Misc fixes and improvements
[vrm.git] / vrm.py
diff --git a/vrm.py b/vrm.py
index d85b085..f7382a7 100755 (executable)
--- a/vrm.py
+++ b/vrm.py
@@ -1,9 +1,17 @@
 #!BPY
 """
 Name: 'VRM'
-Blender: 241
-Group: 'Export'
-Tooltip: 'Vector Rendering Method Export Script 0.3'
+Blender: 242
+Group: 'Render'
+Tooltip: 'Vector Rendering Method script'
+"""
+
+__author__ = "Antonio Ospite"
+__url__ = ["http://projects.blender.org/projects/vrm"]
+__version__ = "0.3"
+
+__bpydoc__ = """\
+    Render the scene and save the result in vector format.
 """
 
 # ---------------------------------------------------------------------
@@ -25,25 +33,158 @@ Tooltip: 'Vector Rendering Method Export Script 0.3'
 #
 # ---------------------------------------------------------------------
 #
-#    NOTE: I do not know who is the original author of 'vrm'.
-#    The present code is almost entirely rewritten from scratch,
-#    but if I have to give credits to anyone, please let me know,
-#    so I can update the copyright.
+# Additional credits:
+#   Thanks to Emilio Aguirre for S2flender from which I took inspirations :)
+#   Thanks to Nikola Radovanovic, the author of the original VRM script,
+#       the code you read here has been rewritten _almost_ entirely
+#       from scratch but Nikola gave me the idea, so I thank him publicly.
 #
 # ---------------------------------------------------------------------
+# 
+# Things TODO for a next release:
+#   - Use multiple lighting sources in color calculation,
+#     (this is part of the "shading refactor") and use light color!
+#   - FIX the issue with negative scales in object tranformations!
+#   - Use a better depth sorting algorithm
+#   - Implement clipping of primitives and do handle object intersections.
+#     (for now only clipping away whole objects is supported).
+#   - Review how selections are made (this script uses selection states of
+#     primitives to represent visibility infos)
+#   - Use a data structure other than Mesh to represent the 2D image? 
+#     Think to a way to merge (adjacent) polygons that have the same color.
+#     Or a way to use paths for silhouettes and contours.
+#   - Consider SMIL for animation handling instead of ECMA Script? (Firefox do
+#     not support SMIL for animations)
+#   - Switch to the Mesh structure, should be considerably faster
+#    (partially done, but with Mesh we cannot sort faces, yet)
+#   - Implement Edge Styles (silhouettes, contours, etc.) (partially done).
+#   - Implement Shading Styles? (for now we use Flat Shading) (partially done).
+#   - Add Vector Writers other than SVG.
 #
-# Additional credits:
-#   Thanks to Emilio Aguirre for S2flender from which I took inspirations :)
-#   Thanks to Anthony C. D'Agostino for the original backface.py script   
+# ---------------------------------------------------------------------
+#
+# Changelog:
+#
+#   vrm-0.3.py  -   2006-05-19
+#    * First release after code restucturing.
+#      Now the script offers a useful set of functionalities
+#      and it can render animations, too.
 #
 # ---------------------------------------------------------------------
 
 import Blender
-from Blender import Scene, Object, NMesh, Lamp, Camera
+from Blender import Scene, Object, Mesh, NMesh, Material, Lamp, Camera
 from Blender.Mathutils import *
 from math import *
 
 
+# Some global settings
+
+class config:
+    polygons = dict()
+    polygons['SHOW'] = True
+    polygons['SHADING'] = 'TOON'
+    # Hidden to the user for now
+    polygons['EXPANSION_TRICK'] = True
+
+    edges = dict()
+    edges['SHOW'] = True
+    edges['SHOW_HIDDEN'] = False
+    edges['STYLE'] = 'SILHOUETTE'
+    edges['WIDTH'] = 2
+    edges['COLOR'] = [0, 0, 0]
+
+    output = dict()
+    output['FORMAT'] = 'SVG'
+    output['ANIMATION'] = False
+    output['JOIN_OBJECTS'] = True
+
+
+
+# ---------------------------------------------------------------------
+#
+## Utility Mesh class
+#
+# ---------------------------------------------------------------------
+class MeshUtils:
+
+    def getEdgeAdjacentFaces(edge, mesh):
+        """Get the faces adjacent to a given edge.
+
+        There can be 0, 1 or more (usually 2) faces adjacent to an edge.
+        """
+        adjface_list = []
+
+        for f in mesh.faces:
+            if (edge.v1 in f.v) and (edge.v2 in f.v):
+                adjface_list.append(f)
+
+        return adjface_list
+
+    def isMeshEdge(e, mesh):
+        """Mesh edge rule.
+
+        A mesh edge is visible if _any_ of its adjacent faces is selected.
+        Note: if the edge has no adjacent faces we want to show it as well,
+        useful for "edge only" portion of objects.
+        """
+
+        adjacent_faces = MeshUtils.getEdgeAdjacentFaces(e, mesh)
+
+        if len(adjacent_faces) == 0:
+            return True
+
+        selected_faces = [f for f in adjacent_faces if f.sel]
+
+        if len(selected_faces) != 0:
+            return True
+        else:
+            return False
+
+    def isSilhouetteEdge(e, mesh):
+        """Silhuette selection rule.
+
+        An edge is a silhuette edge if it is shared by two faces with
+        different selection status or if it is a boundary edge of a selected
+        face.
+        """
+
+        adjacent_faces = MeshUtils.getEdgeAdjacentFaces(e, mesh)
+
+        if ((len(adjacent_faces) == 1 and adjacent_faces[0].sel == 1) or
+            (len(adjacent_faces) == 2 and
+                adjacent_faces[0].sel != adjacent_faces[1].sel)
+            ):
+            return True
+        else:
+            return False
+    
+    def toonShading(u):
+
+        levels = 2
+        texels = 2*levels - 1
+        map = [0.0] + [(i)/float(texels-1) for i in range(1, texels-1) ] + [1.0]
+        
+        v = 1.0
+        for i in range(0, len(map)-1):
+            pivot = (map[i]+map[i+1])/2.0
+            j = int(u>pivot)
+
+            v = map[i+j]
+
+            if v<map[i+1]:
+                return v
+
+        return v
+
+
+    getEdgeAdjacentFaces = staticmethod(getEdgeAdjacentFaces)
+    isMeshEdge = staticmethod(isMeshEdge)
+    isSilhouetteEdge = staticmethod(isSilhouetteEdge)
+    toonShading = staticmethod(toonShading)
+
+
+
 # ---------------------------------------------------------------------
 #
 ## Projections classes
@@ -60,40 +201,35 @@ class Projector:
     parameter list.
     """
 
-    def __init__(self, cameraObj, obMesh, canvasSize):
+    def __init__(self, cameraObj, canvasRatio):
         """Calculate the projection matrix.
 
