""" Pixel converter utilities

This file expose many 32 bits RGBA into various pixel format
"""

__all__ = [
    'rgb1conv',
    'rgb8conv',
    'rgba8conv',
    'rgb16conv',
    'rgba16conv'
]

def rgb24to16(rgb):
    _r = (rgb[0] & 0xff) >> 3
    _g = (rgb[1] & 0xff) >> 2
    _b = (rgb[2] & 0xff) >> 3
    return (_r << 11) | (_g << 5) | _b



def rgb1conv(pixel):
    return pixel == (0, 0, 0)

def rgb8conv(pixel):
    return int((pixel[0] * 7) / 255) << 5   \
        | int((pixel[1] * 4) / 255) << 3    \
        | int((pixel[2] * 7) / 255) << 0

def rgba8conv(pixel):
    return int((pixel[0] * 4) / 256) << 6   \
        | int((pixel[1] * 8) / 256) << 3    \
        | int((pixel[2] * 4) / 256) << 1    \
        | (len(pixel) >= 4 and pixel[3] == 0)

def rgb16conv(pixel):
    return int((pixel[0] * 31) / 255) << 11   \
            | int((pixel[1] * 63) / 255) << 5 \
            | int((pixel[2] * 31) / 255) << 0

def rgba16conv(pixel):
    return int((pixel[0] * 31) / 255) << 11   \
            | int((pixel[1] * 63) / 255) << 6 \
            | int((pixel[2] * 31) / 255) << 1 \
            | (pixel[3] != 0)