Add Cardboard VR

Based on hrydgard/ppsspp/pull/12449

src/android/app/src/main/java/org/citra/citra_emu/features/settings/ui/SettingsFragmentPresenter.java

@@ -358,6 +358,11 @@ private void addGraphicsSettings(ArrayList<SettingsItem> sl) {
         Setting render3dMode = rendererSection.getSetting(SettingsFile.KEY_RENDER_3D);
         Setting factor3d = rendererSection.getSetting(SettingsFile.KEY_FACTOR_3D);
 
+        SettingSection layoutSection = mSettings.getSection(Settings.SECTION_LAYOUT);
+        Setting cardboardScreenSize = layoutSection.getSetting(SettingsFile.KEY_CARDBOARD_SCREEN_SIZE);
+        Setting cardboardXShift = layoutSection.getSetting(SettingsFile.KEY_CARDBOARD_X_SHIFT);
+        Setting cardboardYShift = layoutSection.getSetting(SettingsFile.KEY_CARDBOARD_Y_SHIFT);
+
         sl.add(new HeaderSetting(null, null, R.string.renderer, 0));
         sl.add(new SliderSetting(SettingsFile.KEY_RESOLUTION_FACTOR, Settings.SECTION_RENDERER, R.string.internal_resolution, R.string.internal_resolution_description, 1, 4, "x", 1, resolutionFactor));
         sl.add(new CheckBoxSetting(SettingsFile.KEY_FILTER_MODE, Settings.SECTION_RENDERER, R.string.linear_filtering, R.string.linear_filtering_description, true, filterMode));
@@ -367,6 +372,11 @@ private void addGraphicsSettings(ArrayList<SettingsItem> sl) {
         sl.add(new HeaderSetting(null, null, R.string.stereoscopy, 0));
         sl.add(new SingleChoiceSetting(SettingsFile.KEY_RENDER_3D, Settings.SECTION_RENDERER, R.string.render3d, 0, R.array.render3dModes, R.array.render3dValues, 0, render3dMode));
         sl.add(new SliderSetting(SettingsFile.KEY_FACTOR_3D, Settings.SECTION_RENDERER, R.string.factor3d, R.string.factor3d_description, 0, 100, "%", 0, factor3d));
+
+        sl.add(new HeaderSetting(null, null, R.string.cardboard_vr, 0));
+        sl.add(new SliderSetting(SettingsFile.KEY_CARDBOARD_SCREEN_SIZE, Settings.SECTION_LAYOUT, R.string.cardboard_screen_size, R.string.cardboard_screen_size_description, 30, 100, "%", 85, cardboardScreenSize));
+        sl.add(new SliderSetting(SettingsFile.KEY_CARDBOARD_X_SHIFT, Settings.SECTION_LAYOUT, R.string.cardboard_x_shift, R.string.cardboard_x_shift_description, -100, 100, "%", 0, cardboardXShift));
+        sl.add(new SliderSetting(SettingsFile.KEY_CARDBOARD_Y_SHIFT, Settings.SECTION_LAYOUT, R.string.cardboard_y_shift, R.string.cardboard_y_shift_description, -100, 100, "%", 0, cardboardYShift));
     }
 
     private void addAudioSettings(ArrayList<SettingsItem> sl) {

src/android/app/src/main/java/org/citra/citra_emu/features/settings/utils/SettingsFile.java

@@ -59,6 +59,9 @@ public final class SettingsFile {
 
     public static final String KEY_LAYOUT_OPTION = "layout_option";
     public static final String KEY_SWAP_SCREEN = "swap_screen";
+    public static final String KEY_CARDBOARD_SCREEN_SIZE = "cardboard_screen_size";
+    public static final String KEY_CARDBOARD_X_SHIFT = "cardboard_x_shift";
+    public static final String KEY_CARDBOARD_Y_SHIFT = "cardboard_y_shift";
 
     public static final String KEY_AUDIO_OUTPUT_ENGINE = "output_engine";
     public static final String KEY_ENABLE_AUDIO_STRETCHING = "enable_audio_stretching";

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

@@ -166,6 +166,12 @@ void Config::ReadValues() {
         static_cast<u16>(sdl2_config->GetInteger("Layout", "custom_bottom_right", 360));
     Settings::values.custom_bottom_bottom =
         static_cast<u16>(sdl2_config->GetInteger("Layout", "custom_bottom_bottom", 480));
+    Settings::values.cardboard_screen_size =
+            static_cast<int>(sdl2_config->GetInteger("Layout", "cardboard_screen_size", 85));
+    Settings::values.cardboard_x_shift =
+            static_cast<int>(sdl2_config->GetInteger("Layout", "cardboard_x_shift", 0));
+    Settings::values.cardboard_y_shift =
+            static_cast<int>(sdl2_config->GetInteger("Layout", "cardboard_y_shift", 0));
 
