From e31d0451289108701a037921963107ee74a7466d Mon Sep 17 00:00:00 2001
From: Laurent Rineau <Laurent.Rineau__CGAL@normalesup.org>
Date: Thu, 7 Feb 2008 16:32:31 +0000
Subject: [PATCH] - MarchingCube is now templated with the data type. It means
 that it now   internaly stores a Data_type[] array, instead of a double[]
 array. When   Data_type==char, it uses the 8th of the memory! For a 3D images
 of 182MB   (the "colon" image), that saves 1.2GB.   As a side effect,
 MarchingCubes.cpp is renamed to MarchingCubes_impl.h   (because it is now a
 template class). - Use MarchingCube.set_ext_data, so that the 3D image and
 the MarchingCube   object share the same (unsigned char*) array. That saves
 again a lot of   memory. - call MarchingCube::clean_temps *before* copying
 its result in the demo's   internal structures.

My laptop with 2GB RAM can now call the marching cubes algorithm on the
colon 3D image. It uses 2.8GB of virtual memory, which is just below the
limit of 3GB (Linux's limit on x86 machines)!
---
 .../demo/Surface_mesher/qt4-demo/CMakeLists.txt |  2 +-
 .../demo/Surface_mesher/qt4-demo/volume.cpp     | 17 +++++++++--------
 .../demo/Surface_mesher/qt4-demo/volume.h       |  2 +-
 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/Surface_mesher/demo/Surface_mesher/qt4-demo/CMakeLists.txt b/Surface_mesher/demo/Surface_mesher/qt4-demo/CMakeLists.txt
index 0d005da2943..c7477805ee4 100644
--- a/Surface_mesher/demo/Surface_mesher/qt4-demo/CMakeLists.txt
+++ b/Surface_mesher/demo/Surface_mesher/qt4-demo/CMakeLists.txt
@@ -40,7 +40,7 @@ if ( CGAL_FOUND AND QT_FOUND AND QGLVIEWER_FOUND )
   
   include_directories( ${QGLVIEWER_INCLUDE_DIR} )
 
-  set( sources colorlisteditor.cpp isovalues_list.cpp mainwindow.cpp polyhedral_surface.cpp surface_mesher.cpp viewer.cpp volume.cpp ../../../../Marching_cube/src/mc/MarchingCubes.cpp ../../../../Marching_cube/src/mc/ply.c)
+  set( sources colorlisteditor.cpp isovalues_list.cpp mainwindow.cpp polyhedral_surface.cpp surface_mesher.cpp viewer.cpp volume.cpp ../../../../Marching_cube/src/mc/ply.c)
   
   qt4_automoc( ${sources} )
 
diff --git a/Surface_mesher/demo/Surface_mesher/qt4-demo/volume.cpp b/Surface_mesher/demo/Surface_mesher/qt4-demo/volume.cpp
index 9b417719e00..da1c8c56fb3 100644
--- a/Surface_mesher/demo/Surface_mesher/qt4-demo/volume.cpp
+++ b/Surface_mesher/demo/Surface_mesher/qt4-demo/volume.cpp
@@ -313,19 +313,21 @@ void Volume::display_marchin_cube()
       mc.init_all();
 
       // set data
-      for(unsigned int i=0;i<nx;i++)
-        for(unsigned int j=0;j<ny;j++)
-          for(unsigned int k=0;k<nz;k++)
-          {
-            const float& value = m_image.value(i,j,k);
-            mc.set_data(value,i,j,k);
-          }
+//       for(unsigned int i=0;i<nx;i++)
+//         for(unsigned int j=0;j<ny;j++)
+//           for(unsigned int k=0;k<nz;k++)
+//           {
+//             const float& value = m_image.value(i,j,k);
+//             mc.set_data(value,i,j,k);
+//           }
+      mc.set_ext_data(static_cast<unsigned char*>(m_image.image()->data));
       // compute scaling ratio
       const double xr = m_image.xmax() / nx;
       const double yr = m_image.ymax() / ny;
       const double zr = m_image.zmax() / nz;
 
       mc.run(isovalues_list->isovalue(isovalue_id), xr, yr, zr);
+      mc.clean_temps();
 
       std::vector<double> facets;
       mc.get_facets(facets);
@@ -349,7 +351,6 @@ void Volume::display_marchin_cube()
     timer.stop();
     not_busy();
 
-    mc.clean_temps();
     status_message(QString("Marching cubes...done (%2 facets in %1 s)").arg(timer.time()).arg(m_surface_mc.size()));
   }
   CGAL::Bbox_3 bbox(0,0,0,0,0,0);
diff --git a/Surface_mesher/demo/Surface_mesher/qt4-demo/volume.h b/Surface_mesher/demo/Surface_mesher/qt4-demo/volume.h
index 497f666ee09..28e79a9ed2b 100644
--- a/Surface_mesher/demo/Surface_mesher/qt4-demo/volume.h
+++ b/Surface_mesher/demo/Surface_mesher/qt4-demo/volume.h
@@ -95,7 +95,7 @@ private:
 
   std::vector<Facet> m_surface;
   std::vector<Facet> m_surface_mc;
-  MarchingCubes mc ;
+  MarchingCubes<unsigned char> mc ;
   Tr del;            // 3D-Delaunay triangulation
 
   MainWindow* mw;