Implement OSC stick regions

Stick regions extend the activation area of the sticks to rectangles covering the corresponding half of the screen.
E.g. for the left stick: when any point of the left side of the screen is touched, the stick is repositioned there, and acts as if it was centered in the touched position. When the finger is lifter, the stick is hidden.

app/src/main/java/emu/skyline/EmulationActivity.kt

@@ -337,6 +337,7 @@ class EmulationActivity : AppCompatActivity(), SurfaceHolder.Callback, View.OnTo
             setOnStickStateChangedListener(::onStickStateChanged)
             hapticFeedback = appSettings.onScreenControl && appSettings.onScreenControlFeedback
             recenterSticks = appSettings.onScreenControlRecenterSticks
+            stickRegions = appSettings.onScreenControlUseStickRegions
         }
 
         binding.onScreenControllerToggle.apply {

app/src/main/java/emu/skyline/input/ControllerActivity.kt

@@ -100,6 +100,10 @@ class ControllerActivity : AppCompatActivity() {
                     appSettings.onScreenControlRecenterSticks = item.checked
                 })
 
+                items.add(ControllerCheckBoxViewItem(getString(R.string.osc_use_stick_regions), getString(R.string.osc_use_stick_regions_desc), appSettings.onScreenControlUseStickRegions) { item, position ->
+                    appSettings.onScreenControlUseStickRegions = item.checked
+                })
+
                 items.add(ControllerViewItem(content = getString(R.string.osc_edit), onClick = {
                     startActivity(Intent(this, OnScreenEditActivity::class.java))
                 }))

app/src/main/java/emu/skyline/input/onscreen/OnScreenButton.kt

@@ -60,7 +60,7 @@ abstract class OnScreenButton(
         }
     }
 
-    final override val config = OnScreenConfigurationImpl(onScreenControllerView.context, buttonId, defaultRelativeX, defaultRelativeY, defaultEnabled)
+    final override val config : OnScreenConfiguration = OnScreenConfigurationImpl(onScreenControllerView.context, buttonId, defaultRelativeX, defaultRelativeY, defaultEnabled)
 
     protected val drawable = ContextCompat.getDrawable(onScreenControllerView.context, drawableId)!!
 
@@ -69,7 +69,7 @@ abstract class OnScreenButton(
         typeface = Typeface.create(Typeface.DEFAULT, Typeface.BOLD)
         isAntiAlias = true
     }
-    private val textBoundsRect = Rect()
+    protected val textBoundsRect = Rect()
 
     var relativeX = config.relativeX
     var relativeY = config.relativeY

app/src/main/java/emu/skyline/input/onscreen/OnScreenControllerView.kt

@@ -65,10 +65,16 @@ class OnScreenControllerView @JvmOverloads constructor(context : Context, attrs
             field = value
             controls.joysticks.forEach { it.recenterSticks = recenterSticks }
         }
+    var stickRegions = false
+        set(value) {
+            field = value
+            controls.setStickRegions(value)
+            invalidate()
+        }
     var hapticFeedback = false
         set(value) {
             field = value
-            (controls.circularButtons + controls.rectangularButtons + controls.triggerButtons).forEach { it.hapticFeedback = hapticFeedback }
+            controls.buttons.forEach { it.hapticFeedback = hapticFeedback }
         }
 
     internal val editInfo = OnScreenEditInfo()
@@ -116,7 +122,7 @@ class OnScreenControllerView @JvmOverloads constructor(context : Context, attrs
         val x by lazy { event.getX(actionIndex) }
         val y by lazy { event.getY(actionIndex) }
 
-        (controls.circularButtons + controls.rectangularButtons + controls.triggerButtons).forEach { button ->
+        controls.buttons.forEach { button ->
             when (event.action and event.actionMasked) {
                 MotionEvent.ACTION_UP,
                 MotionEvent.ACTION_POINTER_UP -> {
@@ -174,7 +180,12 @@ class OnScreenControllerView @JvmOverloads constructor(context : Context, attrs
             }
         }
 
