Remove pointers for concurrency

.vscode/launch.json

@@ -0,0 +1,15 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Launch Package",
+            "type": "go",
+            "request": "launch",
+            "mode": "auto",
+            "program": "${workspaceFolder}"
+        }
+    ]
+}

game.conf

@@ -1,5 +1,6 @@
 game.title = "Project Ely"
 game.framerate = 60.0
 
+log.utcTime = false
 log.file = "output.log"
 log.writeToFile = false

internal/config/config.go

@@ -9,6 +9,7 @@ import (
 var defaultConfig gosimpleconf.ConfigMap = gosimpleconf.ConfigMap{
 	"game.title":      "Project Ely",
 	"game.framerate":  "60.0",
+	"log.utcTime":     "false",
 	"log.writeToFile": "false",
 }
 

internal/config/logging.go

@@ -9,19 +9,24 @@ import (
 
 type logWriter struct {
 	writeToFile bool
+	utcTime     bool
 	logFile     *os.File
 }
 
 func (w *logWriter) Write(bytes []byte) (int, error) {
-	t := time.Now().UTC().Format(time.RFC3339)
-	return fmt.Fprintf(w.logFile, "%v %v", t, string(bytes))
+	t := time.Now()
+	if w.utcTime {
+		t = t.UTC()
+	}
+	format := t.Format(time.RFC3339)
+	return fmt.Fprintf(w.logFile, "%v %v", format, string(bytes))
 }
 
 func (w *logWriter) Cleanup() {
 	defer w.logFile.Close()
 }
 
-func SetupLogging(writeToFile bool, logFilename string) (*logWriter, error) {
+func SetupLogging(writeToFile bool, utcTime bool, logFilename string) (*logWriter, error) {
 	var err error
 	log.SetFlags(0)
 
@@ -35,6 +40,7 @@ func SetupLogging(writeToFile bool, logFilename string) (*logWriter, error) {
 
 	writer := &logWriter{
 		writeToFile: writeToFile,
+		utcTime:     utcTime,
 		logFile:     logFile,
 	}
 	log.SetOutput(writer)

internal/game/camera.go

@@ -6,7 +6,7 @@ import "github.com/veandco/go-sdl2/sdl"
 // Since this is only a 2D game with SDL, the projection is relatively simple: window + camera = world.
 // https://gamedev.stackexchange.com/a/123844
 type camera struct {
-	pos *sdl.Point
+	pos sdl.Point
 }
 
 func NewCamera() *camera {

internal/game/entity/animation/entity_animation.go

@@ -5,7 +5,7 @@ import (
 )
 
 type SpriteAnimation interface {
-	Draw(frame int, worldPosition *sdl.Point, angle float64, center *sdl.Point, flip sdl.RendererFlip) error
+	Draw(frame int, worldPosition sdl.Point, angle float64, center sdl.Point, flip sdl.RendererFlip) error
 }
 
 // An entityAnimation will take a SpriteAnimation and may manipulate it somehow (e.g. flipped for walking the other direction)
@@ -15,7 +15,7 @@ type entityAnimation struct {
 	speed           int
 	length          int
 	angle           float64
-	center          *sdl.Point
+	center          sdl.Point
 	flip            sdl.RendererFlip
 }
 
@@ -24,11 +24,11 @@ func NewEntityAnimation(
 	speed int,
 	length int,
 	angle float64,
-	center *sdl.Point,
+	center sdl.Point,
 	flip sdl.RendererFlip,
-) *entityAnimation {
+) entityAnimation {
 
-	e := entityAnimation{
+	return entityAnimation{
 		spriteAnimation: spriteAnimation,
 		speed:           speed,
 		length:          length,
@@ -36,18 +36,23 @@ func NewEntityAnimation(
 		center:          center,
 		flip:            flip,
 	}
-
-	return &e
 }
 
