from operation_vector import *

class Camera:
    def __init__(self, image_nrows, image_ncols, distance_focale):
        self.image_nrows = image_nrows
        self.image_ncols = image_ncols
        self.focal_length = distance_focale

    def ray_at(self, row, col):
        n = self.image_nrows//2
        x = (row-n)/n
        n = self.image_ncols//2
        y = (n-col)/n
        return Vector(x, y, self.focal_length)