diff --git a/src/graphics/arrows.c b/src/graphics/arrows.c
index bc099e7..c46c9da 100644
--- a/src/graphics/arrows.c
+++ b/src/graphics/arrows.c
@@ -173,14 +173,14 @@ static void show_one_arrow_data_1(int offset_vertex, int offset_colors,
            offset_vertex, offset_colors, weight, site, x, y, z);
 }
 
-static void show_one_arrow_data_2(int offset_vertex, float max, int uxi, int uyi, int uzi,
-                                  float ux, float uy, float uz, float vx, float vy, float vz)
+static void show_one_arrow_data_2(int offset_vertex, int max, int uxi, int uyi, int uzi,
+                                  int ux, int uy, int uz, float vx, float vy, float vz)
 {
-    printf("offset_vertex = %d   max = %8.5f\n\
-       xi =   %6d   yi =   %6d   zi =   %6d\n\
-       ux = %8.5f   uy = %8.5f   uz = %8.5f\n\
-       vx = %8.5f   vy = %8.5f   vz = %8.5f\n",\
-       offset_vertex, max, ux, uy, uz, vx, vy, vz);
+    printf("offset_vertex = %d (x3 = %d)   max = %d\n\
+       xi =  %d           yi =  %d     zi =  %d\n\
+       ux = %d      uy =  %d     uz = %d\n\
+       vx = %6.3f       vy = %6.3f vz = %6.3f\n",\
+       offset_vertex, offset_vertex * 3, max, ux, uy, uz, vx, vy, vz);
 }
 
 
@@ -200,17 +200,17 @@ void write_one_arrow(int offset_vertex, int offset_colors, int offset_lines,
           uyi = (2 * y) / space_Y_int,
           uzi = (2 * z) / space_Z_int;
 
-    float ux = uxi, uy = uyi, uz = uzi;
+    int   ux = uxi, uy = uyi, uz = uzi;
 
-    float vx = (ux - 1.0f) * (space_X / max) + (1.0f / max),
-          vy = (uy - 1.0f) * (space_Y / max) + (1.0f / max),
-          vz = (uz - 1.0f) * (space_Z / max) + (1.0f / max);
+    float vx = (ux - 1) * (space_X / max) + (1.0f / max),
+          vy = (uy - 1) * (space_Y / max) + (1.0f / max),
+          vz = (uz - 1) * (space_Z / max) + (1.0f / max);
 
     show_one_arrow_data_2 (offset_vertex, max,
                         uxi, uyi, uzi, ux, uy, uz, vx, vy, vz);
 
     //    arrow_basis_width donne la dimension de l'étoile centrale
-    float arrow_basis_width = 0.3f * (1 / max),
+    GLfloat arrow_basis_width = 0.3f * (1 / max),
 
     //    décale légèrement les pointes des flèches
     //    pour qu'elles n'aillent pas jusqu'aux faces des cubes
@@ -245,7 +245,7 @@ void write_one_arrow(int offset_vertex, int offset_colors, int offset_lines,
 
 
 
-    float nuance = 0.24f;
+    GLfloat nuance = 0.24f;
 
     //  X - X  (EAST - WEST) axis - arrows tips  (red - green)
     graphics_write_vertex (vx + (1 / max) - arrow_tip_padding, vy, vz);
diff --git a/src/graphics/graphics.c b/src/graphics/graphics.c
index 60bfef1..178b2b1 100644
--- a/src/graphics/graphics.c
+++ b/src/graphics/graphics.c
@@ -153,7 +153,7 @@ void graphics_write_vertex (GLfloat x, GLfloat y, GLfloat z)
 
     buffer_vertex_size += 3;
 
-    //printf("Created vertex (%f,%f,%f), size is %d\n", x,y,z, buffer_vertex_size);
+    printf("new vertex :  (%9.6f,  %9.6f,  %9.6f)   <>   buffer size : %3d\n", x,y,z, buffer_vertex_size);
 }
 
 /*
@@ -891,11 +891,12 @@ void  __attribute__((optimize("no-unroll-loops"))) main_test_graphics (void)
 
     show_user_choices(arrows, arrows_nb, space_X, space_Y, space_Z, pref_show_grids, 0, 0, style);
 
-    long offset_vertex = 0, offset_colors = 0, offset_lines = 0;    //  if this function is called first
+    int offset_vertex = 0, offset_colors = 0, offset_lines = 0;    //  if this function is called first
     write_space_ridges (offset_vertex, offset_colors, offset_lines, space_X, space_Y, space_Z);
 
     offset_vertex = 8, offset_colors = 8, offset_lines = 12;    //  if space edges are drawn
-    write_grids_on_space_faces (offset_vertex, offset_colors, offset_lines, space_X, space_Y, space_Z, style);
+    write_grids_on_space_faces (offset_vertex, offset_colors, offset_lines,
+                                space_X, space_Y, space_Z, style);
 
     /* ARROWS */
 
@@ -926,6 +927,8 @@ void  __attribute__((optimize("no-unroll-loops"))) main_test_graphics (void)
                         weight, site, x, y, z);
     }
 
+    show_user_choices(arrows, arrows_nb, space_X, space_Y, space_Z, pref_show_grids, 0, 0, style);
+
     free(arrows);
     arrows = NULL;
     arrows_nb = 0;
diff --git a/src/graphics/grid.c b/src/graphics/grid.c
index c09496c..58606f6 100644
--- a/src/graphics/grid.c
+++ b/src/graphics/grid.c
@@ -19,16 +19,25 @@
  *  GNU Affero General Public License for more details.
  *
  *  You should have received a copy of the GNU Affero General Public License
- *  aint with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include "../../include/base.h"
 #include "../../include/graphics.h"
 
+/* void graphics_write_vertex (GLfloat x, GLfloat y, GLfloat z) { */
+/*     buffer_vertex_origin = g_realloc (buffer_vertex_origin, (buffer_vertex_size + 3) * sizeof(GLfloat)); */
+/*     buffer_vertex_origin[buffer_vertex_size + 0] = x; */
+/*     buffer_vertex_origin[buffer_vertex_size + 1] = y; */
+/*     buffer_vertex_origin[buffer_vertex_size + 2] = z; */
+/*     buffer_vertex_size += 3; */
+/*     //printf("Created vertex (%f,%f,%f), size is %d\n", x,y,z, buffer_vertex_size); */
+/* } */
+
+
 void write_space_ridges (long offset_vertex, long offset_colors, long offset_lines, long x, long y, long z)
 {
     float max = fmax(x, y);  max = fmax(max, z);
-
     graphics_write_vertex (offset_vertex - x / max, offset_vertex - y / max, - z / max);
 
     graphics_write_vertex (offset_vertex + x / max, offset_vertex - y / max, - z / max);