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1 #include "Body.hpp"
2 #include "Orbit.hpp"
3 #include "Planet.hpp"
4 #include "Resource.hpp"
5 #include "Set.hpp"
6 #include "Simulation.hpp"
7 #include "Sun.hpp"
8 #include "Tile.hpp"
9 #include "TileType.hpp"
10
11 #include "../const.hpp"
12 #include "../app/Assets.hpp"
13 #include "../creature/Creature.hpp"
14 #include "../graphics/Viewport.hpp"
15 #include "../rand/OctaveNoise.hpp"
16 #include "../rand/SimplexNoise.hpp"
17
18 #include <algorithm>
19 #include <cmath>
20 #include <iostream>
21 #include <glm/gtc/matrix_transform.hpp>
22 #include <glm/gtx/euler_angles.hpp>
23 #include <glm/gtx/io.hpp>
24 #include <glm/gtx/transform.hpp>
25
26 using blobs::G;
27 using blobs::PI_2p0;
28
29 using std::sin;
30 using std::cos;
31 using std::pow;
32 using std::sqrt;
33
34
35 namespace blobs {
36 namespace world {
37
38 Body::Body()
39 : sim(nullptr)
40 , parent(nullptr)
41 , children()
42 , mass(1.0)
43 , radius(1.0)
44 , orbit()
45 , surface_tilt(0.0, 0.0)
46 , axis_tilt(0.0, 0.0)
47 , rotation(0.0)
48 , angular(0.0)
49 , orbital(1.0)
50 , inverse_orbital(1.0)
51 , local(1.0)
52 , inverse_local(1.0)
53 , creatures()
54 , atmosphere(-1) {
55 }
56
57 Body::~Body() {
58         for (creature::Creature *c : creatures) {
59                 delete c;
60         }
61 }
62
63 void Body::SetSimulation(Simulation &s) noexcept {
64         sim = &s;
65         for (auto child : children) {
66                 child->SetSimulation(s);
67         }
68 }
69
70 void Body::SetParent(Body &p) {
71         if (HasParent()) {
72                 UnsetParent();
73         }
74         parent = &p;
75         parent->AddChild(*this);
76 }
77
78 void Body::UnsetParent() {
79         if (!HasParent()) return;
80         parent->RemoveChild(*this);
81         parent = nullptr;
82 }
83
84 void Body::AddChild(Body &c) {
85         children.push_back(&c);
86         c.SetSimulation(*sim);
87 }
88
89 void Body::RemoveChild(Body &c) {
90         auto entry = std::find(children.begin(), children.end(), &c);
91         if (entry != children.end()) {
92                 children.erase(entry);
93         }
94 }
95
96 double Body::Inertia() const noexcept {
97         // assume solid sphere for now
98         return (2.0/5.0) * Mass() * pow(Radius(), 2);
99 }
100
101 double Body::GravitationalParameter() const noexcept {
102         return G * Mass();
103 }
104
105 double Body::OrbitalPeriod() const noexcept {
106         if (parent) {
107                 return PI_2p0 * sqrt(pow(orbit.SemiMajorAxis(), 3) / (G * (parent->Mass() + Mass())));
108         } else {
109                 return 0.0;
110         }
111 }
112
113 double Body::RotationalPeriod() const noexcept {
114         if (std::abs(angular) < std::numeric_limits<double>::epsilon()) {
115                 return std::numeric_limits<double>::infinity();
116         } else {
117                 return PI_2p0 * Inertia() / angular;
118         }
119 }
120
121 glm::dmat4 Body::ToUniverse() const noexcept {
122         glm::dmat4 m(1.0);
123         const Body *b = this;
124         while (b->HasParent()) {
125                 m = b->ToParent() * m;
126                 b = &b->Parent();
127         }
128         return m;
129 }
130
131 glm::dmat4 Body::FromUniverse() const noexcept {
132         glm::dmat4 m(1.0);
133         const Body *b = this;
134         while (b->HasParent()) {
135                 m *= b->FromParent();
136                 b = &b->Parent();
137         }
138         return m;
139 }
140
141 void Body::Tick(double dt) {
142         rotation += dt * AngularMomentum() / Inertia();
143         Cache();
144         for (creature::Creature *c : Creatures()) {
145                 c->Tick(dt);
146         }
147 }
148
149 void Body::Cache() noexcept {
150         if (parent) {
151                 orbital =
152                         orbit.Matrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()))
153                         * glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
154                 inverse_orbital =
155                         glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x)
156                         * orbit.InverseMatrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()));
157         } else {
158                 orbital = glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
159                 inverse_orbital = glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x);
160         }
161         local =
162                 glm::eulerAngleY(rotation)
163                 * glm::eulerAngleXY(surface_tilt.x, surface_tilt.y);
