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:
			return False 	#self.report({'WARNING'}, "Object must have more than one UV map")

		# 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)