refactor: extract OrbiterVisualizer class

CMakeLists.txt

@@ -32,6 +32,7 @@ add_executable(${PROJECT_NAME}
     src/icosphere.cpp
     src/gfx.cpp
     src/orbitvisualizer.cpp
+    src/orbitervisualizer.cpp
     src/orbiter.cpp
     src/widget.cpp
 )

lib/skein/include/skein/orbit.h

@@ -9,18 +9,26 @@ typedef std::vector<float> Vector6;
 class Orbit
 {
 public:
-    Orbit(float semiMajorAxis, float eccentricity, float inclination,
-        float argumentOfPeriapsis, float longitudeOfAscendingNode);
+    Orbit();
     ~Orbit() = default; 
 
+    float getSemiMajorAxis() const;
     float getEccentricity() const;
+    float getInclination() const;
+    float getArgumentOfPeriapsis() const;
+    float getLongitudeOfAscendingNode() const;
+
+    void setSemiMajorAxis(float semiMajorAxis);
     void setEccentricity(float eccentricity);
+    void setInclination(float inclination);
+    void setArgumentOfPeriapsis(float argumentOfPeriapsis);
+    void setLongitudeOfAscendingNode(float longitudeOfAscendingNode);
 
     // TODO: meanAnomaly in all these arguments actually means eccentricMeanAnomaly,
     // will have to change that when adding non-ellipctical orbits - don't get confused!
-    const glm::vec3 getPosition(const float meanAnomaly) const;
-    glm::vec3 getTangent(const float meanAnomaly);
-    glm::mat4 getLookAlongMatrix(const float meanAnomaly);
+    glm::vec3 getPosition(const float meanAnomaly) const;
+    glm::vec3 getTangent(const float meanAnomaly) const;
+    glm::mat4 getLookAlongMatrix(const float meanAnomaly) const;
 
 private:
     Vector6 _keplerianElements;

lib/skein/src/orbit.cpp

@@ -5,28 +5,57 @@
 
 #include <glm/gtc/matrix_transform.hpp>
 
-Orbit::Orbit(float semiMajorAxis, float eccentricity, float inclination,
-    float argumentOfPeriapsis, float longitudeOfAscendingNode)
+Orbit::Orbit()
 {
     _keplerianElements.resize(6);
+}
+
+float Orbit::getSemiMajorAxis() const
+{
+    return _keplerianElements[astro::semiMajorAxisIndex];
+}
+void Orbit::setSemiMajorAxis(float semiMajorAxis)
+{
     _keplerianElements[astro::semiMajorAxisIndex] = semiMajorAxis;
-    _keplerianElements[astro::eccentricityIndex] = eccentricity;
-    _keplerianElements[astro::inclinationIndex] = inclination;
-    _keplerianElements[astro::argumentOfPeriapsisIndex] = argumentOfPeriapsis;
-    _keplerianElements[astro::longitudeOfAscendingNodeIndex] = semiMajorAxis;
 }
 
 float Orbit::getEccentricity() const
 {
     return _keplerianElements[astro::eccentricityIndex];
 }
-
 void Orbit::setEccentricity(float eccentricity)
 {
     _keplerianElements[astro::eccentricityIndex] = eccentricity;
 }
 
-glm::mat4 Orbit::getLookAlongMatrix(const float meanAnomaly)
+float Orbit::getInclination() const
+{
+    return _keplerianElements[astro::inclinationIndex];
+}
+void Orbit::setInclination(float inclination)
+{
+    _keplerianElements[astro::inclinationIndex] = inclination;
+}
+
+float Orbit::getArgumentOfPeriapsis() const
+{
+    return _keplerianElements[astro::argumentOfPeriapsisIndex];
+}
+void Orbit::setArgumentOfPeriapsis(float argumentOfPeriapsis)
+{
+    _keplerianElements[astro::argumentOfPeriapsisIndex] = argumentOfPeriapsis;
+}
+
+float Orbit::getLongitudeOfAscendingNode() const
+{
+    return _keplerianElements[astro::longitudeOfAscendingNodeIndex];
+}
+void Orbit::setLongitudeOfAscendingNode(float longitudeOfAscendingNode)
+{
+    _keplerianElements[astro::longitudeOfAscendingNodeIndex] = longitudeOfAscendingNode;
+}
+
+glm::mat4 Orbit::getLookAlongMatrix(const float meanAnomaly) const
 {
     glm::vec3 position = getPosition(meanAnomaly);
 