     // Audio
     Settings::values.enable_dsp_lle = sdl2_config->GetBoolean("Audio", "enable_dsp_lle", false);

src/android/app/src/main/jni/default_ini.h

@@ -140,7 +140,7 @@ bg_blue =
 bg_green =
 
 # Whether and how Stereoscopic 3D should be rendered
-# 0 (default): Off, 1: Side by Side, 2: Anaglyph, 3: Interlaced
+# 0 (default): Off, 1: Side by Side, 2: Anaglyph, 3: Interlaced, 4: Reverse Interlaced, 5: Cardboard VR
 render_3d =
 
 # Change 3D Intensity
@@ -182,6 +182,14 @@ custom_bottom_bottom =
 # 0 (default): Top Screen is prominent, 1: Bottom Screen is prominent
 swap_screen =
 
+# Screen placement settings when using Cardboard VR (render3d = 4)
+# 30 - 100: Screen size as a percentage of the viewport. 85 (default)
+cardboard_screen_size =
+# -100 - 100: Screen X-Coordinate shift as a percentage of empty space. 0 (default)
+cardboard_x_shift =
+# -100 - 100: Screen Y-Coordinate shift as a percentage of empty space. 0 (default)
+cardboard_y_shift =
+
 [Audio]
 # Whether or not to enable DSP LLE
 # 0 (default): No, 1: Yes

src/android/app/src/main/res/values/arrays.xml

@@ -159,12 +159,16 @@
         <item>Side by Side</item>
         <item>Anaglyph</item>
         <item>Interlaced</item>
+        <item>Reverse Interlaced</item>
+        <item>Cardboard VR</item>
     </string-array>
 
     <integer-array name="render3dValues">
         <item>0</item>
         <item>1</item>
         <item>2</item>
         <item>3</item>
+        <item>4</item>
+        <item>5</item>
     </integer-array>
 </resources>

src/android/app/src/main/res/values/strings.xml

@@ -93,6 +93,13 @@
     <string name="render3d">Stereoscopic 3D Mode</string>
     <string name="factor3d">Depth</string>
     <string name="factor3d_description">Specifies the value of the 3D slider. This should be set to higher than 0% when Stereoscopic 3D is enabled.</string>
+    <string name="cardboard_vr">Cardboard VR</string>
+    <string name="cardboard_screen_size">Cardboard Screen size</string>
+    <string name="cardboard_screen_size_description">Scales the screen to a percentage of its original size.</string>
+    <string name="cardboard_x_shift">Horizontal shift</string>
+    <string name="cardboard_x_shift_description">Specifies the percentage of empty space to shift the screens horizontally. Positive values move the two eyes closer to the middle, while negative values move them away.</string>
+    <string name="cardboard_y_shift">Vertical shift</string>
+    <string name="cardboard_y_shift_description">Specifies the percentage of empty space to shift the screens vertically. Positive values move the two eyes towards the bottom, while negative values move them towards the top.</string>
 
     <!-- Premium strings -->
     <string name="premium_text">Premium</string>

src/core/frontend/emu_window.cpp

@@ -73,6 +73,14 @@ static bool IsWithinTouchscreen(const Layout::FramebufferLayout& layout, unsigne
                   framebuffer_x < layout.bottom_screen.right / 2) ||
                  (framebuffer_x >= (layout.bottom_screen.left / 2) + (layout.width / 2) &&
                   framebuffer_x < (layout.bottom_screen.right / 2) + (layout.width / 2))));
+    } else if (Settings::values.render_3d == Settings::StereoRenderOption::CardboardVR) {
+        return (framebuffer_y >= layout.bottom_screen.top &&
+                framebuffer_y < layout.bottom_screen.bottom &&
+                ((framebuffer_x >= layout.bottom_screen.left &&
+                  framebuffer_x < layout.bottom_screen.right) ||
+                 (framebuffer_x >= layout.cardboard.bottom_screen_right_eye + (layout.width / 2) &&
+                  framebuffer_x < layout.cardboard.bottom_screen_right_eye +
+                                  layout.bottom_screen.GetWidth() + (layout.width / 2))));
     } else {
         return (framebuffer_y >= layout.bottom_screen.top &&
                 framebuffer_y < layout.bottom_screen.bottom &&
@@ -82,9 +90,14 @@ static bool IsWithinTouchscreen(const Layout::FramebufferLayout& layout, unsigne
 }
 
 std::tuple<unsigned, unsigned> EmuWindow::ClipToTouchScreen(unsigned new_x, unsigned new_y) const {
-    if (Settings::values.render_3d == Settings::StereoRenderOption::SideBySide) {
-        if (new_x >= framebuffer_layout.width / 2)
+    if (new_x >= framebuffer_layout.width / 2) {
+        if (Settings::values.render_3d == Settings::StereoRenderOption::SideBySide)
             new_x -= framebuffer_layout.width / 2;
+        else if (Settings::values.render_3d == Settings::StereoRenderOption::CardboardVR)
+            new_x -= (framebuffer_layout.width / 2) -
+                     (framebuffer_layout.cardboard.user_x_shift * 2);
+    }
+    if (Settings::values.render_3d == Settings::StereoRenderOption::SideBySide) {
         new_x = std::max(new_x, framebuffer_layout.bottom_screen.left / 2);
         new_x = std::min(new_x, framebuffer_layout.bottom_screen.right / 2 - 1);
     } else {
@@ -102,9 +115,13 @@ bool EmuWindow::TouchPressed(unsigned framebuffer_x, unsigned framebuffer_y) {
     if (!IsWithinTouchscreen(framebuffer_layout, framebuffer_x, framebuffer_y))
         return false;
 