-        The projection matrix depends, in this case, on the camera settings,
-        and also on object transformation matrix.
+        The projection matrix depends, in this case, on the camera settings.
+        TAKE CARE: This projector expects vertices in World Coordinates!
         """
 
-        self.size = canvasSize
-
         camera = cameraObj.getData()
 
-        aspect = float(canvasSize[0])/float(canvasSize[1])
+        aspect = float(canvasRatio[0])/float(canvasRatio[1])
         near = camera.clipStart
         far = camera.clipEnd
 
+        scale = float(camera.scale)
+
         fovy = atan(0.5/aspect/(camera.lens/32))
-        fovy = fovy * 360/pi
+        fovy = fovy * 360.0/pi
         
         # What projection do we want?
-        if camera.type:
-            m2 = self._calcOrthoMatrix(fovy, aspect, near, far, 17) #camera.scale
-        else:
-            m2 = self._calcPerspectiveMatrix(fovy, aspect, near, far
+        if camera.type == 0:
+            mP = self._calcPerspectiveMatrix(fovy, aspect, near, far
+        elif camera.type == 1:
+            mP = self._calcOrthoMatrix(fovy, aspect, near, far, scale
         
-
         # View transformation
         cam = Matrix(cameraObj.getInverseMatrix())
         cam.transpose() 
-
-        m1 = Matrix(obMesh.getMatrix())
-        m1.transpose()
         
-        mP = cam * m1
-        mP = m2  * mP
+        mP = mP * cam
 
         self.projectionMatrix = mP
 
@@ -108,32 +244,29 @@ class Projector:
         matrix.
         """
         
-        # Note that we need the vertex expressed using homogeneous coordinates
-        p = self.projectionMatrix * Vector([v[0], v[1], v[2], 1.0])
-        
-        mW = self.size[0]/2
-        mH = self.size[1]/2
-        
-        if p[3]<=0:
-            p[0] = round(p[0]*mW)+mW
-            p[1] = round(p[1]*mH)+mH
-        else:
-            p[0] = round((p[0]/p[3])*mW)+mW
-            p[1] = round((p[1]/p[3])*mH)+mH
-            
-        # For now we want (0,0) in the top-left corner of the canvas
-        # Mirror and translate along y
-        p[1] *= -1
-        p[1] += self.size[1]
-    
+        # Note that we have to work on the vertex using homogeneous coordinates
+        p = self.projectionMatrix * Vector(v).resize4D()
+
+        # Perspective division
+        if p[3] != 0:
+            p[0] = p[0]/p[3]
+            p[1] = p[1]/p[3]
+            p[2] = p[2]/p[3]
+
+        # restore the size
+        p[3] = 1.0
+        p.resize3D()
+
         return p
 
+
     ##
     # Private methods
     #
     
     def _calcPerspectiveMatrix(self, fovy, aspect, near, far):
-        """Return a perspective projection matrix."""
+        """Return a perspective projection matrix.
+        """
         
         top = near * tan(fovy * pi / 360.0)
         bottom = -top
@@ -155,9 +288,11 @@ class Projector:
         return m
 
     def _calcOrthoMatrix(self, fovy, aspect , near, far, scale):
-        """Return an orthogonal projection matrix."""
+        """Return an orthogonal projection matrix.
+        """
         
-        top = near * tan(fovy * pi / 360.0) * (scale * 10)
+        # The 11 in the formula was found emiprically
+        top = near * tan(fovy * pi / 360.0) * (scale * 11)
         bottom = -top 
         left = bottom * aspect
         right= top * aspect
@@ -177,14 +312,15 @@ class Projector:
         return m
 
 
+
 # ---------------------------------------------------------------------
 #
-## Object representation class
+## 2D Object representation class
 #
 # ---------------------------------------------------------------------
 
 # TODO: a class to represent the needed properties of a 2D vector image
-# Just use a NMesh structure?
+# For now just using a [N]Mesh structure.
 
 
 # ---------------------------------------------------------------------
@@ -204,76 +340,148 @@ class VectorWriter:
 
     Every subclasses of VectorWriter must have at last the following public
     methods:
-        - printCanvas(mesh) --- where mesh is as specified before.
+        - open(self)
+        - close(self)
+        - printCanvas(self, scene,
+            doPrintPolygons=True, doPrintEdges=False, showHiddenEdges=False):
     """
     
-    def __init__(self, fileName, canvasSize):
-        """Open the file named #fileName# and set the canvas size."""
+    def __init__(self, fileName):
+        """Set the output file name and other properties"""
+
+        self.outputFileName = fileName
+        self.file = None
         
-        self.file = open(fileName, "w")
-        print "Outputting to: ", fileName
+        context = Scene.GetCurrent().getRenderingContext()
+        self.canvasSize = ( context.imageSizeX(), context.imageSizeY() )
+
+        self.startFrame = 1
+        self.endFrame = 1
+        self.animation = False
 
-        self.canvasSize = canvasSize
-    
 
     ##
     # Public Methods
     #
     
-    def printCanvas(mesh):
-        return
-        
-    ##
-    # Private Methods
-    #
-    
-    def _printHeader():
+    def open(self, startFrame=1, endFrame=1):
+        if startFrame != endFrame:
+            self.startFrame = startFrame
+            self.endFrame = endFrame
+            self.animation = True
+
+        self.file = open(self.outputFileName, "w")
+        print "Outputting to: ", self.outputFileName
+
         return
 
-    def _printFooter():
+    def close(self):
+        self.file.close()
         return
 
+    def printCanvas(self, scene, doPrintPolygons=True, doPrintEdges=False,
+            showHiddenEdges=False):
+        """This is the interface for the needed printing routine.
+        """
+        return
+        
 
 ## SVG Writer
 
 class SVGVectorWriter(VectorWriter):
     """A concrete class for writing SVG output.
-
-    The class does not support animations, yet.
-    Sorry.
     """
 
-    def __init__(self, file, canvasSize):
-        """Simply call the parent Contructor."""
-        VectorWriter.__init__(self, file, canvasSize)
+    def __init__(self, fileName):
+        """Simply call the parent Contructor.
+        """
+        VectorWriter.__init__(self, fileName)
 
 
     ##
     # Public Methods
     #
-    
-    def printCanvas(self, scene):
-        """Convert the scene representation to SVG."""
 
+    def open(self, startFrame=1, endFrame=1):
+        """Do some initialization operations.
+        """
+        VectorWriter.open(self, startFrame, endFrame)
         self._printHeader()
+
+    def close(self):
+        """Do some finalization operation.
+        """
+        self._printFooter()
+
+        # remember to call the close method of the parent
+        VectorWriter.close(self)
+
         
+    def printCanvas(self, scene, doPrintPolygons=True, doPrintEdges=False,
+            showHiddenEdges=False):
+        """Convert the scene representation to SVG.
+        """
+
         Objects = scene.getChildren()
+
+        context = scene.getRenderingContext()
+        framenumber = context.currentFrame()
+
+        if self.animation:
+            framestyle = "display:none"
+        else:
+            framestyle = "display:block"
+        
+        # Assign an id to this group so we can set properties on it using DOM
+        self.file.write("<g id=\"frame%d\" style=\"%s\">\n" %
+                (framenumber, framestyle) )
+
+
         for obj in Objects:
-            self.file.write("<g>\n")
-            
-            for face in obj.getData().faces:
-                self._printPolygon(face)
 
-            self._printWireframe(obj.getData())
+            if(obj.getType() != 'Mesh'):
+                continue
+
+            self.file.write("<g id=\"%s\">\n" % obj.getName())
+
+            mesh = obj.getData(mesh=1)
+
+            if doPrintPolygons:
+                self._printPolygons(mesh)
+
+            if doPrintEdges:
+                self._printEdges(mesh, showHiddenEdges)
             
             self.file.write("</g>\n")
-        
-        self._printFooter()
+
+        self.file.write("</g>\n")
+
     
     ##  
     # Private Methods
     #
     
+    def _calcCanvasCoord(self, v):
+        """Convert vertex in scene coordinates to canvas coordinates.
+        """
+
+        pt = Vector([0, 0, 0])
+        
+        mW = float(self.canvasSize[0])/2.0
+        mH = float(self.canvasSize[1])/2.0
+
+        # rescale to canvas size
+        pt[0] = v.co[0]*mW + mW
+        pt[1] = v.co[1]*mH + mH
+        pt[2] = v.co[2]
+         
+        # For now we want (0,0) in the top-left corner of the canvas.
+        # Mirror and translate along y
+        pt[1] *= -1
+        pt[1] += self.canvasSize[1]
+        
+        return pt
+
     def _printHeader(self):
         """Print SVG header."""
 
