]> git.localhorst.tv Git - blobs.git/blobdiff - src/creature/creature.cpp
overhaul need system
[blobs.git] / src / creature / creature.cpp
index 12924b94b9239651e212392868958d0d041f3915..d0000107b683e5b454d1864ba65c9c4c6dfe3873 100644 (file)
@@ -1,3 +1,4 @@
+#include "Composition.hpp"
 #include "Creature.hpp"
 #include "Genome.hpp"
 #include "Memory.hpp"
@@ -8,9 +9,6 @@
 #include "BlobBackgroundTask.hpp"
 #include "Goal.hpp"
 #include "IdleGoal.hpp"
-#include "InhaleNeed.hpp"
-#include "IngestNeed.hpp"
-#include "Need.hpp"
 #include "../app/Assets.hpp"
 #include "../math/const.hpp"
 #include "../world/Body.hpp"
 namespace blobs {
 namespace creature {
 
+Composition::Composition()
+: components() {
+}
+
+Composition::~Composition() {
+}
+
+namespace {
+bool CompositionCompare(const Composition::Component &a, const Composition::Component &b) {
+       return b.value < a.value;
+}
+}
+
+void Composition::Add(int res, double amount) {
+       bool found = false;
+       for (auto &c : components) {
+               if (c.resource == res) {
+                       c.value += amount;
+                       found = true;
+                       break;
+               }
+       }
+       if (!found) {
+               components.emplace_back(res, amount);
+       }
+       std::sort(components.begin(), components.end(), CompositionCompare);
+}
+
+bool Composition::Has(int res) const noexcept {
+       for (auto &c : components) {
+               if (c.resource == res) {
+                       return true;
+               }
+       }
+       return false;
+}
+
+double Composition::Get(int res) const noexcept {
+       for (auto &c : components) {
+               if (c.resource == res) {
+                       return c.value;
+               }
+       }
+       return 0.0;
+}
+
+
 Creature::Creature(world::Simulation &sim)
 : sim(sim)
 , name()
 , genome()
 , properties()
-, cur_prop(0)
+, composition()
 , base_color(1.0)
-, highlight_color(0.0)
+, highlight_color(0.0, 0.0, 0.0, 1.0)
 , mass(1.0)
-, density(1.0)
 , size(1.0)
 , birth(sim.Time())
-, health(1.0)
 , on_death()
 , removable(false)
+, stats()
 , memory(*this)
 , bg_task()
-, needs()
 , goals()
 , situation()
 , steering(*this)
@@ -59,37 +102,52 @@ Creature::Creature(world::Simulation &sim)
 Creature::~Creature() {
 }
 
-glm::dvec4 Creature::HighlightColor() const noexcept {
-       return glm::dvec4(highlight_color, AgeLerp(CurProps().highlight, NextProps().highlight));
-}
-
-void Creature::Ingest(int res, double amount) noexcept {
-       const Genome::Composition *cmp = nullptr;
-       for (const auto &c : genome.composition) {
-               if (c.resource == res) {
-                       cmp = &c;
-                       break;
+void Creature::AddMass(int res, double amount) {
+       composition.Add(res, amount);
+       double mass = 0.0;
+       double nonsolid = 0.0;
+       double volume = 0.0;
+       for (const auto &c : composition) {
+               mass += c.value;
+               volume += c.value / sim.Assets().data.resources[c.resource].density;
+               if (sim.Assets().data.resources[c.resource].state != world::Resource::SOLID) {
+                       nonsolid += c.value;
                }
        }
-       if (cmp) {
-               const double max_mass = AgeLerp(CurProps().mass, NextProps().mass);
-               Mass(std::min(max_mass, mass + amount));
-       } else {
-               // foreign material. poisonous?
-       }
+       Mass(mass);
+       Size(std::cbrt(volume));
+       highlight_color.a = nonsolid / mass;
 }
 
