drawdfs query? nope lol

engine/drawdfs.go

@@ -30,16 +30,52 @@ type DrawDFS struct {
 }
 
 func (d *DrawDFS) Draw(screen *ebiten.Image, opts *ebiten.DrawImageOptions) {
-	if d.Hidden() {
-		return
+	if true {
+		d.drawRecursive(d, screen, *opts)
+	} else {
+		d.drawWithQuery(screen, opts)
 	}
-	d.drawRecursive(d.Child, screen, *opts)
 }
 
 // ManagesDrawingSubcomponents is present so DrawDFS is recognised as a
 // DrawManager.
 func (DrawDFS) ManagesDrawingSubcomponents() {}
 
+// This doesn't work! This misses Hiders, Transformers that are not Drawers.
+func (d *DrawDFS) drawWithQuery(screen *ebiten.Image, opts *ebiten.DrawImageOptions) {
+	stack := []ebiten.DrawImageOptions{*opts}
+	d.game.Query(d, DrawerType,
+		// visitPre
+		func(x interface{}) error {
+			if h, ok := x.(Hider); ok && h.Hidden() {
+				return Skip
+			}
+			opts := stack[len(stack)-1]
+			if tf, ok := x.(Transformer); ok {
+				opts = concatOpts(tf.Transform(), opts)
+				stack = append(stack, opts)
+			}
+			if x == d {
+				return nil
+			}
+			if dr, ok := x.(Drawer); ok {
+				dr.Draw(screen, &opts)
+			}
+			if _, isDM := x.(DrawManager); isDM {
+				return Skip
+			}
+			return nil
+		},
+		// visitPost
+		func(x interface{}) error {
+			if _, ok := x.(Transformer); ok {
+				stack = stack[:len(stack)-1]
+			}
+			return nil
+		},
+	)
+}
+
 func (d *DrawDFS) drawRecursive(component interface{}, screen *ebiten.Image, opts ebiten.DrawImageOptions) {
 	// Hidden? stop drawing
 	if h, ok := component.(Hider); ok && h.Hidden() {
@@ -49,16 +85,17 @@ func (d *DrawDFS) drawRecursive(component interface{}, screen *ebiten.Image, opt
 	if tf, ok := component.(Transformer); ok {
 		opts = concatOpts(tf.Transform(), opts)
 	}
-	// Does it draw itself? Draw
-	if dr, ok := component.(Drawer); ok {
-		dr.Draw(screen, &opts)
-	}
-	// Is it a DrawManager? It manages drawing all its subcomponents.
-	if _, ok := component.(DrawManager); ok {
-		return
+	if component != d {
+		// Does it draw itself? Draw
+		if dr, ok := component.(Drawer); ok {
+			dr.Draw(screen, &opts)
+		}
+		// Is it a DrawManager? It manages drawing all its subcomponents.
+		if _, ok := component.(DrawManager); ok {
+			return
+		}
 	}
 	// Has subcomponents? recurse
-	// TODO: use g.Query?
 	d.game.Children(component).Scan(func(x interface{}) error {
 		d.drawRecursive(x, screen, opts)
 		return nil