Sketcher: DrawSketchHandler draw multiple edit curves

=====================================================

Extension of the framework to draw an arbitrary curve in draw sketch handlers, so that
a plurality of curves can be handled.

DrawSketchHandler is extended to additionally offer drawing several curves:
- void drawEdit(const std::list<std::vector<Base::Vector2d>> &list);
- void drawEdit(const std::vector<Part::Geometry *> &geometries);

A new class, CurveConverter, enables to convert individual Part::Geometry or vectors of them
to appropriate vectors or list of vectors of Vector2d representing the curves. This can be
used in a specific DrawSketchHandler to combine Part::Geometries and arbritary curves.

src/Mod/Sketcher/Gui/DrawSketchHandler.cpp

@@ -86,6 +86,11 @@ inline void ViewProviderSketchDrawSketchHandlerAttorney::drawEdit(ViewProviderSk
     vp.drawEdit(EditCurve);
 }
 
+inline void ViewProviderSketchDrawSketchHandlerAttorney::drawEdit(ViewProviderSketch &vp, const std::list<std::vector<Base::Vector2d>> &list)
+{
+    vp.drawEdit(list);
+}
+
 inline void ViewProviderSketchDrawSketchHandlerAttorney::drawEditMarkers(ViewProviderSketch &vp, const std::vector<Base::Vector2d> &EditMarkers, unsigned int augmentationlevel)
 {
     vp.drawEditMarkers(EditMarkers, augmentationlevel);
@@ -111,6 +116,101 @@ inline int ViewProviderSketchDrawSketchHandlerAttorney::getPreselectCross(const
     return vp.getPreselectCross();
 }
 
+
+/**************************** CurveConverter **********************************************/
+
+CurveConverter::CurveConverter()
+{
+    try {
+        ParameterGrp::handle hGrp = App::GetApplication().GetParameterGroupByPath("User parameter:BaseApp/Preferences/View");
+        hGrp->Attach(this);
+    }
+    catch(const Base::ValueError & e) { // ensure that if parameter strings are not well-formed, the exception is not propagated
+        Base::Console().Error("CurveConverter: Malformed parameter string: %s\n", e.what());
+    }
+
+    updateCurvedEdgeCountSegmentsParameter();
+}
+
+CurveConverter::~CurveConverter()
+{
+    try {
+        ParameterGrp::handle hGrp = App::GetApplication().GetParameterGroupByPath("User parameter:BaseApp/Preferences/View");
+        hGrp->Detach(this);
+    }
+    catch(const Base::ValueError & e) {// ensure that if parameter strings are not well-formed, the program is not terminated when calling the noexcept destructor.
+        Base::Console().Error("CurveConverter: Malformed parameter string: %s\n", e.what());
+    }
+}
+
+std::vector<Base::Vector2d> CurveConverter::toVector2D(const Part::Geometry * geometry)
+{
+    std::vector<Base::Vector2d> vector2d;
+
+    const auto type = geometry->getTypeId();
+
+    auto emplaceasvector2d = [&vector2d](const Base::Vector3d & point) {
+        vector2d.emplace_back(point.x,point.y);
+    };
+
+    auto isconic = type.isDerivedFrom(Part::GeomConic::getClassTypeId());
+    auto isbounded = type.isDerivedFrom(Part::GeomBoundedCurve::getClassTypeId());
+
+    if (type == Part::GeomLineSegment::getClassTypeId()) { // add a line
+        auto geo = static_cast<const Part::GeomLineSegment *>(geometry);
+
+        emplaceasvector2d(geo->getStartPoint());
+        emplaceasvector2d(geo->getEndPoint());
+    }
+    else if ( isconic || isbounded ) {
+
+        auto geo = static_cast<const Part::GeomConic *>(geometry);
+
+        double segment = (geo->getLastParameter() - geo->getFirstParameter()) / curvedEdgeCountSegments;
+
+        for (int i=0; i < curvedEdgeCountSegments; i++)
+            emplaceasvector2d(geo->value(i*segment));
+
+        // either close the curve for untrimmed conic or set the last point for bounded curves
+        emplaceasvector2d(isconic ? geo->value(0) : geo->value(geo->getLastParameter()));
+    }
+
+    return vector2d;
+}
+
+std::list<std::vector<Base::Vector2d>> CurveConverter::toVector2DList(const std::vector<Part::Geometry *> &geometries)
+{
+    std::list<std::vector<Base::Vector2d>> list;
+
+    for(const auto & geo : geometries)
+        list.push_back(toVector2D(geo));
+
+    return list;
+}
+
+void CurveConverter::updateCurvedEdgeCountSegmentsParameter()
+{
+    ParameterGrp::handle hGrp = App::GetApplication().GetParameterGroupByPath("User parameter:BaseApp/Preferences/View");
+    int stdcountsegments = hGrp->GetInt("SegmentsPerGeometry", 50);
+
+    // value cannot be smaller than 6
+    if (stdcountsegments < 6)
+        stdcountsegments = 6;
+
+    curvedEdgeCountSegments = stdcountsegments;
+};
+
+/** Observer for parameter group. */
+void CurveConverter::OnChange(Base::Subject<const char*> &rCaller, const char * sReason)
+{
+    (void) rCaller;
+
+    if(strcmp(sReason, "SegmentsPerGeometry") == 0) {
+        updateCurvedEdgeCountSegmentsParameter();
+    }
+
+}
+
 /**************************** DrawSketchHandler *******************************************/
 
