blender/release/scripts/bpymodules/BPyMesh.py

# ***** BEGIN GPL LICENSE BLOCK *****
#
# 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
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# ***** END GPL LICENCE BLOCK *****
# --------------------------------------------------------------------------


import Blender
import bpy
import BPyMesh_redux # seperated because of its size.
# reload(BPyMesh_redux)
redux= BPyMesh_redux.redux

# python 2.3 has no reversed() iterator. this will only work on lists and tuples
try:
	reversed
except:
	def reversed(l): return l[::-1]


# If python version is less than 2.4, try to get set stuff from module
try:
	set
except:
	try:
		from sets import Set as set
	except:
		set= None





def meshWeight2List(me):
	''' Takes a mesh and return its group names and a list of lists, one list per vertex.
	aligning the each vert list with the group names, each list contains float value for the weight.
	These 2 lists can be modified and then used with list2MeshWeight to apply the changes.
	'''
	
	# Clear the vert group.
	groupNames= me.getVertGroupNames()
	len_groupNames= len(groupNames)
	
	if not len_groupNames:
		# no verts? return a vert aligned empty list
		return [[] for i in xrange(len(me.verts))], []
	
	else:
		vWeightList= [[0.0]*len_groupNames for i in xrange(len(me.verts))]
	
	for group_index, group in enumerate(groupNames):
		for vert_index, weight in me.getVertsFromGroup(group, 1): # (i,w)  tuples.
			vWeightList[vert_index][group_index]= weight
	
	# removed this because me may be copying teh vertex groups.
	#for group in groupNames:
	#	me.removeVertGroup(group)
	
	return groupNames, vWeightList


def list2MeshWeight(me, groupNames, vWeightList):
	''' Takes a list of groups and a list of vertex Weight lists as created by meshWeight2List
	and applys it to the mesh.'''
	
	if len(vWeightList) != len(me.verts):
		raise 'Error, Lists Differ in size, do not modify your mesh.verts before updating the weights'
	
	act_group = me.activeGroup
	
	# Clear the vert group.
	currentGroupNames= me.getVertGroupNames()
	for group in currentGroupNames:
		me.removeVertGroup(group) # messes up the active group.
	
	# Add clean unused vert groupNames back
	currentGroupNames= me.getVertGroupNames()
	for group in groupNames:
		me.addVertGroup(group)
	
	add_ = Blender.Mesh.AssignModes.ADD
	
	vertList= [None]
	for i, v in enumerate(me.verts):
		vertList[0]= i
		for group_index, weight in enumerate(vWeightList[i]):
			if weight:
				try:
					me.assignVertsToGroup(groupNames[group_index], vertList, min(1, max(0, weight)), add_)
				except:
					pass # vert group is not used anymore.
	
	try:	me.activeGroup = act_group
	except:	pass
	
	me.update()




def meshWeight2Dict(me):
	''' Takes a mesh and return its group names and a list of dicts, one dict per vertex.
	using the group as a key and a float value for the weight.
	These 2 lists can be modified and then used with dict2MeshWeight to apply the changes.
	'''
	
	vWeightDict= [dict() for i in xrange(len(me.verts))] # Sync with vertlist.
	
	# Clear the vert group.
	groupNames= me.getVertGroupNames()
	
	for group in groupNames:
		for vert_index, weight in me.getVertsFromGroup(group, 1): # (i,w)  tuples.
			vWeightDict[vert_index][group]= weight
	
	# removed this because me may be copying teh vertex groups.
	#for group in groupNames:
	#	me.removeVertGroup(group)
	
	return groupNames, vWeightDict


def dict2MeshWeight(me, groupNames, vWeightDict):
	''' Takes a list of groups and a list of vertex Weight dicts as created by meshWeight2Dict
	and applys it to the mesh.'''
	
	if len(vWeightDict) != len(me.verts):
		raise 'Error, Lists Differ in size, do not modify your mesh.verts before updating the weights'
	
	act_group = me.activeGroup
	
	# Clear the vert group.
	currentGroupNames= me.getVertGroupNames()
	for group in currentGroupNames:
		if group not in groupNames:
			me.removeVertGroup(group) # messes up the active group.
		else:
			me.removeVertsFromGroup(group)
	
	# Add clean unused vert groupNames back
	currentGroupNames= me.getVertGroupNames()
	for group in groupNames:
		if group not in currentGroupNames:
			me.addVertGroup(group)
	
	add_ = Blender.Mesh.AssignModes.ADD
	
	vertList= [None]
	for i, v in enumerate(me.verts):
		vertList[0]= i
		for group, weight in vWeightDict[i].iteritems():
			try:
				me.assignVertsToGroup(group, vertList, min(1, max(0, weight)), add_)
			except:
				pass # vert group is not used anymore.
	
