# -*- indent-tabs-mode: t; tab-width: 8; python-indent: 4; -*-
# vim: sw=4:ts=8:sts=4
import traceback
import math

class TweenObject:
    TWEEN_TYPE_NORMAL = 0
    #TWEEN_TYPE_RELOCATE = 1
    TWEEN_TYPE_SCALE = 1

    def __init__(self,doc,dom):
        self.document = doc
	self.dom = dom
	try:
	    self.width = float(dom.getAttribute("width"))
	    self.height = float(dom.getAttribute("height"))
	except:
	    self.width = 640
	    self.height = 480

    def updateMapping(self):
	self.nodeToItem={}
	root = self.dom
	self.updateMappingNode(root)
    def updateMappingNode(self,node):
	for c in node.childList():
	    self.updateMappingNode(c)
	    try:
	        self.nodeToItem[c.getAttribute("id")] = c
	    except:
	        pass
    def updateTweenContent(self, duplicate_group, tween_type,
			   start_scene_group, stop_scene_group, percent):
	"""
	    Update the content of the duplicate scene group.  We will
	    use precent, start_scene_group, stop_scene_group to
	    compute transform matrix and update duplicate scene group
	    specified.
	"""
	# Collect ref from the obj
	node = duplicate_group.firstChild()
	dup_nodes = {}
	while node:
	    try:
	        ref = node.getAttribute("ref")
		dup_nodes[ref] = node
	    except:
		ref = None
		pass
	    node = node.next()
	    pass

	# Collect all nodes in stop scene
	stop_nodes = {}
	node = stop_scene_group.firstChild()
	while node:
	    try:
		node_label = node.getAttribute("ns0:duplicate-src")
		stop_nodes[node_label] = node
	    except:
		pass
	    node = node.next()
	    pass

	# Remove duplicate nodes that is not in the set of stop nodes
	for node_ref in dup_nodes:
	    if node_ref not in stop_nodes:
		node = dup_nodes[node_ref]
		duplicate_group.removeChild(node)
		pass
	    pass

	#
	# Node ID of a node of start scene must be mapped to
	# 'ns0:duplicate-src' attribute of a node of stop scene.  The
	# nodes which can not be mapped to a node of stop scene are
	# not manipulated by the tween.
	#
	# When a scene is duplicated, 'ns0:duplicate-src' attribute of
	# nodes, in the new scene, must be setted to ID of respective
	# one in the duplicated scene.
	#
	start_node = start_scene_group.firstChild()
	while start_node:
	    start_node_id = start_node.getAttribute('id')
	    try:
		stop_node = stop_nodes[start_node_id]
	    except KeyError:
		self.updateTweenObject(duplicate_group, tween_type,
				       start_node, start_node,
				       percent, dup_node)
		start_node = start_node.next()
		continue
	    
	    dup_node = dup_nodes.setdefault(start_node_id, None)
	    
	    self.updateTweenObject(duplicate_group, tween_type,
				   start_node, stop_node,
				   percent, dup_node)
	    start_node = start_node.next()
	    pass
	pass

    def parseTransform(self,obj):
	"""
	    Return the transform matrix of an object
	"""
	try:
	    t = obj.getAttribute("transform")
	    print t
	    if t[0:9] == 'translate':
		print "translate"
		fields = t[10:].split(',')
		x = float(fields[0])
		fields = fields[1].split(')')
		y = float(fields[0])
		return [1,0,0,1,x,y]
	    elif t[0:6] == 'matrix':
		print "matrix"
		fields=t[7:].split(')')
		fields = fields[0].split(',')
		return [float(fields[0]),float(fields[1]),float(fields[2]),float(fields[3]),float(fields[4]),float(fields[5])]
	except:
	    #traceback.print_exc()
	    return [1,0,0,1,0,0]

    def invA(self,m):
        d = m[0]*m[3]-m[2]*m[1]
	return [m[3]/d, -m[1]/d, -m[2]/d, m[0]/d, (m[1]*m[5]-m[4]*m[3])/d, (m[4]*m[2]-m[0]*m[5])/d]
	
    def mulA(self,a,b):
        return [a[0]*b[0]+a[1]*b[2],
	        a[0]*b[1]+a[1]*b[3],
		a[2]*b[0]+a[3]*b[2],
		a[2]*b[1]+a[3]*b[3],
		a[0]*b[4]+a[1]*b[5]+a[4],
		a[2]*b[4]+a[3]*b[5]+a[5]]

    def decomposition(self,m):
	"""
	Decompose the affine matrix into production of translation,rotation,shear and scale.
	The algorithm is documented at http://lists.w3.org/Archives/Public/www-style/2010Jun/0602.html
	"""
        if m[0]*m[3] == m[1]*m[2]:
	    print "The affine matrix is singular"
	    return [1,0,0,1,0,0]
	A=m[0]
	B=m[2]
	C=m[1]
	D=m[3]
	E=m[4]
	F=m[5]
	sx = math.sqrt(A*A+B*B)
	A = A/sx
	B = B/sx
	shear = m[0]*m[1]+m[2]*m[3]
	C = C - A*shear
	D = D - B*shear
	sy = math.sqrt(C*C+D*D)
	C = C/sy
	D = D/sy
	r = A*D-B*C
	if r == -1:
	    shear = -shear
	    sy = -sy
	R = math.atan2(B,A)
	return [sx,sy, R, E,F]

