#include "Body.hpp"
+#include "Orbit.hpp"
#include "Planet.hpp"
#include "Simulation.hpp"
#include "Sun.hpp"
#include <algorithm>
#include <cmath>
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtx/euler_angles.hpp>
#include <glm/gtx/transform.hpp>
using blobs::G;
, children()
, mass(1.0)
, radius(1.0)
-, sma(1.0)
-, ecc(0.0)
-, inc(0.0)
-, asc(0.0)
-, arg(0.0)
-, mna(0.0) {
+, orbit()
+, surface_tilt(0.0, 0.0)
+, axis_tilt(0.0, 0.0)
+, rotation(0.0)
+, angular(0.0) {
}
Body::~Body() {
}
}
-double Body::Mass() const noexcept {
- return mass;
+double Body::Inertia() const noexcept {
+ // assume solid sphere for now
+ return (2.0/5.0) * Mass() * pow(Radius(), 2);
+}
+
+double Body::GravitationalParameter() const noexcept {
+ return G * Mass();
+}
+
+double Body::OrbitalPeriod() const noexcept {
+ if (parent) {
+ return PI_2p0 * sqrt(pow(orbit.SemiMajorAxis(), 3) / (G * (parent->Mass() + Mass())));
+ } else {
+ return 0.0;
+ }
+}
+
+double Body::RotationalPeriod() const noexcept {
+ if (std::abs(angular) < std::numeric_limits<double>::epsilon()) {
+ return std::numeric_limits<double>::infinity();
+ } else {
+ return PI_2p0 * Inertia() / angular;
+ }
+}
+
+glm::dmat4 Body::LocalTransform() const noexcept {
+ glm::dmat4 srf = glm::eulerAngleXY(surface_tilt.x, surface_tilt.y);
+ glm::dmat4 rot = glm::eulerAngleY(rotation);
+ glm::dmat4 tilt = glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
+ return tilt * rot * srf;
}
-void Body::Mass(double m) noexcept {
- mass = m;
+glm::dmat4 Body::InverseTransform() const noexcept {
+ glm::dmat4 srf = glm::eulerAngleYX(-surface_tilt.y, -surface_tilt.x);
+ glm::dmat4 rot = glm::eulerAngleY(-rotation);
+ glm::dmat4 tilt = glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x);
+ return srf * rot * tilt;
+}
+
+glm::dmat4 Body::ToParent() const noexcept {
+ if (!parent) {
+ return glm::dmat4(1.0);
+ }
+ return orbit.InverseMatrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()));
+}
+
+glm::dmat4 Body::FromParent() const noexcept {
+ if (!parent) {
+ return glm::dmat4(1.0);
+ }
+ return orbit.Matrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()));
}
-double Body::Radius() const noexcept {
- return radius;
+
+Orbit::Orbit()
+: sma(1.0)
+, ecc(0.0)
+, inc(0.0)
+, asc(0.0)
+, arg(0.0)
+, mna(0.0) {
}
-void Body::Radius(double r) noexcept {
- radius = r;
+Orbit::~Orbit() {
}
-double Body::SemiMajorAxis() const noexcept {
+double Orbit::SemiMajorAxis() const noexcept {
return sma;
}
-void Body::SemiMajorAxis(double s) noexcept {
+Orbit &Orbit::SemiMajorAxis(double s) noexcept {
sma = s;
+ return *this;
}
-double Body::Eccentricity() const noexcept {
+double Orbit::Eccentricity() const noexcept {
return ecc;
}
-void Body::Eccentricity(double e) noexcept {
+Orbit &Orbit::Eccentricity(double e) noexcept {
ecc = e;
+ return *this;
}
-double Body::Inclination() const noexcept {
+double Orbit::Inclination() const noexcept {
return inc;
}
-void Body::Inclination(double i) noexcept {
+Orbit &Orbit::Inclination(double i) noexcept {
inc = i;
+ return *this;
}
-double Body::LongitudeAscending() const noexcept {
+double Orbit::LongitudeAscending() const noexcept {
return asc;
}
-void Body::LongitudeAscending(double l) noexcept {
+Orbit &Orbit::LongitudeAscending(double l) noexcept {
asc = l;
+ return *this;
}
-double Body::ArgumentPeriapsis() const noexcept {
+double Orbit::ArgumentPeriapsis() const noexcept {
return arg;
}
-void Body::ArgumentPeriapsis(double a) noexcept {
+Orbit &Orbit::ArgumentPeriapsis(double a) noexcept {
arg = a;
+ return *this;
}
-double Body::MeanAnomaly() const noexcept {
+double Orbit::MeanAnomaly() const noexcept {
return mna;
}
-void Body::MeanAnomaly(double m) noexcept {
+Orbit &Orbit::MeanAnomaly(double m) noexcept {
mna = m;
+ return *this;
}
-double Body::GravitationalParameter() const noexcept {
- return G * Mass();
-}
-
-double Body::OrbitalPeriod() const noexcept {
- if (parent) {
- return PI_2p0 * sqrt((sma * sma * sma) / (G * (parent->Mass() + Mass())));
- } else {
- return 0.0;
- }
-}
-
-glm::mat4 Body::ToParent() const noexcept {
- if (!parent) {
- return glm::mat4(1.0f);
- }
-
- double T = OrbitalPeriod();
-
- double M = mna + PI_2p0 * (GetSimulation().Time() / T); // + time
+namespace {
+double mean2eccentric(double M, double e) {
double E = M; // eccentric anomaly, solve M = E - e sin E
- while (true) {
- double dE = (E - ecc * sin(E) - M) / (1 - ecc * cos(E));
+ // limit to 100 steps to prevent deadlocks in impossible situations
+ for (int i = 0; i < 100; ++i) {
+ double dE = (E - e * sin(E) - M) / (1 - e * cos(E));
E -= dE;
if (abs(dE) < 1.0e-6) break;
}
+ return E;
+}
- // coordinates in orbital plane
+}
+
+glm::dmat4 Orbit::Matrix(double t) const noexcept {
+ double M = mna + t;
+ double E = mean2eccentric(M, ecc);
+
+ // coordinates in orbital plane, P=x, Q=-z
double P = sma * (cos(E) - ecc);
double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
- // tile by argument of periapsis, …
- double x = cos(arg) * P - sin(arg) * Q;
- double y = sin(arg) * P + cos(arg) * Q;
- // …inclination, …
- double z = sin(inc) * x;
- x = cos(inc) * x;
- // …and longitude of ascending node
- glm::vec3 pos(
- cos(asc) * x - sin(asc) * y,
- sin(asc) * x + cos(asc) * y,
- z);
-
- // TODO: calculate complete matrix
- return glm::translate(-pos);
+ return glm::translate(glm::yawPitchRoll(asc, inc, arg), glm::dvec3(P, 0.0, -Q));
}
-glm::mat4 Body::FromParent() const noexcept {
- if (!parent) {
- return glm::mat4(1.0f);
- }
- // TODO: calculate real position
- return glm::translate(glm::vec3(-sma, 0.0f, 0.0f));
+glm::dmat4 Orbit::InverseMatrix(double t) const noexcept {
+ double M = mna + t;
+ double E = mean2eccentric(M, ecc);
+ double P = sma * (cos(E) - ecc);
+ double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
+ return glm::transpose(glm::yawPitchRoll(asc, inc, arg)) * glm::translate(glm::dvec3(-P, 0.0, Q));
}
, sidelength(sidelength)
, tiles(new Tile[TilesTotal()])
, vao() {
+ Radius(double(sidelength) / 2.0);
}
Planet::~Planet() {
projects / blobs.git / blobdiff