project-ely/internal/game/game.go

package game

import (
	"context"
	"fmt"
	"log"
	"strconv"
	"sync"

	"gitea.wisellama.rocks/Project-Ely/project-ely/internal/game/entity"
	"gitea.wisellama.rocks/Project-Ely/project-ely/internal/game/entity/player"
	"gitea.wisellama.rocks/Project-Ely/project-ely/internal/game/sprite"
	"gitea.wisellama.rocks/Project-Ely/project-ely/internal/vector"
	"gitea.wisellama.rocks/Wisellama/gosimpleconf"
	"github.com/veandco/go-sdl2/sdl"
)

type Entity interface {
	Run()
	GetCommandChan() chan entity.EntityCommand
	Draw() error
	Update() error
}

// 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()

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

	gameWindow, err := 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
	}
	defer sprite.CleanupSpriteCache()

	entity.DefinePenguinAnimations()

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

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

	// Setup Player 1
	// Let them control a penguin to start with
	player1 := player.NewPlayer(ctx)
	penguin := entity.NewPenguin(ctx, renderer)
	penguin.SetSpeed(2.0)
	entityList = append(entityList, penguin)
	player1.SetEntityChan(penguin.GetCommandChan())
	wg.Add(1)
	go func() {
		defer wg.Done()
		penguin.Run()
	}()

	p2 := entity.NewPenguin(ctx, renderer)
	p2.SetPosition(&vector.Vec2F{X: 100, Y: 100})
	p2.SetAnimation(entity.PENGUIN_WALK_LEFT)
	entityList = append(entityList, p2)
	wg.Add(1)
	go func() {
		defer wg.Done()
		p2.Run()
	}()

	// And now starting the main loop
	wg.Add(1)
	go func() {
		defer wg.Done()
		player1.Run()
	}()

	running := true
	for running {

		// Allow us to exit gracefully if the context is done
		select {
		case <-ctx.Done():
			running = false
		default:
			// Keep 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 so other components can do whatever they need with it
						player1.GetSdlEventsChan() <- *e
					}
				}

				event = sdl.PollEvent()
			}
		})

		// 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)
			}
		})

		// Everything else
		for _, e := range entityList {
			//e.GetCommandChan() <- entity.NewEntityCommand(entity.COMMAND_UPDATE, 0)
			//e.GetCommandChan() <- entity.NewEntityCommand(entity.COMMAND_DRAW, 0)
			err = e.Update()
			if err != nil {
				log.Printf("error updating: %v", err)
			}

			err = e.Draw()
			if err != nil {
				log.Printf("error drawing: %v", err)
			}
		}

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

	close(player1.GetSdlEventsChan())
	for _, e := range entityList {
		close(e.GetCommandChan())
	}

	wg.Wait()

	return nil
}