further clear screen debugging

TODO.md

@@ -1,5 +1,11 @@
 - add all other options like size etc
-- clear screen  disabled leads to zoom artifacts when  zooming out and
-  canvas  is smaller  than  screen workaround:  using  screen copy  in
-  game.Screen. Play  copies screen to it  and Menu draws it  to screen
-  before drawing the menus
+
+- Clear screen problem:
+  - it works when hitting the K key, immediately
+  - its being turned off correctly when entering menu and on when leaving it
+  - but  regardless of the setting,  after turning it off,  the engine
+    seems to run a couple of  ticks with the old setting before switching
+    scenes
+  - looks like a race condition
+  - obviously  with K there  are more loops before  actually switching
+    scenes, which doesn't happen with ESC

game.go

@@ -31,6 +31,7 @@ func NewGame(config *Config, startscene SceneName) *Game {
 	ebiten.SetWindowSize(game.ScreenWidth, game.ScreenHeight)
 	ebiten.SetWindowTitle("golsky - conway's game of life")
 	ebiten.SetWindowResizingMode(ebiten.WindowResizingModeEnabled)
+	ebiten.SetScreenClearedEveryFrame(true)
 
 	game.Screen = ebiten.NewImage(game.ScreenWidth, game.ScreenHeight)
 	return game
@@ -50,6 +51,7 @@ func (game *Game) Update() error {
 	scene := game.GetCurrentScene()
 	scene.Update()
 
+	// FIXME: should work, but doesn't
 	//ebiten.SetScreenClearedEveryFrame(scene.Clearscreen())
 
 	next := scene.GetNext()
@@ -62,11 +64,12 @@ func (game *Game) Update() error {
 		game.CurrentScene = next
 	}
 
+	//fmt.Printf("Clear Screen: %t\n", ebiten.IsScreenClearedEveryFrame())
+
 	return nil
 }
 
 func (game *Game) Draw(screen *ebiten.Image) {
 	scene := game.GetCurrentScene()
-	ebiten.SetScreenClearedEveryFrame(scene.Clearscreen())
 	scene.Draw(screen)
 }

scene-menu.go

@@ -54,7 +54,7 @@ func (scene *SceneMenu) Update() error {
 	scene.Ui.Update()
 
 	if inpututil.IsKeyJustPressed(ebiten.KeyEscape) || inpututil.IsKeyJustPressed(ebiten.KeyQ) {
-		scene.SetNext(Play)
+		scene.Leave()
 	}
 
 	return nil
@@ -62,15 +62,20 @@ func (scene *SceneMenu) Update() error {
 }
 
 func (scene *SceneMenu) Draw(screen *ebiten.Image) {
-	op := &ebiten.DrawImageOptions{}
-	op.GeoM.Reset()
-	op.GeoM.Translate(0, 0)
+	//op := &ebiten.DrawImageOptions{}
+	// op.GeoM.Reset()
+	// op.GeoM.Translate(0, 0)
 
-	screen.DrawImage(scene.Game.Screen, op)
+	// screen.DrawImage(scene.Game.Screen, op)
 
 	scene.Ui.Draw(screen)
 }
 
+func (scene *SceneMenu) Leave() {
+	ebiten.SetScreenClearedEveryFrame(true)
+	scene.SetNext(Play)
+}
+
 func (scene *SceneMenu) Init() {
 	rowContainer := NewRowContainer("Main Menu")
 
@@ -78,20 +83,20 @@ func (scene *SceneMenu) Init() {
 		func(args *widget.ButtonClickedEventArgs) {
 			scene.Config.Empty = true
 			scene.Config.Restart = true
-			scene.SetNext(Play)
+			scene.Leave()
 		})
 
 	random := NewMenuButton("Start with random patterns",
 		func(args *widget.ButtonClickedEventArgs) {
 			scene.Config.Restart = true
-			scene.SetNext(Play)
+			scene.Leave()
 		})
 
 	copy := NewMenuButton("Save Copy as RLE",
 		func(args *widget.ButtonClickedEventArgs) {
 			scene.Config.Markmode = true
 			scene.Config.Paused = true
-			scene.SetNext(Play)
+			scene.Leave()
 		})
 
 	options := NewMenuButton("Options",
@@ -105,7 +110,7 @@ func (scene *SceneMenu) Init() {
 
 	cancel := NewMenuButton("Close Window",
 		func(args *widget.ButtonClickedEventArgs) {
-			scene.SetNext(Play)
+			scene.Leave()
 		})
 
 	quit := NewMenuButton("Exit Golsky",

scene-play.go

@@ -24,6 +24,8 @@ type ScenePlay struct {
 	Next   SceneName
 	Whoami SceneName
 
+	Clear bool
+
 	Grids                                      []*Grid // 2 grids: one current, one next
 	History                                    *Grid   // holds state of past dead cells for evolution traces
 	Index                                      int     // points to current grid
@@ -156,16 +158,25 @@ func (scene *ScenePlay) CheckInput() {
 		os.Exit(0)
 	}
 
+	// FIXME: works from here
+	if inpututil.IsKeyJustPressed(ebiten.KeyK) {
+		scene.Clear = !scene.Clear
+		fmt.Printf("Clear: %t\n", scene.Clear)
+		ebiten.SetScreenClearedEveryFrame(scene.Clear)
+	}
+
+	// FIXME: and this does have no effect. WHY?!?!?
+	if inpututil.IsKeyJustPressed(ebiten.KeyEscape) {
+		ebiten.SetScreenClearedEveryFrame(false)
+		scene.SetNext(Menu)
+	}
+
 	if inpututil.IsKeyJustPressed(ebiten.KeyC) {
 		fmt.Println("mark mode on")
 		scene.Config.Markmode = true
 		scene.Config.Paused = true
 	}
 
-	if inpututil.IsKeyJustPressed(ebiten.KeyEscape) {
-		scene.SetNext(Menu)
-	}
-
 	if scene.Config.Markmode {
 		return
 	}
@@ -483,9 +494,9 @@ func (scene *ScenePlay) DrawDebug(screen *ebiten.Image) {
 		}
 
 		debug := fmt.Sprintf(
-			"FPS: %0.2f, TPG: %d, Mem: %0.2fMB, Gen: %d, Scale: %.02f, Z: %d  %s",
+			"FPS: %0.2f, TPG: %d, Mem: %0.2fMB, Gen: %d, Scale: %.02f, Z: %d, Clear: %t  %s",
 			ebiten.ActualTPS(), scene.TPG, GetMem(), scene.Generations,
-			scene.Game.Scale, scene.Camera.ZoomFactor, paused)
+			scene.Game.Scale, scene.Camera.ZoomFactor, ebiten.IsScreenClearedEveryFrame(), paused)
 
 		FontRenderer.Renderer.SetSizePx(10 + int(scene.Game.Scale*10))
 		FontRenderer.Renderer.SetTarget(screen)