	try:	me.activeGroup = act_group
	except:	pass
	
	me.update()

def dictWeightMerge(dict_weights):
	'''
	Takes dict weight list and merges into 1 weight dict item and returns it
	'''
	
	if not dict_weights:
		return {}
	
	keys= []
	for weight in dict_weights:
		keys.extend([ (k, 0.0) for k in weight.iterkeys() ])
	
	new_wdict = dict(keys)
	
	len_dict_weights= len(dict_weights)
	
	for weight in dict_weights:
		for group, value in weight.iteritems():
			new_wdict[group] += value/len_dict_weights
	
	return new_wdict


FLIPNAMES=[\
('Left','Right'),\
('_L','_R'),\
('-L','-R'),\
('.L','.R'),\
]

def dictWeightFlipGroups(dict_weight, groupNames, createNewGroups):
	'''
	Returns a weight with flip names
	dict_weight - 1 vert weight.
	groupNames - because we may need to add new group names.
	dict_weight - Weather to make new groups where needed.
	'''
	
	def flipName(name):
		for n1,n2 in FLIPNAMES:
			for nA, nB in ( (n1,n2), (n1.lower(),n2.lower()), (n1.upper(),n2.upper()) ):
				if createNewGroups:
					newName= name.replace(nA,nB)
					if newName!=name:
						if newName not in groupNames:
							groupNames.append(newName)
						return newName
					
					newName= name.replace(nB,nA)
					if newName!=name:
						if newName not in groupNames:
							groupNames.append(newName)
						return newName
				
				else:
					newName= name.replace(nA,nB)
					if newName!=name and newName in groupNames:
						return newName
					
					newName= name.replace(nB,nA)
					if newName!=name and newName in groupNames:
						return newName
		
		return name
		
	if not dict_weight:
		return dict_weight, groupNames
	
	
	new_wdict = {}
	for group, weight in dict_weight.iteritems():
		flipname= flipName(group)
		new_wdict[flipname]= weight
	
	return new_wdict, groupNames


def mesh2linkedFaces(me):
	'''
	Splits the mesh into connected parts,
	these parts are returned as lists of faces.
	used for seperating cubes from other mesh elements in the 1 mesh
	'''
	
	# Build vert face connectivity
	vert_faces= [[] for i in xrange(len(me.verts))]
	for f in me.faces:
		for v in f:
			vert_faces[v.index].append(f)
	
	# sort faces into connectivity groups
	face_groups= [[f] for f in me.faces]
	face_mapping = range(len(me.faces)) # map old, new face location
	
	# Now clump faces iterativly
	ok= True
	while ok:
		ok= False
		
		for i, f in enumerate(me.faces):
			mapped_index= face_mapping[f.index]
			mapped_group= face_groups[mapped_index]
			
			for v in f:
				for nxt_f in vert_faces[v.index]:
					if nxt_f != f:
						nxt_mapped_index= face_mapping[nxt_f.index]
						
						# We are not a part of the same group
						if mapped_index != nxt_mapped_index:
							
							ok= True
							
							# Assign mapping to this group so they all map to this group
							for grp_f in face_groups[nxt_mapped_index]:
								face_mapping[grp_f.index] = mapped_index
							
							# Move faces into this group
							mapped_group.extend(face_groups[nxt_mapped_index])
							
							# remove reference to the list
							face_groups[nxt_mapped_index]= None 
						
						
	# return all face groups that are not null
	# this is all the faces that are connected in their own lists.
	return [fg for fg in face_groups if fg]


def getFaceLoopEdges(faces, seams=[]):
	'''
	Takes me.faces or a list of faces and returns the edge loops
	These edge loops are the edges that sit between quads, so they dont touch
	1 quad, not not connected will make 2 edge loops, both only containing 2 edges.
	
	return a list of edge key lists
	[ [(0,1), (4, 8), (3,8)], ...]
	
	optionaly, seams are edge keys that will be removed
	'''
	
	OTHER_INDEX = 2,3,0,1 # opposite face index
	
	edges = {}
	
	for f in faces:
		if len(f) == 4:
			edge_keys = f.edge_keys
			for i, edkey in enumerate(f.edge_keys):
				edges.setdefault(edkey, []).append(edge_keys[OTHER_INDEX[i]])
	
	for edkey in seams:
		edges[edkey] = []
	
	# Collect edge loops here
	edge_loops = []	
	
	for edkey, ed_adj in edges.iteritems():
		if 0 <len(ed_adj) < 3: # 1 or 2
			# Seek the first edge
			context_loop = [edkey, ed_adj[0]]
			edge_loops.append(context_loop)
			if len(ed_adj) == 2:
				other_dir = ed_adj[1]
			else:
				other_dir = None
			
			ed_adj[:] = []
			
			flipped = False
			
			while 1:
				# from knowing the last 2, look for th next.
				ed_adj = edges[context_loop[-1]]
				if len(ed_adj) != 2:
					
					if other_dir and flipped==False: # the original edge had 2 other edges
						flipped = True # only flip the list once
						context_loop.reverse()
						ed_adj[:] = []
						context_loop.append(other_dir) # save 1 lookiup
						
						ed_adj = edges[context_loop[-1]]
						if len(ed_adj) != 2:
							ed_adj[:] = []
							break
					else:
						ed_adj[:] = []
						break
				
				i = ed_adj.index(context_loop[-2])
				context_loop.append( ed_adj[ not  i] )
				
				# Dont look at this again
				ed_adj[:] = []

	
	return edge_loops
	


def getMeshFromObject(ob, container_mesh=None, apply_modifiers=True, vgroups=True, scn=None):
	'''
	ob - the object that you want to get the mesh from
	container_mesh - a Blender.Mesh type mesh that is reused to avoid a new datablock per call to getMeshFromObject
	apply_modifiers - if enabled, subsurf bones etc. will be applied to the returned mesh. disable to get a copy of the mesh.
	vgroup - For mesh objects only, apply the vgroup to the the copied mesh. (slower)
	scn - Scene type. avoids getting the current scene each time getMeshFromObject is called.
	
