From ab5b40060861fd86759830a9a3eb39c17896d146 Mon Sep 17 00:00:00 2001
From: Cat Flynn <me@ktyl.dev>
Date: Sun, 29 Sep 2024 00:17:18 +0100
Subject: [PATCH] feat: draw apo/periapses

---
 src/orbitvisualizer.cpp    | 37 ++++++++++++++++++++++++-------------
 src/orbitvisualizer.hpp    |  1 +
 src/particlevisualizer.cpp |  7 -------
 3 files changed, 25 insertions(+), 20 deletions(-)

diff --git a/src/orbitvisualizer.cpp b/src/orbitvisualizer.cpp
index a45c4a1..91b9593 100644
--- a/src/orbitvisualizer.cpp
+++ b/src/orbitvisualizer.cpp
@@ -1,5 +1,6 @@
 #include "orbitvisualizer.hpp"
 #include "gfx.hpp"
+#include "icosphere.hpp"
 
 OrbitVisualizer::OrbitVisualizer(const ParticleMap& map, const std::string& particleId, const GLuint shaderProgram, float scale)
     : _map(map), _particleId(particleId), _shaderProgram(shaderProgram), _scale(scale)
@@ -23,12 +24,32 @@ void OrbitVisualizer::render(const float time)
     glBindBuffer(GL_ARRAY_BUFFER, _vbo);
 
     glDrawArrays(GL_LINE_LOOP, 0, _vertices.size() / 3);
+
+    glm::dvec3 position;
+
+    Icosphere apoapsis(0.01, 2, _shaderProgram);
+    position = getPositionOnOrbit(3.142);
+    position /= _scale;
+    apoapsis.setPosition(position);
+    apoapsis.render(time);
+
+    Icosphere periapsis(0.01, 2, _shaderProgram);
+    position = getPositionOnOrbit(0.0);
+    position /= _scale;
+    periapsis.setPosition(position);
+    periapsis.render(time);
+
+}
+
+glm::dvec3 OrbitVisualizer::getPositionOnOrbit(double trueAnomaly) const
+{
+    Orbit orbit(_map.getOrbit(_particleId));
+    orbit.setTrueAnomaly(trueAnomaly);
+    return orbit.getPosition(1);
 }
 
 void OrbitVisualizer::regenerateVertices(const glm::vec3& basePos)
 {
-    Orbit orbit(_map.getOrbit(_particleId));
-
     _vertices.clear();
     for (int i = 0; i < _vertexCount; i++)
     {
@@ -36,18 +57,8 @@ void OrbitVisualizer::regenerateVertices(const glm::vec3& basePos)
         // better to actually create a first-class ellipse object and use that to generate
         // a nice continuous mesh, instead of using orbital positions. 
         float t = (float)i / (float)_vertexCount * 2.0 * _pi;
-        orbit.setTrueAnomaly(t);
-        //glm::vec3 pos = orbit.getPositionFromMeanAnomaly(t, 1);
-        glm::vec3 pos = orbit.getPosition(1);
+        glm::vec3 pos = getPositionOnOrbit(t);
         pos += basePos;
-
-        // Vertices come out of the library with X and Y being in the 'flat' plane. Re-order them
-        // here such that Z is up.
-        float y = pos.z;
-        pos.z = pos.y;
-        pos.y = y;
-        pos.z *= -1;
-
         pos /= _scale;
 
         _vertices.push_back(pos.x);
diff --git a/src/orbitvisualizer.hpp b/src/orbitvisualizer.hpp
index 9b9783a..c3b66e9 100644
--- a/src/orbitvisualizer.hpp
+++ b/src/orbitvisualizer.hpp
@@ -25,5 +25,6 @@ class OrbitVisualizer
         GLuint _vao;
         std::vector<float> _vertices;
 
+        glm::dvec3 getPositionOnOrbit(double trueAnomaly) const;
         void regenerateVertices(const glm::vec3& basePos);
 };
diff --git a/src/particlevisualizer.cpp b/src/particlevisualizer.cpp
index 3f1fd22..edb431e 100644
--- a/src/particlevisualizer.cpp
+++ b/src/particlevisualizer.cpp
@@ -9,14 +9,7 @@ ParticleVisualizer::ParticleVisualizer(const ParticleMap& map, const std::string
 
 void ParticleVisualizer::render(float time)
 {
-    // TODO: get mean anomly from particle which has the mass!!
-    //const float meanAnomaly = time;
     glm::vec3 pos = _map.getParticlePosition(_particleId);
-    float y = pos.z;
-    pos.z = pos.y;
-    pos.y = y;
-    pos.z *= -1;
-
     pos /= _scale;
 
     // TODO: extract widget to its own visualizer since we know it wants an orbit but we