// 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/settings.h"
#include "core/3ds.h"
#include "core/frontend/framebuffer_layout.h"

namespace Layout {

static const float TOP_SCREEN_ASPECT_RATIO =
    static_cast<float>(Core::kScreenTopHeight) / Core::kScreenTopWidth;
static const float BOT_SCREEN_ASPECT_RATIO =
    static_cast<float>(Core::kScreenBottomHeight) / Core::kScreenBottomWidth;
static const float TOP_SCREEN_UPRIGHT_ASPECT_RATIO =
    static_cast<float>(Core::kScreenTopWidth) / Core::kScreenTopHeight;
static const float BOT_SCREEN_UPRIGHT_ASPECT_RATIO =
    static_cast<float>(Core::kScreenBottomWidth) / Core::kScreenBottomHeight;

u32 FramebufferLayout::GetScalingRatio() const {
    if (is_rotated) {
        return static_cast<u32>(((top_screen.GetWidth() - 1) / Core::kScreenTopWidth) + 1);
    } else {
        return static_cast<u32>(((top_screen.GetWidth() - 1) / Core::kScreenTopHeight) + 1);
    }
}

// Finds the largest size subrectangle contained in window area that is confined to the aspect ratio
template <class T>
static Common::Rectangle<T> maxRectangle(Common::Rectangle<T> window_area,
                                         float screen_aspect_ratio) {
    float scale = std::min(static_cast<float>(window_area.GetWidth()),
                           window_area.GetHeight() / screen_aspect_ratio);
    return Common::Rectangle<T>{0, 0, static_cast<T>(std::round(scale)),
                                static_cast<T>(std::round(scale * screen_aspect_ratio))};
}

FramebufferLayout DefaultFrameLayout(u32 width, u32 height, bool swapped, bool upright) {
    ASSERT(width > 0);
    ASSERT(height > 0);

    FramebufferLayout res{width, height, true, true, {}, {}, !upright};
    Common::Rectangle<u32> screen_window_area;
    Common::Rectangle<u32> top_screen;
    Common::Rectangle<u32> bot_screen;
    float emulation_aspect_ratio;
    if (upright) {
        // Default layout gives equal screen sizes to the top and bottom screen
        screen_window_area = {0, 0, width / 2, height};
        top_screen = maxRectangle(screen_window_area, TOP_SCREEN_UPRIGHT_ASPECT_RATIO);
        bot_screen = maxRectangle(screen_window_area, BOT_SCREEN_UPRIGHT_ASPECT_RATIO);
        // both screens width are taken into account by dividing by 2
        emulation_aspect_ratio = TOP_SCREEN_UPRIGHT_ASPECT_RATIO / 2;
    } else {
        // Default layout gives equal screen sizes to the top and bottom screen
        screen_window_area = {0, 0, width, height / 2};
        top_screen = maxRectangle(screen_window_area, TOP_SCREEN_ASPECT_RATIO);
        bot_screen = maxRectangle(screen_window_area, BOT_SCREEN_ASPECT_RATIO);
        // both screens height are taken into account by multiplying by 2
        emulation_aspect_ratio = TOP_SCREEN_ASPECT_RATIO * 2;
    }

    float window_aspect_ratio = static_cast<float>(height) / width;