164         inverse_local =
165                 glm::eulerAngleYX(-surface_tilt.y, -surface_tilt.x)
166                 * glm::eulerAngleY(-rotation);
167 }
168
169 void Body::AddCreature(creature::Creature *c) {
170         creatures.push_back(c);
171 }
172
173 void Body::RemoveCreature(creature::Creature *c) {
174         auto entry = std::find(creatures.begin(), creatures.end(), c);
175         if (entry != creatures.end()) {
176                 creatures.erase(entry);
177         }
178 }
179
180
181 Orbit::Orbit()
182 : sma(1.0)
183 , ecc(0.0)
184 , inc(0.0)
185 , asc(0.0)
186 , arg(0.0)
187 , mna(0.0) {
188 }
189
190 Orbit::~Orbit() {
191 }
192
193 double Orbit::SemiMajorAxis() const noexcept {
194         return sma;
195 }
196
197 Orbit &Orbit::SemiMajorAxis(double s) noexcept {
198         sma = s;
199         return *this;
200 }
201
202 double Orbit::Eccentricity() const noexcept {
203         return ecc;
204 }
205
206 Orbit &Orbit::Eccentricity(double e) noexcept {
207         ecc = e;
208         return *this;
209 }
210
211 double Orbit::Inclination() const noexcept {
212         return inc;
213 }
214
215 Orbit &Orbit::Inclination(double i) noexcept {
216         inc = i;
217         return *this;
218 }
219
220 double Orbit::LongitudeAscending() const noexcept {
221         return asc;
222 }
223
224 Orbit &Orbit::LongitudeAscending(double l) noexcept {
225         asc = l;
226         return *this;
227 }
228
229 double Orbit::ArgumentPeriapsis() const noexcept {
230         return arg;
231 }
232
233 Orbit &Orbit::ArgumentPeriapsis(double a) noexcept {
234         arg = a;
235         return *this;
236 }
237
238 double Orbit::MeanAnomaly() const noexcept {
239         return mna;
240 }
241
242 Orbit &Orbit::MeanAnomaly(double m) noexcept {
243         mna = m;
244         return *this;
245 }
246
247 namespace {
248
249 double mean2eccentric(double M, double e) {
250         double E = M; // eccentric anomaly, solve M = E - e sin E
251         // limit to 100 steps to prevent deadlocks in impossible situations
252         for (int i = 0; i < 100; ++i) {
253                 double dE = (E - e * sin(E) - M) / (1 - e * cos(E));
254                 E -= dE;
255                 if (abs(dE) < 1.0e-6) break;
256         }
257         return E;
258 }
259
260 }
261
262 glm::dmat4 Orbit::Matrix(double t) const noexcept {
263         double M = mna + t;
264         double E = mean2eccentric(M, ecc);
265
266         // coordinates in orbital plane, P=x, Q=-z
267         double P = sma * (cos(E) - ecc);
268         double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
269
270         return glm::yawPitchRoll(asc, inc, arg) * glm::translate(glm::dvec3(P, 0.0, -Q));
271 }
272
273 glm::dmat4 Orbit::InverseMatrix(double t) const noexcept {
274         double M = mna + t;
275         double E = mean2eccentric(M, ecc);
276         double P = sma * (cos(E) - ecc);
277         double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
278         return glm::translate(glm::dvec3(-P, 0.0, Q)) * glm::transpose(glm::yawPitchRoll(asc, inc, arg));
279 }
280
281
282 Planet::Planet(int sidelength)
283 : Body()
284 , sidelength(sidelength)
285 , tiles(TilesTotal())
286 , vao() {
287         Radius(double(sidelength) / 2.0);
288 }
289
290 Planet::~Planet() {
291 }
292
293 const TileType &Planet::TypeAt(int surface, int x, int y) const {
294         return GetSimulation().TileTypes()[TileAt(surface, x, y).type];
295 }
296
297 glm::dvec3 Planet::TileCenter(int surface, int x, int y) const noexcept {
298         glm::dvec3 center(0.0f);
299         center[(surface + 0) % 3] = x + 0.5 - Radius();
300         center[(surface + 1) % 3] = y + 0.5 - Radius();
301         center[(surface + 2) % 3] = surface < 3 ? Radius() : -Radius();
302         return center;
303 }
304
305 void Planet::BuildVAO(const Set<TileType> &ts) {
306         vao.Bind();
307         vao.BindAttributes();
308         vao.EnableAttribute(0);
309         vao.EnableAttribute(1);
310         vao.AttributePointer<glm::vec3>(0, false, offsetof(Attributes, position));
311         vao.AttributePointer<glm::vec3>(1, false, offsetof(Attributes, tex_coord));
312         vao.ReserveAttributes(TilesTotal() * 4, GL_STATIC_DRAW);
313         {
314                 auto attrib = vao.MapAttributes(GL_WRITE_ONLY);
315                 float offset = Radius();
316
317                 // srf  0  1  2  3  4  5
318                 //  up +Z +X +Y -Z -X -Y
319
320                 for (int index = 0, surface = 0; surface < 6; ++surface) {
321                         for (int y = 0; y < sidelength; ++y) {
