diff --git a/src/draw.c b/src/draw.c
index 41f141701bb1b44157814233204bb88227c4500c..ae3ffd92674b9ae027bb547494302a4934073d23 100644
--- a/src/draw.c
+++ b/src/draw.c
@@ -4,9 +4,9 @@
 #include "field.h"
 
 void gfx_draw_line(struct gfx_context_t *ctxt, coordinates_t p0, coordinates_t p1, uint32_t color) {
-	int dx = abs(p1.column - p0.column);
+	int dx = abs((int)p1.column - (int)p0.column);
 	int sx = p0.column < p1.column ? 1 : -1;
-	int dy = -abs(p1.row - p0.row);
+	int dy = -abs((int)p1.row - (int)p0.row);
 	int sy = p0.row < p1.row ? 1 : -1;
 	int error = dx + dy;
 
@@ -50,7 +50,7 @@ void gfx_draw_circle(struct gfx_context_t *ctxt, coordinates c, uint32_t r, uint
         if(d >= 2*x){ 
             d = d-2*x-1;
             x++;
-        }else if(d < 2 * (r-y)){
+        }else if(d < 2 * ((int)r-y)){
             d = d + 2*y-1;
             y--;	
         }else {
diff --git a/src/field.c b/src/field.c
index 356c8dbd35e25aa0a2e88fcbaf51247075357be7..ec6f1e284904cc8eac72f3d81ba74502b8607c24 100644
--- a/src/field.c
+++ b/src/field.c
@@ -1,5 +1,6 @@
 #include <stdbool.h>
 #include <stdlib.h>
+#include <time.h> 
 
 #include "draw.h"
 #include "field.h"
@@ -41,10 +42,10 @@ double compute_delta_x(){
 }
 
 bool is_in_screen(coordinates_t pos){
-	if(pos.column > WID || pos.column < 0)
+	if(pos.column > WID)
 		return false;
 
-	if(pos.row > HEI || pos.row < 0)
+	if(pos.row > HEI)
 		return false;
 	
 	return true;
diff --git a/src/field.h b/src/field.h
index 6266ea334e67d0e42473e9f51d03d6aa9302fbdd..34dd513faace05dfc54467a53db72bb155645ddb 100644
--- a/src/field.h
+++ b/src/field.h
@@ -18,17 +18,6 @@ bool compute_e(charge_t c, vec2 p, double eps, vec2 *e);
 // Return false if for some qiP, norm(qiP) < eps
 bool compute_total_normalized_e(charge_t *charges, int num_charges, vec2 p, double eps, vec2 *e);
 
-// Compute and then draw all the points belonging to a field line,
-// starting from pos0.
-// Returns false if pos0 is not a valid position
-// (for example if pos0 is too close to a charge).
-static bool draw_field_line(struct gfx_context_t *ctxt, charge_t *charges, int num_charges, double dx, vec2 pos0, double x0, double x1, double y0, double y1);
-
-// Draw all the charges
-// A circle with minus sign for negative charges
-// A circle with a plus sign for positive charges
-static void draw_charges(struct gfx_context_t *context, charge_t *charges, int num_charges, double x0, double x1, double y0, double y1);
-
 void draw_everything(
 		struct gfx_context_t *ctxt,
 		charge_t *charges,