	Returns Mesh or None
	'''
	
	if not scn:
		scn= bpy.data.scenes.active
	if not container_mesh:
		mesh = bpy.data.meshes.new(ob.name)	
	else:
		mesh= container_mesh
		mesh.verts= None
	
	ob_type = ob.type
	dataname = ob.getData(1)
	tempob= None
	if apply_modifiers or ob_type != 'Mesh':
		try:
			mesh.getFromObject(ob)
		except:
			return None
	
	else:
		'''
		Dont apply modifiers, copy the mesh. 
		So we can transform the data. its easiest just to get a copy of the mesh. 
		'''
		tempob= scn.objects.new(ob.getData(mesh=1))
		mesh.getFromObject(tempob)
		scn.objects.unlink(tempob)
	
	if ob_type == 'Mesh':
		if vgroups:
			if tempob==None:
				tempob= Blender.Object.New('Mesh')
			
			tempob.link(mesh)
			try:
				# Copy the influences if possible.
				groupNames, vWeightDict= meshWeight2Dict(ob.getData(mesh=1))
				dict2MeshWeight(mesh, groupNames, vWeightDict)
			except:
				# if the modifier changes the vert count then it messes it up for us.
				pass
	
	return mesh


def faceRayIntersect(f, orig, rdir):
	'''
	Returns face, side
	Side is the side of a quad we intersect.
		side 0 == 0,1,2
		side 1 == 0,2,3
	'''
	f_v= f.v
	isect= Blender.Mathutils.Intersect(f_v[0].co, f_v[1].co, f_v[2].co, rdir, orig, 1) # 1==clip
	
	if isect:
		return isect, 0
	
	if len(f_v)==4:
		isect= Blender.Mathutils.Intersect(f_v[0].co, f_v[2].co, f_v[3].co, rdir, orig, 1) # 1==clip
		if isect:
			return isect, 1
	return False, 0


def pickMeshRayFace(me, orig, rdir):
	best_dist= 1000000
	best_isect= best_side= best_face= None
	for f in me.faces:
		isect, side= faceRayIntersect(f, orig, rdir)
		if isect:
			dist= (isect-orig).length
			if dist<best_dist:
				best_dist= dist
				best_face= f
				best_side= side
				best_isect= isect
	
	return best_face, best_isect, best_side


def pickMeshRayFaceWeight(me, orig, rdir):
	f, isect, side = pickMeshRayFace(me, orig, rdir)
	
	if f==None:
		return None, None, None, None, None
	
	f_v= [v.co for v in f]
	if side==1: # we can leave side 0 without changes.
		f_v = f_v[0], f_v[2], f_v[3]
	
	l0= (f_v[0]-isect).length
	l1= (f_v[1]-isect).length
	l2= (f_v[2]-isect).length
	
	w0 = (l1+l2)
	w1 = (l0+l2)
	w2 = (l1+l2)
	
	totw= w0 + w1 + w2
	w0=w0/totw
	w1=w1/totw
	w2=w2/totw
	
	return f, side, w0, w1, w2



def pickMeshGroupWeight(me, act_group, orig, rdir):
	f, side, w0, w1, w2= pickMeshRayFaceWeight(me, orig, rdir)
	
	if f==None:
		return None
		
	f_v= f.v
	if side==0:
		f_vi= (f_v[0].index, f_v[1].index, f_v[2].index)
	else:
		f_vi= (f_v[0].index, f_v[2].index, f_v[3].index)
	
	vws= [0.0,0.0,0.0]
	for i in xrange(3):
		try:		vws[i]= me.getVertsFromGroup(act_group, 1, [f_vi[i],])[0][1]
		except:	pass
	
	return w0*vws[0] + w1*vws[1]  + w2*vws[2]

def pickMeshGroupVCol(me, orig, rdir):
	Vector= Blender.Mathutils.Vector
	f, side, w0, w1, w2= pickMeshRayFaceWeight(me, orig, rdir)
	
	if f==None:
		return None
	
	def col2vec(c):
		return Vector(c.r, c.g, c.b)
	
	if side==0:
		idxs= 0,1,2
	else:
		idxs= 0,2,3
	f_c= f.col
	f_colvecs= [col2vec(f_c[i]) for i in idxs]
	return f_colvecs[0]*w0 +  f_colvecs[1]*w1 + f_colvecs[2]*w2

def edge_face_users(me):
	''' 
	Takes a mesh and returns a list aligned with the meshes edges.
	Each item is a list of the faces that use the edge
	would be the equiv for having ed.face_users as a property
	'''
	