-    if (Settings::values.render_3d == Settings::StereoRenderOption::SideBySide &&
-        framebuffer_x >= framebuffer_layout.width / 2)
-        framebuffer_x -= framebuffer_layout.width / 2;
+    if (framebuffer_x >= framebuffer_layout.width / 2) {
+        if (Settings::values.render_3d == Settings::StereoRenderOption::SideBySide)
+            framebuffer_x -= framebuffer_layout.width / 2;
+        else if (Settings::values.render_3d == Settings::StereoRenderOption::CardboardVR)
+            framebuffer_x -= (framebuffer_layout.width / 2) -
+                             (framebuffer_layout.cardboard.user_x_shift * 2);
+    }
     std::lock_guard guard(touch_state->mutex);
     if (Settings::values.render_3d == Settings::StereoRenderOption::SideBySide) {
         touch_state->touch_x =
@@ -192,6 +209,9 @@ void EmuWindow::UpdateCurrentFramebufferLayout(unsigned width, unsigned height,
         }
         UpdateMinimumWindowSize(min_size);
     }
+    if (Settings::values.render_3d == Settings::StereoRenderOption::CardboardVR) {
+        layout = Layout::GetCardboardSettings(layout);
+    }
     NotifyFramebufferLayoutChanged(layout);
 }
 

src/core/frontend/framebuffer_layout.cpp

@@ -452,9 +452,92 @@ FramebufferLayout FrameLayoutFromResolutionScale(u32 res_scale) {
             break;
         }
     }
+    if (Settings::values.render_3d == 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 / 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;
+    bool is_swapped = Settings::values.swap_screen;
+    bool is_portrait = layout.height > layout.width;
+
+    float cardboardScreenWidth;
+    float cardboardScreenHeight;
+    switch(Settings::values.layout_option) {
+        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 / 100.0f) * cardboardMaxXShift;
+    float cardboardMaxYShift = ((float)layout.height - cardboardScreenHeight) / 2.0f;
+    float cardboardUserYShift = (Settings::values.cardboard_y_shift / 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;

src/core/frontend/framebuffer_layout.h

@@ -9,6 +9,13 @@
 
 namespace Layout {
 
+/// Describes the horizontal coordinates for the right eye screen when using Cardboard VR
+struct CardboardSettings {
+    float top_screen_right_eye;
+    float bottom_screen_right_eye;
+    float user_x_shift;
+};
+
 /// Describes the layout of the window framebuffer (size and top/bottom screen positions)
 struct FramebufferLayout {
     u32 width;
@@ -19,6 +26,8 @@ struct FramebufferLayout {
     Common::Rectangle<u32> bottom_screen;
     bool is_rotated = true;
 
+    CardboardSettings cardboard;
+
     /**
      * Returns the ration of pixel size of the top screen, compared to the native size of the 3DS
      * screen.
@@ -104,6 +113,13 @@ FramebufferLayout CustomFrameLayout(u32 width, u32 height);
  */
 FramebufferLayout FrameLayoutFromResolutionScale(u32 res_scale);
 
+/**
+ * Convenience method for transforming a frame layout when using Cardboard VR
+ * @param layout frame layout to transform
+ * @return layout transformed with the user cardboard settings
+ */
+FramebufferLayout GetCardboardSettings(FramebufferLayout layout);
+
 std::pair<unsigned, unsigned> GetMinimumSizeFromLayout(Settings::LayoutOption layout,
                                                        bool upright_screen);
 

src/core/settings.h

@@ -40,7 +40,7 @@ enum class MicInputType {
     Static,
 };
 
-enum class StereoRenderOption { Off, SideBySide, Anaglyph, Interlaced, ReverseInterlaced };
+enum class StereoRenderOption { Off, SideBySide, Anaglyph, Interlaced, ReverseInterlaced, CardboardVR };
 
 enum class GpuTimingMode {
     Skip,
@@ -209,6 +209,10 @@ struct Values {
     StereoRenderOption render_3d;
     std::atomic<u8> factor_3d;
 
+    int cardboard_screen_size;
+    int cardboard_x_shift;
+    int cardboard_y_shift;
+
     bool filter_mode;
     std::string pp_shader_name;