Vuforia Frame Marker generator (legacy code)

qcarfm.py

from PIL import Image, ImageDraw

DEFAULT_NESW = (292, 246, 177, 472)
OFFSETS_NESW = ((1, 0), (19, 1), (2, 19), (0, 2))

class common(object):


    def __init__(self, fmid = 0):
        self.fmid = fmid

    def get_nesw(self):
        return [(self.fmid ^ i) for i in DEFAULT_NESW]

    def calc_all(self):
        result = [
            self.calc_dots(num, OFFSETS_NESW[index], 
                (index >> 1) & 1, index & 1
            ) for index, num in enumerate(self.get_nesw())
        ]
        return result

    def calc_dots(self, num = 0, offset = (0, 0), reverse = False, vertical = False):
        bits = [(num & (1 << shifts)) >> shifts for shifts in range(8, -1, -1)]
        if reverse: bits.reverse()
        if vertical:
            coords = [(offset[0], y) for y in range(offset[1], 2 * len(bits) + offset[1], 2)]
        else:
            coords = [(x, offset[1]) for x in range(offset[0], 2 * len(bits) + offset[0], 2)]
        return zip(coords, bits)

# ---------------------------------------------->8

class bitmap(common):
    def __init__(self, fmid = 0, scale = 1):
        super(bitmap, self).__init__(fmid)
        self.scale = scale
        self.reset_image()

    def reset_image(self):
        self.image = Image.new('RGBA', (20, 20))

    def plot(self):
        for data in self.calc_all():
            self.plot_dots(data)
        # add an extra white frame (otherwise libqcar won't recongnize the generated image)
        result = Image.new('RGBA', (24, 24), 'white')
        result.paste(Image.new('RGBA', (22, 22), 'black'), (1, 1))
        result.paste(self.image, (2, 2))
        if self.scale != 1:
            return result.resize([24 * self.scale] * 2)
        else:
            return result

    def plot_dots(self, data):
        colors = ['white', 'black']
        draw = ImageDraw.Draw(self.image)
        for xy, b in data:
            draw.point(xy, colors[b])