	face_edges_dict= dict([(ed.key, (ed.index, [])) for ed in me.edges])
	for f in me.faces:
		fvi= [v.index for v in f]# face vert idx's
		for edkey in f.edge_keys:
			face_edges_dict[edkey][1].append(f)
	
	face_edges= [None] * len(me.edges)
	for ed_index, ed_faces in face_edges_dict.itervalues():
		face_edges[ed_index]= ed_faces
	
	return face_edges
		
		
def face_edges(me):
	'''
	Returns a list alligned to the meshes faces.
	each item is a list of lists: that is 
	face_edges -> face indicies
	face_edges[i] -> list referencs local faces v indicies 1,2,3 &| 4
	face_edges[i][j] -> list of faces that this edge uses.
	crap this is tricky to explain :/
	'''
	face_edges= [ [-1] * len(f) for f in me.faces ]
	
	face_edges_dict= dict([(ed.key, []) for ed in me.edges])
	for fidx, f in enumerate(me.faces):
		for i, edkey in enumerate(f.edge_keys):
			edge_face_users= face_edges_dict[edkey]
			edge_face_users.append(f)
			face_edges[fidx][i]= edge_face_users
			
	return face_edges
	

def facesPlanerIslands(me):
	DotVecs= Blender.Mathutils.DotVecs
	
	def roundvec(v):
		return round(v[0], 4), round(v[1], 4), round(v[2], 4)
	
	face_props= [(cent, no, roundvec(no), DotVecs(cent, no)) for f in me.faces    for no, cent in ((f.no, f.cent),)]
	
	face_edge_users= face_edges(me)
	islands= []
	
	used_faces= [0] * len(me.faces)
	while True:
		new_island= False
		for i, used_val in enumerate(used_faces):
			if used_val==0:
				island= [i]
				new_island= True
				used_faces[i]= 1
				break
		
		if not new_island:
			break
		
		island_growing= True
		while island_growing:
			island_growing= False
			for fidx1 in island[:]:
				if used_faces[fidx1]==1:
					used_faces[fidx1]= 2
					face_prop1= face_props[fidx1]
					for ed in face_edge_users[fidx1]:
						for f2 in ed:
							fidx2= f2.index
							if fidx1 != fidx2 and used_faces[fidx2]==0:
								island_growing= True
								face_prop2= face_props[fidx2]
								# normals are the same?
								if face_prop1[2]==face_prop2[2]:
									if abs(face_prop1[3] - DotVecs(face_prop1[1], face_prop2[0])) < 0.000001:
										used_faces[fidx2]= 1
										island.append(fidx2)
		islands.append([me.faces[i] for i in island])
	return islands



def facesUvIslands(me, PREF_IMAGE_DELIMIT=True):
	DotVecs= Blender.Mathutils.DotVecs
	def roundvec(v):
		return round(v[0], 4), round(v[1], 4)
	
	if not me.faceUV:
		return [ list(me.faces), ]
	
	# make a list of uv dicts
	face_uvs= [ [roundvec(uv) for uv in f.uv] for f in me.faces]
	
	# key - face uv || value - list of face idxs
	uv_connect_dict= dict([ (uv, [] ) for f_uvs in face_uvs for uv in f_uvs])
	
	for i, f_uvs in enumerate(face_uvs):
		for uv in f_uvs: # loops through rounded uv values
			uv_connect_dict[uv].append(i)
	islands= []
	
	used_faces= [0] * len(me.faces)
	while True:
		new_island= False
		for i, used_val in enumerate(used_faces):
			if used_val==0:
				island= [i]
				new_island= True
				used_faces[i]= 1
				break
		
		if not new_island:
			break
		
		island_growing= True
		while island_growing:
			island_growing= False
			for fidx1 in island[:]:
				if used_faces[fidx1]==1:
					used_faces[fidx1]= 2
					for uv in face_uvs[fidx1]:
						for fidx2 in uv_connect_dict[uv]:
							if fidx1 != fidx2 and used_faces[fidx2]==0:
								if not PREF_IMAGE_DELIMIT or me.faces[fidx1].image==me.faces[fidx2].image:
									island_growing= True
									used_faces[fidx2]= 1
									island.append(fidx2)
		
		islands.append([me.faces[i] for i in island])
	return islands

#def faceUvBounds(me, faces= None):
	

def facesUvRotate(me, deg, faces= None, pivot= (0,0)):
	'''
	Faces can be None an all faces will be used
	pivot is just the x/y well rotated about
	
	positive deg value for clockwise rotation
	'''
	if faces==None: faces= me.faces
	pivot= Blender.Mathutils.Vector(pivot)
	
	rotmat= Blender.Mathutils.RotationMatrix(-deg, 2)
	
	for f in faces:
		f.uv= [((uv-pivot)*rotmat)+pivot for uv in f.uv]

def facesUvScale(me, sca, faces= None, pivot= (0,0)):
	'''
	Faces can be None an all faces will be used
	pivot is just the x/y well rotated about
	sca can be wither an int/float or a vector if you want to
	  scale x/y seperately.
	  a sca or (1.0, 1.0) will do nothing.
	'''
	def vecmulti(v1,v2):
		'''V2 is unchanged'''
		v1[:]= (v1.x*v2.x, v1.y*v2.y)
		return v1
	
	sca= Blender.Mathutils.Vector(sca)
	if faces==None: faces= me.faces
	pivot= Blender.Mathutils.Vector(pivot)
	
	for f in faces:
		f.uv= [vecmulti(uv-pivot, sca)+pivot for uv in f.uv]

	
def facesUvTranslate(me, tra, faces= None, pivot= (0,0)):
	'''
	Faces can be None an all faces will be used
	pivot is just the x/y well rotated about
	'''
	if faces==None: faces= me.faces
	tra= Blender.Mathutils.Vector(tra)
	
	for f in faces:
		f.uv= [uv+tra for uv in f.uv]

