android: frontend: Add MobileLandscape layout profile for mobile devices.

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

@@ -194,6 +194,8 @@ void Java_org_citra_citra_1android_NativeLibrary_CacheClassesAndMethods(JNIEnv*
 
 void Java_org_citra_citra_1android_NativeLibrary_SwitchScreenLayout(JNIEnv* env, jobject obj) {
     if (Settings::values.layout_option == Settings::LayoutOption::MobilePortrait) {
+        Settings::values.layout_option = Settings::LayoutOption::MobileLandscape;
+    } else if (Settings::values.layout_option == Settings::LayoutOption::MobileLandscape) {
         Settings::values.layout_option = Settings::LayoutOption::SingleScreen;
     } else if (Settings::values.layout_option == Settings::LayoutOption::SingleScreen) {
         Settings::values.layout_option = Settings::LayoutOption::LargeScreen;

src/core/frontend/emu_window.cpp

@@ -170,8 +170,11 @@ void EmuWindow::UpdateCurrentFramebufferLayout(unsigned width, unsigned height)
                                              Settings::values.upright_screen);
             break;
         case Settings::LayoutOption::MobilePortrait:
-            layout =
-                Layout::DefaultFrameLayout(width, height, Settings::values.swap_screen, true, true);
+            layout = Layout::MobilePortraitFrameLayout(width, height, Settings::values.swap_screen);
+            break;
+        case Settings::LayoutOption::MobileLandscape:
+            layout = Layout::MobileLandscapeFrameLayout(width, height, Settings::values.swap_screen,
+                                                        2.25f, false);
             break;
         case Settings::LayoutOption::Default:
         default:

src/core/frontend/framebuffer_layout.cpp

@@ -151,6 +151,48 @@ FramebufferLayout MobilePortraitFrameLayout(u32 width, u32 height, bool swapped)
     return res;
 }
 
+FramebufferLayout MobileLandscapeFrameLayout(u32 width, u32 height, bool swapped,
+                                             float scale_factor, bool center_vertical) {
+    ASSERT(width > 0);
+    ASSERT(height > 0);
+
+    FramebufferLayout res{width, height, true, true, {}, {}};
+    // Split the window into two parts. Give 4x width to the main screen and 1x width to the small
+    // To do that, find the total emulation box and maximize that based on window size
+    float window_aspect_ratio = static_cast<float>(height) / width;
+    float emulation_aspect_ratio =
+        swapped ? Core::kScreenBottomHeight * scale_factor /
+                      (Core::kScreenBottomWidth * scale_factor + Core::kScreenTopWidth)
+                : Core::kScreenTopHeight * scale_factor /
+                      (Core::kScreenTopWidth * scale_factor + Core::kScreenBottomWidth);
+    float large_screen_aspect_ratio = swapped ? BOT_SCREEN_ASPECT_RATIO : TOP_SCREEN_ASPECT_RATIO;
+    float small_screen_aspect_ratio = swapped ? TOP_SCREEN_ASPECT_RATIO : BOT_SCREEN_ASPECT_RATIO;
+
+    Common::Rectangle<u32> screen_window_area{0, 0, width, height};
+    Common::Rectangle<u32> total_rect = maxRectangle(screen_window_area, emulation_aspect_ratio);
+    Common::Rectangle<u32> large_screen = maxRectangle(total_rect, large_screen_aspect_ratio);
+    Common::Rectangle<u32> fourth_size_rect = total_rect.Scale(1.f / scale_factor);
+    Common::Rectangle<u32> small_screen = maxRectangle(fourth_size_rect, small_screen_aspect_ratio);
+
+    if (window_aspect_ratio < emulation_aspect_ratio) {
+        large_screen =
+            large_screen.TranslateX((screen_window_area.GetWidth() - total_rect.GetWidth()) / 2);
+    } else if (center_vertical) {
+        large_screen = large_screen.TranslateY((height - total_rect.GetHeight()) / 2);
+    }
+
+    // Shift the small screen to the bottom right corner
+    small_screen = small_screen.TranslateX(large_screen.right);
+    if (center_vertical) {
+        small_screen.TranslateY(large_screen.GetHeight() + large_screen.top -
+                                small_screen.GetHeight());
+    }
+
+    res.top_screen = swapped ? small_screen : large_screen;
+    res.bottom_screen = swapped ? large_screen : small_screen;
+    return res;
+}
+
 FramebufferLayout SingleFrameLayout(u32 width, u32 height, bool swapped, bool upright) {
     ASSERT(width > 0);
     ASSERT(height > 0);
@@ -385,6 +427,17 @@ FramebufferLayout FrameLayoutFromResolutionScale(u32 res_scale) {
             height = (Core::kScreenTopHeight + Core::kScreenBottomHeight) * res_scale;
             layout = MobilePortraitFrameLayout(width, height, Settings::values.swap_screen);
             break;
+        case Settings::LayoutOption::MobileLandscape:
+            if (Settings::values.swap_screen) {
+                width = (Core::kScreenBottomWidth + Core::kScreenTopWidth / 2.25f) * res_scale;
+                height = Core::kScreenBottomHeight * res_scale;
+            } else {
+                width = (Core::kScreenTopWidth + Core::kScreenBottomWidth / 2.25f) * res_scale;
+                height = Core::kScreenTopHeight * res_scale;
+            }
+            layout = MobileLandscapeFrameLayout(width, height, Settings::values.swap_screen, 2.25f,
+                                                false);
+            break;
         case Settings::LayoutOption::Default:
         default:
             if (Settings::values.upright_screen) {

src/core/frontend/framebuffer_layout.h

@@ -44,6 +44,20 @@ FramebufferLayout DefaultFrameLayout(u32 width, u32 height, bool is_swapped, boo
  */
 FramebufferLayout MobilePortraitFrameLayout(u32 width, u32 height, bool is_swapped);
 
+/**
+ * Factory method for constructing a Frame with the a 4x size Top screen with a 1x size bottom
+ * screen on the right
+ * This is useful in particular because it matches well with a 1920x1080 resolution monitor
+ * @param width Window framebuffer width in pixels
+ * @param height Window framebuffer height in pixels
+ * @param is_swapped if true, the bottom screen will be the large display
+ * @param scale_factor Scale factor to use for bottom screen with respect to top screen
+ * @param center_vertical When true, centers the top and bottom screens vertically
+ * @return Newly created FramebufferLayout object with default screen regions initialized
+ */
+FramebufferLayout MobileLandscapeFrameLayout(u32 width, u32 height, bool is_swapped,
+                                             float scale_factor, bool center_vertical);
+
 /**
  * Factory method for constructing a FramebufferLayout with only the top or bottom screen
  * @param width Window framebuffer width in pixels

src/core/settings.h

@@ -28,6 +28,10 @@ enum class LayoutOption {
     // Similiar to default, but better for mobile devices in portrait mode. Top screen in clamped to
     // the top of the frame, and the bottom screen is enlarged to match the top screen.
     MobilePortrait,
+
+    // Similiar to LargeScreen, but better for mobile devices in landscape mode. The screens are
+    // clamped to the top of the frame, and the bottom screen is a bit bigger.
+    MobileLandscape,
 };
 
 enum class MicInputType {