solveForT: function()

in MotionMark/resources/extensions.js [410:445]

• 31 lines of code
• 9 McCabe index (conditional complexity)

    solveForT: function(x)
    {
        var t0, t1, t2, x2, d2, i;

        for (t2 = x, i = 0; i < 8; ++i) {
            x2 = this.sampleX(t2) - x;
            if (Math.abs(x2) < this.epsilon)
                return t2;
            d2 = this.sampleDerivativeX(t2);
            if (Math.abs(d2) < this.derivativeEpsilon)
                break;
            t2 = t2 - x2 / d2;
        }

        t0 = 0;
        t1 = 1;
        t2 = x;

        if (t2 < t0)
            return t0;
        if (t2 > t1)
            return t1;

        while (t0 < t1) {
            x2 = this.sampleX(t2);
            if (Math.abs(x2 - x) < this.epsilon)
                return t2;
            if (x > x2)
                t0 = t2;
            else
                t1 = t2;
            t2 = (t1 - t0) * .5 + t0;
        }

        return t2;
    }