render.py 文件源码

def sandstroke(self,xys,grains=10):

    pix = self.pix
    rectangle = self.ctx.rectangle
    fill = self.ctx.fill

    dx = xys[:,2] - xys[:,0]
    dy = xys[:,3] - xys[:,1]

    aa = arctan2(dy,dx)
    directions = column_stack([cos(aa),sin(aa)])

    dd = sqrt(square(dx)+square(dy))

    for i,d in enumerate(dd):
      for x,y in xys[i,:2] + directions[i,:]*random((grains,1))*d:
        rectangle(x,y,pix,pix)
        fill()