-void Creature::Hurt(double dt) noexcept {
-       health = std::max(0.0, health - dt);
-       if (health == 0.0) {
-               std::cout << "[" << int(sim.Time()) << "s] "
-                       << name << " died" << std::endl;
+void Creature::HighlightColor(const glm::dvec3 &c) noexcept {
+       highlight_color = glm::dvec4(c, highlight_color.a);
+}
+
+void Creature::Ingest(int res, double amount) noexcept {
+       // TODO: check foreign materials
+       // 10% stays in body
+       AddMass(res, amount * 0.1);
+}
+
+void Creature::Hurt(double amount) noexcept {
+       stats.Damage().Add(amount);
+       if (stats.Damage().Full()) {
+               std::cout << "[" << int(sim.Time()) << "s] " << name << " ";
+               if (stats.Breath().Full()) {
+                       std::cout << "suffocated";
+               } else if (stats.Thirst().Full()) {
+                       std::cout << "died of thirst";
+               } else if (stats.Hunger().Full()) {
+                       std::cout << "starved to death";
+               } else {
+                       std::cout << "succumed to wounds";
+               }
+               std::cout << std::endl;
                Die();
        }
 }
 
 void Creature::Die() noexcept {
-       needs.clear();
        goals.clear();
        steering.Halt();
        if (on_death) {
@@ -98,43 +156,64 @@ void Creature::Die() noexcept {
        Remove();
 }
 
-double Creature::Size() const noexcept {
-       return size;
-}
-
 double Creature::Age() const noexcept {
        return sim.Time() - birth;
 }
 
-std::string Creature::AgeName() const {
-       switch (cur_prop) {
-               case 0:
-                       return "Newborn";
-               case 1:
-                       return "Child";
-               case 2:
-                       return "Youth";
-               case 3:
-                       return "Adult";
-               case 4:
-                       return "Elder";
-               case 5:
-                       return "Dead";
-               default:
-                       return "Unknown";
-       }
+double Creature::AgeFactor(double peak) const noexcept {
+       // shifted inverse hermite, y = 1 - (3t² - 2t³) with t = normalized age - peak
+       // goes negative below -0.5 and starts to rise again above 1.0
+       double t = glm::clamp((Age() / properties.Lifetime()) - peak, -0.5, 1.0);
+       return 1.0 - (3.0 * t * t) + (2.0 * t * t * t);
+}
+
+double Creature::ExhaustionFactor() const noexcept {
+       return 1.0 - (glm::smoothstep(0.5, 1.0, stats.Exhaustion().value) * 0.5);
+}
+
+double Creature::FatigueFactor() const noexcept {
+       return 1.0 - (glm::smoothstep(0.5, 1.0, stats.Fatigue().value) * 0.5);
+}
+
+double Creature::Strength() const noexcept {
+       // TODO: replace all age factors with actual growth and decay
+       return properties.Strength() * ExhaustionFactor() * AgeFactor(0.25);
 }
 
-double Creature::AgeLerp(double from, double to) const noexcept {
-       return glm::mix(from, to, glm::smoothstep(CurProps().age, NextProps().age, Age()));
+double Creature::Stamina() const noexcept {
+       return properties.Stamina() * ExhaustionFactor() * AgeFactor(0.25);
+}
+
+double Creature::Dexerty() const noexcept {
+       return properties.Dexerty() * ExhaustionFactor() * AgeFactor(0.25);
+}
+
+double Creature::Intelligence() const noexcept {
+       return properties.Intelligence() * FatigueFactor() * AgeFactor(0.25);
+}
+
+double Creature::Lifetime() const noexcept {
+       return properties.Lifetime();
 }
 
 double Creature::Fertility() const noexcept {
-       return AgeLerp(CurProps().fertility, NextProps().fertility) * (1.0 / 3600.0);
+       return properties.Fertility() * AgeFactor(0.25);
 }
 
 double Creature::Mutability() const noexcept {
-       return GetProperties().mutability * (1.0 / 3600.0);
+       return properties.Mutability();
+}
+
+double Creature::OffspringMass() const noexcept {
+       return properties.OffspringMass();
+}
+
+double Creature::OffspringChance() const noexcept {
+       return AgeFactor(0.25) * properties.Fertility() * (1.0 / 3600.0);
+}
+
+double Creature::MutateChance() const noexcept {
+       return GetProperties().Mutability() * (1.0 / 3600.0);
 }
 
 void Creature::AddGoal(std::unique_ptr<Goal> &&g) {
@@ -151,62 +230,82 @@ bool GoalCompare(const std::unique_ptr<Goal> &a, const std::unique_ptr<Goal> &b)
 }
 