@@ -60,7 +89,7 @@ const float Orbit::getEccentricAnomaly(const float meanAnomaly) const
 
 // Interpolate a position around the orbit.
 // t is in range 0..1 and wraps.
-const glm::vec3 Orbit::getPosition(const float meanAnomaly) const
+glm::vec3 Orbit::getPosition(const float meanAnomaly) const
 {
     Vector6 cartesian = getCartesianCoordinates(meanAnomaly);
     return glm::vec3(
@@ -85,7 +114,7 @@ const Vector6 Orbit::getCartesianCoordinates(const float meanAnomaly) const
     return astro::convertKeplerianToCartesianElements(kepler, 1.0);
 }
 
-glm::vec3 Orbit::getTangent(const float meanAnomaly)
+glm::vec3 Orbit::getTangent(const float meanAnomaly) const
 {
     float epsilon = 0.01;
     glm::vec3 ahead = getPosition(meanAnomaly + epsilon);

src/main.cpp

@@ -42,6 +42,7 @@
 #include "gfx.hpp"
 #include "icosphere.hpp"
 #include "orbiter.hpp"
+#include "orbitervisualizer.hpp"
 #include "orbitvisualizer.hpp"
 #include "widget.hpp"
 
@@ -94,15 +95,28 @@ int main()
     // set up scene
     Icosphere planet(0.2, 3, litProgram);
 
-    Orbit orbit(.75f, .5, 3.142 / 2.0 + 1, 2.0, 0);
-    OrbitVisualizer orbitVisualizer(orbit, unlitProgram);
+    //Orbiter orbiter(orbiterSphere, orbit, unlitProgram);
+    Orbiter orbiter;
+    Orbit& orbit = orbiter.getOrbit();
+    orbit.setSemiMajorAxis(.75);
+    orbit.setEccentricity(.5);
+    orbit.setInclination(3.142 / 2.0 + 1);
+    orbit.setArgumentOfPeriapsis(2.0);
+    orbit.setLongitudeOfAscendingNode(0.1);
 
     Icosphere orbiterSphere(0.07, 2, litProgram);
-    Orbiter orbiter(orbiterSphere, orbit, unlitProgram);
+    OrbiterVisualizer orbiterVisualizer(orbiter, orbiterSphere, unlitProgram);
+    OrbitVisualizer orbitVisualizer(orbit, unlitProgram);
 
     // register input
     glfwSetKeyCallback(window, keyCallback);
 
+    // TODO: convert these to an enum
+    const int ANIM_ORBITING     = 0;
+    const int ANIM_ECCENTRICITY = 1;
+    int animation = 0;
+    float time = glfwGetTime();
+
     // Main loop
     while (!glfwWindowShouldClose(window))
     {
@@ -114,17 +128,30 @@ int main()
         // apply input
         if (input.cycleAnimation)
         {
-            orbiter.cycleAnimation();
+            animation++;
+            if (animation > ANIM_ECCENTRICITY)
+            {
+                animation = 0;
+            }
+        }
+
+        // only update time if playing the orbiting animation
+        if (animation == ANIM_ORBITING)
+        {
+            time = glfwGetTime();
+        }
+        else
+        {
+            float e = .25 + .2 * sin(glfwGetTime());
+            orbit.setEccentricity(e);
         }
 
         // rendering
         glClearColor(0.2, 0.3, 0.3, 1.0);
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
-        float time = glfwGetTime();
-
         planet.render(time);
-        orbiter.render(time);
+        orbiterVisualizer.render(time);
         orbitVisualizer.render(time);
 
         glfwSwapBuffers(window);

src/orbiter.cpp

@@ -1,66 +1,7 @@
 #include "orbiter.hpp"
 
-#include <iostream>
-
-Orbiter::Orbiter(Icosphere& sphere, Orbit& orbit, GLuint shaderProgram) :
-    _sphere(sphere),
-    _orbit(orbit),
-    _widget(shaderProgram)
+Orbit& Orbiter::getOrbit()
 {
+    return _orbit;
 }
 