322                                 for (int x = 0; x < sidelength; ++x, ++index) {
323                                         float tex = ts[TileAt(surface, x, y).type].texture;
324                                         const float tex_u_begin = surface < 3 ? 1.0f : 0.0f;
325                                         const float tex_u_end = surface < 3 ? 0.0f : 1.0f;
326                                         attrib[4 * index + 0].position[(surface + 0) % 3] = x + 0 - offset;
327                                         attrib[4 * index + 0].position[(surface + 1) % 3] = y + 0 - offset;
328                                         attrib[4 * index + 0].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
329                                         attrib[4 * index + 0].tex_coord[0] = tex_u_begin;
330                                         attrib[4 * index + 0].tex_coord[1] = 1.0f;
331                                         attrib[4 * index + 0].tex_coord[2] = tex;
332
333                                         attrib[4 * index + 1].position[(surface + 0) % 3] = x + 0 - offset;
334                                         attrib[4 * index + 1].position[(surface + 1) % 3] = y + 1 - offset;
335                                         attrib[4 * index + 1].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
336                                         attrib[4 * index + 1].tex_coord[0] = tex_u_end;
337                                         attrib[4 * index + 1].tex_coord[1] = 1.0f;
338                                         attrib[4 * index + 1].tex_coord[2] = tex;
339
340                                         attrib[4 * index + 2].position[(surface + 0) % 3] = x + 1 - offset;
341                                         attrib[4 * index + 2].position[(surface + 1) % 3] = y + 0 - offset;
342                                         attrib[4 * index + 2].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
343                                         attrib[4 * index + 2].tex_coord[0] = tex_u_begin;
344                                         attrib[4 * index + 2].tex_coord[1] = 0.0f;
345                                         attrib[4 * index + 2].tex_coord[2] = tex;
346
347                                         attrib[4 * index + 3].position[(surface + 0) % 3] = x + 1 - offset;
348                                         attrib[4 * index + 3].position[(surface + 1) % 3] = y + 1 - offset;
349                                         attrib[4 * index + 3].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
350                                         attrib[4 * index + 3].tex_coord[0] = tex_u_end;
351                                         attrib[4 * index + 3].tex_coord[1] = 0.0f;
352                                         attrib[4 * index + 3].tex_coord[2] = tex;
353                                 }
354                         }
355                 }
356         }
357         vao.BindElements();
358         vao.ReserveElements(TilesTotal() * 6, GL_STATIC_DRAW);
359         {
360                 auto element = vao.MapElements(GL_WRITE_ONLY);
361                 int index = 0;
362                 for (int surface = 0; surface < 3; ++surface) {
363                         for (int y = 0; y < sidelength; ++y) {
364                                 for (int x = 0; x < sidelength; ++x, ++index) {
365                                         element[6 * index + 0] = 4 * index + 0;
366                                         element[6 * index + 1] = 4 * index + 2;
367                                         element[6 * index + 2] = 4 * index + 1;
368                                         element[6 * index + 3] = 4 * index + 1;
369                                         element[6 * index + 4] = 4 * index + 2;
370                                         element[6 * index + 5] = 4 * index + 3;
371                                 }
372                         }
373                 }
374                 for (int surface = 3; surface < 6; ++surface) {
375                         for (int y = 0; y < sidelength; ++y) {
376                                 for (int x = 0; x < sidelength; ++x, ++index) {
377                                         element[6 * index + 0] = 4 * index + 0;
378                                         element[6 * index + 1] = 4 * index + 1;
379                                         element[6 * index + 2] = 4 * index + 2;
380                                         element[6 * index + 3] = 4 * index + 2;
381                                         element[6 * index + 4] = 4 * index + 1;
