Draft: fixes in DXF exporter - fixes #1590, #1653

* Fixed arc directions
* Turned max spline segment length preference option into a float
* Fixed ellipses export

src/Mod/Draft/Resources/ui/userprefs-import1.ui

@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>496</width>
+    <width>521</width>
-    <height>524</height>
+    <height>528</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -367,10 +367,23 @@
           </property>
          </widget>
         </item>
+        <item>
+         <spacer name="horizontalSpacer">
+          <property name="orientation">
+           <enum>Qt::Horizontal</enum>
+          </property>
+          <property name="sizeHint" stdset="0">
+           <size>
+            <width>40</width>
+            <height>20</height>
+           </size>
+          </property>
+         </spacer>
+        </item>
         <item>
          <widget class="QLabel" name="label_7">
           <property name="text">
-           <string>Max Spline Segment: </string>
+           <string>Max Spline Segment (mm): </string>
           </property>
           <property name="alignment">
            <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
@@ -378,21 +391,21 @@
          </widget>
         </item>
         <item>
-         <widget class="Gui::PrefSpinBox" name="gui::prefspinbox_2">
+         <widget class="Gui::PrefDoubleSpinBox" name="doubleSpinBox">
-          <property name="maximumSize">
-           <size>
-            <width>60</width>
-            <height>16777215</height>
-           </size>
-          </property>
           <property name="toolTip">
            <string>When exporting splines to DXF, they are transformed in polylines. This value is the maximum length of each of the polyline segments. If 0, then the whole spline is treated as a straight segment.</string>
           </property>
+          <property name="alignment">
+           <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+          </property>
+          <property name="maximum">
+           <double>9999.989999999999782</double>
+          </property>
           <property name="value">
-           <number>5</number>
+           <double>5.000000000000000</double>
           </property>
           <property name="prefEntry" stdset="0">
-           <cstring>maxsplinesegment</cstring>
+           <cstring>maxsegmentlength</cstring>
           </property>
           <property name="prefPath" stdset="0">
            <cstring>Mod/Draft</cstring>
@@ -465,11 +478,6 @@
    <extends>Gui::FileChooser</extends>
    <header>Gui/PrefWidgets.h</header>
   </customwidget>
-  <customwidget>
-   <class>Gui::PrefSpinBox</class>
-   <extends>QSpinBox</extends>
-   <header>Gui/PrefWidgets.h</header>
-  </customwidget>
   <customwidget>
    <class>Gui::PrefRadioButton</class>
    <extends>QRadioButton</extends>
@@ -480,6 +488,11 @@
    <extends>QCheckBox</extends>
    <header>Gui/PrefWidgets.h</header>
   </customwidget>
+  <customwidget>
+   <class>Gui::PrefDoubleSpinBox</class>
+   <extends>QDoubleSpinBox</extends>
+   <header>Gui/PrefWidgets.h</header>
+  </customwidget>
  </customwidgets>
  <resources/>
  <connections/>

src/Mod/Draft/importDXF.py

@@ -1348,14 +1348,12 @@ def getArcData(edge):
         ve2 = edge.Vertexes[-1].Point
         ang1 = -math.degrees(DraftVecUtils.angle(ve1.sub(ce)))
         ang2 = -math.degrees(DraftVecUtils.angle(ve2.sub(ce)))
-        
+
-        a1 = -DraftVecUtils.angle(ve1.sub(ce))
+        if round(ang1,Draft.precision()) == round(ang2,Draft.precision()):
-        a2 = -DraftVecUtils.angle(ve2.sub(ce))
-        if round(a1,Draft.precision()) == round(a2,Draft.precision()):
             return None,None, None, None
         if edge.Curve.Axis.z < 0.0:
             ang1, ang2 = ang2, ang1
-        pseudoarc = Part.ArcOfCircle(edge.Curve,a1,a2).toShape()
+        pseudoarc = Part.ArcOfCircle(edge.Curve,math.radians(ang1),math.radians(ang2)).toShape()
         if round(pseudoarc.Length,Draft.precision()) != round(edge.Length,Draft.precision()):
             ang1, ang2 = ang2, ang1
         
@@ -1377,25 +1375,21 @@ def getArcData(edge):
 def getSplineSegs(edge):
     "returns an array of vectors from a Spline or Bezier edge"
     params = FreeCAD.ParamGet("User parameter:BaseApp/Preferences/Mod/Draft")
-    seglength = params.GetInt("maxsplinesegment")
+    seglength = params.GetFloat("maxsegmentlength",5.0)
     points = []
     if seglength == 0:
         points.append(edge.Vertexes[0].Point)
         points.append(edge.Vertexes[-1].Point)
     else:
-        if DraftGeomUtils.geomType(edge) == "BezierCurve":
+        points.append(edge.valueAt(edge.FirstParameter))
-            l = 1.0
-        else:
-            l = edge.Length
-        points.append(edge.valueAt(0))
         if (edge.Length > seglength):
             nbsegs = int(math.ceil(edge.Length/seglength))
-            step = l/nbsegs
+            step = (edge.LastParameter-edge.FirstParameter)/nbsegs
             for nv in range(1,nbsegs):
                 #print "value at",nv*step,"=",edge.valueAt(nv*step)
-                v = edge.valueAt(nv*step)
+                v = edge.valueAt(edge.FirstParameter+(nv*step))
                 points.append(v)
-        points.append(edge.valueAt(l))
+        points.append(edge.valueAt(edge.LastParameter))
     return points
 
 def getWire(wire,nospline=False,lw=True):
@@ -1412,9 +1406,7 @@ def getWire(wire,nospline=False,lw=True):
     # print "processing wire ",wire.Edges
     for edge in edges:
         v1 = edge.Vertexes[0].Point
-        if len(edge.Vertexes) < 2:
+        if DraftGeomUtils.geomType(edge) == "Circle":
-            points.append(fmt(v1))
-        elif DraftGeomUtils.geomType(edge) == "Circle":
             mp = DraftGeomUtils.findMidpoint(edge)
             v2 = edge.Vertexes[-1].Point
             c = edge.Curve.Center
@@ -1445,7 +1437,7 @@ def getWire(wire,nospline=False,lw=True):
             if not DraftGeomUtils.isClockwise(edge):
                 bul = -bul
             points.append(fmt(v1,bul))
-        elif (DraftGeomUtils.geomType(edge) in ["BSplineCurve","BezierCurve"]) and (not nospline):
+        elif (DraftGeomUtils.geomType(edge) in ["BSplineCurve","BezierCurve","Ellipse"]) and (not nospline):
             spline = getSplineSegs(edge)
             spline.pop()
             for p in spline:
@@ -1499,7 +1491,7 @@ def writeShape(sh,ob,dxfobject,nospline=False,lwPoly=False):
             if not(e.hashCode() in processededges): loneedges.append(e)
         # print "lone edges ",loneedges
         for edge in loneedges:
-            if (DraftGeomUtils.geomType(edge) in ["BSplineCurve","BezierCurve"]) and ((not nospline) or (len(edge.Vertexes) == 1)): # splines
+            if (DraftGeomUtils.geomType(edge) in ["BSplineCurve","BezierCurve"]): # splines
                 if (len(edge.Vertexes) == 1) and (edge.Curve.isClosed()):
                     # special case: 1-vert closed spline, approximate as a circle
                     c = DraftGeomUtils.getCircleFromSpline(edge)