Support additional screen layouts.

Allows users to choose a single screen layout or a large screen layout.
Adds a configuration option to change the prominent screen.

src/core/settings.cpp

@@ -7,6 +7,8 @@
 #include "settings.h"
 #include "video_core/video_core.h"
 
+#include "common/emu_window.h"
+
 namespace Settings {
 
 Values values = {};
@@ -20,6 +22,11 @@ void Apply() {
     VideoCore::g_shader_jit_enabled = values.use_shader_jit;
     VideoCore::g_scaled_resolution_enabled = values.use_scaled_resolution;
 
+    if (VideoCore::g_emu_window) {
+        auto layout = VideoCore::g_emu_window->GetFramebufferLayout();
+        VideoCore::g_emu_window->UpdateCurrentFramebufferLayout(layout.width, layout.height);
+    }
+
     AudioCore::SelectSink(values.sink_id);
     AudioCore::EnableStretching(values.enable_audio_stretching);
 }

src/core/settings.h

@@ -10,7 +10,15 @@
 
 namespace Settings {
 
+enum class LayoutOption {
+    Default,
+    SingleScreen,
+    LargeScreen,
+    Custom,
+};
+
 namespace NativeInput {
+
 enum Values {
     // directly mapped keys
     A,
@@ -84,6 +92,9 @@ struct Values {
     bool use_scaled_resolution;
     bool use_vsync;
 
+    LayoutOption layout_option;
+    bool swap_screen;
+
     float bg_red;
     float bg_green;
     float bg_blue;