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/citra/config.cpp

@@ -77,6 +77,10 @@ void Config::ReadValues() {
     Settings::values.bg_green = (float)sdl2_config->GetReal("Renderer", "bg_green", 1.0);
     Settings::values.bg_blue  = (float)sdl2_config->GetReal("Renderer", "bg_blue",  1.0);
 
+    // Layout
+    Settings::values.layout_option = static_cast<Settings::LayoutOption>(sdl2_config->GetInteger("Layout", "layout_option", 0));
+    Settings::values.swap_screen = sdl2_config->GetBoolean("Layout", "swap_screen", false);
+
     // Audio
     Settings::values.sink_id = sdl2_config->Get("Audio", "output_engine", "auto");
     Settings::values.enable_audio_stretching = sdl2_config->GetBoolean("Audio", "enable_audio_stretching", true);

src/citra/default_ini.h

@@ -59,6 +59,16 @@ use_scaled_resolution =
 # 0 (default): Off, 1: On
 use_vsync =
 
+[Layout]
+# Layout for the screen inside the render window.
+# 0 (default): Default Top Bottom Screen, 1: Single Screen Only, 2: Large Screen Small Screen
+layout_option =
+
+# Swaps the prominent screen with the other screen.
+# For example, if Single Screen is chosen, setting this to 1 will display the bottom screen instead of the top screen.
+# 0 (default): Top Screen is prominent, 1: Bottom Screen is prominent
+swap_screen =
+
 # The clear color for the renderer. What shows up on the sides of the bottom screen.
 # Must be in range of 0.0-1.0. Defaults to 1.0 for all.
 bg_red =

src/citra/emu_window/emu_window_sdl2.cpp

@@ -52,10 +52,8 @@ bool EmuWindow_SDL2::IsOpen() const {
 
 void EmuWindow_SDL2::OnResize() {
     int width, height;
-
     SDL_GetWindowSize(render_window, &width, &height);
-
+    UpdateCurrentFramebufferLayout(width, height);
-    NotifyFramebufferLayoutChanged(EmuWindow::FramebufferLayout::DefaultScreenLayout(width, height));
 }
 
 EmuWindow_SDL2::EmuWindow_SDL2() {

src/citra_qt/CMakeLists.txt

@@ -25,6 +25,7 @@ set(SRCS
             configure_graphics.cpp
             configure_system.cpp
             configure_input.cpp
+            configure_layout.cpp
             game_list.cpp
             hotkeys.cpp
             main.cpp
@@ -58,6 +59,7 @@ set(HEADERS
             configure_graphics.h
             configure_system.h
             configure_input.h
+            configure_layout.h
             game_list.h
             game_list_p.h
             hotkeys.h
@@ -78,6 +80,7 @@ set(UIS
             configure_graphics.ui
             configure_system.ui
             configure_input.ui
+            configure_layout.ui
             hotkeys.ui
             main.ui
             )

src/citra_qt/bootmanager.cpp

@@ -163,8 +163,7 @@ void GRenderWindow::OnFramebufferSizeChanged()
     qreal pixelRatio = windowPixelRatio();
     unsigned width = child->QPaintDevice::width() * pixelRatio;
     unsigned height = child->QPaintDevice::height() * pixelRatio;
-
+    UpdateCurrentFramebufferLayout(width, height);
-    NotifyFramebufferLayoutChanged(EmuWindow::FramebufferLayout::DefaultScreenLayout(width, height));
 }
 
 void GRenderWindow::BackupGeometry()

src/citra_qt/config.cpp

@@ -55,6 +55,11 @@ void Config::ReadValues() {
     Settings::values.bg_blue  = qt_config->value("bg_blue",  1.0).toFloat();
     qt_config->endGroup();
 
+    qt_config->beginGroup("Layout");
+    Settings::values.layout_option = static_cast<Settings::LayoutOption>(qt_config->value("layout_option").toInt());
+    Settings::values.swap_screen = qt_config->value("swap_screen", false).toBool();
+    qt_config->endGroup();
+
     qt_config->beginGroup("Audio");
     Settings::values.sink_id = qt_config->value("output_engine", "auto").toString().toStdString();
     Settings::values.enable_audio_stretching = qt_config->value("enable_audio_stretching", true).toBool();
@@ -149,6 +154,11 @@ void Config::SaveValues() {
     qt_config->setValue("bg_blue",  (double)Settings::values.bg_blue);
     qt_config->endGroup();
 
