Blender-TexTools/op_uv_crop.py

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

from . import utilities_uv
from . import utilities_ui


class op(bpy.types.Operator):
    bl_idname = "uv.textools_uv_crop"
    bl_label = "Crop"
    bl_description = "Crop UV area to selected UV faces"
    bl_options = {'REGISTER', 'UNDO'}

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

        if bpy.context.active_object.type != 'MESH':
            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

        return True

    def execute(self, context):
        crop(self, context)
        return {'FINISHED'}


def crop(self, context):
    bm = bmesh.from_edit_mesh(bpy.context.active_object.data)
    uv_layers = bm.loops.layers.uv.verify()

    padding = utilities_ui.get_padding()

    # Scale to fit bounds
    bbox = utilities_uv.getSelectionBBox()
    scale_u = (1.0-padding) / bbox['width']
    scale_v = (1.0-padding) / bbox['height']
    scale = min(scale_u, scale_v)

    bpy.ops.transform.resize(value=(scale, scale, scale), constraint_axis=(
        False, False, False), mirror=False, use_proportional_edit=False)

    # Reposition
    bbox = utilities_uv.getSelectionBBox()

    delta_position = Vector((padding/2, 1-padding/2)) - \
        Vector((bbox['min'].x, bbox['min'].y + bbox['height']))
    bpy.ops.transform.translate(value=(delta_position.x, delta_position.y, 0))


bpy.utils.register_class(op)