    if (window_aspect_ratio < emulation_aspect_ratio) {
        // Window is wider than the emulation content => apply borders to the right and left sides
        if (upright) {
            // Recalculate the bottom screen to account for the height difference between right and
            // left
            screen_window_area = {0, 0, top_screen.GetWidth(), height};
            bot_screen = maxRectangle(screen_window_area, BOT_SCREEN_UPRIGHT_ASPECT_RATIO);
            bot_screen =
                bot_screen.TranslateY((top_screen.GetHeight() - bot_screen.GetHeight()) / 2);
            if (swapped) {
                bot_screen = bot_screen.TranslateX(width / 2 - bot_screen.GetWidth());
            } else {
                top_screen = top_screen.TranslateX(width / 2 - top_screen.GetWidth());
            }
        } else {
            top_screen =
                top_screen.TranslateX((screen_window_area.GetWidth() - top_screen.GetWidth()) / 2);
            bot_screen =
                bot_screen.TranslateX((screen_window_area.GetWidth() - bot_screen.GetWidth()) / 2);
        }
    } else {
        // Window is narrower than the emulation content => apply borders to the top and bottom
        if (upright) {
            top_screen = top_screen.TranslateY(
                (screen_window_area.GetHeight() - top_screen.GetHeight()) / 2);
            bot_screen = bot_screen.TranslateY(
                (screen_window_area.GetHeight() - bot_screen.GetHeight()) / 2);
        } else {
            // Recalculate the bottom screen to account for the width difference between top and
            // bottom
            screen_window_area = {0, 0, width, top_screen.GetHeight()};
            bot_screen = maxRectangle(screen_window_area, BOT_SCREEN_ASPECT_RATIO);
            bot_screen = bot_screen.TranslateX((top_screen.GetWidth() - bot_screen.GetWidth()) / 2);
            if (swapped) {
                bot_screen = bot_screen.TranslateY(height / 2 - bot_screen.GetHeight());
            } else {
                top_screen = top_screen.TranslateY(height / 2 - top_screen.GetHeight());
            }
        }
    }
    if (upright) {
        // Move the top screen to the right if we are swapped.
        res.top_screen = swapped ? top_screen.TranslateX(width / 2) : top_screen;
        res.bottom_screen = swapped ? bot_screen : bot_screen.TranslateX(width / 2);
    } else {
        // Move the top screen to the bottom if we are swapped.
        res.top_screen = swapped ? top_screen.TranslateY(height / 2) : top_screen;
        res.bottom_screen = swapped ? bot_screen : bot_screen.TranslateY(height / 2);
    }
    return res;
}

FramebufferLayout MobilePortraitFrameLayout(u32 width, u32 height, bool swapped) {
    ASSERT(width > 0);
    ASSERT(height > 0);

    FramebufferLayout res{width, height, true, true, {}, {}};
    // Default layout gives equal screen sizes to the top and bottom screen
    Common::Rectangle<u32> screen_window_area{0, 0, width, height / 2};
    Common::Rectangle<u32> top_screen = maxRectangle(screen_window_area, TOP_SCREEN_ASPECT_RATIO);
    Common::Rectangle<u32> bot_screen = maxRectangle(screen_window_area, BOT_SCREEN_ASPECT_RATIO);

    float window_aspect_ratio = static_cast<float>(height) / width;
    // both screens height are taken into account by multiplying by 2
    float emulation_aspect_ratio = TOP_SCREEN_ASPECT_RATIO * 2;

    if (window_aspect_ratio < emulation_aspect_ratio) {
        // Apply borders to the left and right sides of the window.
        top_screen =
            top_screen.TranslateX((screen_window_area.GetWidth() - top_screen.GetWidth()) / 2);
        bot_screen =
            bot_screen.TranslateX((screen_window_area.GetWidth() - bot_screen.GetWidth()) / 2);
    } else {
        // Window is narrower than the emulation content
        // Recalculate the bottom screen to account for the width difference between top and bottom

        bot_screen = bot_screen.TranslateX((top_screen.GetWidth() - bot_screen.GetWidth()) / 2);
    }

    // Move the top screen to the bottom if we are swapped.
    res.top_screen = swapped ? top_screen.TranslateY(bot_screen.GetHeight()) : top_screen;
    res.bottom_screen = swapped ? bot_screen : bot_screen.TranslateY(top_screen.GetHeight());

    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 = 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);
    // The drawing code needs at least somewhat valid values for both screens
    // so just calculate them both even if the other isn't showing.
    FramebufferLayout res{width, height, !swapped, swapped, {}, {}, !upright};

    Common::Rectangle<u32> screen_window_area{0, 0, width, height};
    Common::Rectangle<u32> top_screen;
    Common::Rectangle<u32> bot_screen;
    float emulation_aspect_ratio;
    if (upright) {
        top_screen = maxRectangle(screen_window_area, TOP_SCREEN_UPRIGHT_ASPECT_RATIO);
        bot_screen = maxRectangle(screen_window_area, BOT_SCREEN_UPRIGHT_ASPECT_RATIO);
        emulation_aspect_ratio =
            (swapped) ? BOT_SCREEN_UPRIGHT_ASPECT_RATIO : TOP_SCREEN_UPRIGHT_ASPECT_RATIO;
    } else {
        top_screen = maxRectangle(screen_window_area, TOP_SCREEN_ASPECT_RATIO);
        bot_screen = maxRectangle(screen_window_area, BOT_SCREEN_ASPECT_RATIO);
        emulation_aspect_ratio = (swapped) ? BOT_SCREEN_ASPECT_RATIO : TOP_SCREEN_ASPECT_RATIO;
    }

