#!BPY

# ########################################################################
#
# AutoAlign - Aligns selected vertices to an axis.
# Copyright (C) 2007 Dave Jarvis (http://www.davidjarvis.ca)

# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA  02110-1301, USA.
#
# ########################################################################

"""
Name: 'AutoAlign Vertices'
Blender: 243
Group: 'Mesh'
Tooltip: 'Aligns selected vertices to an axis.'
"""
__author__ = "Dave Jarvis"
__url__ = ("http://www.davidjarvis.ca/blender")
__version__ = "1.0.0"
__bpydoc__ = """
1. Select a group of vertices to align.
2. Select and load this script.
"""

import array, Blender
from Numeric import Float, zeros
from Blender import NMesh, Window, Draw

X_AXIS = 0
Y_AXIS = 1
Z_AXIS = 2

# Remember the state of Edit mode.
#
editMode = Window.EditMode()

# Leave edit mode before changing an active mesh.
#
if editMode: Window.EditMode( 0 )

# Get a handle to the mesh of the active object.
#
objects = Blender.Object.GetSelected()
mesh = NMesh.GetRaw( objects[0].data.name )

min = zeros( 3, Float )
max = zeros( 3, Float )

# Corral only the selected vertices.
#
vertices = [vertex for vertex in mesh.verts if vertex.sel]
vertex = vertices[0]

min[ X_AXIS ] = vertex.co[ X_AXIS ]
min[ Y_AXIS ] = vertex.co[ Y_AXIS ]
min[ Z_AXIS ] = vertex.co[ Z_AXIS ]
max[ X_AXIS ] = vertex.co[ X_AXIS ]
max[ Y_AXIS ] = vertex.co[ Y_AXIS ]
max[ Z_AXIS ] = vertex.co[ Z_AXIS ]

sum = zeros( 3, Float )
count = 0

# For all the selected vertices, determine the
# minimum and maximum extents along each axis.
# While we're at it, sum the distance between
# the points (in preparation for averaging).
#
for vertex in vertices:
	count = count + 1
	
	x = vertex.co[ X_AXIS ]
	y = vertex.co[ Y_AXIS ]
	z = vertex.co[ Z_AXIS ]

	if x < min[ X_AXIS ]: min[ X_AXIS ] = x
	if y < min[ Y_AXIS ]: min[ Y_AXIS ] = y
	if z < min[ Z_AXIS ]: min[ Z_AXIS ] = z

	if x > max[ X_AXIS ]: max[ X_AXIS ] = x
	if y > max[ Y_AXIS ]: max[ Y_AXIS ] = y
	if z > max[ Z_AXIS ]: max[ Z_AXIS ] = z

	sum[ X_AXIS ] += x
	sum[ Y_AXIS ] += y
	sum[ Z_AXIS ] += z

# Find the differences between vertex extents.
#
x = max[ X_AXIS ] - min[ X_AXIS ]
y = max[ Y_AXIS ] - min[ Y_AXIS ]
z = max[ Z_AXIS ] - min[ Z_AXIS ]

# Whichever axis has the least difference between
# the minimum and maximum extents is the axis
# along which the vertices will be flattened.
#
axis = X_AXIS
if y < x: axis = Y_AXIS
if (axis == X_AXIS) and (z < x): axis = Z_AXIS
if (axis == Y_AXIS) and (z < y): axis = Z_AXIS

# Determine the coordinate for the axis by taking
# the average value of all selected vertices along
# the axis of minimum extents.
#
coord = (sum[ axis ] / count)

# Align the vertices to the determined axis at the
# average location.
#
for vertex in mesh.verts:
	if vertex.sel: vertex.co[ axis ] = coord

mesh.update()
Draw.Redraw()

# Restore edit mode to its former state.
#
Window.EditMode( editMode )