From 2b7778ba1adeae0598e61d95d9ca8d5a7fb88f11 Mon Sep 17 00:00:00 2001
From: "tanguy.cavagna" <tanguy.cavagna@etu.hesge.ch>
Date: Tue, 13 Jul 2021 00:19:39 +0200
Subject: [PATCH] Feature : Draw charges on the window.
---
charge.c | 50 +++++++++++++++++++++++++++++++
charge.h | 79 +++++++++++++++++++++++++++++++++++++++++++++++++
main.c | 33 +++++++++++++++++----
utils.c | 4 +--
utils.h | 8 ++---
vector/vector.c | 6 ++++
vector/vector.h | 1 +
7 files changed, 170 insertions(+), 11 deletions(-)
create mode 100644 charge.c
create mode 100644 charge.h
diff --git a/charge.c b/charge.c
new file mode 100644
index 0000000..20733aa
--- /dev/null
+++ b/charge.c
@@ -0,0 +1,50 @@
+/**
+ * @file charge.c
+ * @author Tanguy Cavagna (tanguy.cavagna@etu.hesge.ch)
+ * @brief Chrage library
+ * @version 0.1
+ * @date 2021-07-12
+ *
+ * @copyright Copyright (c) 2021
+ *
+ */
+#include "draw/draw.h"
+#include "vector/vector.h"
+#include "utils.h"
+#include "charge.h"
+
+bool compute_e(charge_t c, vec2 p, double eps, vec2 *e) {
+}
+
+bool compute_total_normalized_e(charge_t *charges, int num_charges, vec2 p, double eps, vec2 *e) {
+}
+
+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) {
+}
+
+void draw_charges(struct gfx_context_t *ctxt, charge_t *charges, int num_charges, double x0, double x1, double y0, double y1) {
+ // Center coordinates
+ coordinates_t c;
+
+ // Charges coordinates
+ coordinates_t ch0;
+ coordinates_t ch1;
+
+ int radius = 45;
+ int chargePadding = 10;
+
+ // Draw charges
+ for (int i = 0; i < num_charges; i++) {
+ coordinates_t chCoord = position_to_coordinates(ctxt->width, ctxt->height, x0, x1, y0, y1, charges[i].pos);
+
+ // Draw sign according to charge value
+ if (charges[i].q < 0) {
+ gfx_draw_line(ctxt, coordinates_create(chCoord.row, chCoord.column - chargePadding), coordinates_create(chCoord.row, chCoord.column + chargePadding), COLOR_BLUE);
+ } else {
+ gfx_draw_line(ctxt, coordinates_create(chCoord.row, chCoord.column - chargePadding), coordinates_create(chCoord.row, chCoord.column + chargePadding), COLOR_RED);
+ gfx_draw_line(ctxt, coordinates_create(chCoord.row - chargePadding, chCoord.column), coordinates_create(chCoord.row + chargePadding, chCoord.column), COLOR_RED);
+ }
+
+ gfx_draw_circle(ctxt, chCoord, radius, charges[i].q < 0 ? COLOR_BLUE : COLOR_RED);
+ }
+}
\ No newline at end of file
diff --git a/charge.h b/charge.h
new file mode 100644
index 0000000..07af84c
--- /dev/null
+++ b/charge.h
@@ -0,0 +1,79 @@
+/**
+ * @file charge.h
+ * @author Tanguy Cavagna (tanguy.cavagna@etu.hesge.ch)
+ * @brief Charge file header
+ * @version 0.1
+ * @date 2021-07-12
+ *
+ * @copyright Copyright (c) 2021
+ *
+ */
+#ifndef _CHARGE_H_
+#define _CHARGE_H_
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include "utils.h"
+#include "vector/vector.h"
+#include "gfx/gfx.h"
+
+/**
+ * @brief Compute E*qP/norm(qP)
+ *
+ * @param c Parent charge
+ * @param p Point on which to compute e
+ * @param eps Minimal gap between field and charge
+ * @param e Electric field
+ * @return bool false norm(qP) < eps
+ */
+bool compute_e(charge_t c, vec2 p, double eps, vec2 *e);
+
+/**
+ * @brief Compute the normilized sum of Ei*qiP/norm(qiP)
+ *
+ * @param charges All the charges
+ * @param num_charges Number of charges in action
+ * @param p Current computed point
+ * @param eps Minimal gap between field and charge
+ * @param e Electric field
+ * @return bool false for some qiP, norm(qiP) < eps
+ */
+bool compute_total_normalized_e(charge_t *charges, int num_charges, vec2 p,
+ double eps, vec2 *e);
+
+/**
+ * @brief Compute and then draw all the points belonging to a field line,
+ * starting from pos0
+ *
+ * @param ctxt Context to draw on
+ * @param charges All the charges
+ * @param num_charges Number of charges in action
+ * @param dx Space between computed points on the field line
+ * @param pos0 First post to start the computing of the field line
+ * @param x0 Minal x of the universe
+ * @param x1 Maximal x of the universe
+ * @param y0 Minal y of the universe
+ * @param y1 Maximal y of the universe
+ * @return bool false if pos0 not a valid pos (e.g. too close to a charge)
+ */
+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);
+
+/**
+ * @brief Draw all charges
+ * A circle with a minus sign for negative charges
