home/jlab/matrix_ft.py

import socket

class Matrix(object):
    '''A Framebuffer display interface that sends a frame via UDP.
    see https://github.com/hzeller/flaschen-taschen/blob/master/doc/protocols.md
    '''

    def __init__(self, host, width, height, layer=1, x_offset=0, y_offset=0, transparent=False, port=1337):
        '''
        Args:
          host: The flaschen taschen server hostname or ip address.
          port: The flaschen taschen server port number.
          width: The width of the flaschen taschen display in pixels.
          height: The height of the flaschen taschen display in pixels.
          layer: The layer of the flaschen taschen display to write to. (layer=0 is permanent, layer > 0 decays, see --layer-timeout server opt)
          transparent: If true, black(0, 0, 0) will be transparent and show the layer below.
        '''
        self.width = width
        self.height = height
        self.layer = layer
        self.transparent = transparent
        self.x_offset = x_offset
        self.y_offset = y_offset

        self._sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        self._sock.connect((host, port))
        self._init_data()

    def _init_data(self):
        header = ''.join(["P6\n",
                          "%d %d\n" % (self.width, self.height),
                          "255\n"]).encode('utf-8')
        footer = ''.join(["%d\n" % self.x_offset,
                          "%d\n" % self.y_offset,
                          "%d\n" % self.layer]).encode('utf-8')
        self._data = bytearray(self.width * self.height * 3 + len(header) + len(footer))
        self._data[0:len(header)] = header
        self._data[-1 * len(footer):] = footer
        self._header_len = len(header)

    def set(self, x, y, color):
        '''Set the pixel at the given coordinates to the specified color.
        Args:
          x: x offset of the pixel to set
          y: y offset of the piyel to set
          color: A 3 tuple of (r, g, b) color values, 0-255
        '''
        if x >= self.width or y >= self.height or x < 0 or y < 0:
            return

        # [dr]: inverted logic
        if color == (0, 0, 0) and self.transparent:
            color = (1, 1, 1)

        offset = (x + y * self.width) * 3 + self._header_len
        self._data[offset] = color[0]
        self._data[offset + 1] = color[1]
        self._data[offset + 2] = color[2]

    def set_offset(self, x, y):
        self.x_offset = x
        self.y_offset = y
        self._init_data()

    def send(self):
        '''Send the updated pixels to the display.'''
        self._sock.send(self._data)

    def clear(self):
        '''clear pane with black (reinit self._data)
        '''
        self._init_data()

if __name__ == '__main__':
    f = Matrix('192.168.178.144', 50, 50)
    import time

    for j in range(10):
        time.sleep(1)
        f.set_offset(j*2, j)
        for i in range(100):
            f.set(i, i, (200, 0, 0))
        f.send()