from polygon import MultiPolygon
from point import Point

class View(object):
    """
    translates a point to a view
    """
    def __init__(self, bbox=None, width=None, height=None, padding=0):
        self.bbox = bbox
        self.width = width
        self.padding = padding
        self.height = height
        if bbox:
            self.scale = min((width-padding*2) / bbox.width, (height-padding*2) / bbox.height)
    
    
    def project(self, pt):
        bbox = self.bbox
        if not bbox:
            return pt
        s = self.scale
        h = self.height
        w = self.width
        if isinstance(pt, Point):
            px = pt.x
            py = pt.y
        else:
            px = pt[0]
            py = pt[1]
        x = (px - bbox.left) * s + (w - bbox.width * s) * .5
        y = (py - bbox.top) * s + (h - bbox.height * s) * .5
        return ((x,y), Point(x, y))[isinstance(pt, Point)]
    
    
    def __str__(self):
        return 'View(w=%f, h=%f, pad=%f, scale=%f, bbox=%s)' % (self.width, self.height, self.padding, self.scale, self.bbox)