look for system installations of ANN, MMG3D, TETGEN and GMM before using contrib/ versions

(modified patch from Christophe Trophime for Debian)

CMakeLists.txt

@@ -451,8 +451,16 @@ if(HAVE_FLTK OR HAVE_QT OR ENABLE_GRAPHICS)
 endif(HAVE_FLTK OR HAVE_QT OR ENABLE_GRAPHICS)
 
 if(ENABLE_ANN)
+  find_library(ANN_LIB ann PATH_SUFFIXES lib)
+  find_path(ANN_INC "ANN.h" PATH_SUFFIXES src include ANN)
+  if(ANN_LIB AND ANN_INC)
+    list(APPEND EXTERNAL_LIBRARIES ${ANN_LIB})
+    list(APPEND EXTERNAL_INCLUDES ${ANN_INC})
+  else(ANN_LIB AND ANN_INC)
+    message(STATUS "System ANN not found - using contrib/ANN instead")
     add_subdirectory(contrib/ANN)
     include_directories(contrib/ANN/include)
+  endif(ANN_LIB AND ANN_INC)
   set_config_option(HAVE_ANN "Ann")
 endif(ENABLE_ANN)
 
@@ -482,7 +490,13 @@ if(ENABLE_DINTEGRATION)
 endif(ENABLE_DINTEGRATION)
 
 if(ENABLE_GMM)
+  find_path(GMM_INC "gmm.h" PATH_SUFFIXES src include include/gmm)
+  if(GMM_INC)
+    list(APPEND EXTERNAL_INCLUDES ${GMM_INC})
+  else(GMM_INC)
+    message(STATUS "System GMM not found - using contrib/gmm instead")
     include_directories(contrib/gmm)
+  endif(GMM_INC)
   set_config_option(HAVE_GMM "Gmm")
 endif(ENABLE_GMM)
 
@@ -548,8 +562,16 @@ if(HAVE_MESH)
   endif(ENABLE_BAMG)
 
   if(ENABLE_MMG3D)
+    find_library(MMG3D_LIB mmg3dlib4.0 PATH_SUFFIXES lib)
+    find_path(MMG3D_INC "libmmg3d.h" PATH_SUFFIXES src include)
+    if(MMG3D_LIB AND MMG3D_INC)
+       list(APPEND EXTERNAL_LIBRARIES ${MMG3D_LIB})
+       list(APPEND EXTERNAL_INCLUDES ${MMG3D_INC})
+    else(MMG3D_LIB AND MMG3D_INC)
+       message(STATUS "System MMG3D not found - using contrib/mmg3d instead")
        add_subdirectory(contrib/mmg3d)
        include_directories(contrib/mmg3d/build/sources)
+    endif(MMG3D_LIB AND MMG3D_INC)
     set_config_option(HAVE_MMG3D "Mmg3d")
   endif(ENABLE_MMG3D)
 
@@ -565,9 +587,19 @@ if(HAVE_MESH)
     include_directories(contrib/Tetgen)
     set_config_option(HAVE_TETGEN "Tetgen")
     add_definitions(-DTETLIBRARY)
+  elseif(ENABLE_TETGEN)
+    find_library(TETGEN_LIB tet PATH_SUFFIXES lib)
+    find_path(TETGEN_INC "tetgen.h" PATH_SUFFIXES src include tetgen)
+    if(TETGEN_LIB AND TETGEN_INC)
+      list(APPEND EXTERNAL_LIBRARIES ${TETGEN_LIB})
+      list(APPEND EXTERNAL_INCLUDES ${TETGEN_INC})
+      set_config_option(HAVE_TETGEN "Tetgen")
+    endif(TETGEN_LIB AND TETGEN_INC)
+  endif(ENABLE_TETGEN_NEW AND EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/contrib/TetgenNew/tetgen.h)
+  if(HAVE_TETGEN)
     message("WARNING: By including Tetgen you have to comply with Tetgen's "
             "special licensing requirements stated in contrib/Tetgen/LICENSE.")
-  endif(ENABLE_TETGEN_NEW AND EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/contrib/TetgenNew/tetgen.h)
+  endif(HAVE_TETGEN)
 endif(HAVE_MESH)
 
 if(ENABLE_FOURIER_MODEL)

Mesh/meshGEdge.cpp

@@ -20,13 +20,12 @@
 typedef struct {
   int Num;
   // t is the local coordinate of the point
-  // lc is x'(t)/h((x(t))
+  // lc is x'(t)/h(x(t))
   // p is the value of the primitive
   // xp is the norm of the tangent vector
   double t, lc, p, xp;
 } IntPoint;
 
-
 static double smoothPrimitive(GEdge *ge, double alpha,
                               std::vector<IntPoint> &Points)
 {
@@ -119,7 +118,7 @@ static double F_Transfinite(GEdge *ge, double t_)
 {
   double length = ge->length();
   if(length == 0.0){
-    Msg::Error("Zero-length curve in transfinite mesh");
+    Msg::Error("Zero-length curve %d in transfinite mesh", ge->tag());
     return 1.;
   }
 
@@ -352,8 +351,8 @@ void meshGEdge::operator() (GEdge *ge)
   double a;
   int N;
   if(length == 0. && CTX::instance()->mesh.toleranceEdgeLength == 0.){
-    Msg::Error("Curve %d has a zero length", ge->tag());
-    a = 0;
+    Msg::Warning("Curve %d has a zero length", ge->tag());
+    a = 0.;
     N = 1;
   }
   else if(ge->degenerate(0)){