Simple tool for packing colors into UV maps

uvdata.py

'''
Simple tool for packing colors into UV maps
'''

import bpy
import math
import mathutils

def v2_to_float(v2, precision=4096):
    '''Pack two 0-1 float values into a single float'''
    p = precision - 1
    x, y = v2
    x = math.floor(x * p)
    y = math.floor(y * p)
    f = (x * precision) + y
    return f

def float_to_v2(f, precision=4096):
    '''Unpack two 0-1 float values from a single float'''
    p = precision - 1
    x = math.floor(f / precision) / p
    y = (f % precision) / p
    return x, y

def pack_rgba(obj, uvmap_name, color_name, alpha_name=None, precision=4096):
    uvmap = obj.data.uv_layers[uvmap_name].data
    color = obj.data.vertex_colors[color_name].data

    if alpha_name is None:
        for loop_index, uv_loop in enumerate(uvmap):
            r, g, b, a = color[loop_index].color
            uv_loop.uv.x = v2_to_float((r, g), precision=precision)
            uv_loop.uv.y = v2_to_float((b, a), precision=precision)
    else:
        alpha = obj.data.vertex_colors[alpha_name].data
        for loop_index, uv_loop in enumerate(uvmap):
            r, g, b, a = color[loop_index].color
            a = mathutils.Color((alpha[loop_index].color[:3])).v
            print(a)
            uv_loop.uv.x = v2_to_float((r, g), precision=precision)
            uv_loop.uv.y = v2_to_float((b, a), precision=precision)