#  ------------------------------------------------------------------------------------
#  gbAverageLocator.py - Maya Python Script 
#  ------------------------------------------------------------------------------------
#
#  DESCRIPTION:
#  This script creates a locator in average position between two selected vertex.
#  Something useful when placing joints in the right spot inside the geo.
#
#  USAGE:
#  (PYTHON)  import gbAverageLocator; gbAverageLocator.averageLocator()
#  (MEL)     python("import gbAverageLocator;AverageLocator.averageLocator()")
#
#  AUTHOR:
#  Giorgio Bertolone - mail@giorgiobertolone.com - www.giorgiobertolone.com
#  Copyright (C)2010- Giorgio Bertolone - All Rights Reserved.
#
#  VERSIONS:
#  1.00 - Dec 19, 2010 - Initial Release
#
#  ------------------------------------------------------------------------------------


import maya.cmds as mc

def averageLocator():

# check and warn if nothing is selected
	sel = mc.ls( sl=True, fl=True )
	if sel == []:
		mc.confirmDialog( title="Selection Error", message="Nothing is selected. Please select two vertex.", button=["Ok"], defaultButton="Ok" )

# calculate number of selected vertex and warn in case of selection errors	
	verNum = mc.polyEvaluate( vc=True )
	if verNum == 0:
		mc.confirmDialog( title="Selection Error", message="No vertex selected. Please select two vertex.", button=["Ok"], defaultButton="Ok" )
	if verNum == 1:
		mc.confirmDialog( title="Selection Error", message="Only one vertex selected. Please select two vertex.", button=["Ok"], defaultButton="Ok" )		
	if verNum > 2 and sel != []:
		mc.confirmDialog( title="Selection Error", message="More than two vertex are selected. Please select only two vertex.", button=["Ok"], defaultButton="Ok" )

# if two vertex are selected
	if verNum == 2:

# get the position of both vertex	
		posFir = mc.xform( sel[0], q=True, ws=True, t=True )
		posSec = mc.xform( sel[1], q=True, ws=True, t=True )
		pXFir = posFir[0]
		pYFir = posFir[1]
		pZFir = posFir[2]
		pXSec = posSec[0]
		pYSec = posSec[1]
		pZSec = posSec[2]

# calculate the average between the two
		pXTot =( posFir[0] + posSec[0] ) / 2
		pYTot =( posFir[1] + posSec[1] ) / 2
		pZTot =( posFir[2] + posSec[2] ) / 2

# create a locator in average position
		loc = mc.spaceLocator( p=(pXTot, pYTot, pZTot) )
		
# change the locator color to red to make it more visible. Default green is hard to see.
        mc.setAttr( loc[0] + ".overrideEnabled", 1 )
        mc.setAttr( loc[0] + ".overrideColor", 13 )