Quick display of point sets: only display small subset when moving large point sets

Polyhedron/demo/Polyhedron/Scene_points_with_normal_item.cpp

@@ -17,6 +17,7 @@
 
 #include <QObject>
 #include <QMenu>
+#include <QGLViewer/manipulatedCameraFrame.h>
 
 #include <set>
 #include <stack>
@@ -165,10 +166,15 @@ void Scene_points_with_normal_item::compute_normals_and_vertices() const
     positions_points.reserve(m_points->size() * 3);
     positions_lines.reserve(m_points->size() * 3 * 2);
 
+
+    //Shuffle container to allow quick display random points
+    Point_set_3<Kernel> points = *m_points;
+    std::random_shuffle (points.begin(), points.end());
+    
     //The points
     {
         // The *non-selected* points
-      for (Point_set_3<Kernel>::const_iterator it = m_points->begin(); it != m_points->first_selected(); it++)
+      for (Point_set_3<Kernel>::const_iterator it = points.begin(); it != points.first_selected(); it++)
 	{
 	  const UI_point& p = *it;
 	  positions_points.push_back(p.x());
@@ -177,7 +183,7 @@ void Scene_points_with_normal_item::compute_normals_and_vertices() const
 	}
 
         // Draw *selected* points
-      for (Point_set_3<Kernel>::const_iterator it = m_points->first_selected(); it != m_points->end(); it++)
+      for (Point_set_3<Kernel>::const_iterator it = points.first_selected(); it != points.end(); it++)
 	{
 	  const UI_point& p = *it;
 	  positions_selected_points.push_back(p.x());
@@ -189,10 +195,10 @@ void Scene_points_with_normal_item::compute_normals_and_vertices() const
     //The lines
     {
         // Stock normals
-        Kernel::Sphere_3 region_of_interest = m_points->region_of_interest();
+        Kernel::Sphere_3 region_of_interest = points.region_of_interest();
         float normal_length = (float)std::sqrt(region_of_interest.squared_radius() / 1000.);
 
-	for (Point_set_3<Kernel>::const_iterator it = m_points->begin(); it != m_points->end(); it++)
+	for (Point_set_3<Kernel>::const_iterator it = points.begin(); it != points.end(); it++)
 	  {
 	    const UI_point& p = *it;
 	    const Point_set_3<Kernel>::Vector& n = p.normal();
@@ -417,6 +423,13 @@ void Scene_points_with_normal_item::draw_splats(CGAL::Three::Viewer_interface* v
 
 void Scene_points_with_normal_item::draw_edges(CGAL::Three::Viewer_interface* viewer) const
 {
+    double ratio_displayed = 1.0;
+    if (viewer->quickCameraMode () &&
+        (nb_lines/6 > 300000) && // arbitrary large value
+        (viewer->camera()->frame()->isSpinning()
+         || viewer->camera()->frame()->isManipulated()))
+      ratio_displayed = 6 * 300000. / (double)(nb_lines);
+
     if(!are_buffers_filled)
         initialize_buffers(viewer);
     vaos[Edges]->bind();
@@ -424,7 +437,8 @@ void Scene_points_with_normal_item::draw_edges(CGAL::Three::Viewer_interface* vi
     attrib_buffers(viewer,PROGRAM_NO_SELECTION);
     program->bind();
     program->setAttributeValue("colors", this->color());
-    viewer->glDrawArrays(GL_LINES, 0, static_cast<GLsizei>(nb_lines/3));
+    viewer->glDrawArrays(GL_LINES, 0,
+                         static_cast<GLsizei>(((std::size_t)(ratio_displayed * nb_lines)/3)));
     vaos[Edges]->release();
     program->release();
 }
@@ -433,12 +447,20 @@ void Scene_points_with_normal_item::draw_points(CGAL::Three::Viewer_interface* v
     if(!are_buffers_filled)
         initialize_buffers(viewer);
 