	

def edgeFaceUserCount(me, faces= None):
	'''
	Return an edge aligned list with the count for all the faces that use that edge. -
	can spesify a subset of the faces, so only those will be counted.
	'''
	if faces==None:
		faces= me.faces
		max_vert= len(me.verts)
	else:
		# find the lighest vert index
		pass
	
	edge_users= [0] * len(me.edges)
	
	edges_idx_dict= dict([(ed.key, ed.index) for ed in me.edges])

	for f in faces:
		for edkey in f.edge_keys:
			edge_users[edges_idx_dict[edkey]] += 1 
	
	return edge_users


#============================================================================#
# Takes a face, and a pixel x/y on the image and returns a worldspace x/y/z  #
# will return none if the pixel is not inside the faces UV                   #
#============================================================================#
def getUvPixelLoc(face, pxLoc, img_size = None, uvArea = None):
	TriangleArea= Blender.Mathutils.TriangleArea
	Vector= Blender.Mathutils.Vector
	
	if not img_size:
		w,h = face.image.size
	else:
		w,h= img_size
	
	scaled_uvs= [Vector(uv.x*w, uv.y*h) for uv in f.uv]
	
	if len(scaled_uvs)==3:
		indicies= ((0,1,2),)
	else:
		indicies= ((0,1,2), (0,2,3))
	
	for fidxs in indicies:
		for i1,i2,i3 in fidxs:
			# IS a point inside our triangle?
			# UVArea could be cached?
			uv_area = TriangleArea(scaled_uvs[i1], scaled_uvs[i2], scaled_uvs[i3])
			area0 = TriangleArea(pxLoc, scaled_uvs[i2], scaled_uvs[i3])
			area1 = TriangleArea(pxLoc, scaled_uvs[i1],	scaled_uvs[i3])
			area2 = TriangleArea(pxLoc, scaled_uvs[i1], scaled_uvs[i2])
			if area0 + area1 + area2 > uv_area + 1: # 1 px bleed/error margin.
				pass # if were a quad the other side may contain the pixel so keep looking.
			else:
				# We know the point is in the tri
				area0 /= uv_area
				area1 /= uv_area
				area2 /= uv_area
				
				# New location
				return Vector(\
					face.v[i1].co[0]*area0 + face.v[i2].co[0]*area1 + face.v[i3].co[0]*area2,\
					face.v[i1].co[1]*area0 + face.v[i2].co[1]*area1 + face.v[i3].co[1]*area2,\
					face.v[i1].co[2]*area0 + face.v[i2].co[2]*area1 + face.v[i3].co[2]*area2\
				)
				
	return None


# Used for debugging ngon
"""
def draw_loops(loops):
	
	me= Blender.Mesh.New()
	for l in loops:
		#~ me= Blender.Mesh.New()
		
		
		i= len(me.verts)
		me.verts.extend([v[0] for v in l])
		try:
			me.verts[0].sel= 1
		except:
			pass
		me.edges.extend([ (j-1, j) for j in xrange(i+1, len(me.verts)) ])
		# Close the edge?
		me.edges.extend((i, len(me.verts)-1))
		
		
		#~ ob= Blender.Object.New('Mesh')
		#~ ob.link(me)
		#~ scn= Blender.Scene.GetCurrent()
		#~ scn.link(ob)
		#~ ob.Layers= scn.Layers
		#~ ob.sel= 1
		
		
		
	# Fill
	#fill= Blender.Mathutils.PolyFill(loops)
	#me.faces.extend(fill)
		
	
	ob= Blender.Object.New('Mesh')
	ob.link(me)
	scn= Blender.Scene.GetCurrent()
	scn.link(ob)
	ob.Layers= scn.Layers
	ob.sel= 1
	Blender.Window.RedrawAll()
"""

def ngon(from_data, indices, PREF_FIX_LOOPS= True):
	'''
	Takes a polyline of indices (fgon)
	and returns a list of face indicie lists.
	Designed to be used for importers that need indices for an fgon to create from existing verts.
	
	from_data: either a mesh, or a list/tuple of vectors.
	indices: a list of indicies to use this list is the ordered closed polyline to fill, and can be a subset of the data given.
	PREF_FIX_LOOPS: If this is enabled polylines that use loops to make multiple polylines are delt with correctly.
	'''
	
	if not set: # Need sets for this, otherwise do a normal fill.
		PREF_FIX_LOOPS= False 
	
	Vector= Blender.Mathutils.Vector
	if not indices:
		return []
	
