diff --git a/src/graphics/graphics.c b/src/graphics/graphics.c
index 7c98ee3..c0dc646 100644
--- a/src/graphics/graphics.c
+++ b/src/graphics/graphics.c
@@ -83,7 +83,7 @@ static void show_user_choices(int space_size_x,
         i, *(arrows + i * 5 + 0), *(arrows + i * 5 + 1), *(arrows + i * 5 + 2), *(arrows + i * 5 + 3), *(arrows + i * 5 + 4));
     if (arrows_nb > 0)  printf("   -------------------------------\n");}
 
-static int set_arrow (GLuint *arrows, int weight, int site, int x, int y, int z);
+static int set_arrow (int weight, int site, int x, int y, int z);
 
 static void get_model_data_and_user_preferences()
 {
@@ -106,8 +106,7 @@ static void get_model_data_and_user_preferences()
 
 
 #define DETAIL 0
-static bool rewrite_arrow (GLuint *arrows, int address, int weight,
-                          int site, int x, int y, int z)
+static bool rewrite_arrow (int address, int weight, int site, int x, int y, int z)
 {
     if (DETAIL) printf("write the arrow weight to %d at (%d, %d, %d, %d)\n",\
            weight, site, x, y, z);
@@ -117,7 +116,7 @@ static bool rewrite_arrow (GLuint *arrows, int address, int weight,
     return 1; /* replaces the load of the existing arrow by the load 'weight' */
 }
 
-static bool create_arrow (GLuint *arrows, int weight, int site, int x, int y, int z)
+static bool create_arrow (int weight, int site, int x, int y, int z)
 {
     int arrows_nb = get_arrows_nb();
     arrows_nb ++;
@@ -136,8 +135,7 @@ static bool create_arrow (GLuint *arrows, int weight, int site, int x, int y, in
     return 1;
 }
 
-static bool erase_arrow (GLuint *arrows, int address,
-                         int site, int x, int y, int z)
+static bool erase_arrow (int address, int site, int x, int y, int z)
 {
     int arrows_nb = get_arrows_nb();
     if (DETAIL) printf("erase arrow at address %d with values (%d, %d, %d, %d)",\
@@ -162,7 +160,7 @@ static bool erase_arrow (GLuint *arrows, int address,
     return 1;
 }
 
-static int check_for_arrow (GLuint *arrows, int site, int x, int y, int z)
+static int check_for_arrow (int site, int x, int y, int z)
 {
     int arrows_nb = get_arrows_nb();
     if (arrows_nb == 0) return -1;
@@ -189,7 +187,7 @@ static int check_for_arrow (GLuint *arrows, int site, int x, int y, int z)
 }
 
 
-static void show_arrows_array (GLuint *arrows, int address, int weight, int site, int x, int y, int z)
+static void show_arrows_array (int address, int weight, int site, int x, int y, int z)
 {
     int arrows_nb = get_arrows_nb();
     printf("\n   [ n]   load | site  x    y    z   -----    <  arrows_nb = %d  >    ------", arrows_nb);
@@ -215,15 +213,15 @@ static void show_arrows_array (GLuint *arrows, int address, int weight, int site
 }
 
 
-static int set_arrow (GLuint *arrows, int weight, int site, int x, int y, int z)
+static int set_arrow (int weight, int site, int x, int y, int z)
 {
-    int address = (check_for_arrow (arrows, site, x, y, z));
-    show_arrows_array(arrows, address, weight, site, x, y, z);
+    int address = (check_for_arrow (site, x, y, z));
+    show_arrows_array(address, weight, site, x, y, z);
 
     if (address == -1 && weight == 0) return 0;
-    if (address == -1 && weight  > 0) return create_arrow  (arrows, weight, site, x, y, z);
-    if (address >=  0 && weight == 0) return erase_arrow   (arrows, address, site, x, y, z);
-    if (address >=  0 && weight  > 0) return rewrite_arrow (arrows, address, weight, site, x, y, z);
+    if (address == -1 && weight  > 0) return create_arrow  (weight, site, x, y, z);
+    if (address >=  0 && weight == 0) return erase_arrow   (address, site, x, y, z);
+    if (address >=  0 && weight  > 0) return rewrite_arrow (address, weight, site, x, y, z);
 
     return 0;
 }
@@ -764,7 +762,7 @@ bool graphics_shutdown(const void *gl_area)
 
 void main_test_graphics (void)
 {
-    long    site = 0,
+    long    weight = 0, site = 0,
             x = model_space_size_x,
             y = model_space_size_y,
             z = model_space_size_z;
@@ -795,12 +793,15 @@ void main_test_graphics (void)
     int arrows_nb = get_arrows_nb();
 
     for (int i = 0; i < arrows_nb; i++) {
-        site = arrows[i * 5 + 1];
-        x    = arrows[i * 5 + 2];
-        y    = arrows[i * 5 + 3];
-        z    = arrows[i * 5 + 4];
+        weight = arrows[i * 5 + 0];
+        site   = arrows[i * 5 + 1];
+        x      = arrows[i * 5 + 2];
+        y      = arrows[i * 5 + 3];
+        z      = arrows[i * 5 + 4];
 
-        // cube coordinates = 12 * (stx * x + sty * y + stz * z);
+        set_arrow (weight, site, x, y, z);
+
+        /* // cube coordinates = 12 * (stx * x + sty * y + stz * z); */
         arrow_offset = offset_after_grids + 12 * (stx * x + sty * y + stz * z);
         arrows_write_basis (arrow_offset);