Path的一些參數 1. FillType

1. FillType

path的填充方式，有4種，舉例說明啥效果

    /**
     * Enum for the ways a path may be filled.
     */
    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.
         */
        WINDING         (0),
        /**
         * Specifies that "inside" is computed by an odd number of edge
         * crossings.
         */
        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;
    }

1.1 WINDING

默認值就是這個，測試代碼如下，數學裏的並集，屬於A或者屬於B的部分

        path2.apply {
            reset()
            addCircle(100f,100f,50f,Path.Direction.CW)
        }

        path3.apply {
            reset()
            addCircle(200f,200f,50f,Path.Direction.CW)
        }
        path.apply {
            reset()
            path.addPath(path2)
            path.fillType=Path.FillType.WINDING
            path.addPath(path3)
        }

1.2 INVERSE_WINDING

上邊的效果取反，
測試代碼

        path2.apply {
            reset()
            addCircle(100f,100f,50f,Path.Direction.CW)
        }

        path3.apply {
            reset()
            addCircle(200f,200f,50f,Path.Direction.CW)
        }

        path.apply {
            reset()
            path.addPath(path2)
            path.fillType=Path.FillType.INVERSE_WINDING
            path.addPath(path3)
        }

canvas.drawPath(path,p)

1.3 EVEN_ODD

把交集扣掉，也就是把兩者共有的部分扣掉

        path3.apply {
            reset()
            addCircle(200f,200f,50f,Path.Direction.CW)
        }

        path4.apply {
            reset()
            addCircle(280f,200f,60f,Path.Direction.CW)
        }

        path.apply {
            reset()
            path.addPath(path3)
            path.fillType=Path.FillType.EVEN_ODD
            path.addPath(path4)
        }

1.4 INVERSE_EVEN_ODD

上邊的效果取反