+    qt_config->beginGroup("Layout");
+    qt_config->setValue("layout_option", static_cast<int>(Settings::values.layout_option));
+    qt_config->setValue("swap_screen", Settings::values.swap_screen);
+    qt_config->endGroup();
+
     qt_config->beginGroup("Audio");
     qt_config->setValue("output_engine", QString::fromStdString(Settings::values.sink_id));
     qt_config->setValue("enable_audio_stretching", Settings::values.enable_audio_stretching);

src/citra_qt/configure.ui

@@ -44,6 +44,11 @@
          <string>Audio</string>
        </attribute>
      </widget>
+     <widget class="ConfigureLayout" name="layoutTab">
+      <attribute name="title">
+       <string>Layout</string>
+      </attribute>
+     </widget>
      <widget class="ConfigureDebug" name="debugTab">
       <attribute name="title">
        <string>Debug</string>
@@ -79,6 +84,12 @@
    <header>configure_audio.h</header>
    <container>1</container>
   </customwidget>
+  <customwidget>
+   <class>ConfigureLayout</class>
+   <extends>QWidget</extends>
+   <header>configure_layout.h</header>
+   <container>1</container>
+  </customwidget>
   <customwidget>
    <class>ConfigureDebug</class>
    <extends>QWidget</extends>

src/citra_qt/configure_audio.cpp

@@ -43,5 +43,4 @@ void ConfigureAudio::setConfiguration() {
 void ConfigureAudio::applyConfiguration() {
     Settings::values.sink_id = ui->output_sink_combo_box->itemText(ui->output_sink_combo_box->currentIndex()).toStdString();
     Settings::values.enable_audio_stretching = ui->toggle_audio_stretching->isChecked();
-    Settings::Apply();
 }

src/citra_qt/configure_debug.cpp

@@ -27,5 +27,4 @@ void ConfigureDebug::setConfiguration() {
 void ConfigureDebug::applyConfiguration() {
     Settings::values.use_gdbstub = ui->toggle_gdbstub->isChecked();
     Settings::values.gdbstub_port = ui->gdbport_spinbox->value();
-    Settings::Apply();
 }

src/citra_qt/configure_dialog.cpp

@@ -33,5 +33,7 @@ void ConfigureDialog::applyConfiguration() {
     ui->inputTab->applyConfiguration();
     ui->graphicsTab->applyConfiguration();
     ui->audioTab->applyConfiguration();
+    ui->layoutTab->applyConfiguration();
     ui->debugTab->applyConfiguration();
+    Settings::Apply();
 }

src/citra_qt/configure_general.cpp

@@ -29,5 +29,4 @@ void ConfigureGeneral::applyConfiguration() {
     UISettings::values.gamedir_deepscan = ui->toggle_deepscan->isChecked();
     UISettings::values.confirm_before_closing = ui->toggle_check_exit->isChecked();
     Settings::values.region_value = ui->region_combobox->currentIndex();
-    Settings::Apply();
 }

src/citra_qt/configure_layout.cpp

@@ -0,0 +1,32 @@
+// Copyright 2016 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "citra_qt/configure_layout.h"
+#include "citra_qt/ui_settings.h"
+#include "ui_configure_layout.h"
+
+#include "core/settings.h"
+
+ConfigureLayout::ConfigureLayout(QWidget *parent) :
+    QWidget(parent),
+    ui(new Ui::ConfigureLayout)
+{
+    ui->setupUi(this);
+    this->setConfiguration();
+}
+
+ConfigureLayout::~ConfigureLayout()
+{
+    delete ui;
+}
+
+void ConfigureLayout::setConfiguration() {
+    ui->layout_combobox->setCurrentIndex(static_cast<int>(Settings::values.layout_option));
+    ui->swap_screen->setChecked(Settings::values.swap_screen);
+}
+
+void ConfigureLayout::applyConfiguration() {
+    Settings::values.layout_option = static_cast<Settings::LayoutOption>(ui->layout_combobox->currentIndex());
+    Settings::values.swap_screen = ui->swap_screen->isChecked();
+}

src/citra_qt/configure_layout.h

@@ -0,0 +1,29 @@
+// Copyright 2016 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <QWidget>
+
+namespace Ui {
+class ConfigureLayout;
+}
+
+class ConfigureLayout : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit ConfigureLayout(QWidget *parent = 0);
+    ~ConfigureLayout();
+
+    void applyConfiguration();
+
+private:
+    void setConfiguration();
+
+private:
+    Ui::ConfigureLayout *ui;
+};

