如何区分封闭图形的内部和外部

public static float dp2px(float dp){    return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, Resources.getSystem().getDisplayMetrics());}

    /** 表示 封闭图形 添加到路径中的方向     * Specifies how closed shapes (e.g. rects, ovals) are oriented when they are added to a path.     */    public enum Direction {        /** clockwise */        CW  (0),    // must match enum in SkPath.h 顺时针        /** counter-clockwise */        CCW (1);    // must match enum in SkPath.h 逆时针
        Direction(int ni) {            nativeInt = ni;        }        final int nativeInt;    }

public enum FillType {        // these must match the values in SkPath.h        /**         * Specifies that "inside" is computed by a non-zero sum of signed edge crossings. 判断点是否是内部的依据是，由点向外划一条直线，穿过的边数，顺时针为1逆时针为-1，加起来非0就表示内部；0就是外部。         */        WINDING         (0),        /**         * Specifies that "inside" is computed by an odd number of edge crossings.判断点是否是内部的依据是，由点向外划一条直线，穿过的边数为奇数即为内部。Odd even 奇数偶数。         */        EVEN_ODD        (1),        /**         * Same as {@link #WINDING}, but draws outside of the path, rather than inside.         */        INVERSE_WINDING (2),        /**         * Same as {@link #EVEN_ODD}, but draws outside of the path, rather than inside.         */        INVERSE_EVEN_ODD(3);
        FillType(int ni) {            nativeInt = ni;        }
        final int nativeInt;    }