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/common/framebuffer_layout.h

@@ -0,0 +1,43 @@
+// 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"
+namespace Layout {
+/// Describes the layout of the window framebuffer (size and top/bottom screen positions)
+struct FramebufferLayout {
+    unsigned width;
+    unsigned height;
+    bool top_screen_enabled;
+    bool bottom_screen_enabled;
+    MathUtil::Rectangle<unsigned> top_screen;
+    MathUtil::Rectangle<unsigned> bottom_screen;
+};
+
+/**
+ * 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
+ */
+FramebufferLayout DefaultFrameLayout(unsigned width, unsigned height, bool is_swapped);
+
+/**
+ * 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
+ */
+FramebufferLayout SingleFrameLayout(unsigned width, unsigned 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
+ * @return Newly created FramebufferLayout object with default screen regions initialized
+ */
+FramebufferLayout LargeFrameLayout(unsigned width, unsigned height, bool is_swapped);
+}