src/citra_qt/configure_layout.ui

@@ -0,0 +1,92 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>ConfigureLayout</class>
+ <widget class="QWidget" name="ConfigureLayout">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>300</width>
+    <height>377</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Form</string>
+  </property>
+  <layout class="QHBoxLayout" name="horizontalLayout">
+   <item>
+    <layout class="QVBoxLayout" name="verticalLayout">
+     <item>
+      <widget class="QGroupBox" name="groupBox">
+       <property name="title">
+        <string>General</string>
+       </property>
+       <layout class="QHBoxLayout" name="horizontalLayout_3">
+        <item>
+         <layout class="QVBoxLayout" name="verticalLayout_2">
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout_3">
+            <item>
+             <widget class="QLabel" name="label1">
+              <property name="text">
+               <string>Screen Layout:</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QComboBox" name="layout_combobox">
+              <item>
+               <property name="text">
+                <string notr="true">Default</string>
+               </property>
+              </item>
+              <item>
+               <property name="text">
+                <string notr="true">Single Screen</string>
+               </property>
+              </item>
+              <item>
+               <property name="text">
+                <string notr="true">Large Screen</string>
+               </property>
+              </item><!--
+              <item>
+               <property name="text">
+                <string notr="true">Custom</string>
+               </property>
+              </item>-->
+             </widget>
+            </item>
+           </layout>
+          </item>
+          <item>
+           <widget class="QCheckBox" name="swap_screen">
+            <property name="text">
+             <string>Swap Screens</string>
+            </property>
+           </widget>
+          </item>
+         </layout>
+        </item>
+       </layout>
+      </widget>
+     </item>
+     <item>
+      <widget class="QGroupBox" name="groupBox">
+       <property name="title">
+        <string>Custom Layout Parameters</string>
+       </property>
+       <layout class="QHBoxLayout" name="horizontalLayout_5">
+        <item>
+         <layout class="QVBoxLayout" name="verticalLayout_3"/>
+        </item>
+       </layout>
+      </widget>
+     </item>
+    </layout>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>

src/citra_qt/main.cpp

@@ -512,8 +512,7 @@ void GMainWindow::ToggleWindowMode() {
 void GMainWindow::OnConfigure() {
     ConfigureDialog configureDialog(this, emulation_running);
     auto result = configureDialog.exec();
-    if (result == QDialog::Accepted)
+    if (result == QDialog::Accepted) {
-    {
         configureDialog.applyConfiguration();
         render_window->ReloadSetKeymaps();
         config->Save();

src/common/CMakeLists.txt

@@ -5,6 +5,7 @@ set(SRCS
             break_points.cpp
             emu_window.cpp
             file_util.cpp
+            framebuffer_layout.cpp
             hash.cpp
             key_map.cpp
             logging/filter.cpp
@@ -35,6 +36,7 @@ set(HEADERS
             common_types.h
             emu_window.h
             file_util.h
+            framebuffer_layout.h
             hash.h
             key_map.h
             linear_disk_cache.h

src/common/emu_window.cpp

@@ -42,7 +42,7 @@ void EmuWindow::CirclePadUpdated(float x, float y) {
  * @param framebuffer_y Framebuffer y-coordinate to check
  * @return True if the coordinates are within the touchpad, otherwise false
  */
-static bool IsWithinTouchscreen(const EmuWindow::FramebufferLayout& layout, unsigned framebuffer_x,
+static bool IsWithinTouchscreen(const FramebufferLayout& layout, unsigned framebuffer_x,
                                 unsigned framebuffer_y) {
     return (framebuffer_y >= layout.bottom_screen.top    &&
             framebuffer_y <  layout.bottom_screen.bottom &&
@@ -90,52 +90,21 @@ void EmuWindow::TouchMoved(unsigned framebuffer_x, unsigned framebuffer_y) {
     TouchPressed(framebuffer_x, framebuffer_y);
 }
 
-EmuWindow::FramebufferLayout EmuWindow::FramebufferLayout::DefaultScreenLayout(unsigned width, unsigned height) {
+void EmuWindow::UpdateCurrentFramebufferLayout(unsigned width, unsigned height) {
-    // When hiding the widget, the function receives a size of 0
+    FramebufferLayout layout;
-    if (width == 0) width = 1;
+    switch (Settings::values.layout_option) {
-    if (height == 0) height = 1;
+    case Settings::LayoutOption::SingleScreen:
-
+        layout = FramebufferLayout::SingleFrameLayout(width, height);
-    EmuWindow::FramebufferLayout res = { width, height, {}, {} };
+        break;
-
+    case Settings::LayoutOption::LargeScreen:
-    float window_aspect_ratio = static_cast<float>(height) / width;
+        layout = FramebufferLayout::LargeFrameLayout(width, height);
-    float emulation_aspect_ratio = static_cast<float>(VideoCore::kScreenTopHeight * 2) /
+        break;
-        VideoCore::kScreenTopWidth;
+    case Settings::LayoutOption::Default:
-
+    default:
-    if (window_aspect_ratio > emulation_aspect_ratio) {
+        layout = FramebufferLayout::DefaultFrameLayout(width, height);
-        // Window is narrower than the emulation content => apply borders to the top and bottom
+        break;
-        int viewport_height = static_cast<int>(std::round(emulation_aspect_ratio * width));
-
-        res.top_screen.left = 0;
-        res.top_screen.right = res.top_screen.left + width;
-        res.top_screen.top = (height - viewport_height) / 2;
-        res.top_screen.bottom = res.top_screen.top + viewport_height / 2;
-
-        int bottom_width = static_cast<int>((static_cast<float>(VideoCore::kScreenBottomWidth) /
-            VideoCore::kScreenTopWidth) * (res.top_screen.right - res.top_screen.left));
-        int bottom_border = ((res.top_screen.right - res.top_screen.left) - bottom_width) / 2;
-
-        res.bottom_screen.left = bottom_border;
-        res.bottom_screen.right = res.bottom_screen.left + bottom_width;
-        res.bottom_screen.top = res.top_screen.bottom;
-        res.bottom_screen.bottom = res.bottom_screen.top + viewport_height / 2;
-    } else {
-        // Otherwise, apply borders to the left and right sides of the window.
-        int viewport_width = static_cast<int>(std::round(height / emulation_aspect_ratio));
-
-        res.top_screen.left = (width - viewport_width) / 2;
-        res.top_screen.right = res.top_screen.left + viewport_width;
-        res.top_screen.top = 0;
-        res.top_screen.bottom = res.top_screen.top + height / 2;
-
-        int bottom_width = static_cast<int>((static_cast<float>(VideoCore::kScreenBottomWidth) /
-            VideoCore::kScreenTopWidth) * (res.top_screen.right - res.top_screen.left));
-        int bottom_border = ((res.top_screen.right - res.top_screen.left) - bottom_width) / 2;
-
-        res.bottom_screen.left = res.top_screen.left + bottom_border;
-        res.bottom_screen.right = res.bottom_screen.left + bottom_width;
-        res.bottom_screen.top = res.top_screen.bottom;
-        res.bottom_screen.bottom = res.bottom_screen.top + height / 2;
     }
-
+    // Reverse the screens if the setting has changed
-    return res;
+    layout.ReverseFrames(Settings::values.swap_screen);
+    NotifyFramebufferLayoutChanged(layout);
 }

