"""
This page is in the table of contents.
The obj.py script is an import translator plugin to get a carving from an obj file.

An import plugin is a script in the import_plugins folder which has the function getCarving.  It is meant to be run from the interpret tool.  To ensure that the plugin works on platforms which do not handle file capitalization properly, give the plugin a lower case name.

The getCarving function takes the file name of an obj file and returns the carving.

From wikipedia, OBJ (or .OBJ) is a geometry definition file format first developed by Wavefront Technologies for its Advanced Visualizer animation package:
http://en.wikipedia.org/wiki/Obj

The Object File specification is at:
http://local.wasp.uwa.edu.au/~pbourke/dataformats/obj/

An excellent link page about obj files is at:
http://people.sc.fsu.edu/~burkardt/data/obj/obj.html

This example gets a carving for the obj file box.obj.  This example is run in a terminal in the folder which contains box.obj and obj.py.


> python
Python 2.5.1 (r251:54863, Sep 22 2007, 01:43:31)
[GCC 4.2.1 (SUSE Linux)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import obj
>>> obj.getCarving()
[-62.0579, -41.4791, 0.0, 58.8424, -41.4791, 0.0, -62.0579, 22.1865, 0.0, 58.8424, 22.1865, 0.0,
-62.0579, -41.4791, 39.8714, 58.8424, -41.4791, 39.8714, -62.0579, 22.1865, 39.8714, 58.8424, 22.1865, 39.8714]
[0 [0, 10] [0, 2], 1 [0, 1] [0, 3], 2 [0, 8] [2, 3], 3 [1, 6] [1, 3], 4 [1, 4] [0, 1], 5 [2, 5] [4, 5], 6 [2, 3] [4, 7], 7 [2, 7] [5, 7],
8 [3, 9] [6, 7], 9 [3, 11] [4, 6], 10 [4, 5] [0, 5], 11 [4, 7] [1, 5], 12 [5, 10] [0, 4], 13 [6, 7] [1, 7], 14 [6, 9] [3, 7],
15 [8, 9] [3, 6], 16 [8, 11] [2, 6], 17 [10, 11] [2, 4]]
[0 [0, 1, 2] [0, 2, 3], 1 [3, 1, 4] [3, 1, 0], 2 [5, 6, 7] [4, 5, 7], 3 [8, 6, 9] [7, 6, 4], 4 [4, 10, 11] [0, 1, 5], 5 [5, 10, 12] [5, 4, 0],
6 [3, 13, 14] [1, 3, 7], 7 [7, 13, 11] [7, 5, 1], 8 [2, 15, 16] [3, 2, 6], 9 [8, 15, 14] [6, 7, 3], 10 [0, 17, 12] [2, 0, 4],
11 [9, 17, 16] [4, 6, 2]][11.6000003815, 10.6837882996, 7.80209827423

"""


from __future__ import absolute_import
#Init has to be imported first because it has code to workaround the python bug where relative imports don't work if the module is imported as a main module.
import __init__

from skeinforge_tools.skeinforge_utilities.vector3 import Vector3
from skeinforge_tools.skeinforge_utilities import gcodec
from skeinforge_tools.skeinforge_utilities import triangle_mesh
from struct import unpack

__author__ = "Enrique Perez (perez_enrique@yahoo.com)"
__credits__ = 'Nophead <http://hydraraptor.blogspot.com/>\nArt of Illusion <http://www.artofillusion.org/>'
__date__ = "$Date: 2008/21/04 $"
__license__ = "GPL 3.0"


def addFacesGivenText( objText, triangleMesh ):
	"Add faces given obj text."
	lines = gcodec.getTextLines( objText )
	for line in lines:
		splitLine = line.split()
		firstWord = gcodec.getFirstWord( splitLine )
		if firstWord == 'v':
			triangleMesh.vertices.append( getVertexGivenLine( line ) )
		elif firstWord == 'f':
			triangleMesh.faces.append( getFaceGivenLine( line, triangleMesh ) )

def getFaceGivenLine( line, triangleMesh ):
	"Add face given line index and lines."
	face = triangle_mesh.Face()
	face.index = len( triangleMesh.faces )
	splitLine = line.split()
	for vertexStringIndex in xrange( 1, 4 ):
		vertexString = splitLine[ vertexStringIndex ]
		vertexStringWithSpaces = vertexString.replace( '/', ' ' )
		vertexStringSplit = vertexStringWithSpaces.split()
		vertexIndex = int( vertexStringSplit[ 0 ] ) - 1
		face.vertexIndexes.append( vertexIndex )
	return face

def getCarving( fileName = '' ):
	"Get the triangle mesh for the obj file."
	if fileName == '':
		unmodified = gcodec.getFilesWithFileTypeWithoutWords( 'obj' )
		if len( unmodified ) == 0:
			print( "There is no obj file in this folder." )
			return None
		fileName = unmodified[ 0 ]
	objText = gcodec.getFileText( fileName, 'rb' )
	if objText == '':
		return None
	triangleMesh = triangle_mesh.TriangleMesh()
	addFacesGivenText( objText, triangleMesh )
	triangleMesh.setEdgesForAllFaces()
	return triangleMesh

def getVertexGivenLine( line ):
	"Get vertex given obj vertex line."
	splitLine = line.split()
	return Vector3( float( splitLine[ 1 ] ), float( splitLine[ 2 ] ), float( splitLine[ 3 ] ) )