Example usage for java.awt.geom QuadCurve2D solveQuadratic

Introduction

In this page you can find the example usage for java.awt.geom QuadCurve2D solveQuadratic.

Prototype

public static int solveQuadratic(double[] eqn) 

Source Link

Document

Solves the quadratic whose coefficients are in the eqn array and places the non-complex roots back into the same array, returning the number of roots.

Usage

From source file:Cubic.java

private void getMinMax(double p1, double p2, double p3, double p4, double[] minMax) {
    if (p4 > p1) {
        minMax[0] = p1;/*w  ww .j a  v  a2  s  .c  om*/
        minMax[1] = p4;
    } else {
        minMax[0] = p4;
        minMax[1] = p1;
    }

    double c0 = 3 * (p2 - p1);
    double c1 = 6 * (p3 - p2);
    double c2 = 3 * (p4 - p3);
    double[] eqn = { c0, c1 - 2 * c0, c2 - c1 + c0 };
    int roots = QuadCurve2D.solveQuadratic(eqn);
    for (int r = 0; r < roots; r++) {
        double tv = eqn[r];
        if ((tv <= 0) || (tv >= 1))
            continue;
        tv = ((1 - tv) * (1 - tv) * (1 - tv) * p1 + 3 * tv * (1 - tv) * (1 - tv) * p2
                + 3 * tv * tv * (1 - tv) * p3 + tv * tv * tv * p4);
        if (tv < minMax[0])
            minMax[0] = tv;
        else if (tv > minMax[1])
            minMax[1] = tv;
    }
}

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