src/common/emu_window.h

@@ -8,6 +8,7 @@
 #include <utility>
 
 #include "common/common_types.h"
+#include "common/framebuffer_layout.h"
 #include "common/math_util.h"
 
 #include "core/hle/service/hid/hid.h"
@@ -41,23 +42,6 @@ public:
         std::pair<unsigned,unsigned> min_client_area_size;
     };
 
-    /// Describes the layout of the window framebuffer (size and top/bottom screen positions)
-    struct FramebufferLayout {
-
-        /**
-         * Factory method for constructing a default FramebufferLayout
-         * @param width Window framebuffer width in pixels
-         * @param height Window framebuffer height in pixels
-         * @return Newly created FramebufferLayout object with default screen regions initialized
-         */
-        static FramebufferLayout DefaultScreenLayout(unsigned width, unsigned height);
-
-        unsigned width;
-        unsigned height;
-        MathUtil::Rectangle<unsigned> top_screen;
-        MathUtil::Rectangle<unsigned> bottom_screen;
-    };
-
     /// Swap buffers to display the next frame
     virtual void SwapBuffers() = 0;
 
@@ -215,6 +199,12 @@ public:
         return framebuffer_layout;
     }
 
+    /**
+     * Convenience method to update the VideoCore EmuWindow
+     * Read from the current settings to determine which layout to use.
+     */
+    void UpdateCurrentFramebufferLayout(unsigned width, unsigned height);
+
 protected:
     EmuWindow() {
         // TODO: Find a better place to set this.

