ADD: V1.0 of all planet functions and vec2_coordinates_centered

main.c

@@ -4,32 +4,40 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
+#include <unistd.h>
 
 #define SCREEN_WIDTH 1000
 #define SCREEN_HEIGHT 1000
 
+#define SUN_RADIUS 50
+
+#define DELTA_T 3600.0
+
 int main() {
 	srand(time(NULL));
-	struct gfx_context_t *ctxt = gfx_create("Planetary system", SCREEN_WIDTH, SCREEN_HEIGHT);
+	struct gfx_context_t* ctxt = gfx_create("Planetary system", SCREEN_WIDTH, SCREEN_HEIGHT);
 	if (!ctxt) {
 		fprintf(stderr, "Graphics initialization failed!\n");
 		return EXIT_FAILURE;
 	}
 
-	// TODO : create your system
-	system_t sys = create_system(0.125);
+	// begin : create your system
+	system_t sys = create_system(DELTA_T);
 	// end : create system
 	while (true) {
 		gfx_present(ctxt);
 		gfx_clear(ctxt, COLOR_BLACK);
-		// TODO : draw the current state of your system
+		// begin : draw the current state of your system
+		show_system(ctxt, sys);
 		// end : draw state of system
-		// TODO : update your system
+		// begin : update your system
+		update_system(sys, DELTA_T);
+		usleep(100000);
 		// end : update system
 		if (gfx_keypressed() == SDLK_ESCAPE) { break; }
 	}
 
-	// TODO : Free your system
+	// begin : Free your system
 	free_system(sys);
 	// end : free system
 	gfx_destroy(ctxt);

planet/planet.c

@@ -4,25 +4,6 @@
 #include "constants.h"
 
 
-/*
-typedef struct _planet
-{
-    double mass;
-    vec2 pos;      // x(t)
-    vec2 prec_pos; // x(t - dt)
-} planet_t;
-typedef struct _system
-{
-    planet_t star;       // ex. The sun
-    uint32_t nb_planets; // The number of orbiting planets
-    planet_t *planets;   // An array of orbiting planets
-} system_t;
-*/
-
-
-// TODO : complete all implementations
-
-
 planet_t create_planet(double mass, vec2 pos) {
 	planet_t p;
 	p.mass = mass;
@@ -74,7 +55,17 @@ system_t create_system(double delta_t) {
 
 
 void show_system(struct gfx_context_t* ctxt, system_t* system) {
-	//TODO
+	// draw sun
+	const coordinates xy_sun = vec2_to_coordinates_centered(vec2_normalize(system->star.pos));
+	draw_full_circle(ctxt, xy_sun.column, xy_sun.row, 50, COLOR_YELLOW);
+	// draw planets
+	for (uint32_t i = 0; i < sys.nb_planets; ++i) {
+		const coordinates xy = vec2_to_coordinates_centered(
+				vec2_normalize(sys.planets[i].pos),
+				ctxt->width,
+				ctxt->height);
+		draw_full_circle(ctxt, xy.column, xy.row, 20, COLOR_BLUE);
+	}
 }
 
 

vec2/vec2.c

@@ -7,7 +7,7 @@
 /// @param y_ The second component.
 /// @return The newly created vector.
 vec2 vec2_create(double x_, double y_) {
-	return (vec2){ .x = x_ , .y = y_ };
+	return (vec2) {.x = x_, .y = y_};
 }
 
 /// Create a zero 2d vector.
@@ -21,7 +21,7 @@ vec2 vec2_create_zero() {
 /// @param rhs The right operand.
 /// @return The sum in a new vector.
 vec2 vec2_add(vec2 lhs, vec2 rhs) {
-	return (vec2){ .x = lhs.x + rhs.x , .y = lhs.y + rhs.y };
+	return (vec2) {.x = lhs.x + rhs.x, .y = lhs.y + rhs.y};
 }
 
 /// Substract two vectors.
@@ -29,7 +29,7 @@ vec2 vec2_add(vec2 lhs, vec2 rhs) {
 /// @param rhs The right operand.
 /// @return The difference in a new vector.
 vec2 vec2_sub(vec2 lhs, vec2 rhs) {
-	return (vec2){ .x = lhs.x - rhs.x , .y = lhs.y - rhs.y };
+	return (vec2) {.x = lhs.x - rhs.x, .y = lhs.y - rhs.y};
 }
 
 /// Multiply a vector by a scalar.
@@ -37,7 +37,7 @@ vec2 vec2_sub(vec2 lhs, vec2 rhs) {
 /// @param rhs The right operand, a vector.
 /// @return The product in a new vector.
 vec2 vec2_mul(double scalar, vec2 rhs) {
-	return (vec2){ .x = scalar * rhs.x , .y = scalar * rhs.y };
+	return (vec2) {.x = scalar * rhs.x, .y = scalar * rhs.y};
 }
 
 /// Compute the dot product (scalar product) between two vectors.
@@ -67,7 +67,7 @@ double vec2_norm(vec2 v) {
 /// @return The new normalized vector.
 vec2 vec2_normalize(vec2 v) {
 	double norm = vec2_norm(v);
-	return (vec2){ .x = v.x / norm , .y = v.y / norm };
+	return (vec2) {.x = v.x / norm, .y = v.y / norm};
 }
 
 /// Check whether two vectors are approximately equals within a given tolerance.
@@ -89,15 +89,25 @@ bool vec2_is_approx_equal(vec2 lhs, vec2 rhs, double eps) {
 /// @param height The screen height.
 /// @return The coordinates (rwo, column).
 coordinates vec2_to_coordinates(vec2 v, uint32_t width, uint32_t height) {
-	return (coordinates){
-		.column = (uint32_t)(v.x * width) ,
-		.row    = (uint32_t)(v.y * height)
+	return (coordinates) {
+			.column = (uint32_t)(v.x * width),
+			.row    = (uint32_t)(v.y * height)
 	};
 }
 
 /// Print a vector in the standard output.
 /// @param v The vector.
-void vec2_print(vec2 v)
-{
-    printf("x = %g, y = %g\n", v.x, v.y);
+void vec2_print(vec2 v) {
+	printf("x = %g, y = %g\n", v.x, v.y);
+}
+
+/// Same as vec2_to_coordinates but (0,0) is at the center of the screen.
+/// @param v The 2d vector: components between -1.0 and +1.0
+/// @param width The screen width.
+/// @param height The screen height.
+coordinates vec2_to_coordinates_centered(const vec2 v, const uint32_t width, const uint32_t height) {
+	return (coordinates) {
+			.column = (uint32_t)((v.x + 1.0) * width / 2),
+			.row = (uint32_t)((v.y + 1.0) * height / 2)
+	};
 }

vec2/vec2.h

@@ -38,4 +38,6 @@ coordinates vec2_to_coordinates(vec2 v, uint32_t width, uint32_t height);
 
 void vec2_print(vec2 v);
 
+coordinates vec2_to_coordinates_centered(const vec2 v, const uint32_t width, const uint32_t height);
+
 #endif