 void Creature::Tick(double dt) {
-       if (cur_prop < 5 && Age() > NextProps().age) {
-               ++cur_prop;
-               if (cur_prop == 5) {
-                       std::cout << "[" << int(sim.Time()) << "s] "
-                               << name << " died of old age" << std::endl;
-                       Die();
+       TickState(dt);
+       TickStats(dt);
+       TickBrain(dt);
+}
+
+void Creature::TickState(double dt) {
+       steering.MaxSpeed(Dexerty());
+       steering.MaxForce(Strength());
+       Situation::State state(situation.GetState());
+       Situation::Derivative a(Step(Situation::Derivative(), 0.0));
+       Situation::Derivative b(Step(a, dt * 0.5));
+       Situation::Derivative c(Step(b, dt * 0.5));
+       Situation::Derivative d(Step(c, dt));
+       Situation::Derivative f(
+               (1.0 / 6.0) * (a.vel + 2.0 * (b.vel + c.vel) + d.vel),
+               (1.0 / 6.0) * (a.acc + 2.0 * (b.acc + c.acc) + d.acc)
+       );
+       state.pos += f.vel * dt;
+       state.vel += f.acc * dt;
+       if (length2(state.vel) > 0.000001) {
+               glm::dvec3 nvel(normalize(state.vel));
+               double ang = angle(nvel, state.dir);
+               double turn_rate = PI * 0.5 * dt;
+               if (ang < turn_rate) {
+                       state.dir = normalize(state.vel);
+               } else if (std::abs(ang - PI) < 0.001) {
+                       state.dir = rotate(state.dir, turn_rate, world::Planet::SurfaceNormal(situation.Surface()));
                } else {
-                       std::cout << "[" << int(sim.Time()) << "s] "
-                               << name << " grew up to " << AgeName() << std::endl;
+                       state.dir = rotate(state.dir, turn_rate, normalize(cross(state.dir, nvel)));
                }
        }
+       situation.SetState(state);
+       stats.Exhaustion().Add(length(f.acc) * Mass() / Stamina() * dt);
+}
 
-       {
-               Situation::State state(situation.GetState());
-               Situation::Derivative a(Step(Situation::Derivative(), 0.0));
-               Situation::Derivative b(Step(a, dt * 0.5));
-               Situation::Derivative c(Step(b, dt * 0.5));
-               Situation::Derivative d(Step(c, dt));
-               Situation::Derivative f(
-                       (1.0 / 6.0) * (a.vel + 2.0 * (b.vel + c.vel) + d.vel),
-                       (1.0 / 6.0) * (a.acc + 2.0 * (b.acc + c.acc) + d.acc)
-               );
-               state.pos += f.vel * dt;
-               state.vel += f.acc * dt;
-               if (length2(state.vel) > 0.000001) {
-                       glm::dvec3 nvel(normalize(state.vel));
-                       double ang = angle(nvel, state.dir);
-                       double turn_rate = PI * dt;
-                       if (ang < turn_rate) {
-                               state.dir = normalize(state.vel);
-                       } else if (std::abs(ang - PI) < 0.001) {
-                               state.dir = rotate(state.dir, turn_rate, world::Planet::SurfaceNormal(situation.Surface()));
-                       } else {
-                               state.dir = rotate(state.dir, turn_rate, normalize(cross(state.dir, nvel)));
-                       }
-               }
+Situation::Derivative Creature::Step(const Situation::Derivative &ds, double dt) const noexcept {
+       Situation::State s = situation.GetState();
+       s.pos += ds.vel * dt;
+       s.vel += ds.acc * dt;
+       return {
+               s.vel,
+               steering.Force(s) / Mass()
+       };
+}
 
-               situation.SetState(state);
+void Creature::TickStats(double dt) {
+       for (auto &s : stats.stat) {
+               s.Add(s.gain * dt);
+       }
+       stats.Breath().Add(stats.Breath().gain * stats.Exhaustion().value * dt);
+       // TODO: damage values depending on properties
+       if (stats.Breath().Full()) {
+               constexpr double dps = 1.0 / 4.0;
+               Hurt(dps * dt);
+       }
+       if (stats.Thirst().Full()) {
+               constexpr double dps = 1.0 / 32.0;
+               Hurt(dps * dt);
        }
+       if (stats.Hunger().Full()) {
+               constexpr double dps = 1.0 / 128.0;
+               Hurt(dps * dt);
+       }
+}
 