src/common/framebuffer_layout.cpp

@@ -0,0 +1,338 @@
+// Copyright 2016 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <cmath>
+
+#include "common/assert.h"
+#include "common/framebuffer_layout.h"
+#include "video_core/video_core.h"
+
+void FramebufferLayout::ReverseFrames(bool is_reverse) {
+    if (is_reverse != is_reverse_layout) {
+        *this = inverse(width, height);
+    }
+}
+
+FramebufferLayout::FramebufferLayout() {
+    height = width = 0;
+    top_screen_enabled = bottom_screen_enabled = 0;
+
+}
+
+FramebufferLayout& FramebufferLayout::operator= (const FramebufferLayout &source) {
+    width = source.width;
+    height = source.height;
+    top_screen_enabled = source.top_screen_enabled;
+    bottom_screen_enabled = source.bottom_screen_enabled;
+    inverse = source.inverse;
+    is_reverse_layout = source.is_reverse_layout;
+    top_screen = source.top_screen;
+    bottom_screen = source.bottom_screen;
+    return *this;
+}
+
+FramebufferLayout FramebufferLayout::DefaultFrameLayout(unsigned width, unsigned height) {
+
+    ASSERT(width > 0);
+    ASSERT(height > 0);
+
+    FramebufferLayout res(width, height, true, true, FramebufferLayout::InverseDefaultLayout, {}, {});
+    res.is_reverse_layout = false;
+
+    float window_aspect_ratio = static_cast<float>(height) / width;
+    float emulation_aspect_ratio = static_cast<float>(VideoCore::kScreenTopHeight * 2) /
+        VideoCore::kScreenTopWidth;
+
+    if (window_aspect_ratio > emulation_aspect_ratio) {
+        // Window is narrower than the emulation content => apply borders to the top and bottom
+        int viewport_height = static_cast<int>(std::round(emulation_aspect_ratio * width));
+
+        res.top_screen.left = 0;
+        res.top_screen.right = res.top_screen.left + width;
+        res.top_screen.top = (height - viewport_height) / 2;
+        res.top_screen.bottom = res.top_screen.top + viewport_height / 2;
+
+        int bottom_width = static_cast<int>((static_cast<float>(VideoCore::kScreenBottomWidth) /
+            VideoCore::kScreenTopWidth) * (res.top_screen.right - res.top_screen.left));
+        int bottom_border = ((res.top_screen.right - res.top_screen.left) - bottom_width) / 2;
+
+        res.bottom_screen.left = bottom_border;
+        res.bottom_screen.right = res.bottom_screen.left + bottom_width;
+        res.bottom_screen.top = res.top_screen.bottom;
+        res.bottom_screen.bottom = res.bottom_screen.top + viewport_height / 2;
+    } else {
+        // Otherwise, apply borders to the left and right sides of the window.
+        int viewport_width = static_cast<int>(std::round(height / emulation_aspect_ratio));
+
+        res.top_screen.left = (width - viewport_width) / 2;
+        res.top_screen.right = res.top_screen.left + viewport_width;
+        res.top_screen.top = 0;
+        res.top_screen.bottom = res.top_screen.top + height / 2;
+
+        int bottom_width = static_cast<int>((static_cast<float>(VideoCore::kScreenBottomWidth) /
+            VideoCore::kScreenTopWidth) * (res.top_screen.right - res.top_screen.left));
+        int bottom_border = ((res.top_screen.right - res.top_screen.left) - bottom_width) / 2;
+
+        res.bottom_screen.left = res.top_screen.left + bottom_border;
+        res.bottom_screen.right = res.bottom_screen.left + bottom_width;
+        res.bottom_screen.top = res.top_screen.bottom;
+        res.bottom_screen.bottom = res.bottom_screen.top + height / 2;
+    }
+
+    return res;
+}
+
+FramebufferLayout FramebufferLayout::InverseDefaultLayout(unsigned width, unsigned height) {
+
+    ASSERT(width > 0);
+    ASSERT(height > 0);
+
+    FramebufferLayout res(width, height, true, true, DefaultFrameLayout, {}, {});
+    res.is_reverse_layout = true;
+
+    float window_aspect_ratio = static_cast<float>(height) / width;
+    float emulation_aspect_ratio = static_cast<float>(VideoCore::kScreenTopHeight * 2) /
+        VideoCore::kScreenTopWidth;
+
+    if (window_aspect_ratio > emulation_aspect_ratio) {
+        // Window is narrower than the emulation content => apply borders to the top and bottom
+        int viewport_height = static_cast<int>(std::round(emulation_aspect_ratio * width));
+
+        res.top_screen.left = 0;
+        res.top_screen.right = res.top_screen.left + width;
+
+        int bottom_width = static_cast<int>((static_cast<float>(VideoCore::kScreenBottomWidth) /
+            VideoCore::kScreenTopWidth) * (res.top_screen.right - res.top_screen.left));
+        int bottom_border = ((res.top_screen.right - res.top_screen.left) - bottom_width) / 2;
+
+        res.bottom_screen.left = bottom_border;
+        res.bottom_screen.right = res.bottom_screen.left + bottom_width;
+        res.bottom_screen.top = (height - viewport_height) / 2;
+        res.bottom_screen.bottom = res.bottom_screen.top + viewport_height / 2;
+
+        res.top_screen.top = res.bottom_screen.bottom;
+        res.top_screen.bottom = res.top_screen.top + viewport_height / 2;
+    }
+    else {
