wip calcul texture image x position, and add protection when creating texture

headers/cube3d_struct.h

@@ -26,6 +26,18 @@ typedef struct		s_vec
 	t_coord			end;
 }					t_vec;
 
+/*
+ * struct with all elements for raycasting
+ */
+
+typedef struct		s_wall
+{
+	t_vec			vec;
+	int				height;
+	int				delta;
+	int				posx;
+}					t_wall;
+
 /*
  * struct with all elements for raycasting
  */
@@ -34,7 +46,7 @@ typedef struct		s_rcast
 {
 	t_vec			screen_size;
 	t_vec			ray;
-	t_vec			wall;
+	t_wall			wall;
 	int				screen_width;
 	int				screen_height;
 	int				screen_dist;