-func (e *entityAnimation) Draw(frame int, windowPosition *sdl.Point) error {
+func (e entityAnimation) Draw(frame int, windowPosition sdl.Point) error {
 	return e.spriteAnimation.Draw(frame, windowPosition, e.angle, e.center, e.flip)
 }
 
-func (e *entityAnimation) GetSpeed() int {
+func (e entityAnimation) GetSpeed() int {
 	return e.speed
 }
 
 func DefineAnimations() {
 	DefinePenguinAnimations()
 }
+
+func getCenter(dimensions sdl.Point) sdl.Point {
+	x := dimensions.X / 2
+	y := dimensions.Y / 2
+
+	return sdl.Point{X: x, Y: y}
+}

internal/game/entity/animation/penguin_animations.go

@@ -5,7 +5,7 @@ import (
 	"github.com/veandco/go-sdl2/sdl"
 )
 
-var PenguinAnimations map[int]*entityAnimation
+var PenguinAnimations map[int]entityAnimation
 
 const (
 	PENGUIN_WALK_RIGHT int = iota
@@ -29,21 +29,21 @@ func DefinePenguinAnimations() {
 	var (
 		dimensions sdl.Point
 		offset     sdl.Point
-		center     *sdl.Point
+		center     sdl.Point
 		length     int
 		speed      int
 		border     int
 	)
 
 	dimensions = sdl.Point{X: 13, Y: 17}
-	PenguinAnimations = make(map[int]*entityAnimation)
+	PenguinAnimations = make(map[int]entityAnimation)
 
 	// Walking Right is in the spritesheet.
 	speed = 5
 	offset = sdl.Point{X: 0, Y: 1}
 	length = 5
-	border = 1   // optional border around each sprite
-	center = nil // center is for rotation, nil will default to w/2 h/2
+	border = 1                     // optional border around each sprite
+	center = getCenter(dimensions) // center is for rotation, nil will default to w/2 h/2
 	walkRight := sprite.NewAnimation(filename, dimensions, offset, length, border)
 	PenguinAnimations[PENGUIN_WALK_RIGHT] = NewEntityAnimation(walkRight, speed, length, 0, center, sdl.FLIP_NONE)
 

internal/game/entity/types/common.go

@@ -6,7 +6,7 @@ import (
 )
 
 type EntityAnimation interface {
-	Draw(step int, windowPosition *sdl.Point) error
+	Draw(step int, windowPosition sdl.Point) error
 	GetSpeed() int
 }
 
@@ -21,12 +21,12 @@ const (
 // The following are axis direction vectors based on world coordinates.
 // UP/DOWN is intentionally UP = positive (which is different from window coordinates)
 var (
-	VEC_LEFT  = &vector.Vec2F{X: -1, Y: 0}
-	VEC_RIGHT = &vector.Vec2F{X: 1, Y: 0}
-	VEC_UP    = &vector.Vec2F{X: 0, Y: 1}
-	VEC_DOWN  = &vector.Vec2F{X: 0, Y: -1}
+	VEC_LEFT  = vector.Vec2F{X: -1, Y: 0}
+	VEC_RIGHT = vector.Vec2F{X: 1, Y: 0}
+	VEC_UP    = vector.Vec2F{X: 0, Y: 1}
+	VEC_DOWN  = vector.Vec2F{X: 0, Y: -1}
 
-	VEC_DIRECTIONS = []*vector.Vec2F{
+	VEC_DIRECTIONS = []vector.Vec2F{
 		// Prefer left/right animations by checking them first in the list
 		VEC_LEFT,
 		VEC_RIGHT,
@@ -35,7 +35,7 @@ var (
 	}
 )
 
-func determineClosestDirection(velocity *vector.Vec2F) int {
+func determineClosestDirection(velocity vector.Vec2F) int {
 	closest := DIR_RIGHT
 	max := 0.0
 	buffer := 0.5 // This buffer lets us stick to the left/right animations for diagonal movement

internal/game/entity/types/penguin.go

@@ -20,27 +20,25 @@ type penguin struct {
 	updateAnimation  bool            // if false, don't change the animation
 
