add_library('serial')
import math
import jarray

gamma = 1.7
brightness = 4
errorCount = 0
framerate = 30
dimension = 0 

ledSerial = None
data = None

current_px = 0

def serialConfigure(portName):
    global ledSerial
    try:
        ledSerial = Serial(this, portName)
        if ledSerial is None:
            raise NullPointerException()
        ledSerial.write('?')
    except Exception as e:
        println("Serial port " + portName + " does not exist or is non-functional")
        errorCount += 1
        return
    delay(50);
    line_serial = ledSerial.readStringUntil(10)
    if (line is None):
        println("Serial port " + portName + " is not responding.")
        println("Is it really a Teensy 3.0 running VideoDisplay?")
        errorCount += 1
        return
    
    param = line_serial.split(",")
    if (len(param) != 12):
        println("Error: port " + portName + " did not respond to LED config query")
        errorCount += 1
        return

def image2data(data):
    offset = 3
    for x in xrange(0, dimension, 1):
        pixel = [colorWiring(pixels[x]) for i in range(0, 8)]
        imgmask = 0x800000
        while imgmask != 0:
            b = 0
            for i in range(0, 8):
                if ((pixel[i] & imgmask) != 0):
                    b |= (1 << i)
            if b > 127:
                # Convert to signed bytes (expected by jarray)
                b -= 2**8
            data[offset] = b
            offset += 1
            imgmask >>= 1

def colorWiring(c):
    red = (c & 0xFF0000) >> 16
    green = (c & 0x00FF00) >> 8
    blue = (c & 0x0000FF)
    red = gammatable[red] >> 8
    green = gammatable[green] >> 8
    blue = gammatable[blue] >> 8
    return (green << 16) | (red << 8) | (blue)

def send_serial():
    image2data(data)
    ledSerial.write(data)
    
def prepare_data():
    global data
    data = jarray.zeros(dimension * 24 + 3, "b")
    data[0] = ord('*')
    usec = int((1000000.0 / framerate) * 0.75)
    data[1] = (usec % 256) - 2**8
    data[2] = usec >> 8

def setup():
    global gammatable
    global dimension
    size(700, 1)
    dimension = width * height
    frameRate(framerate)
    serialConfigure("/dev/ttyACM0") 
    if (errorCount > 0):
        exit()
    gammatable = [int((math.pow(i / 255.0, gamma) * 255.0 + 0.5) * brightness) for i in range(0, 256)]
    prepare_data()
    loadPixels()
    for i in range(dimension):
        pixels[i] = color(0, 0, 0)
    updatePixels()

def draw():
    global current_px
    pixels[current_px] = color(0, 255, 0)
    if current_px == 0:
        pixels[len(pixels) - 1] = color(0, 0, 0)
    else:
        pixels[current_px - 1] = color(0, 0, 0)
    updatePixels()
    if current_px == len(pixels) - 1:
        current_px = 0
    else: 
        current_px += 1
    send_serial()