op_align.py

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

from . import utilities_uv


class op(bpy.types.Operator):
    bl_idname = "uv.textools_align"
    bl_label = "Align"
    bl_description = "Align vertices, edges or shells"
    bl_options = {'REGISTER', 'UNDO'}

    direction: bpy.props.StringProperty(name="Direction", default="top")

    @classmethod
    def poll(cls, context):
        if not bpy.context.active_object:
            return False

        # Only in Edit mode
        if bpy.context.active_object.mode != 'EDIT':
            return False

        # Only in UV editor mode
        if bpy.context.area.type != 'IMAGE_EDITOR':
            return False

        # Requires UV map
        if not bpy.context.object.data.uv_layers:
            # self.report({'WARNING'}, "Object must have more than one UV map")
            return False

        # Not in Synced mode
        if bpy.context.scene.tool_settings.use_uv_select_sync:
            return False

        return True

    def execute(self, context):

        align(context, self.direction)
        return {'FINISHED'}


def align(context, direction):
    # Store selection
    utilities_uv.selection_store()

    if bpy.context.tool_settings.transform_pivot_point != 'CURSOR':
        bpy.context.tool_settings.transform_pivot_point = 'CURSOR'

    # B-Mesh
    obj = bpy.context.active_object
    bm = bmesh.from_edit_mesh(obj.data)
    uv_layers = bm.loops.layers.uv.verify()

    if len(obj.data.uv_layers) == 0:
        print("There is no UV channel or UV data set")
        return

    # Collect BBox sizes
    boundsAll = utilities_uv.getSelectionBBox()

    mode = bpy.context.scene.tool_settings.uv_select_mode
    if mode == 'FACE' or mode == 'ISLAND':
        print("____ Align Islands")

        # Collect UV islands
        islands = utilities_uv.getSelectionIslands()

        for island in islands:

            bpy.ops.uv.select_all(action='DESELECT')
            utilities_uv.set_selected_faces(island)
            bounds = utilities_uv.getSelectionBBox()

            # print("Island "+str(len(island))+"x faces, delta: "+str(delta.y))

            if direction == "bottom":
                delta = boundsAll['min'] - bounds['min']
                bpy.ops.transform.translate(value=(0, delta.y, 0))
            elif direction == "top":
                delta = boundsAll['max'] - bounds['max']
                bpy.ops.transform.translate(value=(0, delta.y, 0))
            elif direction == "left":
                delta = boundsAll['min'] - bounds['min']
                bpy.ops.transform.translate(value=(delta.x, 0, 0))
            elif direction == "right":
                delta = boundsAll['max'] - bounds['max']
                bpy.ops.transform.translate(value=(delta.x, 0, 0))
            else:
                print("Unkown direction: "+str(direction))

    elif mode == 'EDGE' or mode == 'VERTEX':
        print("____ Align Verts")

        for f in bm.faces:
            if f.select:
                for l in f.loops:
                    luv = l[uv_layers]
                    if luv.select:
                        # print("Idx: "+str(luv.uv))
                        if direction == "top":
                            luv.uv[1] = boundsAll['max'].y
                        elif direction == "bottom":
                            luv.uv[1] = boundsAll['min'].y
                        elif direction == "left":
                            luv.uv[0] = boundsAll['min'].x
                        elif direction == "right":
                            luv.uv[0] = boundsAll['max'].x

        bmesh.update_edit_mesh(obj.data)

    # Restore selection
    utilities_uv.selection_restore()


bpy.utils.register_class(op)