 	// Physical parameters
-	worldPosition *vector.Vec2F // where is the center of this object
-	velocity      *vector.Vec2F // movement direction to be applied each tick
-	speed         float64       // movement magnitude to multiply with the velocity
+	worldPosition vector.Vec2F // where is the center of this object
+	velocity      vector.Vec2F // movement direction to be applied each tick
+	speed         float64      // movement magnitude to multiply with the velocity
 }
 
-func NewPenguin(renderer *sdl.Renderer) *penguin {
+func NewPenguin(renderer *sdl.Renderer) penguin {
 	position := vector.Vec2F{}
 	velocity := vector.Vec2F{}
 	speed := 1.0
 
-	p := penguin{
+	return penguin{
 		currentAnimation: animation.PenguinAnimations[animation.PENGUIN_DEFAULT],
 		animationStep:    0,
 		direction:        DIR_RIGHT,
 
-		worldPosition: &position,
+		worldPosition: position,
 		speed:         speed,
-		velocity:      &velocity,
+		velocity:      velocity,
 	}
-
-	return &p
 }
 
 func (p *penguin) Draw() error {
@@ -48,7 +46,7 @@ func (p *penguin) Draw() error {
 
 	// TODO
 	//windowPosition := worldPosToWindowPos()
-	windowPosition := &sdl.Point{
+	windowPosition := sdl.Point{
 		X: int32(math.Round(p.worldPosition.X)),
 		Y: int32(math.Round(-1 * p.worldPosition.Y)),
 	}
@@ -63,7 +61,7 @@ func (p *penguin) Draw() error {
 	return nil
 }
 
-func (p *penguin) SetPosition(vec *vector.Vec2F) {
+func (p *penguin) SetPosition(vec vector.Vec2F) {
 	p.worldPosition = vec
 }
 
@@ -91,7 +89,7 @@ func (p *penguin) MoveX(x float64) {
 	defer p.mx.Unlock()
 
 	p.velocity.X = x
-	p.velocity.Normalize()
+	p.velocity = p.velocity.Normalized()
 	p.updateAnimation = true
 }
 
@@ -101,7 +99,7 @@ func (p *penguin) MoveY(y float64) {
 
 	// (0,0) is the top left, so negative y moves up
 	p.velocity.Y = y
-	p.velocity.Normalize()
+	p.velocity.Normalized()
 	p.updateAnimation = true
 }
 

internal/game/game.go

@@ -78,7 +78,6 @@ func Run(ctx context.Context, configMap gosimpleconf.ConfigMap) error {
 		err = fmt.Errorf("failed in InitSpriteCache: %w", err)
 		return err
 	}
-	defer sprite.CleanupSpriteCache()
 
 	animation.DefineAnimations()
 
@@ -93,7 +92,7 @@ func Run(ctx context.Context, configMap gosimpleconf.ConfigMap) error {
 	// Let them control a penguin to start with
 	player1 := player.NewPlayer(ctx, inputHandler)
 	penguinEntity := types.NewPenguin(renderer)
-	penguinCmdHandler := command.NewCommandHandler(ctx, penguinEntity)
+	penguinCmdHandler := command.NewCommandHandler(ctx, &penguinEntity)
 	penguinEntity.SetSpeed(2.0)
 	entityList = append(entityList, penguinCmdHandler)
 	player1.SetEntityChan(penguinCmdHandler.CommandRequest())
@@ -105,9 +104,9 @@ func Run(ctx context.Context, configMap gosimpleconf.ConfigMap) error {
 
 	for i := 0; i < 10; i++ {
 		entity := types.NewPenguin(renderer)
-		entityCmd := command.NewCommandHandler(ctx, entity)
+		entityCmd := command.NewCommandHandler(ctx, &entity)
 		randomPos := vector.Vec2F{X: rand.Float64() * 500, Y: rand.Float64() * -500}
-		entity.SetPosition(&randomPos)
+		entity.SetPosition(randomPos)
 		entity.SetAnimation(rand.Intn(animation.PENGUIN_NUM_ANIMS))
 		entityList = append(entityList, entityCmd)
 
