they walked so they could run when I tweaked the sprite sheet

engine/misc.go

@@ -1,6 +1,7 @@
 package engine
 
 import (
+	"image/color"
 	"unsafe"
 
 	"github.com/hajimehoshi/ebiten/v2"
@@ -30,3 +31,12 @@ func ToGeoMDef(m *ebiten.GeoM) *GeoMDef {
 func (d *GeoMDef) GeoM() *ebiten.GeoM {
 	return (*ebiten.GeoM)(unsafe.Pointer(d))
 }
+
+// Fill fills the image with a colour.
+type Fill struct {
+	Color color.Color
+}
+
+func (f Fill) Draw(screen *ebiten.Image, _ ebiten.GeoM) {
+	screen.Fill(color.Color(f.Color))
+}

engine/sprite.go

@@ -20,7 +20,7 @@ type Sprite struct {
 	ZPos
 
 	vx, vy     float64       // TODO: refactor
-	animIdle, animWalkLeft, animWalkRight *Anim
+	animIdle, animRunLeft, animRunRight *Anim
 }
 
 func (s *Sprite) Draw(screen *ebiten.Image, geom ebiten.GeoM) {
@@ -59,10 +59,10 @@ func (s *Sprite) Update() error {
 	switch {
 	case ebiten.IsKeyPressed(ebiten.KeyLeft):
 		s.vx = -2
-		s.Anim = s.animWalkLeft
+		s.Anim = s.animRunLeft
 	case ebiten.IsKeyPressed(ebiten.KeyRight):
 		s.vx = 2
-		s.Anim = s.animWalkRight
+		s.Anim = s.animRunRight
 	default:
 		s.vx = 0
 		s.Anim = s.animIdle
@@ -74,7 +74,7 @@ func (s *Sprite) Update() error {
 
 func (s *Sprite) Build(g *Game) {
 	// TODO: better than this
-	s.animWalkLeft = &Anim{Def: AnimDefs["aw_walk_left"]}
-	s.animWalkRight = &Anim{Def: AnimDefs["aw_walk_right"]}
+	s.animRunLeft = &Anim{Def: AnimDefs["aw_run_left"]}
+	s.animRunRight = &Anim{Def: AnimDefs["aw_run_right"]}
 	s.animIdle = &Anim{Def: AnimDefs["aw_idle"]}
 }

main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"embed"
 	"image"
+	"image/color"
 	_ "image/png"
 	"log"
 
@@ -57,6 +58,22 @@ func main() {
 				{Frame: 8, Duration: 6},
 			},
 		},
+		"aw_run_right": {
+			Frames: []engine.AnimFrame{
+				{Frame: 9, Duration: 3},
+				{Frame: 10, Duration: 3},
+				{Frame: 11, Duration: 3},
+				{Frame: 12, Duration: 3},
+			},
+		},
+		"aw_run_left": {
+			Frames: []engine.AnimFrame{
+				{Frame: 13, Duration: 3},
+				{Frame: 14, Duration: 3},
+				{Frame: 15, Duration: 3},
+				{Frame: 16, Duration: 3},
+			},
+		},
 	}
 
 	tiles := [][]engine.Tile{
@@ -80,6 +97,9 @@ func main() {
 	level1 := &engine.Scene{
 		ID: "level_1",
 		Components: []interface{}{
+			engine.Fill{
+				Color: color.White,
+			},
 			&engine.Tilemap{
 				ID:       "terrain",
 				Map:      tiles,
@@ -107,7 +127,7 @@ func main() {
 				ID: "protagonist",
 				Actor: engine.Actor{
 					Position: image.Pt(100, 100),
-					Size:     image.Pt(8, 16),
+					Size:     image.Pt(10, 16),
 				},
 				Src:  engine.ImageRef{Path: "assets/aw.png"},
 				ZPos: 1,