astro-domu/internal/sim/world.go

package sim

import (
	"fmt"
	"time"

	"github.com/gorilla/websocket"
	"github.com/jordanorelli/astro-domu/internal/math"
	"github.com/jordanorelli/astro-domu/internal/wire"
	"github.com/jordanorelli/blammo"
)

// world is the entire simulated world. A world consists of many rooms.
type world struct {
	*blammo.Log
	inbox   chan Request
	connect chan connect

	done         chan bool
	lastEntityID int
	rooms        map[string]*room
	players      map[string]*player
}

type connect struct {
	conn   *websocket.Conn
	login  wire.Login
	failed chan error
}

func newWorld(log *blammo.Log) *world {
	bounds := math.CreateRect(10, 10)
	foyer := room{
		Log:     log.Child("foyer"),
		name:    "foyer",
		Rect:    bounds,
		tiles:   make([]tile, bounds.Area()),
		players: make(map[string]*player),
	}
	foyer.tiles[55].here = &entity{
		ID:       777,
		Position: math.Vec{5, 5},
		Glyph:    'd',
		behavior: doNothing{},
	}
	log.Info("created foyer with bounds: %#v having width: %d height: %d area: %d", foyer.Rect, foyer.Width, foyer.Height, foyer.Area())
	return &world{
		Log:     log,
		rooms:   map[string]*room{"foyer": &foyer},
		done:    make(chan bool),
		inbox:   make(chan Request),
		connect: make(chan connect),
		players: make(map[string]*player),
	}
}

func (w *world) run(hz int) {
	defer w.Info("simulation has exited run loop")

	period := time.Second / time.Duration(hz)
	w.Info("starting world with a tick rate of %dhz, frame duration of %v", hz, period)
	ticker := time.NewTicker(period)
	lastTick := time.Now()

	for {
		select {
		case c := <-w.connect:
			w.register(c)

		case req := <-w.inbox:
			w.Info("read from inbox: %v", req)

			if req.From == "" {
				w.Error("request has no from: %v", req)
				break
			}

			p, ok := w.players[req.From]
			if !ok {
				w.Error("received non login request of type %T from unknown player %q", req.Wants, req.From)
			}

			if p.pending == nil {
				p.pending = &req
			} else {
				p.outbox <- wire.ErrorResponse(req.Seq, "you already have a request for this frame")
			}

		case <-ticker.C:
			w.tick(time.Since(lastTick))
			lastTick = time.Now()

		case <-w.done:
			return
		}
	}
}

func (w *world) register(c connect) {
	w.Info("register: %#v", c.login)
	foyer := w.rooms["foyer"]
	if len(foyer.players) >= 100 {
		c.failed <- fmt.Errorf("room is full")
		close(c.failed)
		return
	}

	p := player{
		Log:    w.Log.Child("players").Child(c.login.Name),
		name:   c.login.Name,
		outbox: make(chan wire.Response, 8),
		pending: &Request{
			From:  c.login.Name,
			Seq:   1,
			Wants: &spawnPlayer{},
		},
	}
	foyer.players[c.login.Name] = &p
	w.players[c.login.Name] = &p

	p.start(w.inbox, c.conn, foyer)
}

func (w *world) stop() error {
	w.Info("stopping simulation")
	w.done <- true
	w.Info("simulation stopped")
	return nil
}

func (w *world) tick(d time.Duration) {
	for _, r := range w.rooms {
		r.update(d)
	}
}