There was a problem parsing ARC entities in INSERT entities.

[Mrzhans]

When I parse INSERT entities using ezdxf, I use virtual_entities() to traverse through the various entities in the INSERT, but I find that ARC happens to get the center coordinate wrong, probably because extrusion doesn't fall to (0,0,1), I looked at the official documentation using ezdxf.upright.upright() to handle ARC entities, However, I found that start_angle, end_angle, and center were incorrectly resolved (inconsistent with start_angle, end_angle, and center in AutoCAD). I tried to explode() to unexplode the entities in the INSERT, but I found that the INSERT parsing was missing some entities.

I looked at both OCS and WCS documentation, and this one handles center. But I don't know what to do with start_angle and end_angle in ARC.

If anyone can help me, I would be grateful.

Here is the core snippet of my code:

def loadArcEntity(self, entity, depth, insert_name, insert_center_point, rotate_angle):
        dxf = entity.dxf
        dxftype = entity.dxftype()

        if dxftype != "ARC":
            print("[ERROR][DXFLoader::loadArcEntity]")
            print("\t this entity is a [" + dxftype + "], not a ARC!")
            return False
        
        layer = dxf.layer
        center = dxf.center
        radius = dxf.radius

        start_angle = int(math.ceil(dxf.start_angle))
        end_angle = int(math.ceil(dxf.end_angle))
        start_point = entity.start_point
        end_point = entity.end_point

        # 将圆弧离散化为点集
        flattening = entity.flattening(5)
        flattening_point_list = [
            Point(point[0], point[1], point[2]) for point in flattening
        ]

        new_arc = Arc(Point(center[0], center[1], center[2]), radius,
                      start_angle, end_angle, int(rotate_angle), flattening_point_list, start_point, end_point, depth, insert_name, insert_center_point, layer)
        new_arc.setAttribsDict(entity.dxfattribs())
        self.arc_list.append(new_arc)
        return True

def loadEntity(self, entity, depth=0, insert_name=None, insert_center_point=None, rotate_angle=0.0):
        dxftype = entity.dxftype()

        if dxftype == "LINE":
            if not self.loadLineEntity(entity, depth, insert_name, insert_center_point, rotate_angle):
                print("[ERROR][DXFLoader::loadEntity]")
                print("\t loadLineEntity failed!")
                return False
            return True

        if dxftype == "CIRCLE":
            if not self.loadCircleEntity(entity, depth, insert_name, insert_center_point, rotate_angle):
                print("[ERROR][DXFLoader::loadEntity]")
                print("\t loadCircleEntity failed!")
                return False
            return True

        if dxftype == "ARC":
            if not self.loadArcEntity(entity, depth, insert_name, insert_center_point, rotate_angle):
                print("[ERROR][DXFLoader::loadEntity]")
                print("\t loadArcEntity failed!")
                return False
            return True

        if dxftype == "MTEXT":
            if not self.loadMTextEntity(entity, depth, insert_name, insert_center_point, rotate_angle):
                print("[ERROR][DXFLoader::loadEntity]")
                print("\t loadMTextEntity failed!")
                return False
            return True
        
        if dxftype == "ELLIPSE":
            if not self.loadEllipseEntity(entity, depth, insert_name, insert_center_point, rotate_angle):
                print("[ERROR][DXFLoader::loadEntity]")
                print("\t loadEllipseEntity failed!")
                return False
            return True
        
        if dxftype == "SPLINE":
            if not self.loadSplineEntity(entity, depth, insert_name, insert_center_point, rotate_angle):
                print("[ERROR][DXFLoader::loadEntity]")
                print("\t loadSplineEntity failed!")
                return False
            return True
        
        if dxftype == "HATCH":
            if not self.loadHatchEntity(entity, depth, insert_name, insert_center_point):
                print("[ERROR][DXFLoader::loadEntity]")
                print("\t loadHatchEntity failed!")
                return False
            return True 
        
        if dxftype == "LWPOLYLINE" or dxftype == "POLYLINE":
            if not self.loadLwpolylineEntity(entity, depth, insert_name, insert_center_point, rotate_angle):
                print("[ERROR][DXFLoader::loadEntity]")
                print("\t loadSplineEntity failed!")
                return False
            return True

        if dxftype in ["INSERT"]:
            load_depth = self.load_depth_dict[dxftype]
            if depth >= load_depth and load_depth != -1:
                return True

            insert_name = entity.dxf.name
            insert_center_point = entity.dxf.insert
            rotate_angle = entity.dxf.rotation

            for virtual_entity in entity.virtual_entities():
                upright(virtual_entity)
                if not self.loadEntity(virtual_entity, depth + 1, insert_name, insert_center_point, rotate_angle):
                    return False

[eXponenta]

[mozman]

If that works, it's just a matter of luck. Adding the start and end points of an arc makes no sense.

[eXponenta]

If that works, it's just a matter of luck. Adding the start and end points of an arc makes no sense.

This was written about year ago, and not by me.

I never has problems with it and didn't think about why it so complicated, there were a reasons, I think.
Looks like how fastfix for negative scales of layout.

How said: If it ain’t broke, don’t fix it.

[mozman]

Maybe you shouldn't post a solution if you don't understand it or can't explain it. That doesn't help anyone.

[eXponenta]

@mozman Okay, i apologize. Deleted