export functionality - trial version finished

Author: vicrucann

src/cherish/Settings.h

@@ -220,6 +220,7 @@ const float STROKE_LINE_WIDTH = 4.f;
 const int STROKE_SEGMENTS_NUMBER = 11;
 const float STROKE_FOG_MIN = 4.f;
 const float STROKE_FOG_MAX = 30.f;
+const float STROKE_MESH_RADIUS = 0.01f;
 
 // polygon settings
 const float POLYGON_LINE_WIDTH = 4.f;

src/libSGEntities/Canvas.cpp

@@ -721,6 +721,31 @@ bool entity::Canvas::attachFrame()
     return m_switch->addChild(m_toolFrame.get());
 }
 
+osg::Group *entity::Canvas::attachMeshGroup()
+{
+    osg::ref_ptr<osg::Group> group = new osg::Group;
+    if (!m_groupData->addChild(group.get())){
+        qWarning("Could not add mesh group to the group data. No export will be perfomed.");
+        return nullptr;
+    }
+    return group.release();
+}
+
+bool entity::Canvas::disattachMeshGroup(osg::Group *group)
+{
+    return m_groupData->removeChild(group);
+}
+
+bool entity::Canvas::addToMeshGroup(osg::Group *group, osg::Node *mesh)
+{
+    if (!m_groupData->containsNode(group)){
+        qWarning("The mesh group is not part of the group data, cannot proceed.");
+        return false;
+    }
+    bool added = group->addChild(mesh);
+    return added;
+}
+
 void entity::Canvas::setModeEdit(bool on)
 {
     m_edit = on;

src/libSGEntities/Canvas.h

@@ -263,6 +263,23 @@ class Canvas : public osg::ProtectedGroup {
      * \sa detachFrame */
     bool attachFrame();
 
+    /*! A method to be used only before calling on scene export function. It adds to the group data a new child -
+     * mesh group where all the stroke's meshes will be kept for export purposes.
+     * \return pointer on the added mesh group. */
+    osg::Group* attachMeshGroup();
+
+    /*! A methog to be used only after calling on scene export function. It removed the mesh group as a child of
+     * group data, thus deleting the whole structure.
+     * \return true if deletion was successfull. */
+    bool disattachMeshGroup(osg::Group* group);
+
+    /*! A method to add a stroke mesh to the selected mesh group as a child.  Only to be used to prepare the
+     * user scene for exporting.
+     * \param group is the mesh group which is already a child of a group data,
+     * \param mesh is the stroke mesh which will be added as a child to the group.
+     * \return true if mesh was added sucessfully. */
+    bool addToMeshGroup(osg::Group* group, osg::Node* mesh);
+
     /*! Method to switch the normal canvas mode to edit mode, used for editing canvas position and rotation.
      * \param on is true when the canvas is in the process of editing, and false otherwise.
      * \sa setFrameEditable(). */

src/libSGEntities/RootScene.cpp

@@ -165,12 +165,31 @@ bool RootScene::exportSceneToFile(const std::string &name)
     state->stripDataFrom(this);
     Q_ASSERT(!state->isEmpty());
 
+    std::vector< osg::ref_ptr<osg::Group> > meshes;
     /* for each canvas, detach its tools */
     for (int i=0; i<m_userScene->getNumCanvases(); ++i){
         entity::Canvas* canvas = m_userScene->getCanvas(i);
         if (!canvas) continue;
         canvas->detachFrame();
-        // for all the strokes within canvas, replace them with mesh representation
+
+        /* attach mesh group */
+        meshes.push_back(canvas->attachMeshGroup());
+
+        // for all the strokes within canvas, add the correspondig mesh to the mesh group
+        for (unsigned int j=0; j<canvas->getNumStrokes(); ++j){
+            entity::Stroke* stroke = canvas->getStroke(j);
+            if (!stroke) continue;
+            osg::ref_ptr<osg::Node> mesh = stroke->getMeshRepresentation();
+            if (!mesh.get()){
+                qWarning("Could not obtain mesh represenation from the stroke.");
+                continue;
+            }
+            bool added = meshes.back()->addChild(mesh.get());
+            if (!added){
+                qWarning("Could not attach mesh to the mesh group.");
+                continue;
+            }
+        }
 
