roguish/scratchpad/myecstest.cpp

#include "dinkyecs.hpp"

#include <iostream>
#include <fmt/core.h>

using namespace fmt;
using DinkyECS::Entity, DinkyECS::World;

struct Position {
  double x, y;
};

struct Velocity {
  double x, y;
};

struct Gravity {
  double level;
};

int main() {
  World me;

  Entity test = me.entity();
  Entity test2 = me.entity();

  me.assign<Position>(test, {10,20});
  me.assign<Velocity>(test, {1,2});

  me.assign<Position>(test2, {1,1});
  me.assign<Velocity>(test2, {10,20});

  Position &pos = me.component<Position>(test);
  println("GOT POS x={}, y={}", pos.x, pos.y);

  Velocity &vel = me.component<Velocity>(test);
  println("GOT VELOCITY x={}, y={}", vel.x, vel.y);

  println("--- Position only system:");
  me.system<Position>([](const auto &ent, auto &pos) {
      println("entity={}, pos.x={}, pos.y={}", ent, pos.x, pos.y);
  });

  println("--- Velocity only system:");
  me.system<Velocity>([](const auto &, auto &vel) {
      println("vel.x={}, vel.y={}", vel.x, vel.y);
  });

  println("--- Manually get the velocity in position system:");
  me.system<Position>([&](const auto &ent, auto &pos) {
      Velocity &vel = me.component<Velocity>(ent);
      println("entity={}, vel.x, vel.y, pos.x={}, pos.y={}", ent, vel.x, vel.y, pos.x, pos.y);
  });

  println("--- Creating facts (singletons)");
  me.set<Gravity>({0.9});

  println("--- Query only entities with Position and Velocity:");
  me.system<Position, Velocity>([&](const auto &ent, auto &pos, auto &vel) {
      Gravity &grav = me.get<Gravity>();
      println("grav={}, entity={}, vel.x, vel.y, pos.x={}, pos.y={}", grav.level, ent, vel.x, vel.y, pos.x, pos.y);
  });

  // now remove Velocity
  me.remove<Velocity>(test);

  println("--- After remove test, should only result in test2:");
  me.system<Position, Velocity>([&](const auto &ent, auto &pos, auto &vel) {
      println("entity={}, vel.x, vel.y, pos.x={}, pos.y={}", ent, vel.x, vel.y, pos.x, pos.y);
  });

  println("--- Create a stored system you can save for later.");
  auto movementSystem = me.runner<Position, Velocity>([&](const auto &ent, auto &pos, auto &vel) {
      println("entity={}, vel.x, vel.y, pos.x={}, pos.y={}", ent, vel.x, vel.y, pos.x, pos.y);
  });

  movementSystem();

  return 0;
}