"""Mirror UVs but retain uv edge positions"""

bl_idname = "view3d.dreamuv_uvmirror"

bl_label = "3D View UV Mirror"

bl_options = {"UNDO"}

direction : bpy.props.StringProperty()

def execute(self, context):

mesh = bpy.context.object.data

bm = bmesh.from_edit_mesh(mesh)

bm.faces.ensure_lookup_table()

uv_layer = bm.loops.layers.uv.active

#do this again

faces = list()

#MAKE FACE LIST

for face in bm.faces:

if face.select:

faces.append(face)

#get original size

xmin, xmax = faces[0].loops[0][uv_layer].uv.x, faces[0].loops[0][uv_layer].uv.x

ymin, ymax = faces[0].loops[0][uv_layer].uv.y, faces[0].loops[0][uv_layer].uv.y

for face in faces:

for vert in face.loops:

xmin = min(xmin, vert[uv_layer].uv.x)

xmax = max(xmax, vert[uv_layer].uv.x)

ymin = min(ymin, vert[uv_layer].uv.y)

ymax = max(ymax, vert[uv_layer].uv.y)

#prevent divide by 0:

if (xmax - xmin) == 0:

xmin = .1

if (ymax - ymin) == 0:

ymin = .1

for face in faces:

for loop in face.loops:

loop[uv_layer].uv.x -= xmin

loop[uv_layer].uv.y -= ymin

loop[uv_layer].uv.x /= (xmax-xmin)

loop[uv_layer].uv.y /= (ymax-ymin)

if self.direction == "x":

loop[uv_layer].uv.x = -loop[uv_layer].uv.x + 1.0

if self.direction == "y":

loop[uv_layer].uv.y = -loop[uv_layer].uv.y + 1.0

loop[uv_layer].uv.x *= xmax-xmin

loop[uv_layer].uv.y *= ymax-ymin

loop[uv_layer].uv.x += xmin

loop[uv_layer].uv.y += ymin

bmesh.update_edit_mesh(mesh, loop_triangles=False, destructive=False)

return {'FINISHED'}