SetArcRadians.py

import rhinoscriptsyntax as rs
import scriptcontext as sc
import Rhino
import math

def SetArcRadians():
    pi = math.pi
    def arc_filter( rhino_object, geometry, component_index):
        return geometry.IsArc()
        
    looped = False
    while True:
        angRad = 1
        if sc.sticky.has_key('ARC_EX_ANGLE_radians'):
            angRad = sc.sticky['ARC_EX_ANGLE_radians']
            
        go = Rhino.Input.Custom.GetObject()
        strMessage = "Pick the flip of the arc to move."
        if looped: strMessage = "Pick the flip of the arc to move. Press enter to finish."
        go.SetCommandPrompt(strMessage)
        go.GeometryFilter = Rhino.DocObjects.ObjectType.Curve
        go.SetCustomGeometryFilter(arc_filter)
        opAngRad = Rhino.Input.Custom.OptionDouble(angRad)
        go.AddOptionDouble("AngleRadians", opAngRad)
        go.AcceptNumber(True, False)
        go.EnablePreSelect(False, True)
        rc = go.Get()
        
        if go.CommandResult() != Rhino.Commands.Result.Success:
            return go.CommandResult()
            
        if rc == Rhino.Input.GetResult.Option:
            angRad = opAngRad.CurrentValue
            if angRad > 2*pi or angRad == 0: continue
            sc.sticky['ARC_EX_ANGLE_radians'] = angRad
            continue
            
        if rc == Rhino.Input.GetResult.Number:
            angRad = go.Number()
            if angRad > 2*pi or angRad == 0: continue
            sc.sticky['ARC_EX_ANGLE_radians'] = angRad
            continue
            
        if rc == Rhino.Input.GetResult.Object:
            objref = go.Object(0)
            geo = objref.Geometry()
            selPt = objref.SelectionPoint()
            
            p_rc, par = geo.ClosestPoint(selPt)
            
            flip = False
            if p_rc:
                if par>= geo.Domain.Mid:
                    flip = True
                    print geo.Reverse()
                    
                a_rc, arc = geo.TryGetArc()

                crntSweep = arc.AngleDomain
                
                radius = arc.Radius
                rads = abs(angRad)

                if flip:
                    #print 'flip'
                    if angRad > 0:
                        sweep = Rhino.Geometry.Interval(crntSweep.Max - rads, crntSweep.Max)
                    else:
                        sweep = Rhino.Geometry.Interval( crntSweep.Max , crntSweep.Max + rads)
                else:
                    #print 'start'
                    if angRad > 0:
                        sweep = Rhino.Geometry.Interval(crntSweep.Max - rads, crntSweep.Max )
                    else:
                        sweep = Rhino.Geometry.Interval(crntSweep.Max, crntSweep.Max+ rads )
                        flip = True
                        
                arc.AngleDomain = sweep
                if flip: arc.Reverse()
                
                if arc.IsValid:
                    arcCrv = Rhino.Geometry.ArcCurve(arc)
                    sc.doc.Objects.Replace(objref, arcCrv)
                    print "Arc angle set to " + str(round(angRad, 3))
                looped = True
                sc.doc.Views.Redraw()
            continue
    
if __name__ == '__main__':SetArcRadians()