Merge pull request #9 from kensonjohnson/smooth-entity-movement

Smooth entity movement

component/sprite.go

@@ -2,11 +2,29 @@ package component
 
 import (
 	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/kensonjohnson/roguelike-game-go/config"
 	"github.com/yohamta/donburi"
 )
 
 type SpriteData struct {
-	Image *ebiten.Image
+	Image          *ebiten.Image
+	OffestX        int // The direction the sprite is moving FROM, -1, 0, 1
+	OffestY        int // The direction the sprite is moving FROM, -1, 0, 1
+	AnimationFrame int
+	progress       float64 // The progress of the current animation frame from 0 to 1
+	Animating      bool
+}
+
+// Returns the X and Y offset for the current animation frame. TODO: Add
+// support for animation frames.
+func (sd *SpriteData) GetAnimationStep() (float64, float64) {
+	offsetX := (1 - sd.progress) * config.TileWidth * float64(sd.OffestX)
+	offsetY := (1 - sd.progress) * config.TileHeight * float64(sd.OffestY)
+	return offsetX, offsetY
+}
+
+func (sd *SpriteData) SetProgress(progress float64) {
+	sd.progress = progress
 }
 
 var Sprite = donburi.NewComponentType[SpriteData]()

system/action/monster.go

@@ -20,7 +20,7 @@ func TakeMonsterAction(ecs *ecs.ECS) {
 
 	archetype.MonsterTag.Each(ecs.World, func(entry *donburi.Entry) {
 		position := component.Position.Get(entry)
-
+		sprite := component.Sprite.Get(entry)
 		monsterVision := component.Fov.Get(entry).VisibleTiles
 
 		// Check if the monster can see the player
@@ -37,8 +37,12 @@ func TakeMonsterAction(ecs *ecs.ECS) {
 						// Update the tile this monster is blocking
 						level.GetFromXY(position.X, position.Y).Blocked = false
 						nextTile.Blocked = true
+						sprite.OffestX = position.X - path[1].X
+						sprite.OffestY = position.Y - path[1].Y
 						position.X = path[1].X
 						position.Y = path[1].Y
+						sprite.Animating = true
+						sprite.SetProgress(0)
 						// Since the monster moved, update the field of view
 						monsterVision.Compute(level, position.X, position.Y, 8)
 					}

system/action/player.go

@@ -14,15 +14,6 @@ import (
 func TakePlayerAction(ecs *ecs.ECS) bool {
 	turnTaken := false
 
-	// Grab current level
-	levelEntry := archetype.LevelTag.MustFirst(ecs.World)
-	level := component.Level.Get(levelEntry)
-
-	// Grab player data
-	playerEntry := archetype.PlayerTag.MustFirst(ecs.World)
-	position := component.Position.Get(playerEntry)
-	vision := component.Fov.Get(playerEntry)
-
 	// Capture any keypresses we care about
 	moveX := 0
 	moveY := 0
@@ -55,6 +46,16 @@ func TakePlayerAction(ecs *ecs.ECS) bool {
 		return false
 	}
 
+	// Grab current level
+	levelEntry := archetype.LevelTag.MustFirst(ecs.World)
+	level := component.Level.Get(levelEntry)
+
+	// Grab player data
+	playerEntry := archetype.PlayerTag.MustFirst(ecs.World)
+	position := component.Position.Get(playerEntry)
+	sprite := component.Sprite.Get(playerEntry)
+	vision := component.Fov.Get(playerEntry)
+
 	// TODO: Update so diagonal movement consumes two turns
 	// Attempt to move
 	tile := level.GetFromXY(position.X+moveX, position.Y+moveY)
@@ -66,6 +67,10 @@ func TakePlayerAction(ecs *ecs.ECS) bool {
 		// Update the player's position
 		position.X += moveX
 		position.Y += moveY
+		sprite.OffestX = -moveX
+		sprite.OffestY = -moveY
+		sprite.Animating = true
+		sprite.SetProgress(0)
 		// Update the player's field of view
 		vision.VisibleTiles.Compute(level, position.X, position.Y, 8)
 		// Update any discoverable entities

system/render.go

@@ -36,7 +36,12 @@ func (r *render) Draw(ecs *ecs.ECS, screen *ebiten.Image) {
 
 		if playerVision.IsVisible(position.X, position.Y) {
 			camera.CamImageOptions.GeoM.Reset()
-			camera.CamImageOptions.GeoM.Translate(float64(position.X*config.TileWidth), float64(position.Y*config.TileHeight))
+			if sprite.Animating {
+				offsetX, offsetY := sprite.GetAnimationStep()
+				camera.CamImageOptions.GeoM.Translate(float64(position.X*config.TileWidth)+offsetX, float64(position.Y*config.TileHeight)+offsetY)
+			} else {
+				camera.CamImageOptions.GeoM.Translate(float64(position.X*config.TileWidth), float64(position.Y*config.TileHeight))
+			}
 			camera.MainCamera.Draw(sprite.Image, camera.CamImageOptions, screen)
 		}
 	})

system/turn.go

@@ -28,9 +28,9 @@ const (
 )
 
 func (td *TurnData) Update(ecs *ecs.ECS) {
-	td.TurnCounter++
 
 	if td.TurnState == BeforePlayerAction {
+		td.TurnCounter++
 		// Check if player survived the last cycle of monster turns
 		entry := archetype.PlayerTag.MustFirst(ecs.World)
 		playerHealth := component.Health.Get(entry)
@@ -52,16 +52,30 @@ func (td *TurnData) Update(ecs *ecs.ECS) {
 			}
 		})
 
-		level.Redraw = true
+		component.Sprite.Each(ecs.World, func(entry *donburi.Entry) {
+			sprite := component.Sprite.Get(entry)
+			sprite.SetProgress(float64(td.TurnCounter) / 12)
+		})
 
-		td.progressTurnState()
+		if td.TurnCounter > 12 {
+			// Reset the progress of all sprites
+			component.Sprite.Each(ecs.World, func(entry *donburi.Entry) {
+				sprite := component.Sprite.Get(entry)
+				sprite.SetProgress(0)
+				sprite.Animating = false
+				sprite.OffestX = 0
+				sprite.OffestY = 0
+			})
+
+			level.Redraw = true
+			td.progressTurnState()
+			td.resetCounter()
+		}
 	}
 
-	if td.TurnState == PlayerTurn && td.TurnCounter > 12 {
-		turnTaken := action.TakePlayerAction(ecs)
-		if turnTaken {
+	if td.TurnState == PlayerTurn {
+		if turnTaken := action.TakePlayerAction(ecs); turnTaken {
 			td.progressTurnState()
-			td.resetCounter()
 		}
 	}