@@ -285,66 +493,137 @@ class SVGVectorWriter(VectorWriter):
         self.file.write("\twidth=\"%d\" height=\"%d\" streamable=\"true\">\n\n" %
                 self.canvasSize)
 
+        if self.animation:
+
+            self.file.write("""\n<script><![CDATA[
+            globalStartFrame=%d;
+            globalEndFrame=%d;
+
+            /* FIXME: Use 1000 as interval as lower values gives problems */
+            timerID = setInterval("NextFrame()", 1000);
+            globalFrameCounter=%d;
+
+            function NextFrame()
+            {
+              currentElement  = document.getElementById('frame'+globalFrameCounter)
+              previousElement = document.getElementById('frame'+(globalFrameCounter-1))
+
+              if (!currentElement)
+              {
+                return;
+              }
+
+              if (globalFrameCounter > globalEndFrame)
+              {
+                clearInterval(timerID)
+              }
+              else
+              {
+                if(previousElement)
+                {
+                    previousElement.style.display="none";
+                }
+                currentElement.style.display="block";
+                globalFrameCounter++;
+              }
+            }
+            \n]]></script>\n
+            \n""" % (self.startFrame, self.endFrame, self.startFrame) )
+                
     def _printFooter(self):
         """Print the SVG footer."""
 
         self.file.write("\n</svg>\n")
-        self.file.close()
 
-    def _printWireframe(self, mesh):
-        """Print the wireframe using mesh edges... is this the correct way?
+    def _printPolygons(self, mesh): 
+        """Print the selected (visible) polygons.
         """
 
-        print mesh.edges
-        print
-        print mesh.verts
-        
-        stroke_width=0.5
-        stroke_col = [0, 0, 0]
+        if len(mesh.faces) == 0:
+            return
+
+        self.file.write("<g>\n")
+
+        for face in mesh.faces:
+            if not face.sel:
+               continue
+
+            self.file.write("<path d=\"")
+
+            p = self._calcCanvasCoord(face.verts[0])
+            self.file.write("M %g,%g L " % (p[0], p[1]))
+
+            for v in face.verts[1:]:
+                p = self._calcCanvasCoord(v)
+                self.file.write("%g,%g " % (p[0], p[1]))
+            
+            # get rid of the last blank space, just cosmetics here.
+            self.file.seek(-1, 1) 
+            self.file.write("\"\n")
+            
+            # take as face color the first vertex color
+            # TODO: the average of vetrex colors?
+            if face.col:
+                fcol = face.col[0]
+                color = [fcol.r, fcol.g, fcol.b, fcol.a]
+            else:
+                color = [255, 255, 255, 255]
+
+            # Convert the color to the #RRGGBB form
+            str_col = "#%02X%02X%02X" % (color[0], color[1], color[2])
+
+            # use the stroke property to alleviate the "adjacent edges" problem,
+            # we simulate polygon expansion using borders,
+            # see http://www.antigrain.com/svg/index.html for more info
+            stroke_width = 0.5
+
+            # Handle transparent polygons
+            opacity_string = ""
+            if color[3] != 255:
+                opacity = float(color[3])/255.0
+                opacity_string = " fill-opacity: %g; stroke-opacity: %g; opacity: 1;" % (opacity, opacity)
+
+            self.file.write("\tstyle=\"fill:" + str_col + ";")
+            self.file.write(opacity_string)
+            if config.polygons['EXPANSION_TRICK']:
+                self.file.write(" stroke-width:" + str(stroke_width) + ";\n")
+                self.file.write(" stroke-linecap:round;stroke-linejoin:round")
+            self.file.write("\"/>\n")
+
+        self.file.write("</g>\n")
+
+    def _printEdges(self, mesh, showHiddenEdges=False):
+        """Print the wireframe using mesh edges.
+        """
+
+        stroke_width = config.edges['WIDTH']
+        stroke_col = config.edges['COLOR']
         
         self.file.write("<g>\n")
 
         for e in mesh.edges:
+            
+            hidden_stroke_style = ""
+            
+            if e.sel == 0:
+                if showHiddenEdges == False:
+                    continue
+                else:
+                    hidden_stroke_style = ";\n stroke-dasharray:3, 3"
+
+            p1 = self._calcCanvasCoord(e.v1)
+            p2 = self._calcCanvasCoord(e.v2)
+            
             self.file.write("<line x1=\"%g\" y1=\"%g\" x2=\"%g\" y2=\"%g\"\n"
-                    % ( e.v1[0], e.v1[1], e.v2[0], e.v2[1] ) )
+                    % ( p1[0], p1[1], p2[0], p2[1] ) )
             self.file.write(" style=\"stroke:rgb("+str(stroke_col[0])+","+str(stroke_col[1])+","+str(stroke_col[2])+");")
             self.file.write(" stroke-width:"+str(stroke_width)+";\n")
             self.file.write(" stroke-linecap:round;stroke-linejoin:round")
+            self.file.write(hidden_stroke_style)
             self.file.write("\"/>\n")
 
         self.file.write("</g>\n")
-            
-        
-
-    def _printPolygon(self, face):
-        """Print our primitive, finally.
-        """
-        
-        wireframe = False
-        
-        stroke_width=0.5
-        
-        self.file.write("<polygon points=\"")
-
-        for v in face:
-            self.file.write("%g,%g " % (v[0], v[1]))
-        
-        self.file.seek(-1,1) # get rid of the last space
-        self.file.write("\"\n")
-        
-        #take as face color the first vertex color
-        fcol = face.col[0]
-        color = [fcol.r, fcol.g, fcol.b]
 
-        stroke_col = [0, 0, 0]
-        if not wireframe:
-            stroke_col = color
-
-        self.file.write("\tstyle=\"fill:rgb("+str(color[0])+","+str(color[1])+","+str(color[2])+");")
-        self.file.write(" stroke:rgb("+str(stroke_col[0])+","+str(stroke_col[1])+","+str(stroke_col[2])+");")
-        self.file.write(" stroke-width:"+str(stroke_width)+";\n")
-        self.file.write(" stroke-linecap:round;stroke-linejoin:round")
-        self.file.write("\"/>\n")
 
 
 # ---------------------------------------------------------------------
@@ -353,346 +632,890 @@ class SVGVectorWriter(VectorWriter):
 #
 # ---------------------------------------------------------------------
 
-def RotatePoint(PX,PY,PZ,AngleX,AngleY,AngleZ):
-    
-    NewPoint = []
-    # Rotate X
-    NewY = (PY * cos(AngleX))-(PZ * sin(AngleX))
-    NewZ = (PZ * cos(AngleX))+(PY * sin(AngleX))
-    # Rotate Y
-    PZ = NewZ
-    PY = NewY
-    NewZ = (PZ * cos(AngleY))-(PX * sin(AngleY))
-    NewX = (PX * cos(AngleY))+(PZ * sin(AngleY))
-    PX = NewX
-    PZ = NewZ
-    # Rotate Z
-    NewX = (PX * cos(AngleZ))-(PY * sin(AngleZ))
-    NewY = (PY * cos(AngleZ))+(PX * sin(AngleZ))
-    NewPoint.append(NewX)
-    NewPoint.append(NewY)
-    NewPoint.append(NewZ)
-    return NewPoint
+# A dictionary to collect different shading style methods
+shadingStyles = dict()
+shadingStyles['FLAT'] = None
+shadingStyles['TOON'] = None
+
+# A dictionary to collect different edge style methods
+edgeStyles = dict()
+edgeStyles['MESH'] = MeshUtils.isMeshEdge
+edgeStyles['SILHOUETTE'] = MeshUtils.isSilhouetteEdge
+
+# A dictionary to collect the supported output formats
+outputWriters = dict()
+outputWriters['SVG'] = SVGVectorWriter
+
 
 class Renderer:
     """Render a scene viewed from a given camera.
     
-    This class is responsible of the rendering process, hence transormation
-    and projection of the ojects in the scene are invoked by the renderer.
+    This class is responsible of the rendering process, transformation and
+    projection of the objects in the scene are invoked by the renderer.
 