-        for (joystick in controls.joysticks) {
+        if (handled) {
+            invalidate()
+            return@OnTouchListener true
+        }
+
+        controls.joysticks.forEach { joystick ->
             when (event.actionMasked) {
                 MotionEvent.ACTION_UP,
                 MotionEvent.ACTION_POINTER_UP,

app/src/main/java/emu/skyline/input/onscreen/OnScreenEditActivity.kt

@@ -100,6 +100,7 @@ class OnScreenEditActivity : AppCompatActivity() {
             getSystemService(VIBRATOR_SERVICE) as Vibrator
 
         binding.onScreenControllerView.recenterSticks = appSettings.onScreenControlRecenterSticks
+        binding.onScreenControllerView.stickRegions = appSettings.onScreenControlUseStickRegions
 
         val snapToGrid = appSettings.onScreenControlSnapToGrid
         binding.onScreenControllerView.setSnapToGrid(snapToGrid)

app/src/main/java/emu/skyline/input/onscreen/OnScreenItemDefinitions.kt

@@ -6,7 +6,11 @@
 package emu.skyline.input.onscreen
 
 import android.graphics.Canvas
+import android.graphics.Paint
 import android.graphics.PointF
+import android.graphics.Rect
+import android.graphics.RectF
+import android.graphics.Typeface
 import android.os.SystemClock
 import androidx.core.graphics.minus
 import emu.skyline.R
@@ -15,6 +19,7 @@ import emu.skyline.input.ButtonId.*
 import emu.skyline.input.StickId
 import emu.skyline.input.StickId.Left
 import emu.skyline.input.StickId.Right
+import emu.skyline.utils.SwitchColors
 import emu.skyline.utils.add
 import emu.skyline.utils.multiply
 import kotlin.math.roundToInt
@@ -45,7 +50,7 @@ open class CircularButton(
     override fun isTouched(x : Float, y : Float) : Boolean = (PointF(currentX, currentY) - (PointF(x, y))).length() <= radius
 }
 
-class JoystickButton(
+open class JoystickButton(
     onScreenControllerView : OnScreenControllerView,
     val stickId : StickId,
     defaultRelativeX : Float,
@@ -61,7 +66,7 @@ class JoystickButton(
 ) {
     private val innerButton = CircularButton(onScreenControllerView, buttonId, config.relativeX, config.relativeY, defaultRelativeRadiusToX * 0.75f, R.drawable.ic_stick)
 
-    var recenterSticks = false
+    open var recenterSticks = false
     private var initialTapPosition = PointF()
     private var fingerDownTime = 0L
     private var fingerUpTime = 0L
@@ -157,6 +162,85 @@ class JoystickButton(
     }
 }
 
+class JoystickRegion(
+    onScreenControllerView : OnScreenControllerView,
+    stickId : StickId,
+    defaultRelativeX : Float,
+    defaultRelativeY : Float,
+    defaultRelativeRadiusToX : Float,
+    private val relativeRegionPosition : RectF,
+    regionColor : Int
+) : JoystickButton(
+    onScreenControllerView,
+    stickId,
+    defaultRelativeX,
+    defaultRelativeY,
+    defaultRelativeRadiusToX
+) {
+    /**
+     * A stick region always re-centers the stick, it always positions the stick at the initial touch position
+     */
+    override var recenterSticks = true
+        set(_) = Unit
+
+    private val left get() = relativeRegionPosition.left * width
+    private val top get() = relativeRegionPosition.top * height
+    private val pixelWidth get() = relativeRegionPosition.width() * width
+    private val pixelHeight get() = relativeRegionPosition.height() * height
+
+    private val regionBounds get() = Rect(left.toInt(), top.toInt(), (left + pixelWidth).toInt(), (top + pixelHeight).toInt())
+
+    override fun isTouched(x : Float, y : Float) = regionBounds.contains(x.roundToInt(), y.roundToInt())
+
+    private val regionPaint = Paint().apply {
+        this.color = regionColor
+        alpha = 40
+        style = Paint.Style.FILL
+    }
+    private val buttonSymbolPaint = Paint().apply {
+        this.color = SwitchColors.WHITE.color
+        this.alpha = 40
+        typeface = Typeface.create(Typeface.DEFAULT, Typeface.BOLD)
+        textAlign = Paint.Align.LEFT
+    }
+
+    /**
+     * Tracks whether the finger is currently down on the stick region.
+     * The Stick is only rendered when the finger is down.
+     */
+    private var isFingerDown = false
+
+    override fun render(canvas : Canvas) {
+        if (isFingerDown || editInfo.isEditing)
+            super.render(canvas)
+
+        // Only draw the stick region area when in edit mode
+        if (!editInfo.isEditing)
+            return
+
+        canvas.drawRect(regionBounds, regionPaint)
+
+        val text = stickId.button.short!!
+        val x = left + pixelWidth / 2f
+        val y = top + pixelHeight / 2f
+        buttonSymbolPaint.apply {
+            textSize = pixelWidth.coerceAtMost(pixelHeight) * 0.4f
+            getTextBounds(text, 0, text.length, textBoundsRect)
+        }
+        canvas.drawText(text, x - textBoundsRect.width() / 2f - textBoundsRect.left, y + textBoundsRect.height() / 2f - textBoundsRect.bottom, buttonSymbolPaint)
+    }
+
+    override fun onFingerDown(x : Float, y : Float) : Boolean {
+        isFingerDown = true
+        return super.onFingerDown(x, y)
+    }
+
+    override fun onFingerUp(x : Float, y : Float) : Boolean {
+        isFingerDown = false
+        return super.onFingerUp(x, y)
+    }
+}
+
 open class RectangularButton(
     onScreenControllerView : OnScreenControllerView,
     buttonId : ButtonId,
@@ -236,14 +320,41 @@ class Controls(onScreenControllerView : OnScreenControllerView) {
         CircularButton(onScreenControllerView, Menu, 0.5f, 0.85f, 0.029f)
     )
 
