Draw half field line

src/charge.c

@@ -14,15 +14,13 @@ const double THRESHOLD_CHARGES_DISTANCES = 0.5;
 const double EPSILON = 0.05;
 
 double compute_delta_x(int width, int height) {
-    printf("aaa %lf\n", 1.0 / sqrt((width * width) + (height * height)));
     return 1.0 / sqrt((width * width) + (height * height));
 }
 
 bool compute_next_point(charge_t *charges, int num_charges, vector2_t current_pos, double eps, vector2_t *new_pos, double dx) {
     vector2_t electric_field;
-    if (!compute_total_normalized_e(charges, num_charges, current_pos, eps, &electric_field)) {
+    if (compute_total_normalized_e(charges, num_charges, current_pos, eps, &electric_field)) {
         *new_pos = vector2_add(current_pos, vector2_multiply(electric_field, dx));
-        printf("adf %lf\n", dx);
         return true;
     }
 
@@ -49,10 +47,12 @@ bool compute_e(charge_t c, vector2_t p, double eps, vector2_t *e) {
         *e = vector2_multiply(*e, -1);
     }
 
-    return norm_r < eps;
+    return norm_r >= eps;
 }
 
 bool compute_total_normalized_e(charge_t *charges, int num_charges, vector2_t p, double eps, vector2_t *e) {
+    *e = vector2_create_zero();
+
     for (int i = 0; i < num_charges; i += 1) {
         vector2_t tmp;
         if (!compute_e(charges[i], p, eps, &tmp)) {
@@ -72,24 +72,18 @@ void draw_field_line(struct gfx_context_t *ctxt, charge_t *charges, int num_char
     while (true) {
         vector2_t new_pos;
 
-        if (!compute_next_point(charges, num_charges, current_pos, EPSILON, &new_pos, dx)) {
+        if (!compute_next_point(charges, num_charges, current_pos, 4.5e-2, &new_pos, dx)) {
             break;
         }
 
-        vector2_print(current_pos);
-        vector2_print(new_pos);
-
         if (is_out_of_bounds(new_pos, x0, x1, y0, y1)) {
             break;
         }
 
         coordinates_t current_coordinates = position_to_coordinates(SCREEN_WIDTH, SCREEN_HEIGHT, x0, x1, y0, y1, current_pos);
-        printf("%d %d\n", current_coordinates.row, current_coordinates.column);
         coordinates_t new_coordinates = position_to_coordinates(SCREEN_WIDTH, SCREEN_HEIGHT, x0, x1, y0, y1, new_pos);
-        printf("%d %d\n", new_coordinates.row, new_coordinates.column);
         gfx_draw_line(ctxt, current_coordinates, new_coordinates, COLOR_BLUE);
         current_pos = new_pos;
-        break;
     }
 }
 

src/main.c

@@ -24,15 +24,14 @@ int main(int argc, char *argv[]) {
 
     int num_charges = 2;
     charge_t *charges = (charge_t *)malloc(sizeof(charge_t) * num_charges);
-    charges[0] = charge_create(-ELEMENTARY_CHARGE, vector2_create(.5, .5));
+    charges[0] = charge_create(-ELEMENTARY_CHARGE, vector2_create(.25, .5));
     charges[1] = charge_create(ELEMENTARY_CHARGE, vector2_create(.75, .5));
 
     double dx = compute_delta_x(SCREEN_WIDTH, SCREEN_HEIGHT);
 
     gfx_clear(canvas, COLOR_BLACK);
     draw_charges(canvas, charges, num_charges, x0, x1, y0, y1);
-    printf("adadf a %lf\n", dx);
-    draw_field_line(canvas, charges, num_charges, dx, vector2_create(.5, .2), x0, x1, y0, y1);
+    draw_field_line(canvas, charges, num_charges, dx, vector2_create(.5, .25), x0, x1, y0, y1);
     gfx_present(canvas);
 
     while (true) {

src/utils.c

@@ -5,8 +5,8 @@
 
 #include "vector2.h"
 
-const int SCREEN_WIDTH = 1000;
-const int SCREEN_HEIGHT = 1000;
+const int SCREEN_WIDTH = 500;
+const int SCREEN_HEIGHT = 500;
 
 coordinates_t coordinates_create(int row_, int column_) {
     coordinates_t c = {.row = row_, .column = column_};

src/vector2.c

@@ -49,5 +49,5 @@ vector2_t vector2_fit_canvas(vector2_t v, int32_t width, int32_t height) {
 }
 
 void vector2_print(vector2_t v) {
-    printf("(%lf, %lf)\n", v.x, v.y);
+    printf("(%.40lf, %.40lf)\n", v.x, v.y);
 }