@@ -204,6 +203,8 @@ func Run(ctx context.Context, configMap gosimpleconf.ConfigMap) error {
 		e.CloseRequests()
 	}
 
+	sprite.CleanupSpriteCache()
+
 	wg.Wait()
 
 	return nil

internal/game/sprite/sprite_animation.go

@@ -22,26 +22,24 @@ func NewAnimation(
 	offset sdl.Point,
 	length int,
 	border int,
-) *spriteAnimation {
+) spriteAnimation {
 
 	spritesheet := GetSpritesheet(filename)
 
-	a := spriteAnimation{
+	return spriteAnimation{
 		spritesheet: spritesheet,
 		dimensions:  dimensions,
 		offset:      offset,
 		length:      length,
 		border:      border,
 	}
-
-	return &a
 }
 
-func (a *spriteAnimation) Draw(
+func (a spriteAnimation) Draw(
 	frame int,
-	windowPosition *sdl.Point,
+	windowPosition sdl.Point,
 	angle float64,
-	center *sdl.Point,
+	center sdl.Point,
 	flip sdl.RendererFlip,
 ) error {
 
@@ -64,7 +62,7 @@ func (a *spriteAnimation) Draw(
 		H: height,
 	}
 
-	err := a.checkBounds(&section)
+	err := a.checkBounds(section)
 	if err != nil {
 		return err
 	}
@@ -76,7 +74,7 @@ func (a *spriteAnimation) Draw(
 		H: height * 2,
 	}
 
-	err = a.spritesheet.Draw(&section, &placement, angle, center, flip)
+	err = a.spritesheet.Draw(section, placement, angle, center, flip)
 	if err != nil {
 		return err
 	}
@@ -84,7 +82,7 @@ func (a *spriteAnimation) Draw(
 	return nil
 }
 
-func (a *spriteAnimation) checkBounds(section *sdl.Rect) error {
+func (a spriteAnimation) checkBounds(section sdl.Rect) error {
 	width := a.spritesheet.surface.W
 	height := a.spritesheet.surface.H
 
@@ -103,7 +101,7 @@ func (a *spriteAnimation) checkBounds(section *sdl.Rect) error {
 	}
 
 	if outOfBounds {
-		return fmt.Errorf("draw section was out of bounds - section: %v, image: %v", *section, a.spritesheet.surface.Bounds())
+		return fmt.Errorf("draw section was out of bounds - section: %v, image: %v", section, a.spritesheet.surface.Bounds())
 	}
 
 	return nil

internal/game/sprite/spritesheet.go

@@ -49,39 +49,33 @@ func NewSprite(renderer *sdl.Renderer, filename string) (*spritesheet, error) {
 }
 
 func (s *spritesheet) Cleanup() {
-	// Clean up image
-	defer func() {
-		if s.surface != nil {
-			sdl.Do(func() {
-				s.surface.Free()
-			})
-		}
-	}()
-
-	// Clean up spritesheet
-	defer func() {
+	sdl.Do(func() {
+		// Clean up spritesheet
 		if s.texture != nil {
-			sdl.Do(func() {
-				err := s.texture.Destroy()
-				if err != nil {
-					log.Printf("error destroying spritesheet %v: %v\n", s.filename, err)
-				}
-			})
+			err := s.texture.Destroy()
+			if err != nil {
+				log.Printf("error destroying spritesheet %v: %v\n", s.filename, err)
+			}
 		}
-	}()
+
+		// Clean up image
+		if s.surface != nil {
+			s.surface.Free()
+		}
+	})
 }
 
