#!BPY

"""
Name: 'LightWave (.lwo)...'
Blender: 232
Group: 'Import'
Tooltip: 'Import LightWave Object File Format (.lwo)'
"""

__author__ = "Anthony D'Agostino (Scorpius)"
__url__ = ("blender", "elysiun",
"Author's homepage, http://www.redrival.com/scorpius")
__version__ = "Part of IOSuite 0.5"

__bpydoc__ = """\
This script imports LightWave files to Blender.

LightWave is a full-featured commercial modeling and rendering
application. The lwo file format is composed of 'chunks,' is well
defined, and easy to read and write. It is similar in structure to the
trueSpace cob format.

Usage:<br>
	Execute this script from the "File->Import" menu and choose a LightWave
file to open.

Supported:<br>
	Meshes only.

Missing:<br>
    Materials, UV Coordinates, and Vertex Color info will be ignored.

Known issues:<br>
	Triangulation of convex polygons works fine, and uses a very simple
fanning algorithm. Convex polygons (i.e., shaped like the letter "U")
require a different algorithm, and will be triagulated incorrectly.

Notes:<br>
	Also reads lwo files in the old LW v5.5 format.
"""

# $Id$
#
# +---------------------------------------------------------+
# | Copyright (c) 2002 Anthony D'Agostino                   |
# | http://www.redrival.com/scorpius                        |
# | scorpius@netzero.com                                    |
# | April 21, 2002                                          |
# | Released under the Blender Artistic Licence (BAL)       |
# | Import Export Suite v0.5                                |
# +---------------------------------------------------------+
# | Read and write LightWave Object File Format (*.lwo)     |
# +---------------------------------------------------------+

import Blender, meshtools
import struct, chunk, os, cStringIO, time, operator

# =============================
# === Read LightWave Format ===
# =============================
def read(filename):
	start = time.clock()
	file = open(filename, "rb")

	# === LWO header ===
	form_id, form_size, form_type = struct.unpack(">4s1L4s",  file.read(12))
	if (form_type != "LWOB") and (form_type != "LWO2"):
		print "Can't read a file with the form_type:", form_type
		return

	objname = os.path.splitext(os.path.basename(filename))[0]

	while 1:
		try:
			lwochunk = chunk.Chunk(file)
		except EOFError:
			break
		if lwochunk.chunkname == "LAYR":
			objname = read_layr(lwochunk)
		elif lwochunk.chunkname == "PNTS":                         # Verts
			verts = read_verts(lwochunk)
		elif lwochunk.chunkname == "POLS" and form_type == "LWO2": # Faces v6.0
			faces = read_faces_6(lwochunk)
			meshtools.create_mesh(verts, faces, objname)
		elif lwochunk.chunkname == "POLS" and form_type == "LWOB": # Faces v5.5
			faces = read_faces_5(lwochunk)
			meshtools.create_mesh(verts, faces, objname)
		else:													   # Misc Chunks
			lwochunk.skip()

	Blender.Window.DrawProgressBar(1.0, "")    # clear progressbar
	file.close()
	end = time.clock()
	seconds = " in %.2f %s" % (end-start, "seconds")
	if form_type == "LWO2": fmt = " (v6.0 Format)"
	if form_type == "LWOB": fmt = " (v5.5 Format)"
	message = "Successfully imported " + os.path.basename(filename) + fmt + seconds
	meshtools.print_boxed(message)

# ==================
# === Read Verts ===
# ==================
def read_verts(lwochunk):
	data = cStringIO.StringIO(lwochunk.read())
	numverts = lwochunk.chunksize/12
	#$verts = []
	verts = [None] * numverts
	for i in range(numverts):
		if not i%100 and meshtools.show_progress:
			Blender.Window.DrawProgressBar(float(i)/numverts, "Reading Verts")
		x, y, z = struct.unpack(">fff", data.read(12))
		#$verts.append((x, z, y))
		verts[i] = (x, z, y)
	return verts

# =================
# === Read Name ===
# =================
def read_name(file):
	name = ""
	while 1:
		char = file.read(1)
		if char == "\0": break
		else: name += char
	return name

# ==================
# === Read Layer ===
# ==================
def read_layr(lwochunk):
	data = cStringIO.StringIO(lwochunk.read())
	idx, flags = struct.unpack(">hh", data.read(4))
	pivot = struct.unpack(">fff", data.read(12))
	layer_name = read_name(data)
	if not layer_name: layer_name = "No Name"
	return layer_name

# ======================
# === Read Faces 5.5 ===
# ======================
def read_faces_5(lwochunk):
	data = cStringIO.StringIO(lwochunk.read())
	faces = []
	i = 0
	while i < lwochunk.chunksize:
		if not i%100 and meshtools.show_progress:
		   Blender.Window.DrawProgressBar(float(i)/lwochunk.chunksize, "Reading Faces")
		facev = []
		numfaceverts, = struct.unpack(">H", data.read(2))
		for j in range(numfaceverts):
			index, = struct.unpack(">H", data.read(2))
			facev.append(index)
		facev.reverse()
		faces.append(facev)
		surfaceindex, = struct.unpack(">H", data.read(2))
		if surfaceindex < 0:
			print "detail polygons follow, error."
			return
		i += (4+numfaceverts*2)
	return faces

# ==================================
# === Read Variable-Length Index ===
# ==================================
def read_vx(data):
	byte1, = struct.unpack(">B", data.read(1))
	if byte1 != 0xFF:	# 2-byte index
		byte2, = struct.unpack(">B", data.read(1))
		index = byte1*256 + byte2
		index_size = 2
	else:				# 4-byte index
		byte2, byte3, byte4 = struct.unpack(">3B", data.read(3))
		index = byte2*65536 + byte3*256 + byte4
		index_size = 4
	return index, index_size

# ======================
# === Read Faces 6.0 ===
# ======================
def read_faces_6(lwochunk):
	data = cStringIO.StringIO(lwochunk.read())
	faces = []
	polygon_type = data.read(4)
	if polygon_type != "FACE":
		print "No Faces Were Found. Polygon Type:", polygon_type
		return ""
	i = 0
	while(i < lwochunk.chunksize-4):
		if not i%100 and meshtools.show_progress:
		   Blender.Window.DrawProgressBar(float(i)/lwochunk.chunksize, "Reading Faces")
		facev = []
		numfaceverts, = struct.unpack(">H", data.read(2))
		i += 2

		for j in range(numfaceverts):
			index, index_size = read_vx(data)
			i += index_size
			facev.append(index)
		facev.reverse()
		faces.append(facev)
	return faces

def fs_callback(filename):
	read(filename)

Blender.Window.FileSelector(fs_callback, "Import LWO")
