back to previous way of doing camera

engine/camera.go

@@ -11,6 +11,7 @@ import (
 var _ interface {
 	Identifier
 	Prepper
+	Scanner
 	Transformer
 } = &Camera{}
 
@@ -18,11 +19,10 @@ func init() {
 	gob.Register(&Camera{})
 }
 
-// Camera models a camera that is viewing a scene. (Camera is a child of the
+// Camera models a camera that is viewing something.
-// scene it is viewing, for various reasons.) Changes to the fields take effect
-// immediately.
 type Camera struct {
 	ID
+	Child interface{}
 
 	// Camera controls
 	Centre   image.Point // world coordinates
@@ -39,6 +39,9 @@ func (c *Camera) Prepare(game *Game) error {
 	return nil
 }
 
+// Scan returns s.Child.
+func (c *Camera) Scan() []interface{} { return []interface{}{c.Child} }
+
 // Transform returns the camera transform.
 func (c *Camera) Transform() (opts ebiten.DrawImageOptions) {
 	opts.GeoM.Translate(float2(c.Centre.Mul(-1)))

engine/interface.go

@@ -146,7 +146,6 @@ type Scener interface {
 	Hider
 	Identifier
 	Scanner
-	Transformer
 }
 
 // Saver components can be saved to disk.

engine/scene.go

@@ -2,8 +2,6 @@ package engine
 
 import (
 	"encoding/gob"
-
-	"github.com/hajimehoshi/ebiten/v2"
 )
 
 // Ensure Scene satisfies Scener.
@@ -17,7 +15,6 @@ func init() {
 type Scene struct {
 	ID
 	Bounds     // world coordinates
-	Camera     *Camera // optional; applies a bunch of transforms to draw calls
 	Components []interface{}
 	Disabled
 	Hidden
@@ -105,18 +102,5 @@ func (s *Scene) Draw(screen *ebiten.Image, opts ebiten.DrawImageOptions) {
 }
 */
 
-// Transform returns the camera transform
-func (s *Scene) Transform() ebiten.DrawImageOptions {
-	if s.Camera == nil {
-		return ebiten.DrawImageOptions{}
-	}
-	return s.Camera.Transform()
-}
-
 // Scan returns all immediate subcomponents (including the camera, if not nil).
-func (s *Scene) Scan() []interface{} {
+func (s *Scene) Scan() []interface{} { return s.Components }
-	if s.Camera != nil {
-		return append(s.Components, s.Camera)
-	}
-	return s.Components
-}

engine/sceneref.go

@@ -5,8 +5,6 @@ import (
 	"image"
 	"io/fs"
 	"path/filepath"
-
-	"github.com/hajimehoshi/ebiten/v2"
 )
 
 // Ensure SceneRef satisfies interfaces.
@@ -76,6 +74,3 @@ func (r SceneRef) Ident() string { return r.scene.Ident() }
 
 // Scan returns the components in the scene.
 func (r SceneRef) Scan() []interface{} { return r.scene.Scan() }
-
-// Transform returns the value of Transform from the scene.
-func (r SceneRef) Transform() ebiten.DrawImageOptions { return r.scene.Transform() }

main.go

@@ -33,7 +33,7 @@ func main() {
 	ebiten.SetWindowTitle("TODO")
 
 	// Change to true to rewrite level1.gobz
-	if true && runtime.GOOS != "js" {
+	if false && runtime.GOOS != "js" {
 		writeLevel1()
 	}
 
@@ -43,7 +43,10 @@ func main() {
 		Root: &engine.Scene{
 			ID: "root",
 			Components: []interface{}{
-				&engine.SceneRef{Path: "assets/level1.gobz"},
+				&engine.Camera{
+					ID:    "game_camera",
+					Child: &engine.SceneRef{Path: "assets/level1.gobz"},
+				},
 				&engine.DebugToast{ID: "toast", Pos: image.Pt(0, 15)},
 				engine.PerfDisplay{},
 			},
@@ -107,9 +110,6 @@ func writeLevel1() {
 	level1 := &engine.Scene{
 		ID:     "level_1",
 		Bounds: engine.Bounds(image.Rect(-32, -32, 320+32, 240+32)),
-		Camera: &engine.Camera{
-			ID: "game_camera",
-		},
 		Components: []interface{}{
 			&engine.Fill{
 				ID:     "bg_fill",