-    The user can optionally provide a specific camera for the rendering, see
-    the #doRendering# method for more informations.
+    The rendering is done using the active camera for the current scene.
     """
 
     def __init__(self):
-        """Set the canvas size to a defaulr value.
-        
-        The only instance attribute here is the canvas size, which can be
-        queryed to the renderer by other entities.
+        """Make the rendering process only for the current scene by default.
+
+        We will work on a copy of the scene, be sure that the current scene do
+        not get modified in any way.
         """
-        self.canvasSize = (0.0, 0.0)
+
+        # Render the current Scene, this should be a READ-ONLY property
+        self._SCENE = Scene.GetCurrent()
+        
+        # Use the aspect ratio of the scene rendering context
+        context = self._SCENE.getRenderingContext()
+
+        aspect_ratio = float(context.imageSizeX())/float(context.imageSizeY())
+        self.canvasRatio = (float(context.aspectRatioX())*aspect_ratio,
+                            float(context.aspectRatioY())
+                            )
+
+        # Render from the currently active camera 
+        self.cameraObj = self._SCENE.getCurrentCamera()
+
+        # Get a projector for this camera.
+        # NOTE: the projector wants object in world coordinates,
+        # so we should remember to apply modelview transformations
+        # _before_ we do projection transformations.
+        self.proj = Projector(self.cameraObj, self.canvasRatio)
+
+        # Get the list of lighting sources
+        obj_lst = self._SCENE.getChildren()
+        self.lights = [ o for o in obj_lst if o.getType() == 'Lamp']
+
+        # When there are no lights we use a default lighting source
+        # that have the same position of the camera
+        if len(self.lights) == 0:
+            l = Lamp.New('Lamp')
+            lobj = Object.New('Lamp')
+            lobj.loc = self.cameraObj.loc
+            lobj.link(l) 
+            self.lights.append(lobj)
 
 
     ##
     # Public Methods
     #
 
-    def getCanvasSize(self):
-        """Return the current canvas size read from Blender rendering context"""
-        return self.canvasSize
+    def doRendering(self, outputWriter, animation=False):
+        """Render picture or animation and write it out.
         
-    def doRendering(self, scene, cameraObj=None):
-        """Control the rendering process.
+        The parameters are:
+            - a Vector writer object that will be used to output the result.
+            - a flag to tell if we want to render an animation or only the
+              current frame.
+        """
         
-        Here we control the entire rendering process invoking the operation
-        needed to transforma project the 3D scene in two dimensions.
+        context = self._SCENE.getRenderingContext()
+        origCurrentFrame = context.currentFrame()
+
+        # Handle the animation case
+        if not animation:
+            startFrame = origCurrentFrame
+            endFrame = startFrame
+            outputWriter.open()
+        else:
+            startFrame = context.startFrame()
+            endFrame = context.endFrame()
+            outputWriter.open(startFrame, endFrame)
+        
+        # Do the rendering process frame by frame
+        print "Start Rendering!"
+        for f in range(startFrame, endFrame+1):
+            context.currentFrame(f)
+
+            # Use some temporary workspace, a full copy of the scene
+            inputScene = self._SCENE.copy(2)
+            # And Set our camera accordingly
+            self.cameraObj = inputScene.getCurrentCamera()
+
+            try:
+                renderedScene = self.doRenderScene(inputScene)
+            except :
+                print "There was an error! Aborting."
+                import traceback
+                print traceback.print_exc()
+
+                self._SCENE.makeCurrent()
+                Scene.unlink(inputScene)
+                del inputScene
+                return
+
+            outputWriter.printCanvas(renderedScene,
+                    doPrintPolygons = config.polygons['SHOW'],
+                    doPrintEdges    = config.edges['SHOW'],
+                    showHiddenEdges = config.edges['SHOW_HIDDEN'])
+            
+            # clear the rendered scene
+            self._SCENE.makeCurrent()
+            #Scene.unlink(renderedScene)
+            #del renderedScene
 
-        Parameters:
-        scene --- the Blender Scene to render
-        cameraObj --- the camera object to use for the viewing processing
-        """
+        outputWriter.close()
+        print "Done!"
+        context.currentFrame(origCurrentFrame)
 
-        if cameraObj == None:
-            cameraObj = scene.getCurrentCamera()
-        
-        context = scene.getRenderingContext()
-        self.canvasSize = (context.imageSizeX(), context.imageSizeY())
+
+    def doRenderScene(self, workScene):
+        """Control the rendering process.
         
-        Objects = scene.getChildren()
+        Here we control the entire rendering process invoking the operation
+        needed to transform and project the 3D scene in two dimensions.
+        """
         
-        # A structure to store the transformed scene
-        newscene = Scene.New("flat"+scene.name)
+        # global processing of the scene
+
+        self._doSceneClipping(workScene)
+
+        self._doConvertGeometricObjToMesh(workScene)
+
+        if config.output['JOIN_OBJECTS']:
+            self._joinMeshObjectsInScene(workScene)
+
+        self._doSceneDepthSorting(workScene)
         
+        # Per object activities
+
+        Objects = workScene.getChildren()
         for obj in Objects:
-            
-            if (obj.getType() != "Mesh"):
-                print "Type:", obj.getType(), "\tSorry, only mesh Object supported!"
+
+            if obj.getType() != 'Mesh':
+                print "Only Mesh supported! - Skipping type:", obj.getType()
                 continue
 
-            # Get a projector for this object
-            proj = Projector(cameraObj, obj, self.canvasSize)
+            print "Rendering: ", obj.getName()
 
-            # Let's store the transformed data
-            transformed_mesh = NMesh.New("flat"+obj.name)
-            transformed_mesh.hasVertexColours(1)
+            mesh = obj.getData(mesh=1)
 
-            # process Edges
-            for v in obj.getData().verts:
-                transformed_mesh.verts.append(v)
-            transformed_mesh.edges = self._processEdges(obj.getData().edges)
-            print transformed_mesh.edges
+            self._doModelingTransformation(mesh, obj.matrix)
+
+            self._doBackFaceCulling(mesh)
+
+            self._doPerVertexLighting(mesh)
+
+            # Do "projection" now so we perform further processing
+            # in Normalized View Coordinates
+            self._doProjection(mesh, self.proj)
+
+            self._doViewFrustumClipping(mesh)
+
+            self._doMeshDepthSorting(mesh)
+
+            self._doEdgesStyle(mesh, edgeStyles[config.edges['STYLE']])
 
             
-            # Store the materials
-            materials = obj.getData().getMaterials()
-
-            meshfaces = obj.getData().faces
-
-            for face in meshfaces:
-
-                # if the face is visible flatten it on the "picture plane"
-                if self._isFaceVisible_old(face, obj, cameraObj):
-                    
-                    # Store transformed face
-                    newface = NMesh.Face()
-
-                    for vert in face:
-
-                        p = proj.doProjection(vert.co)
-
-                        tmp_vert = NMesh.Vert(p[0], p[1], p[2])
-
-                        # Add the vert to the mesh
-                        transformed_mesh.verts.append(tmp_vert)
-                        
-                        newface.v.append(tmp_vert)
-                        
-                    
-                    # Per-face color calculation
-                    # code taken mostly from the original vrm script
-                    # TODO: understand the code and rewrite it clearly
-                    ambient = -150
-                    
-                    fakelight = Object.Get("Lamp").loc
-                    if fakelight == None:
-                        fakelight = [1.0, 1.0, -0.3]
-
-                    norm = Vector(face.no)
-                    vektori = (norm[0]*fakelight[0]+norm[1]*fakelight[1]+norm[2]*fakelight[2])
-                    vduzine = fabs(sqrt(pow(norm[0],2)+pow(norm[1],2)+pow(norm[2],2))*sqrt(pow(fakelight[0],2)+pow(fakelight[1],2)+pow(fakelight[2],2)))
-                    intensity = floor(ambient + 200*acos(vektori/vduzine))/200
-                    if intensity < 0:
-                        intensity = 0
-
-                    if materials:
-                        tmp_col = materials[face.mat].getRGBCol()
-                    else:
-                        tmp_col = [0.5, 0.5, 0.5]
-                        
-                    tmp_col = [ (c>intensity) and int(round((c-intensity)*10)*25.5) for c in tmp_col ]
-
-                    vcol = NMesh.Col(tmp_col[0], tmp_col[1], tmp_col[2])
-                    newface.col = [vcol, vcol, vcol, 255]
-                    
-                    transformed_mesh.addFace(newface)
-
-            # at the end of the loop on obj
-            
-            transformed_obj = Object.New(obj.getType(), "flat"+obj.name)
-            transformed_obj.link(transformed_mesh)
-            transformed_obj.loc = obj.loc
-            newscene.link(transformed_obj)
+            # Update the object data, important! :)
+            mesh.update()
 