+ * A circle with a plus sign for positive charges
+ *
+ * @param ctxt Context to draw on
+ * @param charges All the charges
+ * @param num_charges Number of charges in action
+ * @param x0 Minal x of the universe
+ * @param x1 Maximal x of the universe
+ * @param y0 Minal y of the universe
+ * @param y1 Maximal y of the universe
+ */
+void draw_charges(struct gfx_context_t *ctxt, charge_t *charges,
+ int num_charges, double x0, double x1, double y0, double y1);
+
+#endif // _CHARGE_H_
\ No newline at end of file
diff --git a/main.c b/main.c
index 8369978..f70c311 100644
--- a/main.c
+++ b/main.c
@@ -1,21 +1,44 @@
+/**
+ * @file main.c
+ * @author Tanguy Cavagna (tanguy.cavagna@etu.hesge.ch)
+ * @brief Main file for the electric field exercice
+ * @version 0.1
+ * @date 2021-07-12
+ *
+ * @copyright Copyright (c) 2021
+ *
+ */
+#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
#include "gfx/gfx.h"
+#include "charge.h"
-int main(void) {
- const int WINDOW_SIZE_X = 500;
- const int WINDOW_SIZE_Y = 500;
+#define WINDOW_WIDTH 500
+#define WINDOW_HEIGHT 500
+#define x0 0 // Minimal x of the universe
+#define x1 1 // Maximal x of the universe
+#define y0 0 // Minimal y of the universe
+#define y1 1 // Maximal y of the universe
+#define NB_CHARGES 2
+int main(void) {
srand(time(NULL));
- struct gfx_context_t *ctxt = gfx_create("draw", WINDOW_SIZE_X, WINDOW_SIZE_Y);
-
+ // GFX initialization
+ struct gfx_context_t *ctxt = gfx_create("draw", WINDOW_WIDTH, WINDOW_HEIGHT);
if (!ctxt) {
fprintf(stderr, "Graphics initialization failed !\n");
return EXIT_FAILURE;
}
+ charge_t charges[NB_CHARGES];
+ charges[0] = charge_create(10, init_vector(0.25, 0.5));
+ charges[1] = charge_create(-10, init_vector(0.75, 0.5));
+ draw_charges(ctxt, charges, NB_CHARGES, x0, x1, y0, y1);
+
+ // GFX Draw loop
while (gfx_keypressed() != SDLK_ESCAPE){
gfx_present(ctxt);
}
diff --git a/utils.c b/utils.c
index fc22d8a..86e1a7c 100644
--- a/utils.c
+++ b/utils.c
@@ -4,7 +4,7 @@
#include "utils.h"
// Transform a position in the univers [x0,y0]x[x1,y1] to a screen position
-coordinates_t position_to_coordinates(int width, int height, double x0, double x1, double y0, double y1, vector pos)
+coordinates_t position_to_coordinates(int width, int height, double x0, double x1, double y0, double y1, vec2 pos)
{
double dx = x1 - x0;
double dy = y1 - y0;
@@ -16,7 +16,7 @@ double rand_one()
return (double)rand() / (double)RAND_MAX;
}
-charge_t charge_create(double q, vector pos)
+charge_t charge_create(double q, vec2 pos)
{
charge_t c = {.q = q, .pos = pos};
return c;
diff --git a/utils.h b/utils.h
index 81f456e..54d49d0 100644
--- a/utils.h
+++ b/utils.h
@@ -8,17 +8,17 @@
#include "vector/vector.h"
#include "draw/draw.h"
-typedef struct
+typedef struct _charge_t
{
double q;
- vector pos;
+ vec2 pos;
} charge_t;
// Transform a position in the univers [x0,y0]x[x1,y1] to a screen position
-coordinates_t position_to_coordinates(int width, int height, double x0, double x1, double y0, double y1, vector pos);
+coordinates_t position_to_coordinates(int width, int height, double x0, double x1, double y0, double y1, vec2 pos);
double rand_one();
-charge_t charge_create(double q, vector pos);
+charge_t charge_create(double q, vec2 pos);
#endif
\ No newline at end of file
diff --git a/vector/vector.c b/vector/vector.c
index 5aaaae3..bbe8504 100644
--- a/vector/vector.c
+++ b/vector/vector.c
@@ -11,6 +11,12 @@
#include <stdio.h>
#include "vector.h"
+vec2 init_vector(double x, double y) {
+ vec2 v = {x, y};
+
+ return v;
+}
+
/*! \fn vector add_vector(vector v1, vector v2)
\brief Add two vector and return the final vector
\param v1 First vector to add
diff --git a/vector/vector.h b/vector/vector.h
index d78bbc5..205768d 100644
--- a/vector/vector.h
+++ b/vector/vector.h
@@ -21,6 +21,7 @@ typedef struct {
double a; /* Angle of the vector */
} polarVector;
+vec2 init_vector(double x, double y); /* Initialize a new vector */
vec2 add_vector(vec2 v1, vec2 v2); /* Add a vector to another and return the result as a vector */
vec2 sub_vector(vec2 v1, vec2 v2); /* Substract a vector to another vector and return the result as a vector */
vec2 mult_by_scalar(vec2 v1, int scalar); /* Multiply a vector by a scalar */
--
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