Exemplo n.º 1
0
/// compute interpolation parameters from keyframes and an iterator
/// to the next keyframe (the first with time > t)
static void
interParams(const KeyFrameSet &keyFrames,
            double t,
            const KeyFrameSet::const_iterator &itup,
            double *tcur,
            double *vcur,
            double *vcurDerivRight,
            Natron::KeyframeType *interp,
            double *tnext,
            double *vnext,
            double *vnextDerivLeft,
            Natron::KeyframeType *interpNext)
{
    assert(itup == keyFrames.end() || t < itup->getTime());
    if (itup == keyFrames.begin()) {
        //if all keys have a greater time
        // get the first keyframe
        *tnext = itup->getTime();
        *vnext = itup->getValue();
        *vnextDerivLeft = itup->getLeftDerivative();
        *interpNext = itup->getInterpolation();
        *tcur = *tnext - 1.;
        *vcur = *vnext;
        *vcurDerivRight = 0.;
        *interp = Natron::KEYFRAME_NONE;
    } else if (itup == keyFrames.end()) {
        //if we found no key that has a greater time
        // get the last keyframe
        KeyFrameSet::const_reverse_iterator itlast = keyFrames.rbegin();
        *tcur = itlast->getTime();
        *vcur = itlast->getValue();
        *vcurDerivRight = itlast->getRightDerivative();
        *interp = itlast->getInterpolation();
        *tnext = *tcur + 1.;
        *vnext = *vcur;
        *vnextDerivLeft = 0.;
        *interpNext = Natron::KEYFRAME_NONE;
    } else {
        // between two keyframes
        // get the last keyframe with time <= t
        KeyFrameSet::const_iterator itcur = itup;
        --itcur;
        assert(itcur->getTime() <= t);
        *tcur = itcur->getTime();
        *vcur = itcur->getValue();
        *vcurDerivRight = itcur->getRightDerivative();
        *interp = itcur->getInterpolation();
        *tnext = itup->getTime();
        *vnext = itup->getValue();
        *vnextDerivLeft = itup->getLeftDerivative();
        *interpNext = itup->getInterpolation();
    }
}
Exemplo n.º 2
0
void
CurveGui::nextPointForSegment(const double x, // < in curve coordinates
                              const KeyFrameSet & keys,
                              const bool isPeriodic,
                              const double parametricXMin,
                              const double parametricXMax,
                              KeyFrameSet::const_iterator* lastUpperIt,
                              double* x2WidgetCoords,
                              KeyFrame* x1Key,
                              bool* isx1Key)
{
    // always running in the main thread
    assert( qApp && qApp->thread() == QThread::currentThread() );
    assert( !keys.empty() );

    *isx1Key = false;

    // If non periodic and out of curve range, draw straight lines from widget border to
    // the keyframe on the side
    if (!isPeriodic && x < keys.begin()->getTime()) {
        *x2WidgetCoords = keys.begin()->getTime();
        double y;
        _imp->curveWidget->toWidgetCoordinates(x2WidgetCoords, &y);
        *x1Key = *keys.begin();
        *isx1Key = true;
        return;
    } else if (!isPeriodic && x >= keys.rbegin()->getTime()) {
        *x2WidgetCoords = _imp->curveWidget->width() - 1;
        return;
    }



    // We're between 2 keyframes or the curve is periodic, get the upper and lower keyframes widget coordinates

    // Points to the first keyframe with a greater time (in widget coords) than x1
    KeyFrameSet::const_iterator upperIt = keys.end();

    // If periodic, bring back x in the period range (in widget coordinates)
    double xClamped = x;
    double period = parametricXMax - parametricXMin;

    {
        //KeyFrameSet::const_iterator start = keys.begin();
        const double xMin = parametricXMin;// + start->getTime();
        const double xMax = parametricXMax;// + start->getTime();
        if ((x < xMin || x > xMax) && isPeriodic) {
            xClamped = std::fmod(x - xMin, period) + parametricXMin;
            if (xClamped < xMin) {
                xClamped += period;
            }
            assert(xClamped >= xMin && xClamped <= xMax);
        }
    }
    {

