RebuildArcSegments.py

import Rhino
import rhinoscriptsyntax as rs
import scriptcontext as sc
import math
"""
rebuild arc segments of a polycurve
"""
def RebuildArc(arcCrv, deg):
    pi = math.pi
    a = arcCrv.Arc.Angle
    spans = (2*a)/pi

    pts3 = 4
    pts5 = 6
    
    if 0 < spans <=.5:
        pts3 = 4
    elif .5 < spans <= .75:
        pts3 = 5
    elif .75 < spans<= 1.1:
        pts3 = 6
        
    x = int((spans-1.1)/.08)
    if x<0: x = 0
    
    pts3 += x
    pts5 += x
    out = None
    if deg ==0:
        out = arcCrv.Rebuild(pts3, 3, True)
    elif deg == 1:
        out = arcCrv.Rebuild(pts5, 5, True)
    else:
        degree = 5
        pts = pts5
        if a <= pi/4:
            degree = 3
            pts = pts3
        out = arcCrv.Rebuild(pts , degree, True)
    return out

def RebuildArcSegments():
    """
    offer degree 3 or 5 or Auto
    
    Auto = degree5,6 pts per 90 degrees, <=45 degree = 3 4 pts.
    Degree: 6 pts per 90, if 3, reduce to four by 45 deg 

    """
    def filter_polycurve(rhino_object, geometry, component_index):
        if  isinstance(geometry, Rhino.Geometry.PolyCurve):
            return True
        elif isinstance(geometry, Rhino.Geometry.PolylineCurve):
            return True
        return False
    
    while True:
        deg = 0
        degList = ['Degree3','Degree5','Auto']
        delete = True
        tan = True
        
        if sc.sticky.has_key('ARC_REBUILD_DEG'):
            deg = sc.sticky['ARC_REBUILD_DEG']
            
        go = Rhino.Input.Custom.GetObject()
        go.GeometryFilter = Rhino.DocObjects.ObjectType.Curve
        go.SetCustomGeometryFilter (filter_polycurve)
        
        go.AddOptionList('RebuildMode', degList, deg)

        go.AcceptNothing (True)
        go.AcceptNumber(True, False)
        
        rc = go.Get()
        
        if go.CommandResult()!=Rhino.Commands.Result.Success:
            #conduit.Enabled=False
            return
        if rc == Rhino.Input.GetResult.Object:
            oref = go.Object(0)
            id = oref.ObjectId
            crv = oref.Geometry()
            pt = oref.SelectionPoint()
            par = crv.ClosestPoint(oref.SelectionPoint())[1]
            break
            
        if rc == Rhino.Input.GetResult.Option:
            idx = go.OptionIndex()
            #deg = opDeg.CurrentValue
            deg = go.Option().CurrentListOptionIndex
            sc.sticky['ARC_REBUILD_DEG'] = deg
            continue

            #conduit.Enabled=False
        elif rc == Rhino.Input.GetResult.Number:
            num = go.Number()
            if int(num) ==3:
                deg = int(num)
                sc.sticky['ARC_REBUILD_DEG'] = deg
                #conduit.Enabled=False
            elif int(num) ==5:
                deg = int(num)
                sc.sticky['ARC_REBUILD_DEG'] = deg
            continue
                
        elif rc == Rhino.Input.GetResult.Nothing:
            #conduit.Enabled=False
            return
            
        elif rc == Rhino.Input.GetResult.Cancel:
            print('Cancelled')
            #conduit.Enabled=False
            return
    segs = [crv.SegmentCurve(n) for n in range(crv.SegmentCount)]
    
    pc = Rhino.Geometry.PolyCurve()
    
    for n in range(len(segs)):
        if segs[n].IsArc():
            segs[n] = RebuildArc(segs[n], deg)

        pc.Append(segs[n])
        
    pc.CleanUp()
        
    sc.doc.Objects.Replace(id, pc)
    sc.doc.Views.Redraw()
                

    
if __name__ == '__main__':RebuildArcSegments()