overshootOrAmplitude < 1)
            {
                overshootOrAmplitude = 1;
                s = period / 4;
            }
            else
            {
                s = period / _TwoPi * (float)Math.Asin(1 / overshootOrAmplitude);
            }
            if (time < 1)
            {
                return(-0.5f * (overshootOrAmplitude * (float)Math.Pow(2, 10 * (time -= 1)) * (float)Math.Sin((time * duration - s) * _TwoPi / period)));
            }
            return(overshootOrAmplitude * (float)Math.Pow(2, -10 * (time -= 1)) * (float)Math.Sin((time * duration - s) * _TwoPi / period) * 0.5f + 1);

        case Ease.InBack:
            return((time /= duration) * time * ((overshootOrAmplitude + 1) * time - overshootOrAmplitude));

        case Ease.OutBack:
            return((time = time / duration - 1) * time * ((overshootOrAmplitude + 1) * time + overshootOrAmplitude) + 1);

        case Ease.InOutBack:
            if ((time /= duration * 0.5f) < 1)
            {
                return(0.5f * (time * time * (((overshootOrAmplitude *= (1.525f)) + 1) * time - overshootOrAmplitude)));
            }
            return(0.5f * ((time -= 2) * time * (((overshootOrAmplitude *= (1.525f)) + 1) * time + overshootOrAmplitude) + 2));

        case Ease.InBounce:
            return(Bounce.EaseIn(time, duration, overshootOrAmplitude, period));

        case Ease.OutBounce:
            return(Bounce.EaseOut(time, duration, overshootOrAmplitude, period));

        case Ease.InOutBounce:
            return(Bounce.EaseInOut(time, duration, overshootOrAmplitude, period));

        case Ease.INTERNAL_Custom:
            return(customEase(time, duration, overshootOrAmplitude, period));

        case Ease.INTERNAL_Zero:
            // 0 duration tween
            return(1);

        // Extra custom eases ////////////////////////////////////////////////////
        case Ease.Flash:
            return(Flash.Ease(time, duration, overshootOrAmplitude, period));

        case Ease.InFlash:
            return(Flash.EaseIn(time, duration, overshootOrAmplitude, period));

        case Ease.OutFlash:
            return(Flash.EaseOut(time, duration, overshootOrAmplitude, period));

        case Ease.InOutFlash:
            return(Flash.EaseInOut(time, duration, overshootOrAmplitude, period));

        // Default
        default:
            // OutQuad
            return(-(time /= duration) * (time - 2));
        }
    }