java.awt.geom.Line2D#ptLineDistSq ( )源码实例Demo

@Override
public double getMeanDistance ()
{
    if (line == null) {
        computeLine();
    }

    if (meanDistance == null) {
        Line2D straight = new Line2D.Double(startPoint, stopPoint);

        double totalDistSq = 0;
        int pointCount = points.size() - 2; // Only intermediate points!

        for (int i = 1, iMax = pointCount; i <= iMax; i++) {
            totalDistSq += straight.ptLineDistSq(points.get(i));
        }

        if (pointCount > 0) {
            meanDistance = Math.sqrt(totalDistSq / pointCount);
        }
    }

    return (meanDistance != null) ? meanDistance : 0;
}
 

/**
 * Computation of rotation from first to last point, with middle as approximate
 * middle point of the curve.
 *
 * @param line   straight line from curve start to curve stop
 * @param middle middle point of curve
 * @return central rotation angle (in radians) from curve start to curve stop.
 */
public static double rotation (Line2D line,
                               Point2D middle)
{
    double dx = line.getX2() - line.getX1();
    double dy = line.getY2() - line.getY1();
    double halfChordLengthSq = ((dx * dx) + (dy * dy)) / 4;
    double sagittaSq = line.ptLineDistSq(middle);

    return 4 * Math.atan(Math.sqrt(sagittaSq / halfChordLengthSq));
}
 

@Override
public boolean isHitAt(Point localPoint) {
    return Line2D.ptLineDistSq(from.x, from.y, to.x, to.y, localPoint.x, localPoint.y) <= BORDER * BORDER;
}
 

@Override
public boolean isHitAt(Point localPoint) {
    return Line2D.ptLineDistSq(from.x, from.y, to.x, to.y, localPoint.x, localPoint.y) <= BORDER * BORDER;
}
 

@Override
public boolean isHitAt(Point localPoint) {
    return Line2D.ptLineDistSq(from.x, from.y, to.x, to.y, localPoint.x, localPoint.y) <= BORDER * BORDER;
}
 

@Override
public boolean isHitAt(Point localPoint) {
    return Line2D.ptLineDistSq(from.x, from.y, to.x, to.y, localPoint.x, localPoint.y) <= BORDER * BORDER;
}
 

@Override
public boolean isHitAt(Point localPoint) {
    return Line2D.ptLineDistSq(from.x, from.y, to.x, to.y, localPoint.x, localPoint.y) <= BORDER * BORDER;
}
 

@Override
public boolean isHitAt(Point localPoint) {
    return Line2D.ptLineDistSq(from.x, from.y, to.x, to.y, localPoint.x, localPoint.y) <= BORDER * BORDER;
}
 

@Override
public boolean isHitAt(Point localPoint) {
    return Line2D.ptLineDistSq(from.x, from.y, to.x, to.y, localPoint.x, localPoint.y) <= BORDER * BORDER;
}
 

@Override
public boolean isHitAt(Point localPoint) {
    return Line2D.ptLineDistSq(from.x, from.y, to.x, to.y, localPoint.x, localPoint.y) <= BORDER * BORDER;
}