-float Orbiter::getMeanAnomaly()
-{
-    float time = glfwGetTime();
-    return time;
-}
-
-void Orbiter::cycleAnimation()
-{
-    _animation++;
-
-    if (_animation > ANIM_ECCENTRICITY)
-    {
-        _animation = 0;
-    }
-}
-
-glm::vec3 Orbiter::getPosition(const float time)
-{
-    //int animation = (int)(time/ORBITAL_PERIOD) % 2 == 1;
-
-    if (_animation == ANIM_ORBITING)
-        return _orbit.getPosition(time);
-
-    // TODO: modify the eccentricity of the orbit with a control instead 
-    // of an automatic animation
-    if (_animation == ANIM_ECCENTRICITY)
-    {
-        float e = .25 + .2 * sin(time);
-        _orbit.setEccentricity(e);
-
-        return _orbit.getPosition(0);
-    }
-
-    std::cerr << "unknown animation " << _animation << std::endl;
-    throw 1;
-}
-
-void Orbiter::render(const float time)
-{
-    const float meanAnomaly = time;
-    glm::vec3 pos = getPosition(meanAnomaly);
-
-    // render widget
-    glm::mat4 widgetMatrix = _orbit.getLookAlongMatrix(time);
-    _widget.setModelMatrix(widgetMatrix);
-    _widget.render(time);
-
-    // render sphere
-    _sphere.setPosition(pos);
-    _sphere.render(time);
-}
-
-Orbiter::~Orbiter()
-{
-}

src/orbiter.hpp

@@ -1,37 +1,15 @@
 #pragma once
 
-#include "gfx.hpp"
-#include "icosphere.hpp"
-#include "widget.hpp"
-
-#include <GLFW/glfw3.h>
 #include <skein/orbit.h>
 
 class Orbiter
 {
 public:
-    Orbiter(Icosphere& sphere, Orbit& orbit, GLuint shaderProgram);
-    ~Orbiter();
+    Orbiter() = default;
+    ~Orbiter() = default;
 
-    void render(const float time);
-
-    void cycleAnimation();
+    Orbit& getOrbit();
 
 private:
-    void updateModelMatrix();
-    float getMeanAnomaly();
-    glm::vec3 getPosition(const float time);
-    void getOrbitalElements(const float time, Vector6& keplerianElements);
-
-    Icosphere& _sphere;
-    Orbit& _orbit;
-    Widget _widget;
-
-    const float ORBITAL_PERIOD = 6.284;
-
-    // TODO: convert these to an enum
-    const int ANIM_ORBITING     = 0;
-    const int ANIM_ECCENTRICITY = 1;
-
-    int _animation = ANIM_ORBITING;
+    Orbit _orbit;
 };

src/orbitervisualizer.cpp

@@ -0,0 +1,23 @@
+#include "orbitervisualizer.hpp"
+
+OrbiterVisualizer::OrbiterVisualizer(Orbiter& orbiter, Icosphere& sphere, GLuint shaderProgram)
+    : _orbiter(orbiter), _sphere(sphere), _widget(shaderProgram)
+{
+}
+
+void OrbiterVisualizer::render(float time)
+{
+    const Orbit& orbit = _orbiter.getOrbit();
+
+    const float meanAnomaly = time;
+    glm::vec3 pos = orbit.getPosition(meanAnomaly);
+
+    // render widget
+    glm::mat4 widgetMatrix = orbit.getLookAlongMatrix(time);
+    _widget.setModelMatrix(widgetMatrix);
+    _widget.render(time);
+
+    // render sphere
+    _sphere.setPosition(pos);
+    _sphere.render(time);
+}

src/orbitervisualizer.hpp

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "widget.hpp"
+#include "icosphere.hpp"
+#include "orbiter.hpp"
+
+class OrbiterVisualizer
+{
+    public:
+        OrbiterVisualizer(Orbiter& orbiter, Icosphere& sphere, GLuint shaderProgram);
+        ~OrbiterVisualizer() = default;
+
+        void render(float time);
+
+    private:
+        void updateModelMatrix();
+
+        Orbiter& _orbiter;
+        Icosphere& _sphere;
+        Widget _widget;
+};

src/orbitvisualizer.cpp

@@ -6,12 +6,12 @@ OrbitVisualizer::OrbitVisualizer(const Orbit& orbit, const GLuint shaderProgram)
 {
     glGenVertexArrays(1, &_vao);
     glGenBuffers(1, &_vbo);
-
-    regenerateVertices();
 }
 
 void OrbitVisualizer::render(const float time)
 {
+    regenerateVertices();
+
     glUseProgram(_shaderProgram);
     updateModelViewProjectionMatrix(_shaderProgram, time);