    float window_aspect_ratio = static_cast<float>(height) / width;

    if (window_aspect_ratio < emulation_aspect_ratio) {
        top_screen =
            top_screen.TranslateX((screen_window_area.GetWidth() - top_screen.GetWidth()) / 2);
        bot_screen =
            bot_screen.TranslateX((screen_window_area.GetWidth() - bot_screen.GetWidth()) / 2);
    } else {
        top_screen = top_screen.TranslateY((height - top_screen.GetHeight()) / 2);
        bot_screen = bot_screen.TranslateY((height - bot_screen.GetHeight()) / 2);
    }
    res.top_screen = top_screen;
    res.bottom_screen = bot_screen;
    return res;
}

FramebufferLayout LargeFrameLayout(u32 width, u32 height, bool swapped, bool upright) {
    ASSERT(width > 0);
    ASSERT(height > 0);

    FramebufferLayout res{width, height, true, true, {}, {}, !upright};
    // 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;
    float large_screen_aspect_ratio;
    float small_screen_aspect_ratio;
    if (upright) {
        if (swapped) {
            emulation_aspect_ratio = (Core::kScreenBottomWidth * 4.0f + Core::kScreenTopWidth) /
                                     (Core::kScreenBottomHeight * 4);
            large_screen_aspect_ratio = BOT_SCREEN_UPRIGHT_ASPECT_RATIO;
            small_screen_aspect_ratio = TOP_SCREEN_UPRIGHT_ASPECT_RATIO;
        } else {
            emulation_aspect_ratio = (Core::kScreenTopWidth * 4.0f + Core::kScreenBottomWidth) /
                                     (Core::kScreenTopHeight * 4);
            large_screen_aspect_ratio = TOP_SCREEN_UPRIGHT_ASPECT_RATIO;
            small_screen_aspect_ratio = BOT_SCREEN_UPRIGHT_ASPECT_RATIO;
        }
    } else {
        if (swapped) {
            emulation_aspect_ratio = Core::kScreenBottomHeight * 4 /
                                     (Core::kScreenBottomWidth * 4.0f + Core::kScreenTopWidth);
            large_screen_aspect_ratio = BOT_SCREEN_ASPECT_RATIO;
            small_screen_aspect_ratio = TOP_SCREEN_ASPECT_RATIO;
        } else {
            emulation_aspect_ratio = Core::kScreenTopHeight * 4 /
                                     (Core::kScreenTopWidth * 4.0f + Core::kScreenBottomWidth);
            large_screen_aspect_ratio = TOP_SCREEN_ASPECT_RATIO;
            small_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(.25f);
    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((width - total_rect.GetWidth()) / 2);
    } else {
        large_screen = large_screen.TranslateY((height - total_rect.GetHeight()) / 2);
    }
    if (upright) {
        large_screen = large_screen.TranslateY(small_screen.GetHeight());
        small_screen = small_screen.TranslateX(large_screen.right - small_screen.GetWidth())
                           .TranslateY(large_screen.top - small_screen.GetHeight());
    } else {
        // Shift the small screen to the bottom right corner
        small_screen =
            small_screen.TranslateX(large_screen.right)
                .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 SideFrameLayout(u32 width, u32 height, bool swapped, bool upright) {
    ASSERT(width > 0);
    ASSERT(height > 0);

    FramebufferLayout res{width, height, true, true, {}, {}, !upright};

    // Aspect ratio of both screens side by side
    float emulation_aspect_ratio =
        upright ? static_cast<float>(Core::kScreenTopWidth + Core::kScreenBottomWidth) /
                      Core::kScreenTopHeight
                : static_cast<float>(Core::kScreenTopHeight) /
                      (Core::kScreenTopWidth + Core::kScreenBottomWidth);

    float window_aspect_ratio = static_cast<float>(height) / width;
    Common::Rectangle<u32> screen_window_area{0, 0, width, height};
    // Find largest Rectangle that can fit in the window size with the given aspect ratio
    Common::Rectangle<u32> screen_rect = maxRectangle(screen_window_area, emulation_aspect_ratio);
    // Find sizes of top and bottom screen
    Common::Rectangle<u32> top_screen =
        upright ? maxRectangle(screen_rect, TOP_SCREEN_UPRIGHT_ASPECT_RATIO)
                : maxRectangle(screen_rect, TOP_SCREEN_ASPECT_RATIO);
    Common::Rectangle<u32> bot_screen =
        upright ? maxRectangle(screen_rect, BOT_SCREEN_UPRIGHT_ASPECT_RATIO)
                : maxRectangle(screen_rect, BOT_SCREEN_ASPECT_RATIO);