     }
 
@@ -185,6 +204,12 @@ bool RootScene::exportSceneToFile(const std::string &name)
             qCritical("RootScene::writeSceneToFile: could not attach the tools back");
             result = false;
         }
+        /* delete the mesh group */
+        if ( !canvas->disattachMeshGroup(meshes.at(i).get()) ){
+            qCritical("Failed to remove helper meshes. The scene graph is messed up.");
+            return false;
+        }
+
     }
 
     bool stateset = this->setSceneState(state);

src/libSGEntities/Stroke.cpp

@@ -10,6 +10,7 @@
 
 #include "CameraCallbacks.h"
 #include "CurveFitting/libPathFitter/OsgPathFitter.h"
+#include "ParallelTransportFrame/libPTFTube/PTFTube.h"
 
 const GLenum STROKE_PHANTOM_TYPE = GL_LINE_STRIP;
 
@@ -133,6 +134,32 @@ bool entity::Stroke::redefineToShape(osg::MatrixTransform *t)
     return true;
 }
 
+osg::Node *entity::Stroke::getMeshRepresentation() const
+{
+    if (!m_isCurved){
+        qCritical("The stroke was never sampled and cannot be converted to the mesh.");
+        return nullptr;
+    }
+    const osg::Vec3Array* vertices = static_cast<const osg::Vec3Array*>(this->getVertexArray());
+    if (!vertices){
+        qWarning("Could not extract the vertices.");
+        return nullptr;
+    }
+    std::vector<osg::Vec3f> path;
+    for (unsigned int i=0; i<vertices->size(); ++i){
+        if (i>0){
+            if (path.back() == vertices->at(i))
+                continue;
+        }
+        path.push_back(vertices->at(i));
+    }
+
+    PTFTube extrusion(path, cher::STROKE_MESH_RADIUS, 8);
+    extrusion.build();
+
+    return extrusion.generateTriMesh();
+}
+
 // read more on why: http://stackoverflow.com/questions/36655888/opengl-thick-and-smooth-non-broken-lines-in-3d
 bool entity::Stroke::redefineToShader(osg::MatrixTransform *t)
 {
@@ -202,7 +229,7 @@ osg::Vec3Array *entity::Stroke::getCurvePoints(const osg::Vec3Array *bezierPts)
     osg::ref_ptr<osg::Vec3Array> points = new osg::Vec3Array;
 
     float delta = 1.f / cher::STROKE_SEGMENTS_NUMBER;
-    for (unsigned int j=0; j<bezierPts->size(); j=j+4){
+    for (unsigned int j=0; j<bezierPts->size(); j=j+4) {
         auto b0 = bezierPts->at(j)
                 , b1 = bezierPts->at(j+1)
                 , b2 = bezierPts->at(j+2)

src/libSGEntities/Stroke.h

@@ -83,6 +83,10 @@ class Stroke : public entity::ShaderedEntity2D {
      * \return true upon success. */
     virtual bool redefineToShape(osg::MatrixTransform* t = 0);
 
+    /*! A method that generates mesh representation of the stroke using Parallel Transport Algorithm.
+     * \return pointer on the cretated mesh structure. The structure is not attached to the scene graph. */
+    osg::Node* getMeshRepresentation() const;
+
 protected:
     /*! A method to tune the look of the stroke with smoother connections and thicker linewidth.
      * So that to avoid broken and thin look of the default OpenGL functionality when using GL_LINE_STRIP_ADJACENCY and such. */
@@ -107,6 +111,7 @@ class Stroke : public entity::ShaderedEntity2D {
 
 protected:
 
+    /*! \return Sampled points from provided set of bezier control points. */
     osg::Vec3Array* getCurvePoints(const osg::Vec3Array* bezierPts) const;
 
     /*! A method to make sure the curve is not too small, neither too large for a fitter tolerance level.