	#	return []
	def rvec(co): return round(co.x, 6), round(co.y, 6), round(co.z, 6)
	def mlen(co): return abs(co[0])+abs(co[1])+abs(co[2]) # manhatten length of a vector, faster then length
	
	def vert_treplet(v, i):
		return v, rvec(v), i, mlen(v)
	
	def ed_key_mlen(v1, v2):
		if v1[3] > v2[3]:
			return v2[1], v1[1]
		else:
			return v1[1], v2[1]
	
	
	if not PREF_FIX_LOOPS:
		'''
		Normal single concave loop filling
		'''
		if type(from_data) in (tuple, list):
			verts= [Vector(from_data[i]) for ii, i in enumerate(indices)]
		else:
			verts= [from_data.verts[i].co for ii, i in enumerate(indices)]
		
		for i in xrange(len(verts)-1, 0, -1): # same as reversed(xrange(1, len(verts))):
			if verts[i][1]==verts[i-1][0]:
				verts.pop(i-1)
		
		fill= Blender.Geometry.PolyFill([verts])
		
	else:
		'''
		Seperate this loop into multiple loops be finding edges that are used twice
		This is used by lightwave LWO files a lot
		'''
		
		if type(from_data) in (tuple, list):
			verts= [vert_treplet(Vector(from_data[i]), ii) for ii, i in enumerate(indices)]
		else:
			verts= [vert_treplet(from_data.verts[i].co, ii) for ii, i in enumerate(indices)]
			
		edges= [(i, i-1) for i in xrange(len(verts))]
		if edges:
			edges[0]= (0,len(verts)-1)
		
		if not verts:
			return []
		
		
		edges_used= set()
		edges_doubles= set()
		# We need to check if any edges are used twice location based.
		for ed in edges:
			edkey= ed_key_mlen(verts[ed[0]], verts[ed[1]])
			if edkey in edges_used:
				edges_doubles.add(edkey)
			else:
				edges_used.add(edkey)
		
		# Store a list of unconnected loop segments split by double edges.
		# will join later
		loop_segments= [] 
		
		v_prev= verts[0]
		context_loop= [v_prev]
		loop_segments= [context_loop]
		
		for v in verts:
			if v!=v_prev:
				# Are we crossing an edge we removed?
				if ed_key_mlen(v, v_prev) in edges_doubles:
					context_loop= [v]
					loop_segments.append(context_loop)
				else:
					if context_loop and context_loop[-1][1]==v[1]:
						#raise "as"
						pass
					else:
						context_loop.append(v)
				
				v_prev= v
		# Now join loop segments
		
		def join_seg(s1,s2):
			if s2[-1][1]==s1[0][1]: # 
				s1,s2= s2,s1
			elif s1[-1][1]==s2[0][1]:
				pass
			else:
				return False
			
			# If were stuill here s1 and s2 are 2 segments in the same polyline
			s1.pop() # remove the last vert from s1
			s1.extend(s2) # add segment 2 to segment 1
			
			if s1[0][1]==s1[-1][1]: # remove endpoints double
				s1.pop()
			
			s2[:]= [] # Empty this segment s2 so we dont use it again.
			return True
		
		joining_segments= True
		while joining_segments:
			joining_segments= False
			segcount= len(loop_segments)
			
			for j in xrange(segcount-1, -1, -1): #reversed(xrange(segcount)):
				seg_j= loop_segments[j]
				if seg_j:
					for k in xrange(j-1, -1, -1): # reversed(xrange(j)):
						if not seg_j:
							break
						seg_k= loop_segments[k]
						
						if seg_k and join_seg(seg_j, seg_k):
							joining_segments= True
		
		loop_list= loop_segments
		
		for verts in loop_list:
			while verts and verts[0][1]==verts[-1][1]:
				verts.pop()
		
		loop_list= [verts for verts in loop_list if len(verts)>2]
		# DONE DEALING WITH LOOP FIXING
		
		
		# vert mapping
		vert_map= [None]*len(indices)
		ii=0
		for verts in loop_list:
			if len(verts)>2:
				for i, vert in enumerate(verts):
					vert_map[i+ii]= vert[2]
				ii+=len(verts)
		
		fill= Blender.Geometry.PolyFill([ [v[0] for v in loop] for loop in loop_list ])
		#draw_loops(loop_list)
		#raise 'done loop'
		# map to original indicies
		fill= [[vert_map[i] for i in reversed(f)] for f in fill]
	
	
	if not fill:
		print 'Warning Cannot scanfill, fallback on a triangle fan.'
		fill= [ [0, i-1, i] for i in xrange(2, len(indices)) ]
	else:
		# Use real scanfill.
		# See if its flipped the wrong way.
		flip= None
		for fi in fill:
			if flip != None:
				break
			for i, vi in enumerate(fi):
				if vi==0 and fi[i-1]==1:
					flip= False
					break
				elif vi==1 and fi[i-1]==0:
					flip= True
					break
		
		if not flip:
			for i, fi in enumerate(fill):
				fill[i]= tuple([ii for ii in reversed(fi)])
		
		
		
	
	return fill
	


# EG
'''
scn= Scene.GetCurrent()
me = scn.getActiveObject().getData(mesh=1)
ind= [v.index for v in me.verts if v.sel] # Get indices

indices = ngon(me, ind) # fill the ngon.

