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src/CelestialObject.c

@@ -58,6 +58,7 @@ Vector2 calculate_gravitational_acceleration(int32_t object_index, CelestialObje
         Vector2 r = vector2_substract((i < object_index) ? objects[i]->previous_position : objects[i]->position, objects[object_index]->position);
         // Calculates the acceleration.
         double a_scalar = G * objects[i]->mass * pow(pow(vector2_norm(r), 2), -1);
+        // Sum the acceleration.
         a = vector2_add(a, vector2_multiply(vector2_normalize(r), a_scalar));
     }
 
@@ -69,12 +70,12 @@ void celestial_object_first_update(int32_t object_index, CelestialObject **objec
     CelestialObject *main_object = objects[main_object_index];
 
     // Speed at the periapsis.
-    double periapsis_speed_scalar = sqrt((G * main_object->mass * (1 + object->eccentricity)) / (object->semi_major_axis * (1 - object->eccentricity)));
+    double periapsis_speed = sqrt((G * main_object->mass * (1 + object->eccentricity)) / (object->semi_major_axis * (1 - object->eccentricity)));
     // Adds the speed of the main object.
-    periapsis_speed_scalar += vector2_norm(vector2_substract(main_object->position, main_object->previous_position));
+    periapsis_speed += vector2_norm(vector2_substract(main_object->position, main_object->previous_position));
 
     Vector2 r = vector2_normalize(vector2_create(object->position.y, -object->position.x));
-    Vector2 periapsis_velocity = vector2_multiply(r, periapsis_speed_scalar);
+    Vector2 periapsis_velocity = vector2_multiply(r, periapsis_speed);
 
     // Adds the position of the main object.
     object->position = vector2_add(object->position, main_object->previous_position);
@@ -82,7 +83,7 @@ void celestial_object_first_update(int32_t object_index, CelestialObject **objec
     // Calculates the new position of the object according to its velocity at periapsis.
     Vector2 new_position = vector2_add(object->position, periapsis_velocity);
     Vector2 a = calculate_gravitational_acceleration(object_index, objects, objects_length);
-    // Adds the acceleration.
+    // Apply the acceleration.
     new_position = vector2_add(new_position, vector2_multiply(a, 0.5));
 
     object->previous_position = object->position;