Unsuccessfully optimize text method.

I tried to group all the texts in one single graphic object, but it
does not work. 'text' create one text object per position whatever
you do.
So the text plotting routines are still slow.

src/@deproj/add_plot_ids.m

 function hts = add_plot_ids( obj, ax )
 %ADD_PLOT_IDS Add the epicell ids to the specified plot axes.
 
-    epicells = obj.epicells;
-    n_objects = numel( epicells );
-    hts = NaN( n_objects, 1 );
-    
-    for i = 1 :  n_objects
-        o = epicells( i );
-        center = double( o.center );
-        hts(i ) = text( ax,  ...
-            center(1), center(2), center(3) + 0.5, ...
-            num2str( o.id ), ...
-            'HorizontalAlignment', 'center', ...
-            'VerticalAlignment', 'middle', ...
-            'Clipping', 'on' );
-    end
+    texts = num2cell( vertcat( obj.epicells.id ) );
+    hts = obj.plot_text( texts, ax );
 end
 

src/@deproj/deproj.m

@@ -72,7 +72,9 @@ classdef deproj
         % Plot the tissue with the cell contour approximated by the junctions, colored by the specified values.
         hts = plot_values_junction( obj, values, ax )
         
-                
+        % Plot text at cell centers.
+        hts = plot_text( obj, texts, ax )
+      
     end
     
      %% Public static methods: builders & util.

src/@deproj/plot_text.m

+function hts = plot_text( obj, texts, ax )
+%PLOT_TEXT Plot text at cell centers.
+
+
+    C = double( vertcat( obj.epicells.center ) );
+    X = C( :, 1 );
+    Y = C( :, 2 );
+    Z = C( :, 3 ) + 0.5;
+    
+    hts = text( ax, X, Y, Z, texts, ...
+        'HorizontalAlignment', 'center', ...
+        'VerticalAlignment', 'middle', ...
+        'Clipping', 'on', ...
+        'Interpreter', 'none', ...
+        'FontSize', 9 );
+end
+