-        
-        return newscene
+        return workScene
 
 
     ##
     # Private Methods
     #
 
-    def _isFaceVisible_old(self, face, obj, cameraObj):
-        """Determine if the face is visible from the current camera.
-
-        The following code is taken basicly from the original vrm script.
-        """
-
-        camera = cameraObj
-
-        numvert = len(face)
-
-        # backface culling
-
-        # translate and rotate according to the object matrix
-        # and then translate according to the camera position
-        #m = obj.getMatrix()
-        #m.transpose()
-        
-        #a = m*Vector(face[0]) - Vector(cameraObj.loc)
-        #b = m*Vector(face[1]) - Vector(cameraObj.loc)
-        #c = m*Vector(face[numvert-1]) - Vector(cameraObj.loc)
-        
-        a = []
-        a.append(face[0][0])
-        a.append(face[0][1])
-        a.append(face[0][2])
-        a = RotatePoint(a[0], a[1], a[2], obj.RotX, obj.RotY, obj.RotZ)
-        a[0] += obj.LocX - camera.LocX
-        a[1] += obj.LocY - camera.LocY
-        a[2] += obj.LocZ - camera.LocZ
-        b = []
-        b.append(face[1][0])
-        b.append(face[1][1])
-        b.append(face[1][2])
-        b = RotatePoint(b[0], b[1], b[2], obj.RotX, obj.RotY, obj.RotZ)
-        b[0] += obj.LocX - camera.LocX
-        b[1] += obj.LocY - camera.LocY
-        b[2] += obj.LocZ - camera.LocZ
-        c = []
-        c.append(face[numvert-1][0])
-        c.append(face[numvert-1][1])
-        c.append(face[numvert-1][2])
-        c = RotatePoint(c[0], c[1], c[2], obj.RotX, obj.RotY, obj.RotZ)
-        c[0] += obj.LocX - camera.LocX
-        c[1] += obj.LocY - camera.LocY
-        c[2] += obj.LocZ - camera.LocZ
-
-        norm = [0, 0, 0]
-        norm[0] = (b[1] - a[1])*(c[2] - a[2]) - (c[1] - a[1])*(b[2] - a[2])
-        norm[1] = -((b[0] - a[0])*(c[2] - a[2]) - (c[0] - a[0])*(b[2] - a[2]))
-        norm[2] = (b[0] - a[0])*(c[1] - a[1]) - (c[0] - a[0])*(b[1] - a[1])
-
-        d = norm[0]*a[0] + norm[1]*a[1] + norm[2]*a[2]
-        #d = DotVecs(Vector(norm), Vector(a))
-
-        return (d<0)
-    
-    def _isFaceVisible(self, face, obj, cameraObj):
-        """Determine if the face is visible from the current camera.
+    # Utility methods
 
-        The following code is taken basicly from the original vrm script.
+    def _getObjPosition(self, obj):
+        """Return the obj position in World coordinates.
         """
+        return obj.matrix.translationPart()
 
-        camera = cameraObj
+    def _cameraViewVector(self):
+        """Get the View Direction form the camera matrix.
+        """
+        return Vector(self.cameraObj.matrix[2]).resize3D()
 
-        numvert = len(face)
 
-        # backface culling
+    # Faces methods
 
-        # translate and rotate according to the object matrix
-        # and then translate according to the camera position
-        m = obj.getMatrix()
-        m.transpose()
+    def _isFaceVisible(self, face):
+        """Determine if a face of an object is visible from the current camera.
         
-        a = m*Vector(face[0]) - Vector(cameraObj.loc)
-        b = m*Vector(face[1]) - Vector(cameraObj.loc)
-        c = m*Vector(face[numvert-1]) - Vector(cameraObj.loc)
+        The view vector is calculated from the camera location and one of the
+        vertices of the face (expressed in World coordinates, after applying
+        modelview transformations).
+
+        After those transformations we determine if a face is visible by
+        computing the angle between the face normal and the view vector, this
+        angle has to be between -90 and 90 degrees for the face to be visible.
+        This corresponds somehow to the dot product between the two, if it
+        results > 0 then the face is visible.
 
-        norm = m*Vector(face.no)
+        There is no need to normalize those vectors since we are only interested in
+        the sign of the cross product and not in the product value.
 
-        d = DotVecs(norm, a)
+        NOTE: here we assume the face vertices are in WorldCoordinates, so
+        please transform the object _before_ doing the test.
+        """
 
-        return (d<0)
+        normal = Vector(face.no)
+        camPos = self._getObjPosition(self.cameraObj)
+        view_vect = None
 
+        # View Vector in orthographics projections is the view Direction of
+        # the camera
+        if self.cameraObj.data.getType() == 1:
+            view_vect = self._cameraViewVector()
 
-    def _doClipping():
-        return
+        # View vector in perspective projections can be considered as
+        # the difference between the camera position and one point of
+        # the face, we choose the farthest point from the camera.
+        if self.cameraObj.data.getType() == 0:
+            vv = max( [ ((camPos - Vector(v.co)).length, (camPos - Vector(v.co))) for v in face] )
+            view_vect = vv[1]
+
+
+        # if d > 0 the face is visible from the camera
+        d = view_vect * normal
+        
+        if d > 0:
+            return True
+        else:
+            return False
+
+
+    # Scene methods
+
+    def _doSceneClipping(self, scene):
+        """Clip whole objects against the View Frustum.
+
+        For now clip away only objects according to their center position.
+        """
+
+        cpos = self._getObjPosition(self.cameraObj)
+        view_vect = self._cameraViewVector()
+
+        near = self.cameraObj.data.clipStart
+        far  = self.cameraObj.data.clipEnd
+
+        aspect = float(self.canvasRatio[0])/float(self.canvasRatio[1])
+        fovy = atan(0.5/aspect/(self.cameraObj.data.lens/32))
+        fovy = fovy * 360.0/pi
+
+        Objects = scene.getChildren()
+        for o in Objects:
+            if o.getType() != 'Mesh': continue;
 
+            obj_vect = Vector(cpos) - self._getObjPosition(o)
 
