metro-rts/src/enemy_world_state.cpp

#include "enemy_world_state.hpp"
#include "entity_health.hpp"
#include "unit.hpp"
#include "goap/goal.hpp"
#include "utils/godot_macros.hpp"
#include <cmath>

void EnemyWorldState::_bind_methods() {
#define CLASSNAME EnemyWorldState
    GDPROPERTY_HINTED(editor_available_goals,
                      gd::Variant::ARRAY,
                      gd::PROPERTY_HINT_ARRAY_TYPE,
                      GDRESOURCETYPE("Goal"));
}

void EnemyWorldState::_ready() { GDGAMEONLY();
    this->awareness_area = this->get_node<gd::Area3D>("%AwarenessArea");
    this->awareness_area->connect("body_entered", callable_mp(this, &EnemyWorldState::on_awareness_entered));
    // this->awareness_area->connect("body_exited", callable_mp(this, &EnemyWorldState::on_awareness_exited));
    this->health = this->get_node<EntityHealth>("%EntityHealth");
    this->health->connect("damage", callable_mp(this, &EnemyWorldState::on_damaged));
    this->parent_unit->connect("plan_interrupted", callable_mp(this, &EnemyWorldState::select_and_set_target));
}

void EnemyWorldState::on_awareness_entered(gd::Node3D *node) {
    Unit *unit{gd::Object::cast_to<Unit>(node)};
    if(unit == nullptr)
        return;
    if(unit == this->parent_unit)
        return;
    if(unit->get_entity_health()->get_is_dead())
        return;
    unit->get_entity_health()->connect("death", this->aware_unit_death.bind(unit));
    this->known_enemies.push_back(unit);
    this->try_set_target(this->select_target_from_known());
}

void EnemyWorldState::on_awareness_exited(gd::Node3D *node) {
    Unit *unit{gd::Object::cast_to<Unit>(node)};
    if(unit == nullptr)
        return;
    if(this->known_enemies.has(unit)) {
        unit->get_entity_health()->disconnect("death", this->aware_unit_death.bind(unit));
        this->known_enemies.erase(unit);
    }
    if(unit == this->target_node) {
        this->select_and_set_target();
    }
}

void EnemyWorldState::on_damaged(int remaining, int delta, Unit *source) {
    if(!this->known_enemies.has(source)) {
        source->get_entity_health()->connect("death", this->aware_unit_death.bind(source));
        this->known_enemies.push_back(source);
    }
    if(!this->parent_unit->has_plan())
        this->try_set_target(this->select_target_from_known());
}

Unit *EnemyWorldState::select_target_from_known_with_priority(float *out_priority) {
    Unit *out{nullptr};
    *out_priority = -INFINITY;
    for(Unit *unit : this->known_enemies) {
        float const priority{this->calculate_priority(unit)};
        if(priority > *out_priority) {
            out = unit;
            *out_priority = priority;
        }
    }
    return out;
}

Unit *EnemyWorldState::select_target_from_known() {
    float dummy{};
    return this->select_target_from_known_with_priority(&dummy);
}

void EnemyWorldState::on_aware_unit_death(Unit *_, Unit *dead_entity) {
    this->on_awareness_exited(dead_entity);
}

void EnemyWorldState::select_and_set_target() {
    this->try_set_target(this->select_target_from_known());
}

float EnemyWorldState::calculate_priority(Unit *target) {
    return target->get_global_position().distance_squared_to(this->parent_unit->get_global_position());
}

gd::Ref<goap::Goal> EnemyWorldState::get_goal_for_target(Unit *unit) {
    gd::Node3D *store{this->target_node};
    this->target_node = unit;
    for(gd::Ref<goap::Goal> const &goal : this->available_goals) {
        if(goal->check_requirements_met(this)) {
            this->target_node = store;
            return goal;
        }
    }
    this->target_node = store;
    return nullptr;
}

void EnemyWorldState::try_set_target(Unit *unit) {
    if(unit == nullptr) {
        this->target_node = nullptr;
        this->parent_unit->stop_plan();
        return;
    }
    gd::Ref<goap::Goal> goal{this->get_goal_for_target(unit)};
    if(goal.is_valid())
        this->parent_unit->set_target_goal(unit, goal);
}

void EnemyWorldState::set_editor_available_goals(gd::Array array) {
    this->available_goals.clear();
    while(!array.is_empty()) {
        gd::Ref<goap::Goal> goal{array.pop_front()};
        this->available_goals.push_back(goal);
    }
}

gd::Array EnemyWorldState::get_editor_available_goals() const {
    gd::Array a{};
    for(gd::Ref<goap::Goal> const &goal : this->available_goals)
        a.push_back(goal);
    return a;
}