Change move functions

internal/game/entity/penguin.go

@@ -13,6 +13,7 @@ type penguin struct {
 	currentAnimation *entityAnimation
 	animationStep    int32
 	facingRight      bool
+	updateAnimation  bool
 
 	// Physical parameters
 	worldPosition *vector.Vec2F
@@ -75,48 +76,22 @@ func (p *penguin) SetAnimation(name string) {
 	p.currentAnimation = a
 }
 
-func (p *penguin) MoveRight() {
-	p.direction.X = 1
-	p.facingRight = true
-	p.SetMoveAnimation()
+func (p *penguin) MoveX(x float64) {
+	p.direction.X = x
+	p.updateAnimation = true
 }
 
-func (p *penguin) MoveLeft() {
-	p.direction.X = -1
-	p.facingRight = false
-	p.SetMoveAnimation()
-}
-
-func (p *penguin) MoveUp() {
+func (p *penguin) MoveY(y float64) {
 	// (0,0) is the top left, so negative y moves up
-	p.direction.Y = -1
-	p.SetMoveAnimation()
-}
-
-func (p *penguin) MoveDown() {
-	// positive y moves down
-	p.direction.Y = 1
-	p.SetMoveAnimation()
-}
-
-func (p *penguin) StopMove() {
-	p.direction.X = 0
-	p.direction.Y = 0
-	p.SetMoveAnimation()
-}
-
-func (p *penguin) StopHorizontal() {
-	p.direction.X = 0
-	p.SetMoveAnimation()
-}
-
-func (p *penguin) StopVertical() {
-	p.direction.Y = 0
-	p.SetMoveAnimation()
+	p.direction.Y = y
+	p.updateAnimation = true
 }
 
 func (p *penguin) SetMoveAnimation() {
-	if p.direction.X == 0 && p.direction.Y == 0 {
+	x := p.direction.X
+	y := p.direction.Y
+
+	if x == 0 && y == 0 {
 		// Stationary
 		if p.facingRight {
 			p.SetAnimation(PENGUIN_STATIONARY_RIGHT)
@@ -125,6 +100,16 @@ func (p *penguin) SetMoveAnimation() {
 		}
 	} else {
 		// Moving
+
+		// Update which direction we're facing
+		if x > 0 {
+			p.facingRight = true
+		} else if x < 0 {
+			p.facingRight = false
+		}
+
+		// if x == 0, stay facing whatever direction we were previously facing
+
 		if p.facingRight {
 			p.SetAnimation(PENGUIN_WALK_RIGHT)
 		} else {
@@ -134,6 +119,11 @@ func (p *penguin) SetMoveAnimation() {
 }
 
 func (p *penguin) Update() error {
+	if p.updateAnimation {
+		p.SetMoveAnimation()
+		p.updateAnimation = false
+	}
+
 	p.direction.Normalize()
 	x := p.direction.X * p.speed
 	y := p.direction.Y * p.speed

internal/vector/vector.go

@@ -3,7 +3,7 @@ package vector
 import "math"
 
 // This is a small-scale vector implementation for a Vec2F.
-// If you need anything more complicated than just normals and dot-products,
+// If you need anything more complicated than normals and dot-products,
 // then you should probably just switch to the glmath library instead.
 
 type Vec2F struct {

main.go

@@ -126,23 +126,24 @@ func run(configMap gosimpleconf.ConfigMap) error {
 		}
 
 		if keystates[sdl.K_d] {
-			penguin.MoveRight()
+			penguin.MoveX(1)
 		} else if keystates[sdl.K_a] {
-			penguin.MoveLeft()
+			penguin.MoveX(-1)
 		} else {
-			penguin.StopHorizontal()
+			penguin.MoveX(0)
 		}
 
 		if keystates[sdl.K_w] {
-			penguin.MoveUp()
+			penguin.MoveY(-1)
 		} else if keystates[sdl.K_s] {
-			penguin.MoveDown()
+			penguin.MoveY(1)
 		} else {
-			penguin.StopVertical()
+			penguin.MoveY(0)
 		}
 
 		if !keystates[sdl.K_a] && !keystates[sdl.K_d] && !keystates[sdl.K_w] && !keystates[sdl.K_s] {
-			penguin.StopMove()
+			penguin.MoveX(0)
+			penguin.MoveY(0)
 		}
 
 		// Background