+            d = obj_vect*view_vect
+            theta = AngleBetweenVecs(obj_vect, view_vect)
+            
+            # if the object is outside the view frustum, clip it away
+            if (d < near) or (d > far) or (theta > fovy):
+                scene.unlink(o)
+
+    def _doConvertGeometricObjToMesh(self, scene):
+        """Convert all "geometric" objects to mesh ones.
+        """
+        geometricObjTypes = ['Mesh', 'Surf', 'Curve', 'Text']
+
+        Objects = scene.getChildren()
+        objList = [ o for o in Objects if o.getType() in geometricObjTypes ]
+        for obj in objList:
+            old_obj = obj
+            obj = self._convertToRawMeshObj(obj)
+            scene.link(obj)
+            scene.unlink(old_obj)
+
+
+            # XXX Workaround for Text and Curve which have some normals
+            # inverted when they are converted to Mesh, REMOVE that when
+            # blender will fix that!!
+            if old_obj.getType() in ['Curve', 'Text']:
+                me = obj.getData(mesh=1)
+                for f in me.faces: f.sel = 1;
+                for v in me.verts: v.sel = 1;
+                me.remDoubles(0)
+                me.triangleToQuad()
+                me.recalcNormals()
+                me.update()
+
+
+    def _doSceneDepthSorting(self, scene):
+        """Sort objects in the scene.
+
+        The object sorting is done accordingly to the object centers.
+        """
+
+        c = self._getObjPosition(self.cameraObj)
+
+        by_center_pos = (lambda o1, o2:
+                (o1.getType() == 'Mesh' and o2.getType() == 'Mesh') and
+                cmp((self._getObjPosition(o1) - Vector(c)).length,
+                    (self._getObjPosition(o2) - Vector(c)).length)
+            )
+
+        # TODO: implement sorting by bounding box, if obj1.bb is inside obj2.bb,
+        # then ob1 goes farther than obj2, useful when obj2 has holes
+        by_bbox = None
+        
+        Objects = scene.getChildren()
+        Objects.sort(by_center_pos)
+        
+        # update the scene
+        for o in Objects:
+            scene.unlink(o)
+            scene.link(o)
+
+    def _joinMeshObjectsInScene(self, scene):
+        """Merge all the Mesh Objects in a scene into a single Mesh Object.
+        """
+
+        oList = [o for o in scene.getChildren() if o.getType()=='Mesh']
+
+        # FIXME: Object.join() do not work if the list contains 1 object
+        if len(oList) == 1:
+            return
+
+        mesh = Mesh.New('BigOne')
+        bigObj = Object.New('Mesh', 'BigOne')
+        bigObj.link(mesh)
+
+        scene.link(bigObj)
+
+        try:
+            bigObj.join(oList)
+        except RuntimeError:
+            print "\nCan't Join Objects\n"
+            scene.unlink(bigObj)
+            return
+        except TypeError:
+            print "Objects Type error?"
+        
+        for o in oList:
+            scene.unlink(o)
+
+        scene.update()
+
     # Per object methods
 
-    def _doVisibleSurfaceDetermination(object):
-        return
+    def _convertToRawMeshObj(self, object):
+        """Convert geometry based object to a mesh object.
+        """
+        me = Mesh.New('RawMesh_'+object.name)
+        me.getFromObject(object.name)
 
-    def _doColorizing(object):
-        return
+        newObject = Object.New('Mesh', 'RawMesh_'+object.name)
+        newObject.link(me)
+
+        # If the object has no materials set a default material
+        if not me.materials:
+            me.materials = [Material.New()]
+            #for f in me.faces: f.mat = 0
+
+        newObject.setMatrix(object.getMatrix())
+
+        return newObject
+
+    def _doModelingTransformation(self, mesh, matrix):
+        """Transform object coordinates to world coordinates.
 
-    def _doStylizingEdges(self, object, style):
-        """Process Mesh Edges. (For now copy the edge data, in next version it
-        can be a place where recognize silouhettes and/or contours).
+        This step is done simply applying to the object its tranformation
+        matrix and recalculating its normals.
+        """
+        # XXX FIXME: blender do not transform normals in the right way when
+        # there are negative scale values
+        if matrix[0][0] < 0 or matrix[1][1] < 0 or matrix[2][2] < 0:
+            print "WARNING: Negative scales, expect incorrect results!"
+
+        mesh.transform(matrix, True)
 
-        input: an edge list
-        return: a processed edge list
+    def _doBackFaceCulling(self, mesh):
+        """Simple Backface Culling routine.
+        
+        At this level we simply do a visibility test face by face and then
+        select the vertices belonging to visible faces.
         """
+        
+        # Select all vertices, so edges can be displayed even if there are no
+        # faces
+        for v in mesh.verts:
+            v.sel = 1
+        
+        Mesh.Mode(Mesh.SelectModes['FACE'])
+        # Loop on faces
+        for f in mesh.faces:
+            f.sel = 0
+            if self._isFaceVisible(f):
+                f.sel = 1
+
+    def _doPerVertexLighting(self, mesh):
+        """Apply an Illumination ans shading model to the object.
+
+        The model used is the Phong one, it may be inefficient,
+        but I'm just learning about rendering and starting from Phong seemed
+        the most natural way.
+        """
+
+        # If the mesh has vertex colors already, use them,
+        # otherwise turn them on and do some calculations
+        if mesh.vertexColors:
+            return
+        mesh.vertexColors = 1
+
+        materials = mesh.materials
+        
+        # TODO: use multiple lighting sources
+        light_obj = self.lights[0]
+        light_pos = self._getObjPosition(light_obj)
+        light = light_obj.data
+
+        camPos = self._getObjPosition(self.cameraObj)
+
+        # We do per-face color calculation (FLAT Shading), we can easily turn
+        # to a per-vertex calculation if we want to implement some shading
+        # technique. For an example see:
+        # http://www.miralab.unige.ch/papers/368.pdf
+        for f in mesh.faces:
+            if not f.sel:
+                continue
+
+            mat = None
+            if materials:
+                mat = materials[f.mat]
+
+            # A new default material
+            if mat == None:
+                mat = Material.New('defMat')
+            
+            L = Vector(light_pos).normalize()
+
+            V = (Vector(camPos) - Vector(f.cent)).normalize()
+
+            N = Vector(f.no).normalize()
+
+            R = 2 * (N*L) * N - L
+
+            # TODO: Attenuation factor (not used for now)
+            a0 = 1.0; a1 = 0.0; a2 = 1.0
+            d = (Vector(f.v[0].co) - Vector(light_pos)).length
+            fd = min(1, 1.0/(a0 + a1*d + a2*(d*d)))
+
+            # Ambient component
+            Ia = 1.0
+            ka = mat.getAmb() * Vector([0.1, 0.1, 0.1])
+            Iamb = Ia * ka
+            
+            # Diffuse component (add light.col for kd)
+            kd = mat.getRef() * Vector(mat.getRGBCol())
+            Ip = light.getEnergy()
+            
+            if config.polygons['SHADING'] == 'FLAT':
+                Idiff = Ip * kd * max(0, (N*L))
+            elif config.polygons['SHADING'] == 'TOON':
+                Idiff = Ip * kd * MeshUtils.toonShading(N*L)
+
+            # Specular component
+            ks = mat.getSpec() * Vector(mat.getSpecCol())
+            ns = mat.getHardness()
+            Ispec = Ip * ks * pow(max(0, (V*R)), ns)
+
+            # Emissive component
+            ki = Vector([mat.getEmit()]*3)
+
+            I = ki + Iamb + (Idiff + Ispec)
+
+
+            # Set Alpha component
+            I = list(I)
+            I.append(mat.getAlpha())
+
+            # Clamp I values between 0 and 1
+            I = [ min(c, 1) for c in I]
+            I = [ max(0, c) for c in I]
+
+            # Convert to a value between 0 and 255
+            tmp_col = [ int(c * 255.0) for c in I]
+
+            for c in f.col:
+                c.r = tmp_col[0]
+                c.g = tmp_col[1]
+                c.b = tmp_col[2]
+                c.a = tmp_col[3]
+
+    def _doProjection(self, mesh, projector):
+        """Apply Viewing and Projection tranformations.
+        """
+
+        for v in mesh.verts:
+            p = projector.doProjection(v.co)
+            v.co[0] = p[0]
+            v.co[1] = p[1]
+            v.co[2] = p[2]
+
+        # We could reeset Camera matrix, since now
+        # we are in Normalized Viewing Coordinates,
+        # but doung that would affect World Coordinate
+        # processing for other objects
+
+        #self.cameraObj.data.type = 1
+        #self.cameraObj.data.scale = 2.0
+        #m = Matrix().identity()
+        #self.cameraObj.setMatrix(m)
+
+    def _doViewFrustumClipping(self, mesh):
+        """Clip faces against the View Frustum.
+        """
+
+    def test_extensions(self, f1, f2):
+        for v1, v2 in [ (v1, v2) for v1 in f1 for v2 in f2 ]:
+            pass
+
+    def depth_sort(self, faces):
         return
+            
+
+    def _doMeshDepthSorting(self, mesh):
+        """Sort faces in an object.
+
+        The faces in the object are sorted following the distance of the
+        vertices from the camera position.
+        """
+        if len(mesh.faces) == 0:
+            return
 