+        // Otherwise, apply borders to the left and right sides of the window.
+        int viewport_width = static_cast<int>(std::round(height / emulation_aspect_ratio));
+        res.top_screen.left = (width - viewport_width) / 2;
+        res.top_screen.right = res.top_screen.left + viewport_width;
+
+        int bottom_width = static_cast<int>((static_cast<float>(VideoCore::kScreenBottomWidth) /
+            VideoCore::kScreenTopWidth) * (res.top_screen.right - res.top_screen.left));
+        int bottom_border = ((res.top_screen.right - res.top_screen.left) - bottom_width) / 2;
+
+        res.bottom_screen.left = res.top_screen.left + bottom_border;
+        res.bottom_screen.right = res.bottom_screen.left + bottom_width;
+        res.bottom_screen.top = 0;
+        res.bottom_screen.bottom = res.bottom_screen.top + height / 2;
+
+        res.top_screen.top = res.bottom_screen.bottom;
+        res.top_screen.bottom = res.top_screen.top + height / 2;
+    }
+
+    return res;
+}
+
+FramebufferLayout FramebufferLayout::SingleFrameLayout(unsigned width, unsigned height) {
+
+    ASSERT(width > 0);
+    ASSERT(height > 0);
+
+    FramebufferLayout res(width, height, true, false, InverseSingleLayout, {}, {});
+    res.is_reverse_layout = false;
+
+    float window_aspect_ratio = static_cast<float>(height) / width;
+    float emulation_aspect_ratio = static_cast<float>(VideoCore::kScreenTopHeight) /
+        VideoCore::kScreenTopWidth;
+
+    if (window_aspect_ratio > emulation_aspect_ratio) {
+        // Window is narrower than the emulation content => apply borders to the top and bottom
+        int viewport_height = static_cast<int>(std::round(emulation_aspect_ratio * width));
+
+        res.top_screen.left = 0;
+        res.top_screen.right = res.top_screen.left + width;
+        res.top_screen.top = (height - viewport_height) / 2;
+        res.top_screen.bottom = res.top_screen.top + viewport_height;
+
+        res.bottom_screen.left = 0;
+        res.bottom_screen.right = VideoCore::kScreenBottomWidth;
+        res.bottom_screen.top = 0;
+        res.bottom_screen.bottom = VideoCore::kScreenBottomHeight;
+    }
+    else {
+        // Otherwise, apply borders to the left and right sides of the window.
+        int viewport_width = static_cast<int>(std::round(height / emulation_aspect_ratio));
+
+        res.top_screen.left = (width - viewport_width) / 2;
+        res.top_screen.right = res.top_screen.left + viewport_width;
+        res.top_screen.top = 0;
+        res.top_screen.bottom = res.top_screen.top + height;
+
+        // The Rasterizer still depends on these fields to maintain the right aspect ratio
+        res.bottom_screen.left = 0;
+        res.bottom_screen.right = VideoCore::kScreenBottomWidth;
+        res.bottom_screen.top = 0;
+        res.bottom_screen.bottom = VideoCore::kScreenBottomHeight;
+    }
+
+    return res;
+}
+
+FramebufferLayout FramebufferLayout::InverseSingleLayout(unsigned width, unsigned height) {
+
+    ASSERT(width > 0);
+    ASSERT(height > 0);
+
+    FramebufferLayout res(width, height, false, true, SingleFrameLayout, {}, {});
+    res.is_reverse_layout = true;
+
+    float window_aspect_ratio = static_cast<float>(height) / width;
+    float emulation_aspect_ratio = static_cast<float>(VideoCore::kScreenBottomHeight) /
+        VideoCore::kScreenBottomWidth;
+
+    if (window_aspect_ratio > emulation_aspect_ratio) {
+        // Window is narrower than the emulation content => apply borders to the top and bottom
+        int viewport_height = static_cast<int>(std::round(emulation_aspect_ratio * width));
+
+        res.bottom_screen.left = 0;
+        res.bottom_screen.right = res.bottom_screen.left + width;
+        res.bottom_screen.top = (height - viewport_height) / 2;
+        res.bottom_screen.bottom = res.bottom_screen.top + viewport_height;
+
+        // The Rasterizer still depends on these fields to maintain the right aspect ratio
+        res.top_screen.left = 0;
+        res.top_screen.right = VideoCore::kScreenTopWidth;
+        res.top_screen.top = 0;
+        res.top_screen.bottom = VideoCore::kScreenTopHeight;
+    }
+    else {
+        // Otherwise, apply borders to the left and right sides of the window.
+        int viewport_width = static_cast<int>(std::round(height / emulation_aspect_ratio));
+
+        res.bottom_screen.left = (width - viewport_width) / 2;
+        res.bottom_screen.right = res.bottom_screen.left + viewport_width;
+        res.bottom_screen.top = 0;
+        res.bottom_screen.bottom = res.bottom_screen.top + height;
+
+        res.top_screen.left = 0;
+        res.top_screen.right = VideoCore::kScreenTopWidth;
+        res.top_screen.top = 0;
+        res.top_screen.bottom = VideoCore::kScreenTopHeight;
+    }
+
+    return res;
+}
+
+FramebufferLayout FramebufferLayout::LargeFrameLayout(unsigned width, unsigned height) {
+
+    ASSERT(width > 0);
+    ASSERT(height > 0);
+
+    FramebufferLayout res(width, height, true, true, InverseLargeLayout, {}, {});
+    res.is_reverse_layout = false;
+
