From ad281f5b68e0015ba19aed2e7bda53b25f030647 Mon Sep 17 00:00:00 2001
From: ktyl <me@ktyl.dev>
Date: Sun, 8 Oct 2023 00:13:32 +0100
Subject: [PATCH] feat(orbit-animation): cycle animation

---
 src/main.cpp | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index ef40713..0828e25 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -73,12 +73,25 @@ int main()
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
         float time = glfwGetTime();
+        const float orbitalPeriod = 6.284;
 
-        float e = .25 + .2 * sin(time);
-        keplerianElements[astro::eccentricityIndex] = e;
-        orbit.setElements(keplerianElements);
+        const int ANIM_ORBITING = 0;
+        const int ANIM_ECCENTRICITY = 1;
+        int animation = (int)(time / orbitalPeriod) % 2 == 1;
 
-        glm::vec3 pos = orbit.getPosition(time);
+        glm::vec3 pos;
+        if (animation == ANIM_ORBITING)
+        {
+            pos = orbit.getPosition(time);
+        }
+        else if (animation == ANIM_ECCENTRICITY)
+        {
+            float e = .25 + .2 * sin(time);
+            keplerianElements[astro::eccentricityIndex] = e;
+            orbit.setElements(keplerianElements);
+
+            pos = orbit.getPosition(0);
+        }
         orbiter.setPosition(pos);
 
         // Render lit objects