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(2.0f)
  20 , flee_speed(-5.0f)
  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         if (Target().Dead()) {
  32                 Controlled().Kill();
  33                 return;
  34         }
  35
  36         glm::vec3 diff(Target().AbsoluteDifference(Controlled()));
  37         float dist = length(diff);
  38         if (dist < std::numeric_limits<float>::epsilon()) {
  39                 Controlled().TargetVelocity(glm::vec3(0.0f));
  40                 return;
  41         }
  42         glm::vec3 norm_diff(diff / dist);
  43
  44         bool line_of_sight = true;
  45         Ray aim{Target().Position() - diff, norm_diff};
  46         WorldCollision coll;
  47         if (world.Intersection(aim, glm::mat4(1.0f), Target().ChunkCoords(), coll)) {
  48                 line_of_sight = coll.depth > dist;
  49         }
  50
  51         if (!line_of_sight) {
  52                 Controlled().TargetVelocity(glm::vec3(0.0f));
  53         } else if (dist > stop_dist) {
  54                 Controlled().TargetVelocity(norm_diff * chase_speed);
  55         } else if (dist < flee_dist) {
  56                 Controlled().TargetVelocity(norm_diff * flee_speed);
  57         } else {
  58                 Controlled().TargetVelocity(glm::vec3(0.0f));
  59         }
  60 }
  61
  62
  63 Controller::Controller(Entity &e) noexcept
  64 : entity(e) {
  65         entity.Ref();
  66 }
  67
  68 Controller::~Controller() {
  69         entity.UnRef();
  70 }
  71
  72
  73 RandomWalk::RandomWalk(Entity &e, std::uint64_t seed) noexcept
  74 : Controller(e)
  75 , random(seed)
  76 , start_vel(e.Velocity())
  77 , target_vel(start_vel)
  78 , switch_time(0)
  79 , lerp_max(1.0f)
  80 , lerp_time(0.0f) {
  81
  82 }
  83
  84 RandomWalk::~RandomWalk() {
  85
  86 }
  87
  88 void RandomWalk::Update(int dt) {
  89         switch_time -= dt;
  90         lerp_time -= dt;
  91         if (switch_time < 0) {
  92                 switch_time += 2500 + (random.Next<unsigned short>() % 5000);
  93                 lerp_max = 1500 + (random.Next<unsigned short>() % 1000);
  94                 lerp_time = lerp_max;
  95                 Change();
  96         } else if (lerp_time > 0) {
  97                 float a = std::min(lerp_time / lerp_max, 1.0f);
  98                 Controlled().TargetVelocity(mix(target_vel, start_vel, a));
  99         } else {
 100                 Controlled().TargetVelocity(target_vel);
 101         }
 102 }
 103
 104 void RandomWalk::Change() noexcept {
 105         start_vel = target_vel;
 106
 107         constexpr float base = 0.001f;
 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
 114 }