Add SNES emulation support with bundled Snes9x core

Bundles snes9x_libretro_android.so (~2.8 MB) as an asset and wires up
SnesCore with full SNES button mappings (B/A/Y/X/L/R/Select/Start/D-pad).

app/src/main/java/com/lazy/emulate/emulation/ConsoleType.kt

@@ -28,6 +28,7 @@ enum class ConsoleType(
         displayName = "Super Nintendo",
         manufacturer = "Nintendo",
         fileExtensions = listOf("sfc", "smc", "fig", "swc"),
+        isImplemented = true,
         fallbackAspectRatio = 4f / 3f,
         libretroThumbnailRepo = "Nintendo_-_Super_Nintendo_Entertainment_System"
     ),

app/src/main/java/com/lazy/emulate/emulation/EmulationEngine.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import com.lazy.emulate.emulation.cores.NesCore
 import com.lazy.emulate.emulation.cores.PlaceholderCore
 import com.lazy.emulate.emulation.cores.Ps1Core
+import com.lazy.emulate.emulation.cores.SnesCore
 import com.lazy.emulate.input.ButtonMappingManager
 
 object EmulationEngine {
@@ -15,7 +16,7 @@ object EmulationEngine {
         return when (consoleType) {
             ConsoleType.PS1 -> Ps1Core(context, buttonMappingManager)
             ConsoleType.NES -> NesCore(context, buttonMappingManager)
-            ConsoleType.SNES -> PlaceholderCore(ConsoleType.SNES)
+            ConsoleType.SNES -> SnesCore(context, buttonMappingManager)
             ConsoleType.N64 -> PlaceholderCore(ConsoleType.N64)
             ConsoleType.GENESIS -> PlaceholderCore(ConsoleType.GENESIS)
             ConsoleType.PS2 -> PlaceholderCore(ConsoleType.PS2)