 
@@ -800,6 +900,20 @@ void DrawSketchHandler::drawEdit(const std::vector<Base::Vector2d> &EditCurve)
     ViewProviderSketchDrawSketchHandlerAttorney::drawEdit(*sketchgui, EditCurve);
 }
 
+void DrawSketchHandler::drawEdit(const std::list<std::vector<Base::Vector2d>> &list)
+{
+    ViewProviderSketchDrawSketchHandlerAttorney::drawEdit(*sketchgui, list);
+}
+
+void DrawSketchHandler::drawEdit(const std::vector<Part::Geometry *> &geometries)
+{
+    static CurveConverter c;
+
+    auto list = c.toVector2DList(geometries);
+
+    drawEdit(list);
+}
+
 void DrawSketchHandler::drawEditMarkers(const std::vector<Base::Vector2d> &EditMarkers, unsigned int augmentationlevel)
 {
     ViewProviderSketchDrawSketchHandlerAttorney::drawEditMarkers(*sketchgui, EditMarkers, augmentationlevel);

src/Mod/Sketcher/Gui/DrawSketchHandler.h

@@ -39,6 +39,33 @@ namespace SketcherGui {
 
 class ViewProviderSketch;
 
+
+
+/**
+ * Class to convert Part::Geometry to Vector2d based collections
+ */
+class CurveConverter final : public ParameterGrp::ObserverType {
+
+public:
+    CurveConverter();
+
+    ~CurveConverter();
+
+    std::vector<Base::Vector2d> toVector2D(const Part::Geometry * geometry);
+
+    std::list<std::vector<Base::Vector2d>> toVector2DList(const std::vector<Part::Geometry *> &geometries);
+
+private:
+    void updateCurvedEdgeCountSegmentsParameter();
+
+    /** Observer for parameter group. */
+    virtual void OnChange(Base::Subject<const char*> &rCaller, const char * sReason) override;
+
+private:
+    int curvedEdgeCountSegments;
+};
+
+
 /**
  * In order to enforce a certain degree of encapsulation and promote a not
  * too tight coupling, while still allowing well defined collaboration,
@@ -51,6 +78,7 @@ private:
     static inline void setPositionText(ViewProviderSketch &vp, const Base::Vector2d &Pos);
     static inline void resetPositionText(ViewProviderSketch &vp);
     static inline void drawEdit(ViewProviderSketch &vp, const std::vector<Base::Vector2d> &EditCurve);
+    static inline void drawEdit(ViewProviderSketch &vp, const std::list<std::vector<Base::Vector2d>> &list);
     static inline void drawEditMarkers(ViewProviderSketch &vp, const std::vector<Base::Vector2d> &EditMarkers, unsigned int augmentationlevel = 0);
     static inline void setAxisPickStyle(ViewProviderSketch &vp, bool on);
 
@@ -61,7 +89,6 @@ private:
     friend class DrawSketchHandler;
 };
 