+void Creature::TickBrain(double dt) {
        bg_task->Tick(dt);
        bg_task->Action();
        memory.Tick(dt);
-       for (auto &need : needs) {
-               need->Tick(dt);
-       }
-       for (auto &goal : goals) {
-               goal->Tick(dt);
-       }
        // do background stuff
-       for (auto &need : needs) {
-               need->ApplyEffect(*this, dt);
-       }
        if (goals.empty()) {
                return;
        }
+       for (auto &goal : goals) {
+               goal->Tick(dt);
+       }
        // if active goal can be interrupted, check priorities
        if (goals.size() > 1 && goals[0]->Interruptible()) {
                std::sort(goals.begin(), goals.end(), GoalCompare);
@@ -221,16 +320,6 @@ void Creature::Tick(double dt) {
        }
 }
 
-Situation::Derivative Creature::Step(const Situation::Derivative &ds, double dt) const noexcept {
-       Situation::State s = situation.GetState();
-       s.pos += ds.vel * dt;
-       s.vel += ds.acc * dt;
-       return {
-               s.vel,
-               steering.Acceleration(s)
-       };
-}
-
 glm::dmat4 Creature::LocalTransform() noexcept {
        const double half_size = size * 0.5;
        const glm::dvec3 &pos = situation.Position();
@@ -361,76 +450,30 @@ void Spawn(Creature &c, world::Planet &p) {
        }
 
        Genome genome;
-
-       genome.properties.Birth().age = { 0.0, 0.0 };
-       genome.properties.Birth().mass = { 0.5, 0.05 };
-       genome.properties.Birth().fertility = { 0.0, 0.0 };
-       genome.properties.Birth().highlight = { 0.0, 0.0 };
-
-       genome.properties.Child().age = { 30.0, 1.0 };
-       genome.properties.Child().mass = { 0.7, 0.05 };
-       genome.properties.Child().fertility = { 0.0, 0.0 };
-       genome.properties.Child().highlight = { 0.2, 0.05 };
-
-       genome.properties.Youth().age = { 60.0, 5.0 };
-       genome.properties.Youth().mass = { 0.9, 0.1 };
-       genome.properties.Youth().fertility = { 0.5, 0.03 };
-       genome.properties.Youth().highlight = { 0.9, 0.1 };
-
-       genome.properties.Adult().age = { 120.0, 10.0 };
-       genome.properties.Adult().mass = { 1.3, 0.1 };
-       genome.properties.Adult().fertility = { 0.4, 0.01 };
-       genome.properties.Adult().highlight = { 0.7, 0.1 };
-
-       genome.properties.Elder().age = { 360.0, 30.0 };
-       genome.properties.Elder().mass = { 1.0, 0.05 };
-       genome.properties.Elder().fertility = { 0.1, 0.01 };
-       genome.properties.Elder().highlight = { 0.6, 0.1 };
-
-       genome.properties.Death().age = { 480.0, 60.0 };
-       genome.properties.Death().mass = { 0.9, 0.05 };
-       genome.properties.Death().fertility = { 0.0, 0.0 };
-       genome.properties.Death().highlight = { 0.5, 0.1 };
-
-       genome.properties.strength = { 1.0, 0.1 };
-       genome.properties.stamina = { 1.0, 0.1 };
-       genome.properties.dexerty = { 1.0, 0.1 };
-       genome.properties.intelligence = { 1.0, 0.1 };
-       genome.properties.mutability = { 1.0, 0.1 };
+       genome.properties.Strength() = { 2.0, 0.1 };
+       genome.properties.Stamina() = { 4.0, 0.1 };
+       genome.properties.Dexerty() = { 2.0, 0.1 };
+       genome.properties.Intelligence() = { 1.0, 0.1 };
+       genome.properties.Lifetime() = { 480.0, 60.0 };
+       genome.properties.Fertility() = { 0.5, 0.03 };
+       genome.properties.Mutability() = { 1.0, 0.1 };
+       genome.properties.OffspringMass() = { 0.3, 0.02 };
 
        glm::dvec3 color_avg(0.0);
        double color_divisor = 0.0;
 