# Extand the faces to show what the scanfill looked like.
print len(indices)
me.faces.extend([[me.verts[ii] for ii in i] for i in indices])
'''

def meshCalcNormals(me, vertNormals=None):
	'''
	takes a mesh and returns very high quality normals 1 normal per vertex.
	The normals should be correct, indipendant of topology
	
	vertNormals - a list of vectors at least as long as the number of verts in the mesh
	'''
	Ang= Blender.Mathutils.AngleBetweenVecs
	Vector= Blender.Mathutils.Vector
	SMALL_NUM=0.000001
	# Weight the edge normals by total angle difference
	# EDGE METHOD
	
	if not vertNormals:
		vertNormals= [ Vector() for v in xrange(len(me.verts)) ]
	else:
		for v in vertNormals:
			v.zero()
		
	edges={}
	for f in me.faces:
		f_v = f.v
		for edkey in f.edge_keys:
			edges.setdefault(edkey, []).append(f.no)
	
	# Weight the edge normals by total angle difference
	for fnos in edges.itervalues():
		
		len_fnos= len(fnos)
		if len_fnos>1:
			totAngDiff=0
			for j in xrange(len_fnos-1, -1, -1): # same as reversed(xrange(...))
				for k in xrange(j-1, -1, -1): # same as reversed(xrange(...))
					#print j,k
					try:
						totAngDiff+= (Ang(fnos[j], fnos[k])) # /180 isnt needed, just to keeop the vert small.
					except:
						pass # Zero length face
			
			# print totAngDiff
			if totAngDiff > SMALL_NUM:
				'''
				average_no= Vector()
				for no in fnos:
					average_no+=no
				'''
				average_no= reduce(lambda a,b: a+b, fnos, Vector())
				fnos.append(average_no*totAngDiff) # average no * total angle diff
			#else:
			#	fnos[0]
		else:
			fnos.append(fnos[0])
	
	for ed, v in edges.iteritems():
		vertNormals[ed[0]]+= v[-1]
		vertNormals[ed[1]]+= v[-1]
	for i, v in enumerate(me.verts):
		v.no= vertNormals[i]




def pointInsideMesh(ob, pt):
	Intersect = Blender.Mathutils.Intersect # 2 less dict lookups.
	Vector = Blender.Mathutils.Vector
	
	def ptInFaceXYBounds(f, pt):
		f_v = f.v
		co= f_v[0].co
		xmax= xmin= co.x
		ymax= ymin= co.y
		
		co= f_v[1].co
		xmax= max(xmax, co.x)
		xmin= min(xmin, co.x)
		ymax= max(ymax, co.y)
		ymin= min(ymin, co.y)
		
		co= f_v[2].co
		xmax= max(xmax, co.x)
		xmin= min(xmin, co.x)
		ymax= max(ymax, co.y)
		ymin= min(ymin, co.y)
		
		if len(f_v)==4: 
			co= f_v[3].co
			xmax= max(xmax, co.x)
			xmin= min(xmin, co.x)
			ymax= max(ymax, co.y)
			ymin= min(ymin, co.y)
		
		# Now we have the bounds, see if the point is in it.
		if\
		pt.x < xmin or\
		pt.y < ymin or\
		pt.x > xmax or\
		pt.y > ymax:
			return False # point is outside face bounds
		else:
			return True # point inside.
		#return xmax, ymax, xmin, ymin
	
	def faceIntersect(f):
		f_v = f.v
		isect = Intersect(f_v[0].co, f_v[1].co, f_v[2].co, ray, obSpacePt, 1) # Clipped.
		if not isect and len(f) == 4:
			isect = Intersect(f_v[0].co, f_v[2].co, f_v[3].co, ray, obSpacePt, 1) # Clipped.
				
		if isect and isect.z > obSpacePt.z: # This is so the ray only counts if its above the point. 
			return True
		else:
			return False
	
	obSpacePt = pt*ob.matrixWorld.copy().invert()
	ray = Vector(0,0,-1)
	me= ob.getData(mesh=1)
	
	# Here we find the number on intersecting faces, return true if an odd number (inside), false (outside) if its true.
	return len([None for f in me.faces if ptInFaceXYBounds(f, obSpacePt) if faceIntersect(f)]) % 2


def faceAngles(f):
	'''
	Returns the angle between all corners in a tri or a quad
	
	'''
	AngleBetweenVecs = Blender.Mathutils.AngleBetweenVecs
	def Ang(a1,a2):
		try:		return AngleBetweenVecs(a1,a2)
		except:		return 180
	
	if len(f) == 3:
		if type(f) in (tuple, list):	v1,v2,v3 = f
		else:							v1,v2,v3 = [v.co for v in f]
		a1= Ang(v2-v1,v3-v1)
		a2= Ang(v1-v2,v3-v2)
		a3 = 180 - (a1+a2) # a3= Mathutils.AngleBetweenVecs(v2-v3,v1-v3)
		return a1,a2,a3
	
	else:
		if type(f) in (tuple, list):	v1,v2,v3,v4 = f
		else:							v1,v2,v3,v4 = [v.co for v in f]
		a1= Ang(v2-v1,v4-v1)
		a2= Ang(v1-v2,v3-v2)
		a3= Ang(v2-v3,v4-v3)
		a4= Ang(v3-v4,v1-v4)
		return a1,a2,a3,a4

