[frontend] Slow and Turbo modes (#3525)

Closes #3344

Adds slow and turbo modes with configurable speeds that can then be
toggled by the user. Behavior is:
- Standard/slow limit, toggle turbo = turbo
- Turbo limit, toggle turbo = standard
- Standard/turbo limit, toggle slow = slow
- Slow limit, toggle slow = standard

Enabling the turbo/slow mode enables the frame limiter unconditionally.

This has some conflicts with VSync. For example when I set my refresh
rate to 60hz and enable vsync, turbo mode does nothing. Not sure how to
go about fixing this, @MaranBr probably knows better the proper
solution.

Signed-off-by: crueter <crueter@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3525
Reviewed-by: DraVee <dravee@eden-emu.dev>
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>

src/android/app/src/main/java/org/yuzu/yuzu_emu/NativeLibrary.kt

@@ -203,6 +203,24 @@ object NativeLibrary {
 
     external fun getDebugKnobAt(index: Int): Boolean
 
+    /**
+     * Set the current speed limit to the configured turbo speed.
+     */
+    external fun setTurboSpeedLimit(enabled: Boolean)
+
+    /**
+     * Set the current speed limit to the configured slow speed.
+     */
+    external fun setSlowSpeedLimit(enabled: Boolean)
+
+    /**
+     * Set the current speed limit to the configured standard speed.
+     */
+    external fun setStandardSpeedLimit(enabled: Boolean)
+
+    external fun isTurboMode(): Boolean
+    external fun isSlowMode(): Boolean
+
     /**
      * Returns Vulkan driver version / API version / GPU model
      */

src/android/app/src/main/java/org/yuzu/yuzu_emu/dialogs/QuickSettings.kt

@@ -11,6 +11,7 @@ import android.widget.RadioGroup
 import android.widget.TextView
 import androidx.drawerlayout.widget.DrawerLayout
 import com.google.android.material.color.MaterialColors
+import com.google.android.material.materialswitch.MaterialSwitch
 import org.yuzu.yuzu_emu.R
 import org.yuzu.yuzu_emu.YuzuApplication
 import org.yuzu.yuzu_emu.features.settings.model.BooleanSetting
@@ -135,6 +136,39 @@ class QuickSettings(val emulationFragment: EmulationFragment) {
         container.addView(itemView)
     }
 
+    fun addCustomToggle(
+        name: Int,
+        isChecked: Boolean,
+        isEnabled: Boolean,
+
+        container: ViewGroup,
+        callback: (Boolean) -> Unit
+    ): MaterialSwitch? {
+        val inflater = LayoutInflater.from(emulationFragment.requireContext())
+        val itemView = inflater.inflate(R.layout.item_quick_settings_menu, container, false)
+
+        val switchContainer = itemView.findViewById<ViewGroup>(R.id.switch_container)
+        val titleView = itemView.findViewById<TextView>(R.id.switch_title)
+        val switchView = itemView.findViewById<MaterialSwitch>(R.id.setting_switch)
+
+        titleView.text = YuzuApplication.appContext.getString(name)
+        switchContainer.visibility = View.VISIBLE
+
+        switchView.isChecked = isChecked
+
+        switchView.setOnCheckedChangeListener { _, checked ->
+            callback(checked)
+            saveSettings()
+        }
+
+        switchContainer.setOnClickListener {
+            switchView.toggle()
+        }
+        container.addView(itemView)
+
+        return switchView
+    }
+
     fun addSliderSetting(
         name: Int,
         container: ViewGroup,

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/model/ShortSetting.kt

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: 2023 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -6,7 +9,10 @@ package org.yuzu.yuzu_emu.features.settings.model
 import org.yuzu.yuzu_emu.utils.NativeConfig
 
 enum class ShortSetting(override val key: String) : AbstractShortSetting {
-    RENDERER_SPEED_LIMIT("speed_limit");
+    RENDERER_SPEED_LIMIT("speed_limit"),
+    RENDERER_TURBO_SPEED_LIMIT("turbo_speed_limit"),
+    RENDERER_SLOW_SPEED_LIMIT("slow_speed_limit"),
+    ;
 
     override fun getShort(needsGlobal: Boolean): Short = NativeConfig.getShort(key, needsGlobal)
 

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/model/view/SettingsItem.kt

@@ -180,6 +180,26 @@ abstract class SettingsItem(
                     units = "%"
                 )
             )
+            put(
+                SliderSetting(
+                    ShortSetting.RENDERER_TURBO_SPEED_LIMIT,
+                    titleId = R.string.turbo_speed_limit,
+                    descriptionId = R.string.turbo_speed_limit_description,
+                    min = 1,
+                    max = 400,
+                    units = "%"
+                )
+            )
+            put(
+                SliderSetting(
+                    ShortSetting.RENDERER_SLOW_SPEED_LIMIT,
+                    titleId = R.string.slow_speed_limit,
+                    descriptionId = R.string.slow_speed_limit_description,
+                    min = 1,
+                    max = 400,
+                    units = "%"
+                )
+            )
             put(
                 SingleChoiceSetting(
                     IntSetting.CPU_BACKEND,

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/ui/SettingsFragmentPresenter.kt