+    double ratio_displayed = 1.0;
+    if (viewer->quickCameraMode () &&
+        ((nb_points + nb_selected_points)/3 > 300000) && // arbitrary large value
+        (viewer->camera()->frame()->isSpinning()
+         || viewer->camera()->frame()->isManipulated()))
+      ratio_displayed = 3 * 300000. / (double)(nb_points + nb_selected_points);
+
     vaos[ThePoints]->bind();
     program=getShaderProgram(PROGRAM_NO_SELECTION);
     attrib_buffers(viewer,PROGRAM_NO_SELECTION);
     program->bind();
     program->setAttributeValue("colors", this->color());
-    viewer->glDrawArrays(GL_POINTS, 0, static_cast<GLsizei>(nb_points/3));
+    viewer->glDrawArrays(GL_POINTS, 0,
+                         static_cast<GLsizei>(((std::size_t)(ratio_displayed * nb_points)/3)));
     vaos[ThePoints]->release();
     program->release();
     GLfloat point_size;
@@ -451,7 +473,7 @@ void Scene_points_with_normal_item::draw_points(CGAL::Three::Viewer_interface* v
     program->bind();
     program->setAttributeValue("colors", QColor(255,0,0));
     viewer->glDrawArrays(GL_POINTS, 0,
-                       static_cast<GLsizei>(nb_selected_points/3));
+                         static_cast<GLsizei>(((std::size_t)(ratio_displayed * nb_selected_points)/3)));
     vaos[Selected_points]->release();
     program->release();
     viewer->glPointSize(point_size);

Polyhedron/demo/Polyhedron/Viewer.cpp

@@ -16,7 +16,8 @@ public:
   bool twosides;
   bool macro_mode;
   bool inFastDrawing;
-
+  bool quick_camera;
+  
   void draw_aux(bool with_names, Viewer*);
 
   //! Contains all the programs for the item rendering.
@@ -29,6 +30,7 @@ Viewer::Viewer(QWidget* parent, bool antialiasing)
   d->scene = 0;
   d->antialiasing = antialiasing;
   d->twosides = false;
+  d->quick_camera = true;
   d->macro_mode = false;
   d->shader_programs.resize(NB_OF_PROGRAMS);
   setShortcut(EXIT_VIEWER, 0);
@@ -94,6 +96,18 @@ void Viewer::setTwoSides(bool b)
   updateGL();
 }
 
+
+bool Viewer::quickCameraMode() const
+{
+  return d->quick_camera;
+}
+
+void Viewer::setQuickCameraMode(bool b)
+{
+  d->quick_camera = b;
+  updateGL();
+}
+
 bool Viewer::inFastDrawing() const {
   return d->inFastDrawing;
 }

Polyhedron/demo/Polyhedron/Viewer.h

@@ -57,6 +57,8 @@ public:
   void setScene(CGAL::Three::Scene_draw_interface* scene);
   //! @returns the antialiasing state.
   bool antiAliasing() const;
+  //! @returns the quick camera state.
+  bool quickCameraMode() const;
   //! @returns the fastDrawing state.
   bool inFastDrawing() const;
   //! Implementation of `Viewer_interface::attrib_buffers()`
@@ -70,6 +72,9 @@ public Q_SLOTS:
   //! If b is true, facets will be ligted from both internal and external sides.
   //! If b is false, only the side that is exposed to the light source will be lighted.
   void setTwoSides(bool b);
+  //! If b is true, some items are displayed in a simplified version when moving the camera.
+  //! If b is false, items display is never altered, even when moving.
+  void setQuickCameraMode(bool b);
   //! Make the camera turn around.
   void turnCameraBy180Degres();
   //! @returns a QString containing the position and orientation of the camera.

Three/include/CGAL/Three/Viewer_interface.h

@@ -59,7 +59,9 @@ public:
   virtual void setScene(CGAL::Three::Scene_draw_interface* scene) = 0;
   //! @returns the antialiasing state.
   virtual bool antiAliasing() const = 0;
-
+  //! @returns the quick camera state.
+  virtual bool quickCameraMode() const = 0;
+  
   // Those two functions are defined in Viewer.cpp
   //!Sets the position and orientation of a frame using a QString.
   //!@returns true if it worked.
@@ -138,6 +140,9 @@ public Q_SLOTS:
   //! If b is true, facets will be ligted from both internal and external sides.
   //! If b is false, only the side that is exposed to the light source will be lighted.
   virtual void setTwoSides(bool b) = 0;
+  //! If b is true, some items are displayed in a simplified version when moving the camera.
+  //! If b is false, items display is never altered, even when moving.
+  virtual void setQuickCameraMode(bool b) = 0;
   //! Make the camera turn around.
   virtual void turnCameraBy180Degres() = 0;
   //! @returns a QString containing the position and orientation of the camera.