#include "Body.hpp"
+#include "Orbit.hpp"
#include "Planet.hpp"
#include "Simulation.hpp"
#include "Sun.hpp"
#include "Tile.hpp"
+#include "TileSet.hpp"
+#include "TileType.hpp"
#include "../const.hpp"
#include "../app/Assets.hpp"
#include "../graphics/Viewport.hpp"
+#include "../rand/OctaveNoise.hpp"
+#include "../rand/SimplexNoise.hpp"
#include <algorithm>
#include <cmath>
+#include <iostream>
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtx/euler_angles.hpp>
+#include <glm/gtx/io.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)
+, orbital(1.0)
+, inverse_orbital(1.0)
+, local(1.0)
+, inverse_local(1.0) {
}
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);
}
-void Body::Mass(double m) noexcept {
- mass = m;
+double Body::GravitationalParameter() const noexcept {
+ return G * Mass();
}
-double Body::Radius() const noexcept {
- return radius;
+double Body::OrbitalPeriod() const noexcept {
+ if (parent) {
+ return PI_2p0 * sqrt(pow(orbit.SemiMajorAxis(), 3) / (G * (parent->Mass() + Mass())));
+ } else {
+ return 0.0;
+ }
}
-void Body::Radius(double r) noexcept {
- radius = r;
+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;
}
-double Body::SemiMajorAxis() const noexcept {
+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;
}
-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();
-}
+namespace {
-double Body::OrbitalPeriod() const noexcept {
- if (parent) {
- return PI_2p0 * sqrt((sma * sma * sma) / (G * (parent->Mass() + Mass())));
- } else {
- return 0.0;
+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::mat4 Body::ToParent() const noexcept {
- if (!parent) {
- return glm::mat4(1.0f);
- }
+}
- double T = OrbitalPeriod();
+glm::dmat4 Orbit::Matrix(double t) const noexcept {
+ double M = mna + t;
+ double E = mean2eccentric(M, ecc);
- double M = mna + PI_2p0 * (GetSimulation().Time() / T); // + time
+ // coordinates in orbital plane, P=x, Q=-z
+ double P = sma * (cos(E) - ecc);
+ double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
- double E = M; // eccentric anomaly, solve M = E - e sin E
- while (true) {
- double dE = (E - ecc * sin(E) - M) / (1 - ecc * cos(E));
- E -= dE;
- if (abs(dE) < 1.0e-6) break;
- }
+ return glm::yawPitchRoll(asc, inc, arg) * glm::translate(glm::dvec3(P, 0.0, -Q));
+}
- // coordinates in orbital plane
+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));
-
- // 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);
-}
-
-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));
+ return glm::translate(glm::dvec3(-P, 0.0, Q)) * glm::transpose(glm::yawPitchRoll(asc, inc, arg));
}
, sidelength(sidelength)
, tiles(new Tile[TilesTotal()])
, vao() {
+ Radius(double(sidelength) / 2.0);
}
Planet::~Planet() {
}
-void Planet::BuildVAOs() {
+glm::dvec3 Planet::TileCenter(int surface, int x, int y) const noexcept {
+ glm::dvec3 center(0.0f);
+ center[(surface + 0) % 3] = x + 0.5 - Radius();
+ center[(surface + 1) % 3] = y + 0.5 - Radius();
+ center[(surface + 2) % 3] = surface < 3 ? Radius() : -Radius();
+ return center;
+}
+
+void Planet::BuildVAOs(const TileSet &ts) {
vao.Bind();
vao.BindAttributes();
vao.EnableAttribute(0);
vao.ReserveAttributes(TilesTotal() * 4, GL_STATIC_DRAW);
{
auto attrib = vao.MapAttributes(GL_WRITE_ONLY);
- float offset = sidelength * 0.5f;
+ float offset = Radius();
+
+ // 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) {
- float tex = TileAt(surface, x, y).type;
+ float tex = ts[TileAt(surface, x, y).type].texture;
+ const float tex_u_begin = surface < 3 ? 1.0f : 0.0f;
+ const float tex_u_end = surface < 3 ? 0.0f : 1.0f;
attrib[4 * index + 0].position[(surface + 0) % 3] = x + 0 - offset;
attrib[4 * index + 0].position[(surface + 1) % 3] = y + 0 - offset;
attrib[4 * index + 0].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
- attrib[4 * index + 0].tex_coord[0] = 0.0f;
- attrib[4 * index + 0].tex_coord[1] = 0.0f;
+ attrib[4 * index + 0].tex_coord[0] = tex_u_begin;
+ attrib[4 * index + 0].tex_coord[1] = 1.0f;
attrib[4 * index + 0].tex_coord[2] = tex;
