Merge remote-tracking branch 'origin/physics' into physics

# Conflicts:
#	src/main.c

src/draw.c

 #include "../utils/gfx/gfx.h"
 #include "field.h"
-/*
-(50, 50) → (75, 50)1 , (50, 50) → (72, 62), (50, 50) → (62, 72)
-(50, 50) → (50, 75), (50, 50) → (38, 72), (50, 50) → (28, 62)
-(50, 50) → (25, 50), (50, 50) → (28, 38), (50, 50) → (37, 28)
-(50, 50) → (50, 25), (50, 50) → (62, 28), (50, 50) → (72, 37)
-*/
 
 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);

src/field.c

@@ -5,6 +5,8 @@
 #include "field.h"
 #include "../utils/utils.h"
 
+#define SIGN_SIZE 10
+#define CHARGE_R 25
 
 // Compute E*qP/norm(qP)
 // Return false if norm(qP) < eps
@@ -36,16 +38,32 @@ bool compute_total_normalized_e(charge_t *charges, int num_charges, vec2 p, doub
 // 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) {
+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) {
 	return EXIT_SUCCESS;
 }
 
 // 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) {
+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++)
+	{
+		coordinates_t charge_center = position_to_coordinates(CHARGE_R, CHARGE_R, x0, x1, y0, y1, charges[i].pos);
+		gfx_draw_circle(context, charge_center, CHARGE_R, COLOR_WHITE);
+
+		coordinates_t sign_dst;
+		uint32_t sign_color = COLOR_RED;
+		if (charges[i].q > 0){
+			sign_color = COLOR_BLUE;
+			sign_dst.row = charge_center.row + SIGN_SIZE;
+			gfx_draw_line(context, charge_center, sign_dst, sign_color);
+			sign_dst.row = charge_center.row - SIGN_SIZE;
+			gfx_draw_line(context, charge_center, sign_dst, sign_color);
+		}
+
+		sign_dst.column = charge_center.column + SIGN_SIZE;
+		gfx_draw_line(context, charge_center, sign_dst, sign_color);
+		sign_dst.column = charge_center.column - SIGN_SIZE;
+		gfx_draw_line(context, charge_center, sign_dst, sign_color);
+	}
 }

utils/gfx/gfx.h

@@ -31,7 +31,7 @@ struct gfx_context_t
 
 
 extern void gfx_putpixel(
-    struct gfx_context_t *ctxt, uint32_t column, uint32_t row, uint32_t color);
+struct gfx_context_t *ctxt, uint32_t column, uint32_t row, uint32_t color);
 extern void gfx_clear(struct gfx_context_t *ctxt, uint32_t color);
 extern struct gfx_context_t *gfx_create(char *text, uint32_t width, uint32_t height);
 extern void gfx_destroy(struct gfx_context_t *ctxt);