#include "Body.hpp"
+#include "Orbit.hpp"
#include "Planet.hpp"
+#include "Simulation.hpp"
#include "Sun.hpp"
#include "Tile.hpp"
+#include "../const.hpp"
#include "../app/Assets.hpp"
#include "../graphics/Viewport.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;
+using blobs::PI_2p0;
+
+using std::sin;
+using std::cos;
+using std::pow;
+using std::sqrt;
namespace blobs {
namespace world {
Body::Body()
-: parent(nullptr)
+: sim(nullptr)
+, parent(nullptr)
, children()
, mass(1.0)
-, radius(1.0) {
+, radius(1.0)
+, orbit()
+, surface_tilt(0.0, 0.0)
+, axis_tilt(0.0, 0.0)
+, rotation(0.0)
+, angular(0.0)
+, orbital(1.0)
+, inverse_orbital(1.0)
+, local(1.0)
+, inverse_local(1.0) {
}
Body::~Body() {
}
+void Body::SetSimulation(Simulation &s) noexcept {
+ sim = &s;
+ for (auto child : children) {
+ child->SetSimulation(s);
+ }
+}
+
void Body::SetParent(Body &p) {
if (HasParent()) {
UnsetParent();
void Body::AddChild(Body &c) {
children.push_back(&c);
+ c.SetSimulation(*sim);
}
void Body::RemoveChild(Body &c) {
}
}
+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::ToUniverse() const noexcept {
+ glm::dmat4 m(1.0);
+ const Body *b = this;
+ while (b->HasParent()) {
+ m = b->ToParent() * m;
+ b = &b->Parent();
+ }
+ return m;
+}
+
+glm::dmat4 Body::FromUniverse() const noexcept {
+ glm::dmat4 m(1.0);
+ const Body *b = this;
+ while (b->HasParent()) {
+ m *= b->FromParent();
+ b = &b->Parent();
+ }
+ return m;
+}
+
+void Body::Cache() noexcept {
+ if (parent) {
+ orbital =
+ orbit.Matrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()))
+ * glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
+ inverse_orbital =
+ glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x)
+ * orbit.InverseMatrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()));
+ } else {
+ orbital = glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
+ inverse_orbital = glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x);
+ }
+ local =
+ glm::eulerAngleY(rotation)
+ * glm::eulerAngleXY(surface_tilt.x, surface_tilt.y);
+ inverse_local =
+ glm::eulerAngleYX(-surface_tilt.y, -surface_tilt.x)
+ * glm::eulerAngleY(-rotation);
+}
+
+
+Orbit::Orbit()
+: sma(1.0)
+, ecc(0.0)
+, inc(0.0)
+, asc(0.0)
+, arg(0.0)
+, mna(0.0) {
+}
+
+Orbit::~Orbit() {
+}
+
+double Orbit::SemiMajorAxis() const noexcept {
+ return sma;
+}
+
+Orbit &Orbit::SemiMajorAxis(double s) noexcept {
+ sma = s;
+ return *this;
+}
+
+double Orbit::Eccentricity() const noexcept {
+ return ecc;
+}
+
+Orbit &Orbit::Eccentricity(double e) noexcept {
+ ecc = e;
+ return *this;
+}
+
+double Orbit::Inclination() const noexcept {
+ return inc;
+}
+
+Orbit &Orbit::Inclination(double i) noexcept {
+ inc = i;
+ return *this;
+}
+
+double Orbit::LongitudeAscending() const noexcept {
+ return asc;
+}
+
+Orbit &Orbit::LongitudeAscending(double l) noexcept {
+ asc = l;
+ return *this;
+}
+
+double Orbit::ArgumentPeriapsis() const noexcept {
+ return arg;
+}
+
+Orbit &Orbit::ArgumentPeriapsis(double a) noexcept {
+ arg = a;
+ return *this;
+}
+
+double Orbit::MeanAnomaly() const noexcept {
+ return mna;
+}
+
+Orbit &Orbit::MeanAnomaly(double m) noexcept {
+ mna = m;
+ return *this;
+}
+
+namespace {
+
+double mean2eccentric(double M, double e) {
+ double E = M; // eccentric anomaly, solve M = E - e sin 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;