382                                         element[6 * index + 5] = 4 * index + 3;
383                                 }
384                         }
385                 }
386         }
387         vao.Unbind();
388 }
389
390 void Planet::Draw(app::Assets &assets, graphics::Viewport &viewport) {
391         vao.Bind();
392         const glm::mat4 &MV = assets.shaders.planet_surface.MV();
393         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, 1.0f, 0.0f)));
394         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 0);
395         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(1.0f, 0.0f, 0.0f, 0.0f)));
396         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 1);
397         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 1.0f, 0.0f, 0.0f)));
398         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 2);
399         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, -1.0f, 0.0f)));
400         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 3);
401         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(-1.0f, 0.0f, 0.0f, 0.0f)));
402         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 4);
403         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, -1.0f, 0.0f, 0.0f)));
404         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 5);
405 }
406
407
408 void GenerateEarthlike(const Set<TileType> &tiles, Planet &p) noexcept {
409         rand::SimplexNoise elevation_gen(0);
410         rand::SimplexNoise variation_gen(45623752346);
411
412         const int ice = tiles["ice"].id;
413         const int ocean = tiles["ocean"].id;
414         const int water = tiles["water"].id;
415         const int sand = tiles["sand"].id;
416         const int grass = tiles["grass"].id;
417         const int tundra = tiles["tundra"].id;
418         const int taiga = tiles["taiga"].id;
419         const int desert = tiles["desert"].id;
420         const int mntn = tiles["mountain"].id;
421         const int algae = tiles["algae"].id;
422         const int forest = tiles["forest"].id;
423         const int jungle = tiles["jungle"].id;
424         const int rock = tiles["rock"].id;
425         const int wheat = tiles["wheat"].id;
426
427         constexpr double ocean_thresh = -0.2;
428         constexpr double water_thresh = 0.0;
429         constexpr double beach_thresh = 0.05;
430         constexpr double highland_thresh = 0.4;
431         constexpr double mountain_thresh = 0.5;
432
433         const glm::dvec3 axis(glm::dvec4(0.0, 1.0, 0.0, 0.0) * glm::eulerAngleXY(p.SurfaceTilt().x, p.SurfaceTilt().y));
434         const double cap_thresh = std::abs(std::cos(p.AxialTilt().x));
435         const double equ_thresh = std::abs(std::sin(p.AxialTilt().x)) / 2.0;
436         const double fzone_start = equ_thresh - (equ_thresh - cap_thresh) / 3.0;
437         const double fzone_end = cap_thresh + (equ_thresh - cap_thresh) / 3.0;
438
439         for (int surface = 0; surface <= 5; ++surface) {
440                 for (int y = 0; y < p.SideLength(); ++y) {
441                         for (int x = 0; x < p.SideLength(); ++x) {
442                                 glm::dvec3 to_tile = p.TileCenter(surface, x, y);
443                                 double near_axis = std::abs(glm::dot(glm::normalize(to_tile), axis));
444                                 if (near_axis > cap_thresh) {
445                                         p.TileAt(surface, x, y).type = ice;
446                                         continue;
447                                 }
448                                 float elevation = rand::OctaveNoise(
449                                         elevation_gen,
450                                         to_tile / p.Radius(),
451                                         3,   // octaves
452                                         0.5, // persistence
453                                         5 / p.Radius(), // frequency
454                                         2,   // amplitude
455                                         2    // growth
456                                 );
457                                 float variation = rand::OctaveNoise(
458                                         variation_gen,
459                                         to_tile / p.Radius(),
460                                         3,   // octaves
461                                         0.5, // persistence
462                                         16 / p.Radius(), // frequency
463                                         2,   // amplitude
464                                         2    // growth
