src/ai/ai.cpp

   1 #include "AIController.hpp"
   2
   3 #include "../model/geometry.hpp"
   4 #include "../rand/GaloisLFSR.hpp"
   5 #include "../world/Entity.hpp"
   6 #include "../world/World.hpp"
   7 #include "../world/WorldCollision.hpp"
   8
   9 #include <cmath>
  10 #include <limits>
  11 #include <glm/glm.hpp>
  12
  13
  14 namespace blank {
  15
  16 AIController::AIController(GaloisLFSR &rand)
  17 : random(rand)
  18 , chase_speed(2.0f)
  19 , flee_speed(-5.0f)
  20 , stop_dist(10.0f)
  21 , flee_dist(5.0f)
  22 , wander_pos(1.0f, 0.0f, 0.0f)
  23 , wander_dist(2.0f)
  24 , wander_radius(1.0f)
  25 , wander_disp(1.0f)
  26 , wander_speed(1.0f) {
  27
  28 }
  29
  30 AIController::~AIController() {
  31
  32 }
  33
  34 void AIController::Update(Entity &e, float dt) {
  35         // movement: for now, wander only
  36         glm::vec3 displacement(
  37                 random.SNorm() * wander_disp,
  38                 random.SNorm() * wander_disp,
  39                 random.SNorm() * wander_disp
  40         );
  41         if (dot(displacement, displacement) > std::numeric_limits<float>::epsilon()) {
  42                 wander_pos = normalize(wander_pos + displacement * dt) * wander_radius;
  43         }
  44
  45         if (e.Moving()) {
  46                 // orient head towards heading
  47                 glm::vec3 heading(Heading(e.GetState()));
  48                 float tgt_pitch = std::atan(heading.y / length(glm::vec2(heading.x, heading.z)));
  49                 float tgt_yaw = std::atan2(-heading.x, -heading.z);
  50                 e.SetHead(tgt_pitch, tgt_yaw);
  51         }
  52 }
  53
  54 glm::vec3 AIController::ControlForce(const EntityState &state) const {
  55         return (Heading(state) * wander_dist + wander_pos) * wander_speed;
  56 }
  57
  58 glm::vec3 AIController::Heading(const EntityState &state) noexcept {
  59         if (dot(state.velocity, state.velocity) > std::numeric_limits<float>::epsilon()) {
  60                 return normalize(state.velocity);
  61         } else {
  62                 float cp = std::cos(state.pitch);
  63                 return glm::vec3(std::cos(state.yaw) * cp, std::sin(state.yaw) * cp, std::sin(state.pitch));
  64         }
  65 }
  66
  67 }