        if (p.HasAtmosphere()) {
-               genome.composition.push_back({
-                       p.Atmosphere(),    // resource
-                       { 0.01, 0.00001 }, // mass
-                       { 0.5,  0.001 },   // intake
-                       { 0.1,  0.0005 },  // penalty
-                       { 0.0,  0.0 },     // growth
-               });
+               c.AddMass(p.Atmosphere(), 0.01);
                color_avg += c.GetSimulation().Resources()[p.Atmosphere()].base_color * 0.1;
                color_divisor += 0.1;
        }
        if (liquid > -1) {
-               genome.composition.push_back({
-                       liquid,          // resource
-                       { 0.6,  0.01 },  // mass
-                       { 0.2,  0.001 }, // intake
-                       { 0.01, 0.002 }, // penalty
-                       { 0.1, 0.0 },   // growth
-               });
+               c.AddMass(liquid, 0.3);
                color_avg += c.GetSimulation().Resources()[liquid].base_color * 0.5;
                color_divisor += 0.5;
        }
        if (solid > -1) {
-               genome.composition.push_back({
-                       solid,             // resource
-                       { 0.4,   0.01 },   // mass
-                       { 0.4,   0.001 },  // intake
-                       { 0.001, 0.0001 }, // penalty
-                       { 10.0,  0.002 },   // growth
-               });
+               c.AddMass(solid, 0.1);
                color_avg += c.GetSimulation().Resources()[solid].base_color;
                color_divisor += 1.0;
        }
@@ -453,37 +496,14 @@ void Genome::Configure(Creature &c) const {
 
        c.GetProperties() = Instantiate(properties, random);
 
-       double mass = 0.0;
-       double volume = 0.0;
-       for (const auto &comp : composition) {
-               const world::Resource &resource = c.GetSimulation().Resources()[comp.resource];
-               double comp_mass = comp.mass.FakeNormal(random.SNorm());
-               double intake = comp.intake.FakeNormal(random.SNorm());
-               double penalty = comp.penalty.FakeNormal(random.SNorm());
-
-               mass += comp_mass;
-               volume += comp_mass / c.GetSimulation().Resources()[comp.resource].density;
-
-               std::unique_ptr<Need> need;
-               if (resource.state == world::Resource::SOLID) {
-                       intake *= std::atan(c.GetProperties().strength);
-                       need.reset(new IngestNeed(comp.resource, intake, penalty));
-                       need->gain = intake * 0.05;
-               } else if (resource.state == world::Resource::LIQUID) {
-                       intake *= std::atan(c.GetProperties().stamina);
-                       need.reset(new IngestNeed(comp.resource, intake, penalty));
-                       need->gain = intake * 0.1;
-               } else {
-                       need.reset(new InhaleNeed(comp.resource, intake, penalty));
-                       need->gain = intake * 0.5;
-               }
-               need->name = c.GetSimulation().Resources()[comp.resource].label;
-               need->growth = comp.growth.FakeNormal(random.SNorm());
-               need->value = 0.4;
-               need->inconvenient = 0.5;
-               need->critical = 0.95;
-               c.AddNeed(std::move(need));
-       }
+       // TODO: derive stats from properties
+       c.GetStats().Damage().gain = (-1.0 / 100.0);
+       c.GetStats().Breath().gain = (1.0 / 5.0);
+       c.GetStats().Thirst().gain = (1.0 / 60.0);
+       c.GetStats().Hunger().gain = (1.0 / 200.0);
+       c.GetStats().Exhaustion().gain = (-1.0 / 100.0);
+       c.GetStats().Fatigue().gain = (-1.0 / 100.0);
+       c.GetStats().Boredom().gain = (1.0 / 300.0);
 