-
 // A Simple data type to hold basic information for suggested constraints
 struct AutoConstraint
 {
@@ -154,6 +181,8 @@ protected:
     void setCrosshairCursor(const char* svgName);
 
     void drawEdit(const std::vector<Base::Vector2d> &EditCurve);
+    void drawEdit(const std::list<std::vector<Base::Vector2d>> &list);
+    void drawEdit(const std::vector<Part::Geometry *> &geometries);
     void drawEditMarkers(const std::vector<Base::Vector2d> &EditMarkers, unsigned int augmentationlevel = 0);
     void setAxisPickStyle(bool on);
 

src/Mod/Sketcher/Gui/EditModeCoinManager.cpp

@@ -452,6 +452,38 @@ void EditModeCoinManager::drawEdit(const std::vector<Base::Vector2d> &EditCurve)
     editModeScenegraphNodes.EditCurvesMaterials->diffuseColor.finishEditing();
 }
 
+void EditModeCoinManager::drawEdit(const std::list<std::vector<Base::Vector2d>> &list)
+{
+    int ncoords = 0;
+
+    for(const auto & v : list)
+        ncoords += v.size();
+
+    editModeScenegraphNodes.EditCurveSet->numVertices.setNum(list.size());
+    editModeScenegraphNodes.EditCurvesCoordinate->point.setNum(ncoords);
+    editModeScenegraphNodes.EditCurvesMaterials->diffuseColor.setNum(ncoords);
+    SbVec3f *verts = editModeScenegraphNodes.EditCurvesCoordinate->point.startEditing();
+    int32_t *index = editModeScenegraphNodes.EditCurveSet->numVertices.startEditing();
+    SbColor *color = editModeScenegraphNodes.EditCurvesMaterials->diffuseColor.startEditing();
+
+    int coordindex=0;
+    int indexindex=0;
+    for(const auto & v : list) {
+        for (const auto & p : v) {
+            verts[coordindex].setValue(p.x, p.y, drawingParameters.zEdit);
+            color[coordindex] = drawingParameters.CreateCurveColor;
+            coordindex++;
+        }
+        index[indexindex] = v.size();
+        indexindex++;
+    }
+
+    editModeScenegraphNodes.EditCurvesCoordinate->point.finishEditing();
+    editModeScenegraphNodes.EditCurveSet->numVertices.finishEditing();
+    editModeScenegraphNodes.EditCurvesMaterials->diffuseColor.finishEditing();
+
+}
+
 void EditModeCoinManager::setPositionText(const Base::Vector2d &Pos, const SbString &text)
 {
     editModeScenegraphNodes.textX->string = text;

src/Mod/Sketcher/Gui/EditModeCoinManager.h

@@ -191,6 +191,7 @@ public:
     //@{
     void drawEditMarkers(const std::vector<Base::Vector2d> &EditMarkers, unsigned int augmentationlevel);
     void drawEdit(const std::vector<Base::Vector2d> &EditCurve);
+    void drawEdit(const std::list<std::vector<Base::Vector2d>> &list);
     void setPositionText(const Base::Vector2d &Pos, const SbString &txt);
     void setPositionText(const Base::Vector2d &Pos);
     void resetPositionText(void);

src/Mod/Sketcher/Gui/ViewProviderSketch.cpp

@@ -2586,6 +2586,11 @@ void ViewProviderSketch::drawEdit(const std::vector<Base::Vector2d> &EditCurve)
     editCoinManager->drawEdit(EditCurve);
 }
 
+void ViewProviderSketch::drawEdit(const std::list<std::vector<Base::Vector2d>> &list)
+{
+    editCoinManager->drawEdit(list);
+}
+
 void ViewProviderSketch::drawEditMarkers(const std::vector<Base::Vector2d> &EditMarkers, unsigned int augmentationlevel)
 {
     editCoinManager->drawEditMarkers(EditMarkers, augmentationlevel);

src/Mod/Sketcher/Gui/ViewProviderSketch.h

@@ -707,6 +707,7 @@ private:
 
     /// draw the edit curve
     void drawEdit(const std::vector<Base::Vector2d> &EditCurve);
+    void drawEdit(const std::list<std::vector<Base::Vector2d>> &list);
     /// draw the edit markers
     void drawEditMarkers(const std::vector<Base::Vector2d> &EditMarkers, unsigned int augmentationlevel = 0);
     /// set the pick style of the sketch coordinate axes