TouchScreenMode Fix

Made some fixes to touchscreen control detection:

* TouchScreenMode is activated on the first SDL2 FingerDown
* TouchScreenMode deactivates after the last finger is removed, and a
  mouse event happens at least 5 ticks later.

cmd/doodle/main.go

@@ -19,7 +19,6 @@ import (
 	"git.kirsle.net/SketchyMaze/doodle/pkg/chatbot"
 	"git.kirsle.net/SketchyMaze/doodle/pkg/gamepad"
 	"git.kirsle.net/SketchyMaze/doodle/pkg/log"
-	"git.kirsle.net/SketchyMaze/doodle/pkg/native"
 	"git.kirsle.net/SketchyMaze/doodle/pkg/plus/bootstrap"
 	"git.kirsle.net/SketchyMaze/doodle/pkg/plus/dpp"
 	"git.kirsle.net/SketchyMaze/doodle/pkg/shmem"
@@ -215,9 +214,7 @@ func main() {
 		usercfg.Load()
 
 		// Hide the mouse cursor over the window, we draw our own sprite image for it.
-		if !native.HasTouchscreen(engine) {
 		engine.ShowCursor(false)
-		}
 
 		// Set the app window icon.
 		if engine, ok := game.Engine.(*sdl.Renderer); ok {
@@ -253,7 +250,7 @@ func main() {
 
 		// Log some basic environment details.
 		w, h := engine.WindowSize()
-		log.Info("Has touchscreen? %+v  Window size: %dx%d", native.HasTouchscreen(engine), w, h)
+		log.Info("Window size: %dx%d", w, h)
 
 		game.Run()
 		return nil

pkg/cursor/cursor.go

@@ -25,7 +25,7 @@ var NoCursor = &Cursor{}
 
 // Draw the cursor on screen. NOTE: Does not draw on touchscreen devices.
 func Draw(e render.Engine) {
-	if native.HasTouchscreen(e) {
+	if native.IsTouchScreenMode() {
 		return
 	}
 

pkg/doodle.go

@@ -146,6 +146,9 @@ func (d *Doodle) Run() error {
 			d.width, d.height = d.Engine.WindowSize()
 		}
 
+		// Update touch screen control (mainly whether to show the mouse cursor).
+		native.UpdateTouchScreenMode(ev)
+
 		// Let the gamepad controller check for events, if it's in MouseMode
 		// it will fake the mouse cursor.
 		gamepad.Loop(ev)

pkg/native/engine_sdl.go

@@ -19,14 +19,6 @@ import (
 // Native render engine functions (SDL2 edition),
 // not for JavaScript/WASM yet.
 
-// HasTouchscreen checks if the device has at least one SDL_GetNumTouchDevices.
-func HasTouchscreen(e render.Engine) bool {
-	if _, ok := e.(*sdl.Renderer); ok {
-		return sdl2.GetNumTouchDevices() > 0
-	}
-	return false
-}
-
 // CopyToClipboard puts some text on your clipboard.
 func CopyToClipboard(text string) error {
 	if _, ok := shmem.CurrentRenderEngine.(*sdl.Renderer); ok {

pkg/native/engine_wasm.go

@@ -10,10 +10,6 @@ import (
 	"git.kirsle.net/go/render"
 )
 
-func HasTouchscreen(e render.Engine) bool {
-	return false
-}
-
 func TextToImage(e render.Engine, text render.Text) (image.Image, error) {
 	return nil, errors.New("not supported on WASM")
 }

