Java Curve类代码示例

import sun.awt.geom.Curve; //导入依赖的package包/类
/**
 * Tests if the specified coordinates are inside the closed
 * boundary of the specified {@link PathIterator}.
 * <p>
 * This method provides a basic facility for implementors of
 * the {@link Shape} interface to implement support for the
 * {@link Shape#contains(double, double)} method.
 *
 * @param pi the specified {@code PathIterator}
 * @param x the specified X coordinate
 * @param y the specified Y coordinate
 * @return {@code true} if the specified coordinates are inside the
 *         specified {@code PathIterator}; {@code false} otherwise
 * @since 1.6
 */
public static boolean contains(PathIterator pi, double x, double y) {
    if (x * 0.0 + y * 0.0 == 0.0) {
        /* N * 0.0 is 0.0 only if N is finite.
         * Here we know that both x and y are finite.
         */
        int mask = (pi.getWindingRule() == WIND_NON_ZERO ? -1 : 1);
        int cross = Curve.pointCrossingsForPath(pi, x, y);
        return ((cross & mask) != 0);
    } else {
        /* Either x or y was infinite or NaN.
         * A NaN always produces a negative response to any test
         * and Infinity values cannot be "inside" any path so
         * they should return false as well.
         */
        return false;
    }
}
 

import sun.awt.geom.Curve; //导入依赖的package包/类
/**
 * {@inheritDoc}
 * <p>
 * This method object may conservatively return true in
 * cases where the specified rectangular area intersects a
 * segment of the path, but that segment does not represent a
 * boundary between the interior and exterior of the path.
 * Such a case may occur if some set of segments of the
 * path are retraced in the reverse direction such that the
 * two sets of segments cancel each other out without any
 * interior area between them.
 * To determine whether segments represent true boundaries of
 * the interior of the path would require extensive calculations
 * involving all of the segments of the path and the winding
 * rule and are thus beyond the scope of this implementation.
 *
 * @since 1.6
 */
public final boolean intersects(double x, double y, double w, double h) {
    if (java.lang.Double.isNaN(x+w) || java.lang.Double.isNaN(y+h)) {
        /* [xy]+[wh] is NaN if any of those values are NaN,
         * or if adding the two together would produce NaN
         * by virtue of adding opposing Infinte values.
         * Since we need to add them below, their sum must
         * not be NaN.
         * We return false because NaN always produces a
         * negative response to tests
         */
        return false;
    }
    if (w <= 0 || h <= 0) {
        return false;
    }
    int mask = (windingRule == WIND_NON_ZERO ? -1 : 2);
    int crossings = rectCrossings(x, y, x+w, y+h);
    return (crossings == Curve.RECT_INTERSECTS ||
            (crossings & mask) != 0);
}
 

import sun.awt.geom.Curve; //导入依赖的package包/类
/**
 * Tests whether this <code>Area</code> is rectangular in shape.
 * @return    <code>true</code> if the geometry of this
 * <code>Area</code> is rectangular in shape; <code>false</code>
 * otherwise.
 * @since 1.2
 */
public boolean isRectangular() {
    int size = curves.size();
    if (size == 0) {
        return true;
    }
    if (size > 3) {
        return false;
    }
    Curve c1 = (Curve) curves.get(1);
    Curve c2 = (Curve) curves.get(2);
    if (c1.getOrder() != 1 || c2.getOrder() != 1) {
        return false;
    }
    if (c1.getXTop() != c1.getXBot() || c2.getXTop() != c2.getXBot()) {
        return false;
    }
    if (c1.getYTop() != c2.getYTop() || c1.getYBot() != c2.getYBot()) {
        // One might be able to prove that this is impossible...
        return false;
    }
    return true;
}
 

import sun.awt.geom.Curve; //导入依赖的package包/类
/**
 * {@inheritDoc}
 * @since 1.2
 */
public boolean contains(double x, double y) {
    if (!(x * 0.0 + y * 0.0 == 0.0)) {
        /* Either x or y was infinite or NaN.
         * A NaN always produces a negative response to any test
         * and Infinity values cannot be "inside" any path so
         * they should return false as well.
         */
        return false;
    }
    // We count the "Y" crossings to determine if the point is
    // inside the curve bounded by its closing line.
    double x1 = getX1();
    double y1 = getY1();
    double x2 = getX2();
    double y2 = getY2();
    int crossings =
        (Curve.pointCrossingsForLine(x, y, x1, y1, x2, y2) +
         Curve.pointCrossingsForCubic(x, y,
                                      x1, y1,
                                      getCtrlX1(), getCtrlY1(),
                                      getCtrlX2(), getCtrlY2(),
                                      x2, y2, 0));
    return ((crossings & 1) == 1);
}
 

import sun.awt.geom.Curve; //导入依赖的package包/类
private int rectCrossings(double x, double y, double w, double h) {
    int crossings = 0;
    if (!(getX1() == getX2() && getY1() == getY2())) {
        crossings = Curve.rectCrossingsForLine(crossings,
                                               x, y,
                                               x+w, y+h,
                                               getX1(), getY1(),
                                               getX2(), getY2());
        if (crossings == Curve.RECT_INTERSECTS) {
            return crossings;
        }
    }
    // we call this with the curve's direction reversed, because we wanted
    // to call rectCrossingsForLine first, because it's cheaper.
    return Curve.rectCrossingsForCubic(crossings,
                                       x, y,
                                       x+w, y+h,
                                       getX2(), getY2(),
                                       getCtrlX2(), getCtrlY2(),
                                       getCtrlX1(), getCtrlY1(),
                                       getX1(), getY1(), 0);
}
 

import sun.awt.geom.Curve; //导入依赖的package包/类
/**
 * Tests whether this {@code Area} is rectangular in shape.
 * @return    {@code true} if the geometry of this
 * {@code Area} is rectangular in shape; {@code false}
 * otherwise.
 * @since 1.2
 */
public boolean isRectangular() {
    int size = curves.size();
    if (size == 0) {
        return true;
    }
    if (size > 3) {
        return false;
    }
    Curve c1 = curves.get(1);
    Curve c2 = curves.get(2);
    if (c1.getOrder() != 1 || c2.getOrder() != 1) {
        return false;
    }
    if (c1.getXTop() != c1.getXBot() || c2.getXTop() != c2.getXBot()) {
        return false;
    }
    if (c1.getYTop() != c2.getYTop() || c1.getYBot() != c2.getYBot()) {
        // One might be able to prove that this is impossible...
        return false;
    }
    return true;
}