 func (s *spritesheet) Draw(
-	section *sdl.Rect,
-	placement *sdl.Rect,
+	section sdl.Rect,
+	placement sdl.Rect,
 	angle float64,
-	center *sdl.Point,
+	center sdl.Point,
 	flip sdl.RendererFlip,
 ) error {
 
 	var err error
 	sdl.Do(func() {
-		err = s.renderer.CopyEx(s.texture, section, placement, angle, center, flip)
+		err = s.renderer.CopyEx(s.texture, &section, &placement, angle, &center, flip)
 	})
 	if err != nil {
 		return err
@@ -90,10 +84,9 @@ func (s *spritesheet) Draw(
 	return nil
 }
 
-func (s *spritesheet) Bounds() *sdl.Point {
-	p := sdl.Point{
+func (s *spritesheet) Bounds() sdl.Point {
+	return sdl.Point{
 		X: s.surface.W,
 		Y: s.surface.H,
 	}
-	return &p
 }

internal/game/sprite/spritesheet_cache.go

@@ -28,20 +28,19 @@ var (
 )
 
 func InitSpriteCache(renderer *sdl.Renderer) error {
-	var err error
-
-	defaultSprite, err = createDefaultSprite(renderer)
-	if err != nil {
-		log.Printf("failed to create DefaultSprite: %v", err)
-		return err
-	}
-
 	spriteCache = make(map[string]*spritesheet)
 
 	for _, filename := range fileList {
 		s, err := NewSprite(renderer, filename)
 		if err != nil {
 			log.Printf("error creating sprite %v, using DefaultSprite: %v", filename, err)
+
+			defaultSprite, err = createDefaultSprite(renderer)
+			if err != nil {
+				log.Printf("failed to create DefaultSprite: %v", err)
+				return err
+			}
+
 			spriteCache[filename] = defaultSprite
 		} else {
 			spriteCache[filename] = s
@@ -82,6 +81,7 @@ func createDefaultSprite(renderer *sdl.Renderer) (*spritesheet, error) {
 	}
 
 	s := spritesheet{
+		filename: "DEFAULT_SPRITE",
 		renderer: renderer,
 		texture:  texture,
 		surface:  surface,

internal/vector/vector.go

@@ -11,24 +11,28 @@ type Vec2F struct {
 	Y float64
 }
 
-func (v *Vec2F) Zero() bool {
+func (v Vec2F) Zero() bool {
 	return v.X == 0.0 && v.Y == 0.0
 }
 
-func (v *Vec2F) LengthSquared() float64 {
+func (v Vec2F) LengthSquared() float64 {
 	return v.X*v.X + v.Y*v.Y
 }
 
-func (v *Vec2F) Normalize() {
+func (v Vec2F) Normalized() Vec2F {
+	output := Vec2F{X: v.X, Y: v.Y}
+
 	length := math.Hypot(v.X, v.Y)
 	if length == 0 {
-		return
+		return output
 	}
 
-	v.X = v.X / length
-	v.Y = v.Y / length
+	output.X = v.X / length
+	output.Y = v.Y / length
+
+	return output
 }
 
-func (v *Vec2F) Dot(other *Vec2F) float64 {
+func (v Vec2F) Dot(other Vec2F) float64 {
 	return v.X*other.X + v.Y*other.Y
 }

main.go

@@ -58,8 +58,9 @@ func run(ctx context.Context) error {
 
 	// Setup logging
 	writeToFile := gosimpleconf.Bool(configMap["log.writeToFile"])
+	utcTime := gosimpleconf.Bool(configMap["log.utcTime"])
 	logFilename := configMap["log.file"]
-	logWriter, err := config.SetupLogging(writeToFile, logFilename)
+	logWriter, err := config.SetupLogging(writeToFile, utcTime, logFilename)
 	if err != nil {
 		log.Fatalf("error setting up logging: %v\n", err)
 	}