project-ely/internal/game/game.go

package game

import (
	"context"
	"fmt"
	"log"
	"math/rand"
	"os"
	"strconv"
	"sync"
	"time"

	"git.wisellama.rocks/Project-Ely/project-ely/internal/game/entity/animation"
	"git.wisellama.rocks/Project-Ely/project-ely/internal/game/entity/command"
	"git.wisellama.rocks/Project-Ely/project-ely/internal/game/entity/types"
	"git.wisellama.rocks/Project-Ely/project-ely/internal/game/player"
	"git.wisellama.rocks/Project-Ely/project-ely/internal/game/sprite"
	"git.wisellama.rocks/Project-Ely/project-ely/internal/game/window"
	"git.wisellama.rocks/Project-Ely/project-ely/internal/vector"
	"git.wisellama.rocks/Wisellama/gosimpleconf"
	"github.com/faiface/beep"
	"github.com/faiface/beep/effects"
	"github.com/faiface/beep/flac"
	"github.com/faiface/beep/speaker"
	"github.com/veandco/go-sdl2/sdl"
)

type EntityCmdHandler interface {
	Run()
	CloseRequests()
	CommandRequest() chan command.Command
	DrawRequest() chan bool
	DrawResponse() chan bool
	UpdateRequest() chan bool
	UpdateResponse() chan bool
}

// Run is the main function to start the game.
func Run(ctx context.Context, configMap gosimpleconf.ConfigMap) error {
	var err error

	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

	go musicTest()

	framerate, err := strconv.ParseFloat(configMap["game.framerate"], 64)
	if err != nil {
		err = fmt.Errorf("error parsing framerate: %w", err)
		return err
	}
	framerateDelay := uint32(1000 / framerate)

	err = window.SdlInit()
	if err != nil {
		return err
	}
	defer window.SdlQuit()

	gameWindow, err := window.NewWindow(configMap["game.title"])
	if err != nil {
		err = fmt.Errorf("failed creating GameWindow: %w", err)
		return err
	}
	defer gameWindow.Cleanup()

	var renderer *sdl.Renderer
	sdl.Do(func() {
		renderer, err = sdl.CreateRenderer(gameWindow.SdlWindow, -1, sdl.RENDERER_ACCELERATED)
	})
	if err != nil {
		err = fmt.Errorf("failed creating SDL renderer: %w", err)
		return err
	}
	defer func() {
		sdl.Do(func() {
			err = renderer.Destroy()
			if err != nil {
				log.Printf("error destroying renderer: %v\n", err)
			}
		})
	}()

	err = sprite.InitSpriteCache(renderer)
	if err != nil {
		err = fmt.Errorf("failed in InitSpriteCache: %w", err)
		return err
	}

	animation.DefineAnimations()

	inputHandler := window.NewInputHandler(ctx)

	// Done with main setup, now moving on to creating specific entities

	entityList := make([]EntityCmdHandler, 0)
	wg := sync.WaitGroup{}

	// Setup Player 1
	// Let them control a penguin to start with
	player1 := player.NewPlayer(ctx, inputHandler)
	penguinEntity := types.NewPenguin(renderer)
	penguinCmdHandler := command.NewCommandHandler(ctx, &penguinEntity)
	penguinEntity.SetSpeed(2.0)
	entityList = append(entityList, penguinCmdHandler)
	player1.SetEntityChan(penguinCmdHandler.CommandRequest())
	wg.Add(1)
	go func() {
		defer wg.Done()
		penguinCmdHandler.Run()
	}()

	for i := 0; i < 10; i++ {
		entity := types.NewPenguin(renderer)
		entityCmd := command.NewCommandHandler(ctx, &entity)
		randomPos := vector.Vec2F{X: rand.Float64() * 500, Y: rand.Float64() * -500}
		entity.SetPosition(randomPos)
		entity.SetAnimation(rand.Intn(animation.PENGUIN_NUM_ANIMS))
		entityList = append(entityList, entityCmd)

		wg.Add(1)
		go func() {
			defer wg.Done()
			entityCmd.Run()
		}()
	}

	// Start the inputHandler
	wg.Add(1)
	go func() {
		defer wg.Done()
		inputHandler.Run()
	}()

	// And now starting the main loop
	running := true
	for running {
		// Poll for SDL events
		var event sdl.Event
		sdl.Do(func() {
			event = sdl.PollEvent()

			for event != nil {
				switch e := event.(type) {
				case *sdl.QuitEvent:
					log.Println("QuitEvent quitting")
					cancel()
				case *sdl.KeyboardEvent:
					if e.Keysym.Sym == sdl.K_ESCAPE {
						log.Println("Esc quitting")
						cancel()
					} else {
						// Publish the event to the inputHandler
						inputHandler.KeyboardChan() <- *e
					}
				}

				event = sdl.PollEvent()
			}
		})

		// Allow us to exit early if the context is done
		select {
		case <-ctx.Done():
			running = false
		default:
			// Keep running
		}
		if !running {
			break
		}

		// Players
		player1.Update()

		// Background
		sdl.Do(func() {
			err = renderer.SetDrawColor(0, 120, 0, 255)
			if err != nil {
				log.Printf("error in renderer.SetDrawColor: %v\n", err)
			}

			err = renderer.Clear()
			if err != nil {
				log.Printf("error in renderer.Clear: %v\n", err)
			}
		})

		// Tell everything to Update and Draw
		for _, e := range entityList {
			e.UpdateRequest() <- true
			e.DrawRequest() <- true
		}

		// Wait for each entity to finish their Draw and Update commands before proceeding
		for _, e := range entityList {
			<-e.UpdateResponse()
			<-e.DrawResponse()
		}

		// Draw
		sdl.Do(func() {
			renderer.Present()
			sdl.Delay(framerateDelay)
		})
	}

	inputHandler.CloseChannels()

	for _, e := range entityList {
		e.CloseRequests()
	}

	sprite.CleanupSpriteCache()

	wg.Wait()

	return nil
}

func musicTest() {
	f, err := os.Open("assets/audio/test.flac")
	if err != nil {
		log.Printf("%v", err)
	}

	s, format, err := flac.Decode(f)
	if err != nil {
		log.Printf("%v", err)
	}

	speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/10))
	done := make(chan struct{})
	callbackFunc := func() {
		close(done)
	}

	notify := beep.Callback(callbackFunc)

	v := &effects.Volume{
		Streamer: s,
		Base:     2,
		Volume:   -5,
		Silent:   false,
	}

	v = beep.Loop(-1, s)

	speaker.Play(beep.Seq(v, notify))

	select {
	case <-done:
		break
	}

}