    if (window_aspect_ratio < emulation_aspect_ratio) {
        // Apply borders to the left and right sides of the window.
        u32 shift_horizontal = (screen_window_area.GetWidth() - screen_rect.GetWidth()) / 2;
        top_screen = top_screen.TranslateX(shift_horizontal);
        bot_screen = bot_screen.TranslateX(shift_horizontal);
    } else {
        // Window is narrower than the emulation content => apply borders to the top and bottom
        u32 shift_vertical = (screen_window_area.GetHeight() - screen_rect.GetHeight()) / 2;
        top_screen = top_screen.TranslateY(shift_vertical);
        bot_screen = bot_screen.TranslateY(shift_vertical);
    }
    if (upright) {
        // Leave the top screen at the top if we are swapped.
        res.top_screen = swapped ? top_screen : top_screen.TranslateY(bot_screen.GetHeight());
        res.bottom_screen = swapped ? bot_screen.TranslateY(top_screen.GetHeight()) : bot_screen;
    } else {
        // Move the top screen to the right if we are swapped.
        res.top_screen = swapped ? top_screen.TranslateX(bot_screen.GetWidth()) : top_screen;
        res.bottom_screen = swapped ? bot_screen : bot_screen.TranslateX(top_screen.GetWidth());
    }
    return res;
}

FramebufferLayout SeparateWindowsLayout(u32 width, u32 height, bool is_secondary, bool upright) {
    // When is_secondary is true, we disable the top screen, and enable the bottom screen.
    // The same logic is found in the SingleFrameLayout using the is_swapped bool.
    is_secondary = Settings::values.swap_screen ? !is_secondary : is_secondary;
    return SingleFrameLayout(width, height, is_secondary, upright);
}

FramebufferLayout CustomFrameLayout(u32 width, u32 height, bool is_swapped) {
    ASSERT(width > 0);
    ASSERT(height > 0);

    FramebufferLayout res{width, height, true, true, {}, {}, !Settings::values.upright_screen};

    Common::Rectangle<u32> top_screen{Settings::values.custom_top_left.GetValue(),
                                      Settings::values.custom_top_top.GetValue(),
                                      Settings::values.custom_top_right.GetValue(),
                                      Settings::values.custom_top_bottom.GetValue()};
    Common::Rectangle<u32> bot_screen{Settings::values.custom_bottom_left.GetValue(),
                                      Settings::values.custom_bottom_top.GetValue(),
                                      Settings::values.custom_bottom_right.GetValue(),
                                      Settings::values.custom_bottom_bottom.GetValue()};

    if (is_swapped) {
        res.top_screen = bot_screen;
        res.bottom_screen = top_screen;
    } else {
        res.top_screen = top_screen;
        res.bottom_screen = bot_screen;
    }
    return res;
}