pkg/native/touch_screen.go

@@ -0,0 +1,60 @@
+package native
+
+import (
+	"git.kirsle.net/SketchyMaze/doodle/pkg/log"
+	"git.kirsle.net/SketchyMaze/doodle/pkg/shmem"
+	"git.kirsle.net/go/render/event"
+)
+
+// Common code to handle basic touch screen detection.
+
+var (
+	isTouchScreenMode  bool
+	lastFingerDownTick uint64
+)
+
+// IsTouchScreenMode is activated when the user has touched the screen, and false when the mouse is moved.
+func IsTouchScreenMode() bool {
+	return isTouchScreenMode
+}
+
+/*
+UpdateTouchScreenMode evaluates whether the primary game input is a touch screen rather than a mouse cursor.
+
+The game always hides the OS cursor (if it exists) and may draw its own custom mouse cursor.
+
+On a touch screen device (such as a mobile), the custom mouse cursor should not be drawn, either, as
+it would jump around to wherever the user last touched and be distracting.
+
+TouchScreenMode is activated when a touch event has been triggered (at least one finger was down).
+
+TouchScreenMode deactivates and shows the mouse cursor when no finger is held down, and then a mouse
+event has occurred. So if the user has a touch screen laptop, wiggling the actual mouse input will
+bring the cursor back.
+*/
+func UpdateTouchScreenMode(ev *event.State) {
+
+	// If a finger is presently down, record the current tick.
+	if ev.IsFingerDown {
+		lastFingerDownTick = shmem.Tick
+	}
+
+	if !isTouchScreenMode {
+		// We are NOT in touch screen mode. Touching the screen will change this.
+		if ev.IsFingerDown {
+			log.Info("TouchScreenMode ON")
+			isTouchScreenMode = true
+		}
+	} else {
+		// We ARE in touch screen mode. Wait for all fingers to be lifted.
+		if !ev.IsFingerDown {
+
+			// If we have registered a mouse event a few ticks after the finger was
+			// removed, it is a real mouse cursor and we exit touch screen mode.
+			if ev.IsMouseEvent && shmem.Tick-lastFingerDownTick > 5 {
+				log.Info("TouchScreenMode OFF")
+				isTouchScreenMode = false
+			}
+		}
+	}
+}

pkg/play_scene_touch.go

@@ -5,6 +5,7 @@ import (
 
 	"git.kirsle.net/SketchyMaze/doodle/pkg/balance"
 	"git.kirsle.net/SketchyMaze/doodle/pkg/log"
+	"git.kirsle.net/SketchyMaze/doodle/pkg/native"
 	"git.kirsle.net/SketchyMaze/doodle/pkg/usercfg"
 	"git.kirsle.net/go/render"
 	"git.kirsle.net/go/render/event"
@@ -119,7 +120,9 @@ func (s *PlayScene) LoopTouchable(ev *event.State) {
 
 // DrawTouchable draws any UI elements if needed for the touch UI.
 func (s *PlayScene) DrawTouchable() {
-	if usercfg.Current.HideTouchHints {
+	// If we are not in touch mode (user has not touched their screen at all), don't
+	// show the hints - mouse & keyboard mode. And user opt-out setting.
+	if !native.IsTouchScreenMode() || usercfg.Current.HideTouchHints {
 		return
 	}
 

pkg/uix/canvas_scrolling.go

@@ -56,7 +56,7 @@ func (w *Canvas) loopEditorScroll(ev *event.State) error {
 	}
 
 	// Multitouch events to pan the level, like middle click on desktop.
-	if ev.Touching {
+	if ev.Touching && ev.TouchNumFingers > 1 {
 		// Intention: user drags with 2 fingers to scroll the canvas.
 		// SDL2 will register one finger also as a Button1 mouse click.
 		// We need to record the "mouse cursor" as start point but then

pkg/usercfg/usercfg.go

@@ -18,8 +18,6 @@ import (
 	"path/filepath"
 	"time"
 
-	"git.kirsle.net/SketchyMaze/doodle/pkg/native"
-	"git.kirsle.net/SketchyMaze/doodle/pkg/shmem"
 	"git.kirsle.net/SketchyMaze/doodle/pkg/userdir"
 	"git.kirsle.net/go/render"
 )
@@ -57,12 +55,6 @@ var Current = Defaults()
 // Defaults returns sensible default user settings.
 func Defaults() *Settings {
 	settings := &Settings{}
-
-	// If not a touchscreen device, disable touchscreen hints as default.
-	if !native.HasTouchscreen(shmem.CurrentRenderEngine) {
-		settings.HideTouchHints = true
-	}
-
 	return settings
 }