        glm::dvec3 base_color(
                std::fmod(base_hue.FakeNormal(random.SNorm()) + 1.0, 1.0),
@@ -497,11 +517,6 @@ void Genome::Configure(Creature &c) const {
        );
        c.BaseColor(hsl2rgb(base_color));
        c.HighlightColor(hsl2rgb(highlight_color));
-
-       c.Mass(c.GetProperties().props[0].mass);
-       c.Density(mass / volume);
-       c.GetSteering().MaxAcceleration(1.4 * std::atan(c.GetProperties().strength));
-       c.GetSteering().MaxSpeed(4.4 * std::atan(c.GetProperties().dexerty));
        c.SetBackgroundTask(std::unique_ptr<Goal>(new BlobBackgroundTask(c)));
        c.AddGoal(std::unique_ptr<Goal>(new IdleGoal(c)));
 }
@@ -512,11 +527,14 @@ void Split(Creature &c) {
        const Situation &s = c.GetSituation();
        a->Name(c.GetSimulation().Assets().name.Sequential());
        c.GetGenome().Configure(*a);
+       for (const auto &cmp : c.GetComposition()) {
+               a->AddMass(cmp.resource, cmp.value * 0.5);
+       }
        s.GetPlanet().AddCreature(a);
        // TODO: duplicate situation somehow
        a->GetSituation().SetPlanetSurface(
                s.GetPlanet(), s.Surface(),
-               s.Position() + glm::dvec3(0.0, a->Size() * 0.51, 0.0));
+               s.Position() + glm::dvec3(0.0, a->Size() + 0.1, 0.0));
        a->BuildVAO();
        std::cout << "[" << int(c.GetSimulation().Time()) << "s] "
                << a->Name() << " was born" << std::endl;
@@ -524,10 +542,13 @@ void Split(Creature &c) {
        Creature *b = new Creature(c.GetSimulation());
        b->Name(c.GetSimulation().Assets().name.Sequential());
        c.GetGenome().Configure(*b);
+       for (const auto &cmp : c.GetComposition()) {
+               b->AddMass(cmp.resource, cmp.value * 0.5);
+       }
        s.GetPlanet().AddCreature(b);
        b->GetSituation().SetPlanetSurface(
                s.GetPlanet(), s.Surface(),
-               s.Position() + glm::dvec3(0.0, b->Size() * -0.51, 0.0));
+               s.Position() + glm::dvec3(0.0, b->Size() - 0.1, 0.0));
        b->BuildVAO();
        std::cout << "[" << int(c.GetSimulation().Time()) << "s] "
                << b->Name() << " was born" << std::endl;
@@ -554,6 +575,16 @@ void Memory::TrackStay(const Location &l, double t) {
        const world::TileType &type = l.planet->TypeAt(l.surface, l.coords.x, l.coords.y);
        auto entry = known_types.find(type.id);
        if (entry != known_types.end()) {
+               if (c.GetSimulation().Time() - entry->second.last_been > c.GetProperties().Lifetime() * 0.1) {
+                       // "it's been ages"
+                       if (entry->second.time_spent > c.Age() * 0.25) {
+                               // the place is very familiar
+                               c.GetStats().Boredom().Add(-0.2);
+                       } else {
+                               // infrequent stays
+                               c.GetStats().Boredom().Add(-0.1);
+                       }
+               }
                entry->second.last_been = c.GetSimulation().Time();
                entry->second.last_loc = l;
                entry->second.time_spent += t;
@@ -565,6 +596,9 @@ void Memory::TrackStay(const Location &l, double t) {
                        l,
                        t
                });
+               // completely new place, interesting
+               // TODO: scale by personality trait
+               c.GetStats().Boredom().Add(-0.25);
        }
 }
 
@@ -646,7 +680,7 @@ Steering::Steering(const Creature &c)
 : c(c)
 , target(0.0)
 , haste(0.0)
-, max_accel(1.0)
+, max_force(1.0)
 , max_speed(1.0)
 , min_dist(0.0)
 , max_look(0.0)
@@ -689,9 +723,9 @@ void Steering::GoTo(const glm::dvec3 &t) noexcept {
        arriving = true;
 }
 
-glm::dvec3 Steering::Acceleration(const Situation::State &s) const noexcept {
+glm::dvec3 Steering::Force(const Situation::State &s) const noexcept {
        double speed = max_speed * glm::clamp(max_speed * haste * haste, 0.25, 1.0);
-       double accel = max_speed * glm::clamp(max_accel * haste * haste, 0.5, 1.0);
+       double force = max_speed * glm::clamp(max_force * haste * haste, 0.5, 1.0);
        glm::dvec3 result(0.0);
        if (separating) {
                // TODO: off surface situation
@@ -706,22 +740,22 @@ glm::dvec3 Steering::Acceleration(const Situation::State &s) const noexcept {
                                repulse += normalize(diff) * (1.0 - sep / min_dist);
                        }
                }
-               SumForce(result, repulse, accel);
+               SumForce(result, repulse, force);
        }
        if (halting) {
-               SumForce(result, s.vel * -accel, accel);
+               SumForce(result, s.vel * -force, force);
        }
        if (seeking) {
                glm::dvec3 diff = target - s.pos;
                if (!allzero(diff)) {
-                       SumForce(result, TargetVelocity(s, (normalize(diff) * speed), accel), accel);
+                       SumForce(result, TargetVelocity(s, (normalize(diff) * speed), force), force);
                }
        }
        if (arriving) {
                glm::dvec3 diff = target - s.pos;
                double dist = length(diff);
                if (!allzero(diff) && dist > std::numeric_limits<double>::epsilon()) {
-                       SumForce(result, TargetVelocity(s, diff * std::min(dist * accel, speed) / dist, accel), accel);
+                       SumForce(result, TargetVelocity(s, diff * std::min(dist * force, speed) / dist, force), force);
                }
        }
        return result;