FramebufferLayout FrameLayoutFromResolutionScale(u32 res_scale, bool is_secondary) {
    FramebufferLayout layout;
    if (Settings::values.custom_layout.GetValue() == true) {
        layout = CustomFrameLayout(std::max(Settings::values.custom_top_right.GetValue(),
                                            Settings::values.custom_bottom_right.GetValue()),
                                   std::max(Settings::values.custom_top_bottom.GetValue(),
                                            Settings::values.custom_bottom_bottom.GetValue()),
                                   Settings::values.swap_screen.GetValue());
    } else {
        int width, height;
        switch (Settings::values.layout_option.GetValue()) {
        case Settings::LayoutOption::SingleScreen:
#ifndef ANDROID
        case Settings::LayoutOption::SeparateWindows:
#endif
        {
            const bool swap_screens = is_secondary || Settings::values.swap_screen.GetValue();
            if (Settings::values.upright_screen.GetValue()) {
                if (swap_screens) {
                    width = Core::kScreenBottomHeight * res_scale;
                    height = Core::kScreenBottomWidth * res_scale;
                } else {
                    width = Core::kScreenTopHeight * res_scale;
                    height = Core::kScreenTopWidth * res_scale;
                }
            } else {
                if (swap_screens) {
                    width = Core::kScreenBottomWidth * res_scale;
                    height = Core::kScreenBottomHeight * res_scale;
                } else {
                    width = Core::kScreenTopWidth * res_scale;
                    height = Core::kScreenTopHeight * res_scale;
                }
            }
            layout = SingleFrameLayout(width, height, swap_screens,
                                       Settings::values.upright_screen.GetValue());
            break;
        }
        case Settings::LayoutOption::LargeScreen:
            if (Settings::values.upright_screen.GetValue()) {
                if (Settings::values.swap_screen.GetValue()) {
                    width = Core::kScreenBottomHeight * res_scale;
                    height = (Core::kScreenBottomWidth + Core::kScreenTopWidth / 4) * res_scale;
                } else {
                    width = Core::kScreenTopHeight * res_scale;
                    height = (Core::kScreenTopWidth + Core::kScreenBottomWidth / 4) * res_scale;
                }
            } else {
                if (Settings::values.swap_screen.GetValue()) {
                    width = (Core::kScreenBottomWidth + Core::kScreenTopWidth / 4) * res_scale;
                    height = Core::kScreenBottomHeight * res_scale;
                } else {
                    width = (Core::kScreenTopWidth + Core::kScreenBottomWidth / 4) * res_scale;
                    height = Core::kScreenTopHeight * res_scale;
                }
            }
            layout = LargeFrameLayout(width, height, Settings::values.swap_screen.GetValue(),
                                      Settings::values.upright_screen.GetValue());
            break;
        case Settings::LayoutOption::SideScreen:
            if (Settings::values.upright_screen.GetValue()) {
                width = Core::kScreenTopHeight * res_scale;
                height = (Core::kScreenTopWidth + Core::kScreenBottomWidth) * res_scale;
            } else {
                width = (Core::kScreenTopWidth + Core::kScreenBottomWidth) * res_scale;
                height = Core::kScreenTopHeight * res_scale;
            }
            layout = SideFrameLayout(width, height, Settings::values.swap_screen.GetValue(),
                                     Settings::values.upright_screen.GetValue());
            break;
        case Settings::LayoutOption::MobilePortrait:
            width = Core::kScreenTopWidth * res_scale;
            height = (Core::kScreenTopHeight + Core::kScreenBottomHeight) * res_scale;
            layout =
                MobilePortraitFrameLayout(width, height, Settings::values.swap_screen.GetValue());
            break;
        case Settings::LayoutOption::MobileLandscape:
            if (Settings::values.swap_screen.GetValue()) {
                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.GetValue(), 2.25f, false);
            break;
        case Settings::LayoutOption::Default:
        default:
            if (Settings::values.upright_screen.GetValue()) {
                width = (Core::kScreenTopHeight + Core::kScreenBottomHeight) * res_scale;
                height = Core::kScreenTopWidth * res_scale;
            } else {
                width = Core::kScreenTopWidth * res_scale;
                height = (Core::kScreenTopHeight + Core::kScreenBottomHeight) * res_scale;
            }
            layout = DefaultFrameLayout(width, height, Settings::values.swap_screen.GetValue(),
                                        Settings::values.upright_screen.GetValue());
            break;
        }
    }
    if (Settings::values.render_3d.GetValue() == Settings::StereoRenderOption::CardboardVR) {
        layout = Layout::GetCardboardSettings(layout);
    }
    return layout;
}

FramebufferLayout GetCardboardSettings(FramebufferLayout layout) {
    FramebufferLayout newLayout = layout;
    float top_screen_left = 0;
    float top_screen_top = 0;
    float bottom_screen_left = 0;
    float bottom_screen_top = 0;

    float cardboardScreenScale = Settings::values.cardboard_screen_size.GetValue() / 100.0f;
    float top_screen_width = layout.top_screen.GetWidth() / 2.0f * cardboardScreenScale;
    float top_screen_height = layout.top_screen.GetHeight() / 2.0f * cardboardScreenScale;
    float bottom_screen_width = layout.bottom_screen.GetWidth() / 2.0f * cardboardScreenScale;
    float bottom_screen_height = layout.bottom_screen.GetHeight() / 2.0f * cardboardScreenScale;
    const bool is_swapped = Settings::values.swap_screen.GetValue();
    const bool is_portrait = layout.height > layout.width;