+    float window_aspect_ratio = static_cast<float>(height) / width;
+    float emulation_aspect_ratio = static_cast<float>(VideoCore::kScreenTopHeight * 4) /
+        (VideoCore::kScreenTopWidth * 4 + VideoCore::kScreenBottomWidth);
+
+    if (window_aspect_ratio > emulation_aspect_ratio) {
+        // Window is narrower than the emulation content => apply borders to the top and bottom
+        int viewport_height = static_cast<int>(std::round(emulation_aspect_ratio * width));
+
+        res.top_screen.left = 0;
+        // Top screen occupies 4 / 5ths of the total width
+        res.top_screen.right = static_cast<int>(std::round(width / 5)) * 4;
+        res.top_screen.top = (height - viewport_height) / 2;
+        res.top_screen.bottom = res.top_screen.top + viewport_height;
+
+        int bottom_height = static_cast<int>((static_cast<float>(VideoCore::kScreenBottomHeight) /
+            VideoCore::kScreenBottomWidth) * (width - res.top_screen.right));
+
+        res.bottom_screen.left = res.top_screen.right;
+        res.bottom_screen.right = width;
+        res.bottom_screen.bottom = res.top_screen.bottom;
+        res.bottom_screen.top = res.bottom_screen.bottom - bottom_height;
+    } else {
+        // Otherwise, apply borders to the left and right sides of the window.
+        int viewport_width = static_cast<int>(std::round(height / emulation_aspect_ratio));
+        // Break the viewport into fifths and give top 4 of them
+        int fifth_width = static_cast<int>(std::round(viewport_width / 5));
+
+        res.top_screen.left = (width - viewport_width) / 2;
+        res.top_screen.right = res.top_screen.left + fifth_width * 4;
+        res.top_screen.top = 0;
+        res.top_screen.bottom = height;
+
+        int bottom_height = static_cast<int>((static_cast<float>(VideoCore::kScreenBottomHeight) /
+            VideoCore::kScreenBottomWidth) * (fifth_width));
+
+        res.bottom_screen.left = res.top_screen.right;
+        res.bottom_screen.right = width - (width - viewport_width) / 2;
+        res.bottom_screen.bottom = res.top_screen.bottom;
+        res.bottom_screen.top = res.bottom_screen.bottom - bottom_height;
+    }
+
+    return res;
+}
+
+
+FramebufferLayout FramebufferLayout::InverseLargeLayout(unsigned width, unsigned height) {
+
+    ASSERT(width > 0);
+    ASSERT(height > 0);
+
+    FramebufferLayout res(width, height, true, true, LargeFrameLayout, {}, {});
+    res.is_reverse_layout = true;
+
+    float window_aspect_ratio = static_cast<float>(height) / width;
+    float emulation_aspect_ratio = static_cast<float>(VideoCore::kScreenBottomHeight * 4) /
+        (VideoCore::kScreenBottomWidth * 4 + VideoCore::kScreenTopWidth);
+
+    if (window_aspect_ratio > emulation_aspect_ratio) {
+        // Window is narrower than the emulation content => apply borders to the top and bottom
+        int viewport_height = static_cast<int>(std::round(emulation_aspect_ratio * width));
+
+        res.bottom_screen.left = 0;
+        // Top screen occupies 4 / 5ths of the total width
+        res.bottom_screen.right = static_cast<int>(std::round(width / 5)) * 4;
+        res.bottom_screen.top = (height - viewport_height) / 2;
+        res.bottom_screen.bottom = res.bottom_screen.top + viewport_height;
+
+        int top_height = static_cast<int>((static_cast<float>(VideoCore::kScreenTopHeight) /
+            VideoCore::kScreenTopWidth) * (width - res.bottom_screen.right));
+
+        res.top_screen.left = res.bottom_screen.right;
+        res.top_screen.right = width;
+        res.top_screen.bottom = res.bottom_screen.bottom;
+        res.top_screen.top = res.top_screen.bottom - top_height;
+    } else {
+        // Otherwise, apply borders to the left and right sides of the window.
+        int viewport_width = static_cast<int>(std::round(height / emulation_aspect_ratio));
+        // Break the viewport into fifths and give top 4 of them
+        int fifth_width = static_cast<int>(std::round(viewport_width / 5));
+
+        res.bottom_screen.left = (width - viewport_width) / 2;
+        res.bottom_screen.right = res.bottom_screen.left + fifth_width * 4;
+        res.bottom_screen.top = 0;
+        res.bottom_screen.bottom = height;
+
+        int top_height = static_cast<int>((static_cast<float>(VideoCore::kScreenTopHeight) /
+            VideoCore::kScreenTopWidth) * (fifth_width));
+
+        res.top_screen.left = res.bottom_screen.right;
+        res.top_screen.right = width - (width - viewport_width) / 2;
+        res.top_screen.bottom = res.bottom_screen.bottom;
+        res.top_screen.top = res.top_screen.bottom - top_height;
+    }
+
+    return res;
+}
+
+
+FramebufferLayout::FramebufferLayout(unsigned width, unsigned height, bool tenabled, bool benabled, InverseLayout inverse,
+    MathUtil::Rectangle<unsigned> tscreen, MathUtil::Rectangle<unsigned> bscreen) : width(width),
+    height(height), inverse(inverse), top_screen_enabled(tenabled), bottom_screen_enabled(benabled),
+    top_screen(tscreen), bottom_screen(bscreen) {}

