Do geom on stack?

engine/debug.go

@@ -11,7 +11,7 @@ import (
 // PerfDisplay debugprints CurrentTPS and CurrentFPS in the top left.
 type PerfDisplay struct{}
 
-func (PerfDisplay) Draw(screen *ebiten.Image) {
+func (PerfDisplay) Draw(screen *ebiten.Image, _ ebiten.GeoM) {
 	ebitenutil.DebugPrint(screen, fmt.Sprintf("TPS: %0.2f  FPS: %0.2f", ebiten.CurrentTPS(), ebiten.CurrentFPS()))
 }
 

engine/game.go

@@ -12,9 +12,9 @@ type Updater interface {
 }
 
 // Drawer is a component that can draw itself. Draw is called often.
-// DrawAfter is used to reorder components.
+// Z is used to reorder components.
 type Drawer interface {
-	Draw(*ebiten.Image)
+	Draw(screen *ebiten.Image, geom ebiten.GeoM)
 	Z() float64
 }
 
@@ -47,7 +47,7 @@ func (g *Game) Update() error {
 func (g *Game) Draw(screen *ebiten.Image) {
 	for _, c := range g.Components {
 		if d, ok := c.(Drawer); ok {
-			d.Draw(screen)
+			d.Draw(screen, ebiten.GeoM{})
 		}
 	}
 }

engine/tiles.go

@@ -10,17 +10,16 @@ type Tilemap struct {
 	Map      [][]Tile
 	Src      *ebiten.Image // must be a horizontal tile set
 	TileSize int
-	GeoM     ebiten.GeoM
 
 	ZPos
 }
 
-func (t *Tilemap) Draw(screen *ebiten.Image) {
+func (t *Tilemap) Draw(screen *ebiten.Image, geom ebiten.GeoM) {
 	for j, row := range t.Map {
 		for i, tile := range row {
 			var op ebiten.DrawImageOptions
 			op.GeoM.Translate(float64(i*t.TileSize), float64(j*t.TileSize))
-			op.GeoM.Concat(t.GeoM)
+			op.GeoM.Concat(geom)
 
 			sx := tile.TileIndex() * t.TileSize
 			src := t.Src.SubImage(image.Rect(sx, 0, sx+t.TileSize, t.TileSize)).(*ebiten.Image)