app/src/main/java/com/lazy/emulate/emulation/cores/SnesCore.kt

@@ -0,0 +1,235 @@
+package com.lazy.emulate.emulation.cores
+
+import android.content.Context
+import android.util.Log
+import android.view.Surface
+import com.lazy.emulate.emulation.ConsoleType
+import com.lazy.emulate.emulation.DisplayMode
+import com.lazy.emulate.emulation.EmulatorCore
+import com.lazy.emulate.emulation.NativeLibretro
+import com.lazy.emulate.emulation.SaveSlotInfo
+import com.lazy.emulate.input.ButtonMappingManager
+import com.lazy.emulate.input.GamepadButton
+import java.io.File
+
+class SnesCore(
+    private val context: Context,
+    private val buttonMappingManager: ButtonMappingManager? = null
+) : EmulatorCore {
+
+    override val consoleType = ConsoleType.SNES
+
+    override var isRunning: Boolean = false
+        private set
+
+    private var buttonState: Int = 0
+
+    private val coresDir = File(context.filesDir, "cores")
+    private val systemDir = File(context.filesDir, "system")
+    private val baseSavesDir = File(context.filesDir, "saves")
+    private lateinit var savesDir: File
+
+    override fun loadRom(path: String): Boolean {
+        coresDir.mkdirs()
+        systemDir.mkdirs()
+
+        val romName = File(path).nameWithoutExtension
+        savesDir = File(baseSavesDir, romName)
+        savesDir.mkdirs()
+
+        NativeLibretro.nativeSetSystemDir(systemDir.absolutePath)
+        NativeLibretro.nativeSetSaveDir(savesDir.absolutePath)
+
+        val corePath = findCorePath()
+        if (corePath == null) {
+            Log.e(TAG, "SNES core .so not found. Place snes9x_libretro_android.so in ${coresDir.absolutePath}")
+            return false
+        }
+
+        if (!NativeLibretro.nativeLoadCore(corePath)) {
+            Log.e(TAG, "Failed to load core: $corePath")
+            return false
+        }
+
+        if (!NativeLibretro.nativeLoadGame(path)) {
+            Log.e(TAG, "Failed to load game: $path")
+            return false
+        }
+
+        Log.i(TAG, "Game loaded successfully: $path")
+        return true
+    }
+
+    override fun start() {
+        isRunning = true
+        NativeLibretro.nativeStart()
+    }
+
+    override fun pause() {
+        isRunning = false
+        NativeLibretro.nativePause()
+    }
+
+    override fun resume() {
+        isRunning = true
+        NativeLibretro.nativeResume()
+    }
+
+    override fun stop() {
+        isRunning = false
+        NativeLibretro.nativeStop()
+    }
+
+    override fun reset() {
+        NativeLibretro.nativeReset()
+    }
+
+    override fun setSurface(surface: Surface) {
+        NativeLibretro.nativeSetSurface(surface)
+    }
+
+    override fun onButtonPressed(button: GamepadButton) {
+        val bit = mapButtonToRetroId(button)
+        if (bit >= 0) {
+            buttonState = buttonState or (1 shl bit)
+            NativeLibretro.nativeSetButtonState(buttonState)
+        }
+    }
+
+    override fun onButtonReleased(button: GamepadButton) {
+        val bit = mapButtonToRetroId(button)
+        if (bit >= 0) {
+            buttonState = buttonState and (1 shl bit).inv()
+            NativeLibretro.nativeSetButtonState(buttonState)
+        }
+    }
+
+    override fun onAnalogStick(x: Float, y: Float, stickIndex: Int) {
+        // SNES has no analog sticks
+    }
+
+    override fun saveState(slot: Int): Boolean {
+        val path = File(savesDir, "state_$slot.sav").absolutePath
+        return NativeLibretro.nativeSaveState(path)
+    }
+
+    override fun loadState(slot: Int): Boolean {
+        val path = File(savesDir, "state_$slot.sav").absolutePath
+        return NativeLibretro.nativeLoadState(path)
+    }
+
+    override fun deleteState(slot: Int): Boolean {
+        val state = File(savesDir, "state_$slot.sav")
+        val screenshot = File(savesDir, "state_$slot.jpg")
+        val deleted = state.exists() && state.delete()
+        if (screenshot.exists()) screenshot.delete()
+        return deleted
+    }
+
+    override fun getSaveSlotInfo(slot: Int): SaveSlotInfo {
+        val file = File(savesDir, "state_$slot.sav")
+        val screenshot = File(savesDir, "state_$slot.jpg")
+        return SaveSlotInfo(
+            slot = slot,
+            exists = file.exists(),
+            lastModified = if (file.exists()) file.lastModified() else 0L,
+            screenshotPath = if (screenshot.exists()) screenshot.absolutePath else null
+        )
+    }
+
+    override fun getScreenshotPath(slot: Int): String =
+        File(savesDir, "state_$slot.jpg").absolutePath
+
+    override fun setAudioEnabled(enabled: Boolean) {
+        NativeLibretro.nativeSetAudioEnabled(enabled)
+    }
+
+    override fun setFrameSkip(skip: Int) {
+        NativeLibretro.nativeSetFrameSkip(skip)
+    }
+
+    override fun setDisplayMode(mode: DisplayMode) {
+        NativeLibretro.nativeSetDisplayMode(mode.nativeValue)
+    }
+
+    private fun findCorePath(): String? {
+        val names = listOf(
+            "snes9x_libretro_android.so",
+            "snes9x_libretro.so",
+            "snes9x2010_libretro_android.so",
+            "snes9x2010_libretro.so",
+            "snes9x2005_libretro_android.so",
+            "snes9x2005_libretro.so",
+        )
+        // Check internal cores dir first
+        for (name in names) {
+            val file = File(coresDir, name)
+            if (file.exists()) return file.absolutePath
+        }
+        // Extract bundled core from assets
+        for (name in names) {
+            try {
+                context.assets.open("cores/$name").use { input ->
+                    val dest = File(coresDir, name)
+                    dest.outputStream().use { output -> input.copyTo(output) }
+                    dest.setExecutable(true)
+                    Log.i(TAG, "Extracted bundled core: $name")
+                    return dest.absolutePath
+                }
+            } catch (_: Exception) {
+                // Asset doesn't exist, try next
+            }
+        }
+        // Fallback: auto-import from /sdcard/Games/cores/
+        val sdcardCores = File("/sdcard/Games/cores")
+        if (sdcardCores.exists()) {
+            for (name in names) {
+                val sdFile = File(sdcardCores, name)
+                if (sdFile.exists()) {
+                    val dest = File(coresDir, name)
+                    try {
+                        sdFile.copyTo(dest, overwrite = true)
+                        dest.setExecutable(true)
+                        Log.i(TAG, "Imported core from sdcard: $name")
+                        return dest.absolutePath
+                    } catch (e: Exception) {
+                        Log.e(TAG, "Failed to import core: ${e.message}")
+                    }
+                }
+            }
+        }
+        return null
+    }
+
+    private fun mapButtonToRetroId(button: GamepadButton): Int {
+        if (buttonMappingManager != null) {
+            return buttonMappingManager.getRetroId(consoleType, button)
+        }
+        return defaultMapButtonToRetroId(button)
+    }
+
+    private fun defaultMapButtonToRetroId(button: GamepadButton): Int {
+        // SNES: B, A, Y, X, L, R, Select, Start, D-pad
+        // Libretro joypad IDs: B=0, Y=1, Select=2, Start=3,
+        // Up=4, Down=5, Left=6, Right=7, A=8, X=9, L=10, R=11
+        return when (button) {
+            GamepadButton.FACE_BOTTOM -> 0   // B
+            GamepadButton.FACE_RIGHT -> 8    // A
+            GamepadButton.FACE_LEFT -> 1     // Y
+            GamepadButton.FACE_TOP -> 9      // X
+            GamepadButton.L1 -> 10           // L
+            GamepadButton.R1 -> 11           // R
+            GamepadButton.DPAD_UP -> 4
+            GamepadButton.DPAD_DOWN -> 5
+            GamepadButton.DPAD_LEFT -> 6
+            GamepadButton.DPAD_RIGHT -> 7
+            GamepadButton.SELECT -> 2
+            GamepadButton.START -> 3
+            else -> -1
+        }
+    }
+
+    companion object {
+        private const val TAG = "SnesCore"
+    }
+}

app/src/main/java/com/lazy/emulate/input/ButtonMappingManager.kt

@@ -33,6 +33,20 @@ class ButtonMappingManager(private val preferencesManager: PreferencesManager) {
             GamepadButton.DPAD_RIGHT to 7,
             GamepadButton.SELECT to 2,
             GamepadButton.START to 3
+        ),
+        ConsoleType.SNES to mapOf(
+            GamepadButton.FACE_BOTTOM to 0,   // B
+            GamepadButton.FACE_RIGHT to 8,    // A
+            GamepadButton.FACE_LEFT to 1,     // Y
+            GamepadButton.FACE_TOP to 9,      // X
+            GamepadButton.L1 to 10,           // L
+            GamepadButton.R1 to 11,           // R
+            GamepadButton.DPAD_UP to 4,
+            GamepadButton.DPAD_DOWN to 5,
+            GamepadButton.DPAD_LEFT to 6,
+            GamepadButton.DPAD_RIGHT to 7,
+            GamepadButton.SELECT to 2,
+            GamepadButton.START to 3
         )
     )