from grid import grid
from baker.tools import exact_func

import numpy as np


class simple_rect_grid(grid):
  def __init__(self, xres = 5, yres = 5):
    xmin = -1.0
    xmax =  1.0
    xspan = xmax - xmin
    xdel = xspan / float(xres - 1)

    ymin = -1.0
    ymay =  1.0
    yspan = ymay - ymin
    ydel = yspan / float(yres - 1)


    points = []
    q      = []
    for x in xrange(xres):
      cur_x = xmin + (x * xdel)
      for y in xrange(yres):
        cur_y = ymin + (y * ydel)
        points.append([cur_x, cur_y])
        q.append(exact_func(cur_x, cur_y))
    grid.__init__(self, points, q)
    self.construct_connectivity()

  def for_qhull_generator(self):
    """
      this returns a generator that should be fed into qdelaunay
    """

    yield '2';
    yield '%d' % len(self.points)

    for p in self.points:
      yield "%f %f" % (p[0], p[1])

  def for_qhull(self):
    """
      this returns a single string that should be fed into qdelaunay
    """
    r  = '2\n'
    r += '%d\n' % len(self.points)
    for p in self.points:
      r += "%f %f\n" % (p[0], p[1])
    return r


class simple_random_grid(simple_rect_grid):
  def __init__(self, num_points = 10):
    points = []
    q = []

    r = np.random

    for i in xrange(num_points):
      cur_x = r.rand()
      cur_y = r.rand()

      points.append([cur_x, cur_y])
      q.append(exact_func(cur_x, cur_y))
    grid.__init__(self, points, q)

    self.points = np.array(self.points)
    self.q      = np.array(self.q)