From f56741a124cb3545dac3917167f890f0ff80183c Mon Sep 17 00:00:00 2001
From: Florian Burgener <florian.brgnr@gmail.com>
Date: Wed, 22 Dec 2021 00:03:55 +0100
Subject: [PATCH] Add comment
---
src/CelestialObject.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/src/CelestialObject.c b/src/CelestialObject.c
index 14245a4..e7416c5 100644
--- a/src/CelestialObject.c
+++ b/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;
--
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