-    val joysticks = listOf(
+    private val joystickRegions = listOf<JoystickButton>(
+        JoystickRegion(
+            onScreenControllerView, Left, 0.24f, 0.75f, 0.06f,
+            RectF(0f, 0f, 0.5f, 1f), SwitchColors.NEON_BLUE.color
+        ),
+        JoystickRegion(
+            onScreenControllerView, Right, 0.9f, 0.53f, 0.06f,
+            RectF(0.5f, 0f, 1f, 1f), SwitchColors.NEON_RED.color
+        ),
     )
 
+    private val joystickButtons = listOf(
         JoystickButton(onScreenControllerView, Left, 0.24f, 0.75f, 0.06f),
         JoystickButton(onScreenControllerView, Right, 0.9f, 0.53f, 0.06f)
+    )
+
+    var joysticks = joystickButtons
+        private set
+
     val rectangularButtons = listOf(buttonL, buttonR)
 
     val triggerButtons = listOf(buttonZL, buttonZR)
 
-    val allButtons = circularButtons + joysticks + rectangularButtons + triggerButtons
+    /**
+     * All buttons except the joysticks
+     */
+    val buttons = circularButtons + rectangularButtons + triggerButtons
+
+    var allButtons = getCurrentButtons()
+        private set
+
+    fun setStickRegions(enabled : Boolean) {
+        joysticks = if (enabled) joystickRegions else joystickButtons
+        allButtons = getCurrentButtons()
+    }
+
+    private fun getCurrentButtons() = buttons + joysticks
 }

app/src/main/java/emu/skyline/settings/AppSettings.kt

@@ -31,6 +31,7 @@ class AppSettings @Inject constructor(@ApplicationContext private val context :
     var onScreenControlFeedback by sharedPreferences(context, true)
     var onScreenControlRecenterSticks by sharedPreferences(context, true)
     var onScreenControlSnapToGrid by sharedPreferences(context, false)
+    var onScreenControlUseStickRegions by sharedPreferences(context, false)
 
     // Other
     var refreshRequired by sharedPreferences(context, false)

app/src/main/res/values/strings.xml

@@ -176,6 +176,8 @@
     <string name="confirm">Confirm</string>
     <string name="cancel">Cancel</string>
     <string name="osc_recenter_sticks">Recenter Sticks On Touch</string>
+    <string name="osc_use_stick_regions">Use Stick Regions</string>
+    <string name="osc_use_stick_regions_desc">When enabled, the stick activaation radius is extended to the corresponding half of the screen.</string>
     <string name="controller">Controller</string>
     <string name="config_controller">Configure Controller</string>
     <string name="controller_type">Controller Type</string>