465                                 );
466                                 if (elevation < ocean_thresh) {
467                                         p.TileAt(surface, x, y).type = ocean;
468                                 } else if (elevation < water_thresh) {
469                                         if (variation > 0.3) {
470                                                 p.TileAt(surface, x, y).type = algae;
471                                         } else {
472                                                 p.TileAt(surface, x, y).type = water;
473                                         }
474                                 } else if (elevation < beach_thresh) {
475                                         p.TileAt(surface, x, y).type = sand;
476                                 } else if (elevation < highland_thresh) {
477                                         if (near_axis < equ_thresh) {
478                                                 if (variation > 0.6) {
479                                                         p.TileAt(surface, x, y).type = grass;
480                                                 } else if (variation > 0.2) {
481                                                         p.TileAt(surface, x, y).type = sand;
482                                                 } else {
483                                                         p.TileAt(surface, x, y).type = desert;
484                                                 }
485                                         } else if (near_axis < fzone_start) {
486                                                 if (variation > 0.4) {
487                                                         p.TileAt(surface, x, y).type = forest;
488                                                 } else if (variation < -0.5) {
489                                                         p.TileAt(surface, x, y).type = jungle;
490                                                 } else if (variation > -0.02 && variation < 0.02) {
491                                                         p.TileAt(surface, x, y).type = wheat;
492                                                 } else {
493                                                         p.TileAt(surface, x, y).type = grass;
494                                                 }
495                                         } else if (near_axis < fzone_end) {
496                                                 p.TileAt(surface, x, y).type = tundra;
497                                         } else {
498                                                 p.TileAt(surface, x, y).type = taiga;
499                                         }
500                                 } else if (elevation < mountain_thresh) {
501                                         if (variation > 0.3) {
502                                                 p.TileAt(surface, x, y).type = mntn;
503                                         } else {
504                                                 p.TileAt(surface, x, y).type = rock;
505                                         }
506                                 } else {
507                                         p.TileAt(surface, x, y).type = mntn;
508                                 }
509                         }
510                 }
511         }
512         p.BuildVAO(tiles);
513 }
514
515 void GenerateTest(const Set<TileType> &tiles, Planet &p) noexcept {
516         for (int surface = 0; surface <= 5; ++surface) {
517                 for (int y = 0; y < p.SideLength(); ++y) {
518                         for (int x = 0; x < p.SideLength(); ++x) {
519                                 if (x == p.SideLength() / 2 && y == p.SideLength() / 2) {
520                                         p.TileAt(surface, x, y).type = surface;
521                                 } else {
522                                         p.TileAt(surface, x, y).type = (x == p.SideLength()/2) + (y == p.SideLength()/2) + 6;
523                                 }
524                         }
525                 }
526         }
527         p.BuildVAO(tiles);
528 }
529
530
531 Sun::Sun()
532 : Body() {
533 }
534
535 Sun::~Sun() {
536 }
537
538
539 std::vector<TileType::Yield>::const_iterator TileType::FindResource(int r) const {
540         auto yield = resources.cbegin();
541         for (; yield != resources.cend(); ++yield) {
542                 if (yield->resource == r) {
543                         break;
544                 }
545         }
546         return yield;
547 }
548
549 }
550 }