Koch雪花的构图方法，递归模型的实现算法，建立平面二维坐标系，原点位于屏幕客户区中心，x轴水平向右为正，y轴铅直向上为正。

以原点为圆心绘制半径为r的圆，与y轴交于P0点。从P0点开始，顺时针方向将圆三等分，得到P1和P2点。P0P1P2构成等边三角形。

沿着等边三角形的三条边外侧分别绘制三段递归深度为4，夹角为60°的Koch曲线，形成Koch雪花。

-Koch snowflake patterning method, recursive algorithm model, the establishment of two-dimensional coordinate system, the origin of the client area of ​ ​ the center of the screen, x-axis horizontally to the right is positive, y-axis vertically upward is positive. Draw the origin as the center of the circle of radius r, and the y-axis at point P0. From the start point P0, the circle clockwise three equal portions, get points P1 and P2. P0P1P2 form an equilateral triangle. Along three sides of an equilateral triangle three sections were drawn outside the recursion depth is 4, the Koch curve angle of 60 to form a Koch snowflake.