@@ -227,6 +227,8 @@ class SettingsFragmentPresenter(
             add(StringSetting.DEVICE_NAME.key)
             add(BooleanSetting.RENDERER_USE_SPEED_LIMIT.key)
             add(ShortSetting.RENDERER_SPEED_LIMIT.key)
+            add(ShortSetting.RENDERER_TURBO_SPEED_LIMIT.key)
+            add(ShortSetting.RENDERER_SLOW_SPEED_LIMIT.key)
             add(BooleanSetting.USE_DOCKED_MODE.key)
             add(IntSetting.REGION_INDEX.key)
             add(IntSetting.LANGUAGE_INDEX.key)

src/android/app/src/main/java/org/yuzu/yuzu_emu/fragments/EmulationFragment.kt

@@ -55,6 +55,7 @@ import androidx.window.layout.WindowInfoTracker
 import androidx.window.layout.WindowLayoutInfo
 import com.google.android.material.color.MaterialColors
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
+import com.google.android.material.materialswitch.MaterialSwitch
 import com.google.android.material.textview.MaterialTextView
 import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
@@ -1055,11 +1056,47 @@ class EmulationFragment : Fragment(), SurfaceHolder.Callback {
                 quickSettings.addPerGameConfigStatusIndicator(container)
             }
 
-            quickSettings.addBooleanSetting(
+            lateinit var slowSpeed: MaterialSwitch
+            lateinit var turboSpeed: MaterialSwitch
+
+            turboSpeed = quickSettings.addCustomToggle(
+                R.string.turbo_speed_limit,
+                NativeLibrary.isTurboMode(),
+                BooleanSetting.RENDERER_USE_SPEED_LIMIT.getBoolean(false),
+                container
+            ) { enabled ->
+                if (enabled)
+                    slowSpeed.isChecked = false
+                NativeLibrary.setTurboSpeedLimit(enabled)
+            }!!
+
+            slowSpeed = quickSettings.addCustomToggle(
+                R.string.slow_speed_limit,
+                NativeLibrary.isSlowMode(),
+                BooleanSetting.RENDERER_USE_SPEED_LIMIT.getBoolean(false),
+                container
+            ) { enabled ->
+                if (enabled)
+                    turboSpeed.isChecked = false
+                NativeLibrary.setSlowSpeedLimit(enabled)
+            }!!
+
+            quickSettings.addCustomToggle(
                 R.string.frame_limit_enable,
-                container,
-                BooleanSetting.RENDERER_USE_SPEED_LIMIT,
-            )
+                BooleanSetting.RENDERER_USE_SPEED_LIMIT.getBoolean(false),
+                true,
+                container
+            ) { enabled ->
+                if (!enabled) {
+                    turboSpeed.isChecked = false
+                    slowSpeed.isChecked = false
+                }
+
+                turboSpeed.isEnabled = enabled
+                slowSpeed.isEnabled = enabled
+
+                NativeLibrary.setStandardSpeedLimit(enabled)
+            }!!
 
             quickSettings.addSliderSetting(
                 R.string.frame_limit_slider,

src/android/app/src/main/jni/native.cpp

@@ -1233,6 +1233,39 @@ jboolean Java_org_yuzu_yuzu_1emu_NativeLibrary_getDebugKnobAt(JNIEnv* env, jobje
     return static_cast<jboolean>(Settings::getDebugKnobAt(static_cast<u8>(index)));
 }
 
+void Java_org_yuzu_yuzu_1emu_NativeLibrary_setTurboSpeedLimit(JNIEnv *env, jobject jobj, jboolean enabled) {
+    if (enabled) {
+        Settings::values.use_speed_limit.SetValue(true);
+        Settings::SetSpeedMode(Settings::SpeedMode::Turbo);
+    } else {
+        Settings::SetSpeedMode(Settings::SpeedMode::Standard);
+    }
+}
+
+void Java_org_yuzu_yuzu_1emu_NativeLibrary_setSlowSpeedLimit(JNIEnv *env, jobject jobj, jboolean enabled) {
+    if (enabled) {
+        Settings::values.use_speed_limit.SetValue(true);
+        Settings::SetSpeedMode(Settings::SpeedMode::Slow);
+    } else {
+        Settings::SetSpeedMode(Settings::SpeedMode::Standard);
+    }
+}
+
+void Java_org_yuzu_yuzu_1emu_NativeLibrary_setStandardSpeedLimit(JNIEnv *env, jobject jobj, jboolean enabled) {
+    Settings::values.use_speed_limit.SetValue(enabled);
+    if (enabled) {
+        Settings::SetSpeedMode(Settings::SpeedMode::Standard);
+    }
+}
+
+jboolean Java_org_yuzu_yuzu_1emu_NativeLibrary_isTurboMode(JNIEnv *env, jobject jobj) {
+    return Settings::values.current_speed_mode.GetValue() == Settings::SpeedMode::Turbo;
+}
+
+jboolean Java_org_yuzu_yuzu_1emu_NativeLibrary_isSlowMode(JNIEnv *env, jobject jobj) {
+    return Settings::values.current_speed_mode.GetValue() == Settings::SpeedMode::Slow;
+}
+
 void Java_org_yuzu_yuzu_1emu_NativeLibrary_run(JNIEnv* env, jobject jobj, jstring j_path,
                                                jint j_program_index,
                                                jboolean j_frontend_initiated) {

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

@@ -422,6 +422,10 @@
     <string name="frame_limit_enable_description">Limits emulation speed to a specified percentage of normal speed.</string>
     <string name="frame_limit_slider">Limit speed percent</string>
     <string name="frame_limit_slider_description">Specifies the percentage to limit emulation speed. 100% is the normal speed. Values higher or lower will increase or decrease the speed limit.</string>
+    <string name="turbo_speed_limit">Turbo speed</string>
+    <string name="turbo_speed_limit_description">When Turbo Mode is enabled, emulation will run at this speed.</string>
+    <string name="slow_speed_limit">Slow speed</string>
+    <string name="slow_speed_limit_description">When Slow Mode is enabled, emulation will run at this speed.</string>
     <string name="cpu_backend">CPU backend</string>
     <string name="cpu_accuracy">CPU accuracy</string>
     <string name="value_with_units">%1$s%2$s</string>