src/ai/ai.cpp

   1 #include "Chaser.hpp"
   2 #include "Controller.hpp"
   3 #include "RandomWalk.hpp"
   4
   5 #include "../model/geometry.hpp"
   6 #include "../world/Entity.hpp"
   7 #include "../world/World.hpp"
   8 #include "../world/WorldCollision.hpp"
   9
  10 #include <glm/glm.hpp>
  11
  12
  13 namespace blank {
  14
  15 Chaser::Chaser(World &world, Entity &ctrl, Entity &tgt) noexcept
  16 : Controller(ctrl)
  17 , world(world)
  18 , tgt(tgt)
  19 , chase_speed(0.002f)
  20 , flee_speed(-0.005f)
  21 , stop_dist(10)
  22 , flee_dist(5) {
  23         tgt.Ref();
  24 }
  25
  26 Chaser::~Chaser() {
  27         tgt.UnRef();
  28 }
  29
  30 void Chaser::Update(int dt) {
  31         glm::vec3 diff(Target().AbsoluteDifference(Controlled()));
  32         float dist = length(diff);
  33         if (dist < std::numeric_limits<float>::epsilon()) {
  34                 Controlled().Velocity(glm::vec3(0.0f));
  35                 return;
  36         }
  37         glm::vec3 norm_diff(diff / dist);
  38
  39         bool line_of_sight = true;
  40         Ray aim{Target().Position() - diff, norm_diff};
  41         WorldCollision coll;
  42         if (world.Intersection(aim, glm::mat4(1.0f), Target().ChunkCoords(), coll)) {
  43                 line_of_sight = coll.depth > dist;
  44         }
  45
  46         if (!line_of_sight) {
  47                 Controlled().Velocity(glm::vec3(0.0f));
  48         } else if (dist > stop_dist) {
  49                 Controlled().Velocity(norm_diff * chase_speed);
  50         } else if (dist < flee_dist) {
  51                 Controlled().Velocity(norm_diff * flee_speed);
  52         } else {
  53                 Controlled().Velocity(glm::vec3(0.0f));
  54         }
  55 }
  56
  57
  58 Controller::Controller(Entity &e) noexcept
  59 : entity(e) {
  60         entity.Ref();
  61 }
  62
  63 Controller::~Controller() {
  64         entity.UnRef();
  65 }
  66
  67
  68 RandomWalk::RandomWalk(Entity &e, std::uint64_t seed) noexcept
  69 : Controller(e)
  70 , random(seed)
  71 , start_vel(e.Velocity())
  72 , target_vel(start_vel)
  73 , start_rot(e.AngularVelocity())
  74 , target_rot(start_rot)
  75 , switch_time(0)
  76 , lerp_max(1.0f)
  77 , lerp_time(0.0f) {
  78
  79 }
  80
  81 RandomWalk::~RandomWalk() {
  82
  83 }
  84
  85 void RandomWalk::Update(int dt) {
  86         switch_time -= dt;
  87         lerp_time -= dt;
  88         if (switch_time < 0) {
  89                 switch_time += 2500 + (random.Next<unsigned short>() % 5000);
  90                 lerp_max = 1500 + (random.Next<unsigned short>() % 1000);
  91                 lerp_time = lerp_max;
  92                 Change();
  93         } else if (lerp_time > 0) {
  94                 float a = std::min(lerp_time / lerp_max, 1.0f);
  95                 Controlled().Velocity(mix(target_vel, start_vel, a));
  96                 Controlled().AngularVelocity(mix(target_rot, start_rot, a));
  97         } else {
  98                 Controlled().Velocity(target_vel);
  99                 Controlled().AngularVelocity(target_rot);
 100         }
 101 }
 102
 103 void RandomWalk::Change() noexcept {
 104         start_vel = target_vel;
 105         start_rot = target_rot;
 106
 107         constexpr float base = 0.000001f;
 108
 109         target_vel.x = base * (random.Next<short>() % 1024);
 110         target_vel.y = base * (random.Next<short>() % 1024);
 111         target_vel.z = base * (random.Next<short>() % 1024);
 112
 113         target_rot.x = base * (random.Next<short>() % 1024);
 114         target_rot.y = base * (random.Next<short>() % 1024);
 115         target_rot.z = base * (random.Next<short>() % 1024);
 116 }
 117
 118 }