+        #c = self._getObjPosition(self.cameraObj)
+
+        # In NVC
+        c = [0, 0, 1]
+
+        # hackish sorting of faces
+
+        # Sort faces according to the max distance from the camera
+        by_max_vert_dist = (lambda f1, f2:
+                cmp(max([(Vector(v.co)-Vector(c)).length for v in f2]),
+                    max([(Vector(v.co)-Vector(c)).length for v in f1])))
+        
+        # Sort faces according to the min distance from the camera
+        by_min_vert_dist = (lambda f1, f2:
+                cmp(min([(Vector(v.co)-Vector(c)).length for v in f1]),
+                    min([(Vector(v.co)-Vector(c)).length for v in f2])))
+        
+        # Sort faces according to the avg distance from the camera
+        by_avg_vert_dist = (lambda f1, f2:
+                cmp(sum([(Vector(v.co)-Vector(c)).length for v in f1])/len(f1),
+                    sum([(Vector(v.co)-Vector(c)).length for v in f2])/len(f2)))
+
+
+        # FIXME: using NMesh to sort faces. We should avoid that!
+        nmesh = NMesh.GetRaw(mesh.name)
+        nmesh.faces.sort(by_max_vert_dist)
+        #nmesh.faces.reverse()
+
+        # Depth sort tests
+
+        self.depth_sort(nmesh.faces)
+
+        
+        mesh.faces.delete(1, range(0, len(mesh.faces)))
+
+        for i,f in enumerate(nmesh.faces):
+            fv = [v.index for v in f.v] 
+            mesh.faces.extend(fv)
+            mesh.faces[i].mat = f.mat
+            mesh.faces[i].sel = f.sel
+            for i,c in enumerate(mesh.faces[i].col):
+                c.r = f.col[i].r
+                c.g = f.col[i].g
+                c.b = f.col[i].b
+                c.a = f.col[i].a
+
+    def _doEdgesStyle(self, mesh, edgestyleSelect):
+        """Process Mesh Edges accroding to a given selection style.
+
+        Examples of algorithms:
+
+        Contours:
+            given an edge if its adjacent faces have the same normal (that is
+            they are complanar), than deselect it.
+
+        Silhouettes:
+            given an edge if one its adjacent faces is frontfacing and the
+            other is backfacing, than select it, else deselect.
+        """
+
+        Mesh.Mode(Mesh.SelectModes['EDGE'])
+
+        for e in mesh.edges:
+
+            e.sel = 0
+            if edgestyleSelect(e, mesh):
+                e.sel = 1
+                
 
 
 # ---------------------------------------------------------------------
 #
-## Main Program
+## GUI Class and Main Program
 #
 # ---------------------------------------------------------------------
 
 
-# FIXME: really hackish code, just to test if the other parts work
-def depthSorting(scene):
-
-    cameraObj = Scene.GetCurrent().getCurrentCamera()
-    Objects = scene.getChildren()
+from Blender import BGL, Draw
+from Blender.BGL import *
 
-    Objects.sort(lambda obj1, obj2: 
-            cmp(Vector(Vector(cameraObj.loc) - Vector(obj1.loc)).length,
-                Vector(Vector(cameraObj.loc) - Vector(obj2.loc)).length
-                )
-            )
+class GUI:
     
-    # hackish sorting of faces according to the max z value of a vertex
-    for o in Objects:
+    def _init():
+
+        # Output Format menu 
+        output_format = config.output['FORMAT']
+        default_value = outputWriters.keys().index(output_format)+1
+        GUI.outFormatMenu = Draw.Create(default_value)
+        GUI.evtOutFormatMenu = 0
+
+        # Animation toggle button
+        GUI.animToggle = Draw.Create(config.output['ANIMATION'])
+        GUI.evtAnimToggle = 1
+
+        # Join Objects toggle button
+        GUI.joinObjsToggle = Draw.Create(config.output['JOIN_OBJECTS'])
+        GUI.evtJoinObjsToggle = 2
+
+        # Render filled polygons
+        GUI.polygonsToggle = Draw.Create(config.polygons['SHOW'])
+
+        # Shading Style menu 
+        shading_style = config.polygons['SHADING']
+        default_value = shadingStyles.keys().index(shading_style)+1
+        GUI.shadingStyleMenu = Draw.Create(default_value)
+        GUI.evtShadingStyleMenu = 21
+
+        GUI.evtPolygonsToggle = 3
+        # We hide the config.polygons['EXPANSION_TRICK'], for now
+
+        # Render polygon edges
+        GUI.showEdgesToggle = Draw.Create(config.edges['SHOW'])
+        GUI.evtShowEdgesToggle = 4
+
+        # Render hidden edges
+        GUI.showHiddenEdgesToggle = Draw.Create(config.edges['SHOW_HIDDEN'])
+        GUI.evtShowHiddenEdgesToggle = 5
+
+        # Edge Style menu 
+        edge_style = config.edges['STYLE']
+        default_value = edgeStyles.keys().index(edge_style)+1
+        GUI.edgeStyleMenu = Draw.Create(default_value)
+        GUI.evtEdgeStyleMenu = 6
+
+        # Edge Width slider
+        GUI.edgeWidthSlider = Draw.Create(config.edges['WIDTH'])
+        GUI.evtEdgeWidthSlider = 7
+
+        # Edge Color Picker
+        c = config.edges['COLOR']
+        GUI.edgeColorPicker = Draw.Create(c[0]/255.0, c[1]/255.0, c[2]/255.0)
+        GUI.evtEdgeColorPicker = 71
+
+        # Render Button
+        GUI.evtRenderButton = 8
+
+        # Exit Button
+        GUI.evtExitButton = 9
+
+    def draw():
+
+        # initialize static members
+        GUI._init()
+
+        glClear(GL_COLOR_BUFFER_BIT)
+        glColor3f(0.0, 0.0, 0.0)
+        glRasterPos2i(10, 350)
+        Draw.Text("VRM: Vector Rendering Method script.")
+        glRasterPos2i(10, 335)
+        Draw.Text("Press Q or ESC to quit.")
+
+        # Build the output format menu
+        glRasterPos2i(10, 310)
+        Draw.Text("Select the output Format:")
+        outMenuStruct = "Output Format %t"
+        for t in outputWriters.keys():
+           outMenuStruct = outMenuStruct + "|%s" % t
+        GUI.outFormatMenu = Draw.Menu(outMenuStruct, GUI.evtOutFormatMenu,
+                10, 285, 160, 18, GUI.outFormatMenu.val, "Choose the Output Format")
+
+        # Animation toggle
+        GUI.animToggle = Draw.Toggle("Animation", GUI.evtAnimToggle,
+                10, 260, 160, 18, GUI.animToggle.val,
+                "Toggle rendering of animations")
+
+        # Join Objects toggle
+        GUI.joinObjsToggle = Draw.Toggle("Join objects", GUI.evtJoinObjsToggle,
+                10, 235, 160, 18, GUI.joinObjsToggle.val,
+                "Join objects in the rendered file")
+
+        # Render Button
+        Draw.Button("Render", GUI.evtRenderButton, 10, 210-25, 75, 25+18,
+                "Start Rendering")
+        Draw.Button("Exit", GUI.evtExitButton, 95, 210-25, 75, 25+18, "Exit!")
+
+        # Rendering Styles
+        glRasterPos2i(200, 310)
+        Draw.Text("Rendering Style:")
+
+        # Render Polygons
+        GUI.polygonsToggle = Draw.Toggle("Filled Polygons", GUI.evtPolygonsToggle,
+                200, 285, 160, 18, GUI.polygonsToggle.val,
+                "Render filled polygons")
+
+        if GUI.polygonsToggle.val == 1:
+
+            # Polygon Shading Style
+            shadingStyleMenuStruct = "Shading Style %t"
+            for t in shadingStyles.keys():
+                shadingStyleMenuStruct = shadingStyleMenuStruct + "|%s" % t.lower()
+            GUI.shadingStyleMenu = Draw.Menu(shadingStyleMenuStruct, GUI.evtShadingStyleMenu,
+                    200, 260, 160, 18, GUI.shadingStyleMenu.val,
+                    "Choose the shading style")
+
+
+        # Render Edges
+        GUI.showEdgesToggle = Draw.Toggle("Show Edges", GUI.evtShowEdgesToggle,
+                200, 235, 160, 18, GUI.showEdgesToggle.val,
+                "Render polygon edges")
+
+        if GUI.showEdgesToggle.val == 1:
+            
+            # Edge Style
+            edgeStyleMenuStruct = "Edge Style %t"
+            for t in edgeStyles.keys():
+                edgeStyleMenuStruct = edgeStyleMenuStruct + "|%s" % t.lower()
+            GUI.edgeStyleMenu = Draw.Menu(edgeStyleMenuStruct, GUI.evtEdgeStyleMenu,
+                    200, 210, 160, 18, GUI.edgeStyleMenu.val,
+                    "Choose the edge style")
+
+            # Edge size
+            GUI.edgeWidthSlider = Draw.Slider("Width: ", GUI.evtEdgeWidthSlider,
+                    200, 185, 140, 18, GUI.edgeWidthSlider.val,
+                    0.0, 10.0, 0, "Change Edge Width")
+
+            # Edge Color
+            GUI.edgeColorPicker = Draw.ColorPicker(GUI.evtEdgeColorPicker,
+                    342, 185, 18, 18, GUI.edgeColorPicker.val, "Choose Edge Color")
+
+            # Show Hidden Edges
+            GUI.showHiddenEdgesToggle = Draw.Toggle("Show Hidden Edges",
+                    GUI.evtShowHiddenEdgesToggle,
+                    200, 160, 160, 18, GUI.showHiddenEdgesToggle.val,
+                    "Render hidden edges as dashed lines")
+
+        glRasterPos2i(10, 160)
+        Draw.Text("Antonio Ospite (c) 2006")
+
+    def event(evt, val):
+
+        if evt == Draw.ESCKEY or evt == Draw.QKEY:
+            Draw.Exit()
+        else:
+            return
 