    float cardboardScreenWidth;
    float cardboardScreenHeight;
    switch (Settings::values.layout_option.GetValue()) {
    case Settings::LayoutOption::MobileLandscape:
    case Settings::LayoutOption::SideScreen:
        // If orientation is portrait, only use MobilePortrait
        if (!is_portrait) {
            cardboardScreenWidth = top_screen_width + bottom_screen_width;
            cardboardScreenHeight = is_swapped ? bottom_screen_height : top_screen_height;
            if (is_swapped)
                top_screen_left += bottom_screen_width;
            else
                bottom_screen_left += top_screen_width;
            break;
        } else {
            [[fallthrough]];
        }
    case Settings::LayoutOption::SingleScreen:
    default:
        if (!is_portrait) {
            // Default values when using LayoutOption::SingleScreen
            cardboardScreenWidth = is_swapped ? bottom_screen_width : top_screen_width;
            cardboardScreenHeight = is_swapped ? bottom_screen_height : top_screen_height;
            break;
        } else {
            [[fallthrough]];
        }
    case Settings::LayoutOption::MobilePortrait:
        cardboardScreenWidth = top_screen_width;
        cardboardScreenHeight = top_screen_height + bottom_screen_height;
        bottom_screen_left += (top_screen_width - bottom_screen_width) / 2.0f;
        if (is_swapped)
            top_screen_top += bottom_screen_height;
        else
            bottom_screen_top += top_screen_height;
        break;
    }
    float cardboardMaxXShift = (layout.width / 2.0f - cardboardScreenWidth) / 2.0f;
    float cardboardUserXShift =
        (Settings::values.cardboard_x_shift.GetValue() / 100.0f) * cardboardMaxXShift;
    float cardboardMaxYShift = ((float)layout.height - cardboardScreenHeight) / 2.0f;
    float cardboardUserYShift =
        (Settings::values.cardboard_y_shift.GetValue() / 100.0f) * cardboardMaxYShift;

    // Center the screens and apply user Y shift
    newLayout.top_screen.left = top_screen_left + cardboardMaxXShift;
    newLayout.top_screen.top = top_screen_top + cardboardMaxYShift + cardboardUserYShift;
    newLayout.bottom_screen.left = bottom_screen_left + cardboardMaxXShift;
    newLayout.bottom_screen.top = bottom_screen_top + cardboardMaxYShift + cardboardUserYShift;

    // Set the X coordinates for the right eye and apply user X shift
    newLayout.cardboard.top_screen_right_eye = newLayout.top_screen.left - cardboardUserXShift;
    newLayout.top_screen.left += cardboardUserXShift;
    newLayout.cardboard.bottom_screen_right_eye =
        newLayout.bottom_screen.left - cardboardUserXShift;
    newLayout.bottom_screen.left += cardboardUserXShift;
    newLayout.cardboard.user_x_shift = cardboardUserXShift;

    // Update right/bottom instead of passing new variables for width/height
    newLayout.top_screen.right = newLayout.top_screen.left + top_screen_width;
    newLayout.top_screen.bottom = newLayout.top_screen.top + top_screen_height;
    newLayout.bottom_screen.right = newLayout.bottom_screen.left + bottom_screen_width;
    newLayout.bottom_screen.bottom = newLayout.bottom_screen.top + bottom_screen_height;

    return newLayout;
}

std::pair<unsigned, unsigned> GetMinimumSizeFromLayout(Settings::LayoutOption layout,
                                                       bool upright_screen) {
    unsigned min_width, min_height;

    switch (layout) {
    case Settings::LayoutOption::SingleScreen:
#ifndef ANDROID
    case Settings::LayoutOption::SeparateWindows:
#endif
        min_width = Settings::values.swap_screen ? Core::kScreenBottomWidth : Core::kScreenTopWidth;
        min_height = Core::kScreenBottomHeight;
        break;
    case Settings::LayoutOption::LargeScreen:
        min_width = Settings::values.swap_screen
                        ? Core::kScreenTopWidth / 4 + Core::kScreenBottomWidth
                        : Core::kScreenTopWidth + Core::kScreenBottomWidth / 4;
        min_height = Core::kScreenBottomHeight;
        break;
    case Settings::LayoutOption::SideScreen:
        min_width = Core::kScreenTopWidth + Core::kScreenBottomWidth;
        min_height = Core::kScreenBottomHeight;
        break;
    case Settings::LayoutOption::Default:
    default:
        min_width = Core::kScreenTopWidth;
        min_height = Core::kScreenTopHeight + Core::kScreenBottomHeight;
        break;
    }
    if (upright_screen) {
        return std::make_pair(min_height, min_width);
    } else {
        return std::make_pair(min_width, min_height);
    }
}

} // namespace Layout