FIX: frame edge space and refresh loop for moving window around

.gitignore

@@ -3,3 +3,4 @@ build
 *.o
 *.pdf
 main
+*_tests

src/draw.c

 #include <stdbool.h>
-
 #include "../utils/gfx/gfx.h"
-#include "field.h"
+#include "../utils/utils.h"
+
 
 void gfx_draw_line(struct gfx_context_t *ctxt, coordinates_t p0, coordinates_t p1, uint32_t color) {
 	int dx = abs((int) p1.column - (int) p0.column);
@@ -34,7 +34,8 @@ void gfx_draw_line(struct gfx_context_t *ctxt, coordinates_t p0, coordinates_t p
 	}
 }
 
-void gfx_draw_circle(struct gfx_context_t *ctxt, coordinates c, uint32_t r, uint32_t color) {
+
+void gfx_draw_circle(struct gfx_context_t *ctxt, coordinates_t c, uint32_t r, uint32_t color) {
 	int x = 0;
 	int y = r;
 	int d = r - 1;

src/draw.h

@@ -3,7 +3,10 @@
 
 #include "field.h"
 
+
 void gfx_draw_line(struct gfx_context_t *ctxt, coordinates_t p0, coordinates_t p1, uint32_t color);
+
 void gfx_draw_circle(struct gfx_context_t *ctxt, coordinates_t c, uint32_t r, uint32_t color);
 
+
 #endif

src/field.c

@@ -34,8 +34,7 @@ double compute_delta_x() {
 }
 
 bool is_in_screen(coordinates_t pos) {
-	// TODO: should this not be "<" instead of "<=" ?
-	return pos.column <= WID && pos.row <= HEI;
+	return pos.column < WID && pos.row < HEI;
 }
 
 bool draw_field_line_point(struct gfx_context_t *ctxt, charge_t *charges, int num_charges, double x0, double x1, double y0, double y1, vec2 pos, vec2 *pos_next, double delta) {
@@ -105,7 +104,7 @@ static bool draw_field_line(struct gfx_context_t *ctxt, charge_t *charges, int n
 /// 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) {
-	for (int i = 0; i < num_charges; i++) {
+	for (int i = 0; i < num_charges; ++i) {
 		coordinates_t charge_center = position_to_coordinates(WID, HEI, x0, x1, y0, y1, charges[i].pos);
 		gfx_draw_circle(context, charge_center, CHARGE_R, COLOR_WHITE);
 

src/field.h

@@ -2,9 +2,9 @@
 #define _PHYSIQUE_H_
 
 #include <stdio.h>
-#include "../utils/utils.h"
 #include "../utils/gfx/gfx.h"
 #include "../utils/vec2/vec2.h"
+#include "../utils/utils.h"
 
 #define SIDE_LEN 1000
 #define WID SIDE_LEN

src/main.c

 #include <stdlib.h>
-#include <time.h>
-
-#include "draw.h"
-#include "field.h"
-#include "../utils/utils.h"
 #include "field.h"
 
+
 #define NCHARGES 2
+#define NC 3
 #define DX 25
 #define NLINES 50
 
 
-int main() {
+void main_old() {
 	charge_t charges[NCHARGES] = {
 			charge_create(0.25, vec2_create(0.25, 0.5)),
 			charge_create(-0.25, vec2_create(0.75, 0.5))
@@ -23,5 +20,25 @@ int main() {
 
 	while (gfx_keypressed() != SDLK_ESCAPE);
 	gfx_destroy(ctxt);
+}
+
+
+void main_new() {
+	charge_t charges[NC];
+	for (int i = 0; i < NC; ++i)
+		charges[i] = charge_create(i % 2 == 0 ? rand_one() : -rand_one(), vec2_create(rand_one(), rand_one()));
+	struct gfx_context_t *ctxt = gfx_create("elec", WID, HEI);
+
+	draw_everything(ctxt, charges, NC, NLINES, DX, 0.0, 1.0, 0.0, 1.0);
+	gfx_present(ctxt);
+	while (gfx_keypressed() != SDLK_ESCAPE) {
+		gfx_present(ctxt);
+	}
+	gfx_destroy(ctxt);
+}
+
+
+int main() {
+	main_new();
 	return EXIT_SUCCESS;
 }

utils/utils.c

 #include <math.h>
 #include <stdlib.h>
 #include <time.h>
-#include "utils.h"
 #include "vec2/vec2.h"
+#include "utils.h"
 
 
 coordinates_t coordinates_create(int row_, int column_) {