# NMesh wrapper
Vector= Blender.Mathutils.Vector
class NMesh(object):
	__slots__= 'verts', 'faces', 'edges', 'faceUV', 'materials', 'realmesh'
	def __init__(self, mesh):
		'''
		This is an NMesh wrapper that
		mesh is an Mesh as returned by Blender.Mesh.New()
		This class wraps NMesh like access into Mesh
		
		Running NMesh.update() - with this wrapper,
		Will update the realmesh.
		'''
		self.verts= []
		self.faces= []
		self.edges= []
		self.faceUV= False
		self.materials= []
		self.realmesh= mesh
	
	def addFace(self, nmf):
		self.faces.append(nmf)
	
	def Face(self, v=[]):
		return NMFace(v)
	def Vert(self, x,y,z):
		return NMVert(x,y,z)
	
	def hasFaceUV(self, flag):
		if flag:
			self.faceUV= True
		else:
			self.faceUV= False
	
	def addMaterial(self, mat):
		self.materials.append(mat)
	
	def update(self, recalc_normals=False): # recalc_normals is dummy
		mesh= self.realmesh
		mesh.verts= None # Clears the 
		
		# Add in any verts from faces we may have not added.
		for nmf in self.faces:
			for nmv in nmf.v:
				if nmv.index==-1:
					nmv.index= len(self.verts)
					self.verts.append(nmv)
					
		
		mesh.verts.extend([nmv.co for nmv in self.verts])
		for i, nmv in enumerate(self.verts):
			nmv.index= i
			mv= mesh.verts[i]
			mv.sel= nmv.sel
		
		good_faces= [nmf for nmf in self.faces if len(nmf.v) in (3,4)]
		#print len(good_faces), 'AAA'
		
		
		#mesh.faces.extend([nmf.v for nmf in self.faces])
		mesh.faces.extend([[mesh.verts[nmv.index] for nmv in nmf.v] for nmf in good_faces])
		if len(mesh.faces):
			if self.faceUV:
				mesh.faceUV= 1
			
			#for i, nmf in enumerate(self.faces):
			for i, nmf in enumerate(good_faces):
				mf= mesh.faces[i]
				if self.faceUV:
					if len(nmf.uv) == len(mf.v):
						mf.uv= [Vector(uv[0], uv[1]) for uv in nmf.uv]
					if len(nmf.col) == len(mf.v):
						for c, i in enumerate(mf.col):
							c.r, c.g, c.b= nmf.col[i].r, nmf.col[i].g, nmf.col[i].b
					if nmf.image:
						mf.image= nmf.image
		
		mesh.materials= self.materials[:16]

class NMVert(object):
	__slots__= 'co', 'index', 'no', 'sel', 'uvco'
	def __init__(self, x,y,z):
		self.co= Vector(x,y,z)
		self.index= None # set on appending.
		self.no= Vector(0,0,1) # dummy
		self.sel= 0
		self.uvco= None
class NMFace(object):
	__slots__= 'col', 'flag', 'hide', 'image', 'mat', 'materialIndex', 'mode', 'normal',\
	'sel', 'smooth', 'transp', 'uv', 'v'
	
	def __init__(self, v=[]):
		self.col= []
		self.flag= 0
		self.hide= 0
		self.image= None
		self.mat= 0 # materialIndex needs support too.
		self.mode= 0
		self.normal= Vector(0,0,1)
		self.uv= []
		self.sel= 0
		self.smooth= 0
		self.transp= 0
		self.uv= []
		self.v= [] # a list of nmverts.
	
class NMCol(object):
	__slots__ = 'r', 'g', 'b', 'a'
	def __init__(self):
		self.r= 255
		self.g= 255
		self.b= 255
		self.a= 255


'''
# 
verts_split= [dict() for i in xrange(len(me.verts))]

tot_verts= 0
for f in me.faces:
	f_uv= f.uv
	for i, v in enumerate(f.v):
		vert_index= v.index # mesh index
		vert_dict= verts_split[vert_index] # get the dict for this vert
		
		uv= f_uv[i]
		# now we have the vert and the face uv well make a unique dict.
		
		vert_key= v.x, v.y, v.x, uv.x, uv.y # ADD IMAGE NAME HETR IF YOU WANT TO SPLIT BY THAT TOO
		value= vert_index, tot_verts # ADD WEIGHT HERE IF YOU NEED.
		try:
			vert_dict[vert_key] # if this is missing it will fail.
		except:
			# this stores a mapping between the split and orig vert indicies
			vert_dict[vert_key]= value 
			tot_verts+= 1

# a flat list of split verts - can add custom weight data here too if you need
split_verts= [None]*tot_verts

for vert_split_dict in verts_split:
	for key, value in vert_split_dict.iteritems():
		local_index, split_index= value
		split_verts[split_index]= key

# split_verts - Now you have a list of verts split by their UV.
'''