        KeyFrameSet::const_iterator itKeys = keys.begin();

        if ( *lastUpperIt != keys.end() ) {
            // If we already have called this function before, start from the previously
            // computed iterator to avoid n square complexity
            itKeys = *lastUpperIt;
        } else {
            // Otherwise start from the begining
            itKeys = keys.begin();
        }
        *lastUpperIt = keys.end();
        for (; itKeys != keys.end(); ++itKeys) {
            if (itKeys->getTime() > xClamped) {
                upperIt = itKeys;
                *lastUpperIt = upperIt;
                break;
            }
        }
    }

    double tprev, vprev, vprevDerivRight, tnext, vnext, vnextDerivLeft;
    if ( upperIt == keys.end() ) {
        // We are in a periodic curve: we are in-between the last keyframe and the parametric xMax
        // If the curve is non periodic, it should have been handled in the 2 cases above: we only draw a straightline
        // from the widget border to the first/last keyframe
        assert(isPeriodic);
        KeyFrameSet::const_iterator start = keys.begin();
        KeyFrameSet::const_reverse_iterator last = keys.rbegin();
        tprev = last->getTime();
        vprev = last->getValue();
        vprevDerivRight = last->getRightDerivative();
        tnext = std::fmod(last->getTime() - start->getTime(), period) + tprev;
        //xClamped += period;
        vnext = start->getValue();
        vnextDerivLeft = start->getLeftDerivative();

    } else if ( upperIt == keys.begin() ) {
        // We are in a periodic curve: we are in-between the parametric xMin and the first keyframe
        // If the curve is non periodic, it should have been handled in the 2 cases above: we only draw a straightline
        // from the widget border to the first/last keyframe
        assert(isPeriodic);
        KeyFrameSet::const_reverse_iterator last = keys.rbegin();
        tprev = last->getTime();
        //xClamped -= period;
        vprev = last->getValue();
        vprevDerivRight = last->getRightDerivative();
        tnext = std::fmod(last->getTime() - upperIt->getTime(), period) + tprev;
        vnext = upperIt->getValue();
        vnextDerivLeft = upperIt->getLeftDerivative();

    } else {
        // in-between 2 keyframes
        KeyFrameSet::const_iterator prev = upperIt;
        --prev;
        tprev = prev->getTime();
        vprev = prev->getValue();
        vprevDerivRight = prev->getRightDerivative();
        tnext = upperIt->getTime();
        vnext = upperIt->getValue();
        vnextDerivLeft = upperIt->getLeftDerivative();
    }
    double normalizeTimeRange = tnext - tprev;
    if (normalizeTimeRange == 0) {
        // Only 1 keyframe, draw a horizontal line
        *x2WidgetCoords = _imp->curveWidget->width() - 1;
        return;
    }
    assert(normalizeTimeRange > 0.);

    double t = ( xClamped - tprev ) / normalizeTimeRange;
    double P3 = vnext;
    double P0 = vprev;
    // Hermite coefficients P0' and P3' are for t normalized in [0,1]
    double P3pl = vnextDerivLeft / normalizeTimeRange; // normalize for t \in [0,1]
    double P0pr = vprevDerivRight / normalizeTimeRange; // normalize for t \in [0,1]
    double secondDer = 6. * (1. - t) * (P3 - P3pl / 3. - P0 - 2. * P0pr / 3.) +
    6. * t * (P0 - P3 + 2 * P3pl / 3. + P0pr / 3. );

    double secondDerWidgetCoord = _imp->curveWidget->toWidgetCoordinates(0, secondDer).y();
    double normalizedSecondDerWidgetCoord = std::abs(secondDerWidgetCoord / normalizeTimeRange);

    // compute delta_x so that the y difference between the derivative and the curve is at most
    // 1 pixel (use the second order Taylor expansion of the function)
    double delta_x = std::max(2. / std::max(std::sqrt(normalizedSecondDerWidgetCoord), 0.1), 1.);

    // The x widget coordinate of the next keyframe
    double tNextWidgetCoords = _imp->curveWidget->toWidgetCoordinates(tnext, 0).x();

    // The widget coordinate of the x passed in parameter but clamped to the curve period
    double xClampedWidgetCoords = _imp->curveWidget->toWidgetCoordinates(xClamped, 0).x();

    // The real x passed in parameter in widget coordinates
    double xWidgetCoords = _imp->curveWidget->toWidgetCoordinates(x, 0).x();

    double x2ClampedWidgetCoords = xClampedWidgetCoords + delta_x;

    double deltaXtoNext = (tNextWidgetCoords - xClampedWidgetCoords);
    // If nearby next key, clamp to it
    if (x2ClampedWidgetCoords > tNextWidgetCoords && deltaXtoNext > 1e-6) {
        // x2 is the position of the next keyframe with the period removed
        *x2WidgetCoords = xWidgetCoords + deltaXtoNext;
        x1Key->setValue(vnext);
        x1Key->setTime(x + (tnext - xClamped));
        *isx1Key = true;
    } else {
        // just add the delta to the x widget coord
        *x2WidgetCoords = xWidgetCoords + delta_x;
    }

} // nextPointForSegment