attrib[4 * index + 1].position[(surface + 0) % 3] = x + 0 - offset;
attrib[4 * index + 1].position[(surface + 1) % 3] = y + 1 - offset;
attrib[4 * index + 1].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
- attrib[4 * index + 1].tex_coord[0] = 0.0f;
+ attrib[4 * index + 1].tex_coord[0] = tex_u_end;
attrib[4 * index + 1].tex_coord[1] = 1.0f;
attrib[4 * index + 1].tex_coord[2] = tex;
attrib[4 * index + 2].position[(surface + 0) % 3] = x + 1 - offset;
attrib[4 * index + 2].position[(surface + 1) % 3] = y + 0 - offset;
attrib[4 * index + 2].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
- attrib[4 * index + 2].tex_coord[0] = 1.0f;
+ attrib[4 * index + 2].tex_coord[0] = tex_u_begin;
attrib[4 * index + 2].tex_coord[1] = 0.0f;
attrib[4 * index + 2].tex_coord[2] = tex;
attrib[4 * index + 3].position[(surface + 0) % 3] = x + 1 - offset;
attrib[4 * index + 3].position[(surface + 1) % 3] = y + 1 - offset;
attrib[4 * index + 3].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
- attrib[4 * index + 3].tex_coord[0] = 1.0f;
- attrib[4 * index + 3].tex_coord[1] = 1.0f;
+ attrib[4 * index + 3].tex_coord[0] = tex_u_end;
+ attrib[4 * index + 3].tex_coord[1] = 0.0f;
attrib[4 * index + 3].tex_coord[2] = tex;
}
}
}
-void GenerateTest(Planet &p) {
+void GenerateEarthlike(const TileSet &tiles, Planet &p) noexcept {
+ rand::SimplexNoise elevation_gen(0);
+
+ const int ice = tiles["ice"].id;
+ const int grass = tiles["grass"].id;
+ const int water = tiles["water"].id;
+ const int sand = tiles["sand"].id;
+ const int rock = tiles["rock"].id;
+
+ constexpr double water_thresh = 0.0;
+ constexpr double beach_thresh = 0.1;
+ constexpr double mountain_thresh = 0.5;
+
+ const glm::dvec3 axis(glm::dvec4(0.0, 1.0, 0.0, 0.0) * glm::eulerAngleXY(p.SurfaceTilt().x, p.SurfaceTilt().y));
+ const double cap_thresh = std::cos(p.AxialTilt().x);
+
+ for (int surface = 0; surface <= 5; ++surface) {
+ for (int y = 0; y < p.SideLength(); ++y) {
+ for (int x = 0; x < p.SideLength(); ++x) {
+ glm::dvec3 to_tile = p.TileCenter(surface, x, y);
+ double near_axis = std::abs(glm::dot(glm::normalize(to_tile), axis));
+ if (near_axis > cap_thresh) {
+ p.TileAt(surface, x, y).type = ice;
+ continue;
+ }
+ float elevation = rand::OctaveNoise(
+ elevation_gen,
+ to_tile / p.Radius(),
+ 3, // octaves
+ 0.5, // persistence
+ 2 / p.Radius(), // frequency
+ 2, // amplitude
+ 2 // growth
+ );
+ if (elevation < water_thresh) {
+ p.TileAt(surface, x, y).type = water;
+ } else if (elevation < beach_thresh) {
+ p.TileAt(surface, x, y).type = sand;
+ } else if (elevation < mountain_thresh) {
+ p.TileAt(surface, x, y).type = grass;
+ } else {
+ p.TileAt(surface, x, y).type = rock;
+ }
+ }
+ }
+ }
+ p.BuildVAOs(tiles);
+}
+
+void GenerateTest(const TileSet &tiles, Planet &p) noexcept {
for (int surface = 0; surface <= 5; ++surface) {
for (int y = 0; y < p.SideLength(); ++y) {
for (int x = 0; x < p.SideLength(); ++x) {
- p.TileAt(surface, x, y).type = (x == p.SideLength()/2) + (y == p.SideLength()/2);
+ if (x == p.SideLength() / 2 && y == p.SideLength() / 2) {
+ p.TileAt(surface, x, y).type = surface;
+ } else {
+ p.TileAt(surface, x, y).type = (x == p.SideLength()/2) + (y == p.SideLength()/2) + 6;
+ }
}
}
}
- p.BuildVAOs();
+ p.BuildVAOs(tiles);
}
Sun::~Sun() {
}
+TileSet::TileSet()
+: types()
+, names() {
+}
+
+TileSet::~TileSet() {
+}
+
+int TileSet::Add(const TileType &t) {
+ int id = types.size();
+ if (!names.emplace(t.name, id).second) {
+ throw std::runtime_error("duplicate tile type name " + t.name);
+ }
+ types.emplace_back(t);
+ types.back().id = id;
+ return id;
+}
+
+TileType &TileSet::operator [](const std::string &name) {
+ auto entry = names.find(name);
+ if (entry != names.end()) {
+ return types[entry->second];
+ } else {
+ throw std::runtime_error("unknown tile type " + name);
+ }
+}
+
+const TileType &TileSet::operator [](const std::string &name) const {
+ auto entry = names.find(name);
+ if (entry != names.end()) {
+ return types[entry->second];
+ } else {
+ throw std::runtime_error("unknown tile type " + name);
+ }
+}
+
}
}