src/common/framebuffer_layout.h

@@ -0,0 +1,65 @@
+// Copyright 2016 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "common/math_util.h"
+
+/// Describes the layout of the window framebuffer (size and top/bottom screen positions)
+class FramebufferLayout {
+public:
+    /**
+     * Factory method for constructing a default FramebufferLayout
+     * @param width Window framebuffer width in pixels
+     * @param height Window framebuffer height in pixels
+     * @return Newly created FramebufferLayout object with default screen regions initialized
+     */
+    static FramebufferLayout DefaultFrameLayout(unsigned width, unsigned height);
+
+    /**
+     * Factory method for constructing a FramebufferLayout with only the top screen
+     * @param width Window framebuffer width in pixels
+     * @param height Window framebuffer height in pixels
+     * @return Newly created FramebufferLayout object with default screen regions initialized
+     */
+    static FramebufferLayout SingleFrameLayout(unsigned width, unsigned height);
+
+    /**
+     * 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
+     * @return Newly created FramebufferLayout object with default screen regions initialized
+     */
+    static FramebufferLayout LargeFrameLayout(unsigned width, unsigned height);
+
+    /**
+     * Conditionally changes the layout to its inverse. For example, if a layout has a prominent top frame and a small bottom frame,
+     * this function should switch them so the bottom frame is now large.
+     * @param is_reverse If this is true, and the layout is a reverse layout, then nothing will change. This is a toggle
+     */
+    void ReverseFrames(bool is_reverse);
+
+    FramebufferLayout();
+    FramebufferLayout& operator= (const FramebufferLayout &cSource);
+
+    unsigned width;
+    unsigned height;
+    bool top_screen_enabled;
+    bool bottom_screen_enabled;
+    MathUtil::Rectangle<unsigned> top_screen;
+    MathUtil::Rectangle<unsigned> bottom_screen;
+private:
+
+    typedef FramebufferLayout (*InverseLayout)(unsigned, unsigned);
+
+    static FramebufferLayout InverseDefaultLayout(unsigned width, unsigned height);
+    static FramebufferLayout InverseSingleLayout(unsigned width, unsigned height);
+    static FramebufferLayout InverseLargeLayout(unsigned width, unsigned height);
+
+    FramebufferLayout(unsigned width, unsigned height, bool tenabled, bool benabled, InverseLayout,
+        MathUtil::Rectangle<unsigned> tscreen, MathUtil::Rectangle<unsigned> bscreen);
+    InverseLayout inverse;
+    bool is_reverse_layout;
+};

src/core/settings.cpp

@@ -10,6 +10,8 @@
 
 #include "video_core/video_core.h"
 
+#include "common/emu_window.h"
+
 namespace Settings {
 
 Values values = {};
@@ -23,6 +25,12 @@ 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();
+        layout.ReverseFrames(values.swap_screen);
+        VideoCore::g_emu_window->UpdateCurrentFramebufferLayout(layout.width, layout.height);
+    }
+
     AudioCore::SelectSink(values.sink_id);
     AudioCore::EnableStretching(values.enable_audio_stretching);
 

src/core/settings.h

@@ -50,6 +50,12 @@ static const std::array<Values, NUM_INPUTS> All = {{
 }};
 }
 
+enum class LayoutOption {
+    Default,
+    SingleScreen,
+    LargeScreen,
+    Custom,
+};
 
 struct Values {
     // CheckNew3DS
@@ -74,6 +80,9 @@ struct Values {
     bool use_scaled_resolution;
     bool use_vsync;
 
+    LayoutOption layout_option;
+    bool swap_screen;
+
     float bg_red;
     float bg_green;
     float bg_blue;

src/video_core/renderer_opengl/renderer_opengl.cpp

@@ -386,6 +386,8 @@ void RendererOpenGL::DrawSingleScreenRotated(const ScreenInfo& screen_info, floa
  */
 void RendererOpenGL::DrawScreens() {
     auto layout = render_window->GetFramebufferLayout();
+    auto top_screen = layout.top_screen;
+    auto bottom_screen = layout.bottom_screen;
 
     glViewport(0, 0, layout.width, layout.height);
     glClear(GL_COLOR_BUFFER_BIT);
@@ -399,10 +401,14 @@ void RendererOpenGL::DrawScreens() {
     glActiveTexture(GL_TEXTURE0);
     glUniform1i(uniform_color_texture, 0);
 
-    DrawSingleScreenRotated(screen_infos[0], (float)layout.top_screen.left, (float)layout.top_screen.top,
+    if (layout.top_screen_enabled) {
-        (float)layout.top_screen.GetWidth(), (float)layout.top_screen.GetHeight());
+        DrawSingleScreenRotated(screen_infos[0], (float)top_screen.left, (float)top_screen.top,
-    DrawSingleScreenRotated(screen_infos[1], (float)layout.bottom_screen.left,(float)layout.bottom_screen.top,
+            (float)top_screen.GetWidth(), (float)top_screen.GetHeight());
-        (float)layout.bottom_screen.GetWidth(), (float)layout.bottom_screen.GetHeight());
+    }
+    if (layout.bottom_screen_enabled) {
+        DrawSingleScreenRotated(screen_infos[1], (float)bottom_screen.left,(float)bottom_screen.top,
+            (float)bottom_screen.GetWidth(), (float)bottom_screen.GetHeight());
+    }
 
     m_current_frame++;
 }