-        mesh = o.data
-        mesh.faces.sort(
-            lambda f1, f2:
-                # Sort faces according to the min z coordinate in a face
-                #cmp(min([v[2] for v in f1]), min([v[2] for v in f2])))
+        Draw.Redraw(1)
 
-                # Sort faces according to the max z coordinate in a face
-                cmp(max([v[2] for v in f1]), max([v[2] for v in f2])))
-                
-                # Sort faces according to the avg z coordinate in a face
-                #cmp(sum([v[2] for v in f1])/len(f1), sum([v[2] for v in f2])/len(f2)))
-        mesh.faces.reverse()
-        mesh.update()
-        
-    # update the scene
-    for o in scene.getChildren():
-        scene.unlink(o)
-    for o in Objects:
-        scene.link(o)
-    
+    def button_event(evt):
+
+        if evt == GUI.evtExitButton:
+            Draw.Exit()
+
+        elif evt == GUI.evtOutFormatMenu:
+            i = GUI.outFormatMenu.val - 1
+            config.output['FORMAT']= outputWriters.keys()[i]
+
+        elif evt == GUI.evtAnimToggle:
+            config.outpur['ANIMATION'] = bool(GUI.animToggle.val)
+
+        elif evt == GUI.evtJoinObjsToggle:
+            config.output['JOIN_OBJECTS'] = bool(GUI.joinObjsToggle.val)
+
+        elif evt == GUI.evtPolygonsToggle:
+            config.polygons['SHOW'] = bool(GUI.polygonsToggle.val)
+
+        elif evt == GUI.evtShadingStyleMenu:
+            i = GUI.shadingStyleMenu.val - 1
+            config.polygons['SHADING'] = shadingStyles.keys()[i]
+
+        elif evt == GUI.evtShowEdgesToggle:
+            config.edges['SHOW'] = bool(GUI.showEdgesToggle.val)
+
+        elif evt == GUI.evtShowHiddenEdgesToggle:
+            config.edges['SHOW_HIDDEN'] = bool(GUI.showHiddenEdgesToggle.val)
+
+        elif evt == GUI.evtEdgeStyleMenu:
+            i = GUI.edgeStyleMenu.val - 1
+            config.edges['STYLE'] = edgeStyles.keys()[i]
+
+        elif evt == GUI.evtEdgeWidthSlider:
+            config.edges['WIDTH'] = float(GUI.edgeWidthSlider.val)
+
+        elif evt == GUI.evtEdgeColorPicker:
+            config.edges['COLOR'] = [int(c*255.0) for c in GUI.edgeColorPicker.val]
+
+        elif evt == GUI.evtRenderButton:
+            label = "Save %s" % config.output['FORMAT']
+            # Show the File Selector
+            global outputfile
+            Blender.Window.FileSelector(vectorize, label, outputfile)
+
+        else:
+            print "Event: %d not handled!" % evt
+
+        if evt:
+            Draw.Redraw(1)
+            #GUI.conf_debug()
+
+    def conf_debug():
+        from pprint import pprint
+        print "\nConfig"
+        pprint(config.output)
+        pprint(config.polygons)
+        pprint(config.edges)
+
+    _init = staticmethod(_init)
+    draw = staticmethod(draw)
+    event = staticmethod(event)
+    button_event = staticmethod(button_event)
+    conf_debug = staticmethod(conf_debug)
+
+# A wrapper function for the vectorizing process
 def vectorize(filename):
     """The vectorizing process is as follows:
      
-     - Open the writer
-     - Render the scene
-     - Close the writer
-     
-     If you want to render an animation the second pass should be
-     repeated for any frame, and the frame number should be passed to the
-     renderer.
+     - Instanciate the writer and the renderer
+     - Render!
      """
 
-    print "Filename: %s" % filename
+    if filename == "":
+        print "\nERROR: invalid file name!"
+        return
+
+    from Blender import Window
+    editmode = Window.EditMode()
+    if editmode: Window.EditMode(0)
+
+    actualWriter = outputWriters[config.output['FORMAT']]
+    writer = actualWriter(filename)
     
-    scene = Scene.GetCurrent()
     renderer = Renderer()
-    
-    flatScene = renderer.doRendering(scene)
-    canvasSize = renderer.getCanvasSize()
-
-    depthSorting(flatScene)
+    renderer.doRendering(writer, config.output['ANIMATION'])
 
-    writer = SVGVectorWriter(filename, canvasSize)
-    writer.printCanvas(flatScene)
+    if editmode: Window.EditMode(1) 
 
-    Blender.Scene.unlink(flatScene)
-    del flatScene
 
 # Here the main
 if __name__ == "__main__":
-    # with this trick we can run the script in batch mode
-    try:
-        Blender.Window.FileSelector (vectorize, 'Save SVG', "proba.svg")
-    except:
-        vectorize("proba.svg")
-
+    
+    outputfile = ""
+    basename = Blender.sys.basename(Blender.Get('filename'))
+    if basename != "":
+        outputfile = Blender.sys.splitext(basename)[0] + "." + str(config.output['FORMAT']).lower()
+
+    if Blender.mode == 'background':
+        vectorize(outputfile)
+    else:
+        Draw.Register(GUI.draw, GUI.event, GUI.button_event)