Do obj clipping using bounding box

Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>

diff --git a/vrm.py b/vrm.py
index 0338065..67bcf3a 100755 (executable)
--- a/vrm.py
+++ b/vrm.py
@@ -44,8 +44,6 @@ __bpydoc__ = """\
 # Things TODO for a next release:
 #   - 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? 
@@ -80,9 +78,11 @@ __bpydoc__ = """\
 #       recalculated at each frame!
 #     * PDF output (using reportlab)
 #     * Fixed another problem in the animation code the current frame was off
-#       by one
+#       by one in the case of camera movement.
 #     * Use fps as specified in blender when VectorWriter handles animation
 #     * Remove the real file opening in the abstract VectorWriter
+#     * View frustum clipping
+#     * Scene clipping done using bounding box instead of object center
 #
 # ---------------------------------------------------------------------
 
@@ -1644,12 +1644,8 @@ class SWFVectorWriter(VectorWriter):
             p1 = self._calcCanvasCoord(e.v1)
             p2 = self._calcCanvasCoord(e.v2)
 
-            # FIXME: this is just a qorkaround, remove that after the
-            # implementation of propoer Viewport clipping
-            if abs(p1[0]) < 3000 and abs(p2[0]) < 3000 and abs(p1[1]) < 3000 and abs(p1[2]) < 3000:
-                s.movePenTo(p1[0], p1[1])
-                s.drawLineTo(p2[0], p2[1])
-            
+            s.movePenTo(p1[0], p1[1])
+            s.drawLineTo(p2[0], p2[1])
 
         s.end()
         sprite.add(s)
@@ -1808,10 +1804,7 @@ class PDFVectorWriter(VectorWriter):
             p1 = self._calcCanvasCoord(e.v1)
             p2 = self._calcCanvasCoord(e.v2)
 
-            # FIXME: this is just a workaround, remove that after the
-            # implementation of propoer Viewport clipping
-            if abs(p1[0]) < 3000 and abs(p2[0]) < 3000 and abs(p1[1]) < 3000 and abs(p1[2]) < 3000:
-                self.canvas.line(p1[0], p1[1], p2[0], p2[1])
+            self.canvas.line(p1[0], p1[1], p2[0], p2[1])
 
 
 
@@ -2114,9 +2107,7 @@ class Renderer:
         for o in Objects:
             if o.getType() != 'Mesh': continue;
 
-            # TODO: use the object bounding box (that is already in WorldSpace)
-            # bb = o.getBoundBox() and then: for point in bb: ...
-
+            """
             obj_vect = Vector(cam_pos) - self._getObjPosition(o)
 
             d = obj_vect*view_vect
@@ -2125,6 +2116,30 @@ class Renderer:
             # if the object is outside the view frustum, clip it away
             if (d < near) or (d > far) or (theta > fovy):
                 scene.unlink(o)
+            """
+
+            # Use the object bounding box
+            # (whose points are already in WorldSpace Coordinate)
+
+            bb = o.getBoundBox()
+            
+            points_outside = 0
+            for p in bb:
+                p_vect = Vector(cam_pos) - Vector(p)
+
+                d = p_vect * view_vect
+                theta = AngleBetweenVecs(p_vect, view_vect)
+
+                # Is this point outside the view frustum?
+                if (d < near) or (d > far) or (theta > fovy):
+                    points_outside += 1
+
+            # If the bb is all outside the view frustum we clip the whole
+            # object away
+            if points_outside == len(bb):
+                scene.unlink(o)
+
+
 
     def _doConvertGeometricObjsToMesh(self, scene):
         """Convert all "geometric" objects to mesh ones.
@@ -2162,18 +2177,25 @@ class Renderer:
 
         c = self._getObjPosition(self.cameraObj)
 
-        by_center_pos = (lambda o1, o2:
+        by_obj_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
+        # Implement sorting by bounding box, the object with the bb
+        # nearest to the camera should be drawn as last.
+        by_nearest_bbox_point = (lambda o1, o2:
+                (o1.getType() == 'Mesh' and o2.getType() == 'Mesh') and
+                cmp( min( [(Vector(p) - Vector(c)).length for p in o1.getBoundBox()] ),
+                     min( [(Vector(p) - Vector(c)).length for p in o2.getBoundBox()] )
+                )
+            )
+
         
         Objects = scene.getChildren()
-        Objects.sort(by_center_pos)
+        #Objects.sort(by_obj_center_pos)
+        Objects.sort(by_nearest_bbox_point)
         
         # update the scene
         for o in Objects:
@@ -2441,16 +2463,17 @@ class Renderer:
         for clipface in cvv:
 
             clippedfaces = []
+
             for f in facelist:
                 
                 newfaces = HSR.splitOn(clipface, f, return_positive_faces=False)
 
                 if not newfaces:
-                    # Check if the face is inside the view rectangle
+                    # Check if the face is all outside the view frustum
                     # TODO: Do this test before, it is more efficient
                     points_outside = 0
                     for v in f:
-                        if abs(v[0]) > 1-EPS or abs(v[1]) > 1-EPS:
+                        if abs(v[0]) > 1-EPS or abs(v[1]) > 1-EPS or abs(v[2]) > 1-EPS:
                             points_outside += 1
 
                     if points_outside != len(f):
@@ -2465,9 +2488,9 @@ class Renderer:
                         nf.col = [f.col[0]] * len(nf.v)
 
                         clippedfaces.append(nf)
-
             facelist = clippedfaces[:]
 
+
         nmesh.faces = facelist
         nmesh.update()