Add: ability to paint a text in ImageViewer

visualization/include/pcl/visualization/image_viewer.h

@@ -732,6 +732,31 @@ namespace pcl
         addLine (unsigned int x_min, unsigned int y_min, unsigned int x_max, unsigned int y_max,
                  const std::string &layer_id = "line", double opacity = 1.0);
 
+        /** \brief Add a 2D text with a given color
+          * \param[in] x the X coordinate
+          * \param[in] y the Y coordinate
+          * \param[in] text the text string to be displayed
+          * \param[in] r the red channel of the color that the line should be rendered with (0.0 -> 1.0)
+          * \param[in] g the green channel of the color that the line should be rendered with (0.0 -> 1.0)
+          * \param[in] b the blue channel of the color that the line should be rendered with (0.0 -> 1.0)
+          * \param[in] layer_id the 2D layer ID where we want the extra information to be drawn.
+          * \param[in] opacity the opacity of the layer: 0 for invisible, 1 for opaque. (default: 1.0)
+          */
+        bool
+        addText (unsigned int x, unsigned int y, const std::string& text,
+                 double r, double g, double b,
+                 const std::string &layer_id = "line", double opacity = 1.0);
+
+        /** \brief Add a 2D text with a given color
+          * \param[in] x the X coordinate
+          * \param[in] y the Y coordinate
+          * \param[in] text the text string to be displayed
+          * \param[in] layer_id the 2D layer ID where we want the extra information to be drawn.
+          * \param[in] opacity the opacity of the layer: 0 for invisible, 1 for opaque. (default: 1.0)
+          */
+        bool
+        addText (unsigned int x, unsigned int y, const std::string& text,
+                 const std::string &layer_id = "line", double opacity = 1.0);
 
         /** \brief Add a generic 2D mask to an image 
           * \param[in] image the organized point cloud dataset containing the image data

visualization/include/pcl/visualization/vtk/pcl_context_item.h

@@ -147,6 +147,15 @@ namespace pcl
         static Polygon *New();
         virtual bool Paint (vtkContext2D *painter);
       };
+
+      struct PCL_EXPORTS Text : public PCLContextItem
+      {
+        vtkTypeMacro (Text, PCLContextItem);
+        static Text *New ();
+        virtual bool Paint (vtkContext2D *painter);
+        virtual void set (float x, float y, const std::string& _text);
+        std::string text;
+      };
     }
   }
 }

visualization/src/image_viewer.cpp

@@ -849,6 +849,47 @@ pcl::visualization::ImageViewer::addLine (unsigned int x_min, unsigned int y_min
   return (addLine (x_min, y_min, x_max, y_max, 0.0, 1.0, 0.0, layer_id, opacity));
 }
 
+//////////////////////////////////////////////////////////////////////////////////////////
+bool
+pcl::visualization::ImageViewer::addText (unsigned int x, unsigned int y,
+                                          const std::string& text_string,
+                                          double r, double g, double b,
+                                          const std::string &layer_id, double opacity)
+{
+  // Check to see if this ID entry already exists (has it been already added to the visualizer?)
+  LayerMap::iterator am_it = std::find_if (layer_map_.begin (), layer_map_.end (), LayerComparator (layer_id));
+  if (am_it == layer_map_.end ())
+  {
+    PCL_DEBUG ("[pcl::visualization::ImageViewer::addText] No layer with ID='%s' found. Creating new one...\n", layer_id.c_str ());
+    am_it = createLayer (layer_id, getSize ()[0] - 1, getSize ()[1] - 1, opacity, false);
+#if ((VTK_MAJOR_VERSION == 5) && (VTKOR_VERSION > 10))
+    interactor_style_->adjustCamera (ren_);
+#endif
+  }
+
+  vtkSmartPointer<context_items::Text> text = vtkSmartPointer<context_items::Text>::New ();
+  text->setColors (static_cast<unsigned char> (255.0 * r),
+                   static_cast<unsigned char> (255.0 * g),
+                   static_cast<unsigned char> (255.0 * b));
+  text->setOpacity (opacity);
+#if ((VTK_MAJOR_VERSION == 5) && (VTKOR_VERSION > 10))
+  text->set (static_cast<float> (x), static_cast<float> (y), text_string);
+#else
+  text->set (static_cast<float> (x), static_cast<float> (getSize ()[1] - y), text_string);
+#endif
+  am_it->actor->GetScene ()->AddItem (text);
+
+  return (true);
+}
+
+//////////////////////////////////////////////////////////////////////////////////////////
+bool
+pcl::visualization::ImageViewer::addText (unsigned int x, unsigned int y, const std::string& text,
+                                          const std::string &layer_id, double opacity)
+{
+  return (addText (x, y, text, 0.0, 1.0, 0.0, layer_id, opacity));
+}
+
 //////////////////////////////////////////////////////////////////////////////////////////
 void
 pcl::visualization::ImageViewer::markPoint (

visualization/src/vtk/pcl_context_item.cpp

@@ -41,6 +41,7 @@
 #include <vtkImageData.h>
 #include <vtkPen.h>
 #include <vtkBrush.h>
+#include <vtkTextProperty.h>
 
 #include <pcl/visualization/vtk/pcl_context_item.h>
 
@@ -61,6 +62,7 @@ namespace pcl
       vtkStandardNewMacro (FilledRectangle);
       vtkStandardNewMacro (Points);
       vtkStandardNewMacro (Polygon);
+      vtkStandardNewMacro (Text);
     }
   }
 }
@@ -122,6 +124,15 @@ pcl::visualization::context_items::Line::set (float start_x, float start_y, floa
   params[0] = start_x; params[1] = start_y; params[2] = end_x; params[3] = end_y;
 }
 
+///////////////////////////////////////////////////////////////////////////////////////////
+void
+pcl::visualization::context_items::Text::set (float x, float y, const std::string& _text)
+{
+  params.resize (2);
+  params[0] = x; params[1] = y;
+  text = _text;
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////
 bool
 pcl::visualization::context_items::Circle::Paint (vtkContext2D *painter)
@@ -207,9 +218,23 @@ pcl::visualization::context_items::Points::Paint (vtkContext2D *painter)
   return (true);
 }
 
+///////////////////////////////////////////////////////////////////////////////////////////
+bool
+pcl::visualization::context_items::Text::Paint (vtkContext2D *painter)
+{
+  vtkTextProperty *text_property = painter->GetTextProp ();
+  text_property->SetColor (255.0 * colors[0], 255.0 * colors[1], 255.0 * colors[2]);
+  text_property->SetFontFamilyToArial ();
+  text_property->SetFontSize (10);
+  text_property->SetJustificationToLeft ();
+  text_property->BoldOff ();
+  text_property->ShadowOff ();
+  painter->DrawString (params[0], params[1], text.c_str ());
+  return (true);
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////
 pcl::visualization::PCLContextImageItem::PCLContextImageItem ()
 {
   image = vtkSmartPointer<vtkImageData>::New ();
 }
-