TimeUtils Namespace Reference

Functions
static SkMSec	NanosToMSec (double nanos)
static double	NanosToSeconds (double nanos)
static float	Scaled (float time, float speed, float period=0)
static float	PingPong (double time, float period, float phase, float ends, float mid)
static float	SineWave (double time, float periodInSecs, float phaseInSecs, float min, float max)

Function Documentation

NanosToMSec()

static SkMSec TimeUtils::NanosToMSec ( double  nanos )

inlinestatic

Definition at line 16 of file TimeUtils.h.

                                                   {
        const double msec = nanos * 1e-6;
        SkASSERT(SK_MSecMax >= msec);
        return static_cast<SkMSec>(msec);
    }

NanosToSeconds()

static double TimeUtils::NanosToSeconds ( double  nanos )

inlinestatic

Definition at line 22 of file TimeUtils.h.

                                                      {
        return nanos * 1e-9;
    }

PingPong()

static float TimeUtils::PingPong ( double  time, float  period, float  phase, float  ends, float  mid  )

inlinestatic

Definition at line 37 of file TimeUtils.h.

                                            {
        double value = ::fmod(time + phase, period);
        double half  = period / 2.0;
        double diff  = ::fabs(value - half);
        return (float)(ends + (1.0 - diff / half) * (mid - ends));
    }

Scaled()

static float TimeUtils::Scaled ( float  time, float  speed, float  period = 0  )

inlinestatic

Definition at line 27 of file TimeUtils.h.

                                                                          {
        double value = time * speed;
        if (period) {
            value = ::fmod(value, (double)(period));
        }
        return (float)value;
    }

SineWave()

static float TimeUtils::SineWave ( double  time, float  periodInSecs, float  phaseInSecs, float  min, float  max  )

inlinestatic

Definition at line 48 of file TimeUtils.h.

                                            {
        if (periodInSecs < 0.f) {
            return (min + max) / 2.f;
        }
        double t = NanosToSeconds(time) + phaseInSecs;
        t *= 2 * SK_FloatPI / periodInSecs;
        float halfAmplitude = (max - min) / 2.f;
        return halfAmplitude * std::sin(t) + halfAmplitude + min;
    }