+}
+
+}
+
+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));
+
+ return glm::translate(glm::yawPitchRoll(asc, inc, arg), glm::dvec3(P, 0.0, -Q));
+}
+
+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));
+}
+
Planet::Planet(int sidelength)
: Body()
, sidelength(sidelength)
, tiles(new Tile[TilesTotal()])
, vao() {
+ Radius(double(sidelength) / 2.0);
}
Planet::~Planet() {
auto attrib = vao.MapAttributes(GL_WRITE_ONLY);
float offset = sidelength * 0.5f;
+ // srf 0 1 2 3 4 5
+ // up +Z +X +Y -Z -X -Y
+
for (int index = 0, surface = 0; surface < 6; ++surface) {
for (int y = 0; y < sidelength; ++y) {
for (int x = 0; x < sidelength; ++x, ++index) {
vao.ReserveElements(TilesTotal() * 6, GL_STATIC_DRAW);
{
auto element = vao.MapElements(GL_WRITE_ONLY);
- for (int index = 0, surface = 0; surface < 6; ++surface) {
+ int index = 0;
+ for (int surface = 0; surface < 3; ++surface) {
+ for (int y = 0; y < sidelength; ++y) {
+ for (int x = 0; x < sidelength; ++x, ++index) {
+ element[6 * index + 0] = 4 * index + 0;
+ element[6 * index + 1] = 4 * index + 2;
+ element[6 * index + 2] = 4 * index + 1;
+ element[6 * index + 3] = 4 * index + 1;
+ element[6 * index + 4] = 4 * index + 2;
+ element[6 * index + 5] = 4 * index + 3;
+ }
+ }
+ }
+ for (int surface = 3; surface < 6; ++surface) {
for (int y = 0; y < sidelength; ++y) {
for (int x = 0; x < sidelength; ++x, ++index) {
element[6 * index + 0] = 4 * index + 0;
void Planet::Draw(app::Assets &assets, graphics::Viewport &viewport) {
vao.Bind();
- // TODO: premultiply normal with model matrix (i.e. just take it from M)
- assets.shaders.planet_surface.SetNormal(glm::vec3(0.0f, 0.0f, 1.0f));
- vao.DrawTriangles(TilesTotal() * 4, TilesTotal() * 4 * 0);
- assets.shaders.planet_surface.SetNormal(glm::vec3(1.0f, 0.0f, 0.0f));
- vao.DrawTriangles(TilesTotal() * 4, TilesTotal() * 4 * 1);
- assets.shaders.planet_surface.SetNormal(glm::vec3(0.0f, 1.0f, 0.0f));
- vao.DrawTriangles(TilesTotal() * 4, TilesTotal() * 4 * 2);
- assets.shaders.planet_surface.SetNormal(glm::vec3(0.0f, 0.0f, -1.0f));
- vao.DrawTriangles(TilesTotal() * 4, TilesTotal() * 4 * 3);
- assets.shaders.planet_surface.SetNormal(glm::vec3(-1.0f, 0.0f, 0.0f));
- vao.DrawTriangles(TilesTotal() * 4, TilesTotal() * 4 * 4);
- assets.shaders.planet_surface.SetNormal(glm::vec3(0.0f, -1.0f, 0.0f));
- vao.DrawTriangles(TilesTotal() * 4, TilesTotal() * 4 * 5);
+ const glm::mat4 &MV = assets.shaders.planet_surface.MV();
+ assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, 1.0f, 0.0f)));
+ vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 0);
+ assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(1.0f, 0.0f, 0.0f, 0.0f)));
+ vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 1);
+ assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 1.0f, 0.0f, 0.0f)));
+ vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 2);
+ assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, -1.0f, 0.0f)));
+ vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 3);
+ assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(-1.0f, 0.0f, 0.0f, 0.0f)));
+ vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 4);
+ assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, -1.0f, 0.0f, 0.0f)));
+ vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 5);
}