utilities_color.py

import bpy
import bmesh
import operator
import time
from mathutils import Vector
from collections import defaultdict
from math import pi
from mathutils import Color

from . import settings


material_prefix = "TT_color_"
gamma = 2.2


def assign_slot(obj, index):
    if index < len(obj.material_slots):
        obj.material_slots[index].material = get_material(index)

        # Verify color
        assign_color(index)


def safe_color(color):
    if len(color) == 3:
        if bpy.app.version > (2, 80, 0):
            # Newer blender versions use RGBA
            return (color[0], color[1], color[2], 1)
        else:
            return color
    elif len(color) == 4:
        if bpy.app.version > (2, 80, 0):
            # Newer blender versions use RGBA
            return color
        else:
            return (color[0], color[1], color[2])

    return color


def assign_color(index):
    material = get_material(index)
    if material:
        # material.use_nodes = False

        rgb = get_color(index)
        rgba = (rgb[0], rgb[1], rgb[2], 1)

        if material.use_nodes and bpy.context.scene.render.engine == 'CYCLES' or material.use_nodes and bpy.context.scene.render.engine == 'BLENDER_EEVEE':
            # Cycles material (Preferred for baking)
            material.node_tree.nodes["Principled BSDF"].inputs[0].default_value = rgba
            material.diffuse_color = rgba

        elif not material.use_nodes and bpy.context.scene.render.engine == 'BLENDER_EEVEE':
            # Legacy render engine, not suited for baking
            material.diffuse_color = rgba


def get_material(index):
    name = get_name(index)

    # Material already exists?
    if name in bpy.data.materials:
        material = bpy.data.materials[name]

        # Check for incorrect matreials for current render engine
        if not material:
            replace_material(index)

        if not material.use_nodes and bpy.context.scene.render.engine == 'CYCLES':
            replace_material(index)

        elif material.use_nodes and bpy.context.scene.render.engine == 'BLENDER_EEVEE':
            replace_material(index)

        else:
            return material

    print("Could nt find {} , create a new one??".format(name))

    material = create_material(index)
    assign_color(index)
    return material


# Replaace an existing material with a new one
# This is sometimes necessary after switching the render engine
def replace_material(index):
    name = get_name(index)

    print("Replace material and create new")

    # Check if material exists
    if name in bpy.data.materials:
        material = bpy.data.materials[name]

        # Collect material slots we have to re-assign
        slots = []
        for obj in bpy.context.view_layer.objects:
            for slot in obj.material_slots:
                if slot.material == material:
                    slots.append(slot)

        # Get new material
        material.user_clear()
        bpy.data.materials.remove(material)

        # Re-assign new material to all previous slots
        material = create_material(index)
        for slot in slots:
            slot.material = material


def create_material(index):
    name = get_name(index)

    # Create new image instead
    material = bpy.data.materials.new(name)
    material.preview_render_type = 'FLAT'

    if bpy.context.scene.render.engine == 'CYCLES':
        # Cycles: prefer nodes as it simplifies baking
        material.use_nodes = True

    return material


def get_name(index):
    return (material_prefix+"{:02d}").format(index)


def get_color(index):
    if index < bpy.context.scene.texToolsSettings.color_ID_count:
        return getattr(bpy.context.scene.texToolsSettings, "color_ID_color_{}".format(index))

    # Default return (Black)
    return (0, 0, 0)


def set_color(index, color):
    if index < bpy.context.scene.texToolsSettings.color_ID_count:
        setattr(bpy.context.scene.texToolsSettings,
                "color_ID_color_{}".format(index), color)


def validate_face_colors(obj):
    # Validate face colors and material slots
    previous_mode = bpy.context.object.mode
    count = bpy.context.scene.texToolsSettings.color_ID_count

    # Verify enough material slots
    if len(obj.material_slots) < count:
        for i in range(count):
            if len(obj.material_slots) < count:
                bpy.ops.object.material_slot_add()
                assign_slot(obj, len(obj.material_slots)-1)
            else:
                break

    # TODO: Check face.material_index
    bpy.ops.object.mode_set(mode='EDIT')
    bm = bmesh.from_edit_mesh(obj.data)
    for face in bm.faces:
        face.material_index %= count
    obj.data.update()

    # Remove material slots that are not used
    if len(obj.material_slots) > count:
        bpy.ops.object.mode_set(mode='OBJECT')
        for i in range(len(obj.material_slots) - count):
            if len(obj.material_slots) > count:
                # Remove last
                bpy.context.object.active_material_index = len(
                    obj.material_slots)-1
                bpy.ops.object.material_slot_remove()

    # Restore previous mode
    bpy.ops.object.mode_set(mode=previous_mode)


def hex_to_color(hex):

    hex = hex.strip('#')
    lv = len(hex)
    fin = list(int(hex[i:i + lv // 3], 16) for i in range(0, lv, lv // 3))
    r = pow(fin[0] / 255, gamma)
    g = pow(fin[1] / 255, gamma)
    b = pow(fin[2] / 255, gamma)
    fin.clear()
    fin.append(r)
    fin.append(g)
    fin.append(b)
    return tuple(fin)


def color_to_hex(color):
    rgb = []
    for i in range(3):
        rgb.append(pow(color[i], 1.0/gamma))

    r = int(rgb[0]*255)
    g = int(rgb[1]*255)
    b = int(rgb[2]*255)

    return "#{:02X}{:02X}{:02X}".format(r, g, b)


def get_color_id(index, count):
    # Get unique color
    color = Color()
    color.hsv = (index / (count)), 0.9, 1.0

    return color