android: Add second screen opacity option

Co-authored-by: Reg Tiangha <rtiangha@users.noreply.github.com>
Co-authored-by: OpenSauce04 <opensauce04@gmail.com>

src/android/app/src/main/java/org/citra/citra_emu/features/settings/model/FloatSetting.kt

@@ -1,4 +1,4 @@
-// Copyright Citra Emulator Project / Lime3DS Emulator Project
+// Copyright Citra Emulator Project / Azahar Emulator Project
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
@@ -10,6 +10,7 @@ enum class FloatSetting(
     override val defaultValue: Float
 ) : AbstractFloatSetting {
     LARGE_SCREEN_PROPORTION("large_screen_proportion",Settings.SECTION_LAYOUT,2.25f),
+    SECOND_SCREEN_OPACITY("custom_second_layer_opacity", Settings.SECTION_RENDERER, 100f),
     BACKGROUND_RED("bg_red", Settings.SECTION_RENDERER, 0f),
     BACKGROUND_BLUE("bg_blue", Settings.SECTION_RENDERER, 0f),
     BACKGROUND_GREEN("bg_green", Settings.SECTION_RENDERER, 0f),

src/android/app/src/main/java/org/citra/citra_emu/features/settings/ui/SettingsFragmentPresenter.kt

@@ -1166,6 +1166,20 @@ class SettingsFragmentPresenter(private val fragmentView: SettingsFragmentView)
                     FloatSetting.LARGE_SCREEN_PROPORTION.defaultValue
                 )
             )
+            add(
+                SliderSetting(
+                    FloatSetting.SECOND_SCREEN_OPACITY,
+                    R.string.second_screen_opacity,
+                    R.string.second_screen_opacity_description,
+                    0,
+                    100,
+                    "%",
+                    FloatSetting.SECOND_SCREEN_OPACITY.key,
+                    FloatSetting.SECOND_SCREEN_OPACITY.defaultValue,
+                    // TODO: Remove graphics API check when #895 is merged
+                    isEnabled = IntSetting.SCREEN_LAYOUT.int == 5 && IntSetting.GRAPHICS_API.int == 1
+                )
+            )
             add(HeaderSetting(R.string.bg_color, R.string.bg_color_description))
             val bgRedSetting = object : AbstractIntSetting {
                 override var int: Int

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

@@ -172,6 +172,7 @@ void Config::ReadValues() {
     ReadSetting("Renderer", Settings::values.bg_red);
     ReadSetting("Renderer", Settings::values.bg_green);
     ReadSetting("Renderer", Settings::values.bg_blue);
+    ReadSetting("Renderer", Settings::values.custom_second_layer_opacity);
     ReadSetting("Renderer", Settings::values.delay_game_render_thread_us);
     ReadSetting("Renderer", Settings::values.disable_right_eye_render);
 

src/android/app/src/main/jni/default_ini.h

@@ -170,6 +170,9 @@ bg_red =
 bg_blue =
 bg_green =
 
+# Opacity of second layer when using custom layout option (bottom screen unless swapped). Useful if positioning on top of the first layer. OpenGL only.
+custom_second_layer_opacity =
+
 # Whether and how Stereoscopic 3D should be rendered
 # 0 (default): Off, 1: Side by Side, 2: Reverse Side by Side, 3: Anaglyph, 4: Interlaced, 5: Reverse Interlaced, 6: Cardboard VR
 render_3d =

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

@@ -453,6 +453,8 @@
     <string name="bg_red">Red</string>
     <string name="bg_green">Green</string>
     <string name="bg_blue">Blue</string>
+    <string name="second_screen_opacity">Custom Layout Second Screen Opacity (OpenGL Only)</string>
+    <string name="second_screen_opacity_description">The opacity of the second 3DS screen when using a custom screen layout. Useful if the second screen is to be positioned on top of the first screen.</string>
     <string name="emulation_small_screen_position">Small Screen Position</string>
     <string name="small_screen_position_description">Where should the small screen appear relative to the large one in Large Screen Layout?</string>
     <string name="small_screen_position_top_right">Top Right</string>