	    
    def updateTweenObject(self,obj,typ,s,d,p,newobj):
	"""
	    Generate tweened object in the @obj by using s and d in the @p percent
	    http://lists.w3.org/Archives/Public/www-style/2010Jun/0602.html
	"""
	if typ == self.TWEEN_TYPE_SCALE:
	    self.updateTweenObjectScale(obj,s,d,p,newobj)
	    pass
	elif typ == self.TWEEN_TYPE_NORMAL:
	    newobj = s.duplicate(self.document)
	    newobj.setAttribute("ref", s.getAttribute("id"))
	    top = self.document.createElement("svg:g")
	    top.appendChild(newobj)
	    obj.appendChild(top)
	pass

    def updateTweenObjectScale(self,obj,s,d,p,newobj):
        """
	    Generate a new group which contains the original group and then 
	    add the transform matrix to generate a tween frame between the 
	    origin and destination scene group. 

	    We will parse the transform matrix of the @s and @d and then 
	    generate the matrix which is (1-p) of @s and p percent of @d.
	"""
	if newobj == None:
            newobj = s.duplicate(self.document)
            top = self.document.createElement("svg:g")
	    top.setAttribute("ref",s.getAttribute("id"))
	    top.appendChild(newobj)
	    obj.appendChild(top)
	else:
	    top = newobj
	    newobj = top.firstChild()
	        
	if s.name() == 'svg:g':
	    # Parse the translate or matrix
	    # 
	    # D  = B inv(A)
	    try:
	        item = self.nodeToItem[s.getAttribute("id")]
	        (ox,oy) = item.getCenter()
	    except:
	        ox = 0
   	        oy = 0
	    try:
	        item = self.nodeToItem[d.getAttribute("id")]
	        (dx,dy) = item.getCenter()
	    except:
	        dx = 0
	        dy = 0
		    
	    sm = self.parseTransform(s)
	    ss = self.decomposition(sm)
	    dm = self.parseTransform(d)
	    dd = self.decomposition(dm)
	    sx = (ss[0]*(1-p)+dd[0]*p)/ss[0]
	    sy = (ss[1]*(1-p)+dd[1]*p)/ss[0]
	    a  = ss[2]*(1-p)+dd[2]*p-ss[2]
	    tx = ox*(1-p)+dx*p
	    ty = oy*(1-p)+dy*p
	    m = [math.cos(a),math.sin(a),-math.sin(a),math.cos(a),0,0]
	    m = self.mulA([sx,0,0,sy,0,0],m)
	    m = self.mulA(m,[1,0,0,1,-ox,oy-self.height])
	    m = self.mulA([1,0,0,1,tx,self.height-ty],m)

	    top.setAttribute("transform","matrix(%g,%g,%g,%g,%g,%g)" % (m[0],m[2],m[1],m[3],m[4],m[5]))
        else:
	    try:
	        try:
	            sw = float(s.getAttribute("width"))
		except:
		    sw = 1
		try:
  	            sh = float(s.getAttribute("height"))
		except:
		    sh = 1
		try:
		    dw = float(d.getAttribute("width"))
		except:
		    dw = 1
		try:
		    dh = float(d.getAttribute("height"))
		except:
		    dh = 1
	        try:
	            item = self.nodeToItem[s.getAttribute("id")]
		    (ox,oy) = item.getCenter()
	        except:
		    ox = 0
		    oy = 0
	        try:
	            item = self.nodeToItem[d.getAttribute("id")]
		    (dx,dy) = item.getCenter()
	        except:
		    dx = 0
		    dy = 0
		try:
		    sm = self.parseTransform(s)
		    ss = self.decomposition(sm)
		except:
		    ss = [1,1,0,0,0]
		    pass
		try:
		    dm = self.parseTransform(d)
		    dd = self.decomposition(dm)
		    print "dd=",dd
		except:
		    dd = [1,1,0,0,0]
		dd[0] = dd[0]*dw/sw
		dd[1] = dd[1]*dh/sh
		print "ss[0]=",ss[0],"dd[0]=",dd[0]
		sx = (ss[0]*(1-p)+dd[0]*p)/ss[0]
		sy = (ss[1]*(1-p)+dd[1]*p)/ss[1]
		print "sx=",sx,"sy=",sy
		a  = ss[2]*(1-p)+dd[2]*p-ss[2]
		tx = ox*(1-p)+dx*p
		ty = oy*(1-p)+dy*p
		m = [math.cos(a),math.sin(a),-math.sin(a),math.cos(a),0,0]
		m = self.mulA([sx,0,0,sy,0,0],m)
		m = self.mulA(m,[1,0,0,1,-ox,oy-self.height])
		m = self.mulA([1,0,0,1,tx,self.height-ty],m)

		top.setAttribute("transform","matrix(%g,%g,%g,%g,%g,%g)" % (m[0],m[2],m[1],m[3],m[4],m[5]))
	    except:
	        traceback.print_exc()