Add Cardboard VR

Based on hrydgard/ppsspp/pull/12449

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 @@ void EmuWindow::TouchPressed(unsigned framebuffer_x, unsigned framebuffer_y) {
     if (!IsWithinTouchscreen(framebuffer_layout, framebuffer_x, framebuffer_y))
         return;
 
-    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 =
@@ -191,6 +208,9 @@ 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 +40,14 @@ enum class MicInputType {
     Static,
 };
 
-enum class StereoRenderOption { Off, SideBySide, Anaglyph, Interlaced, ReverseInterlaced };
+enum class StereoRenderOption {
+    Off,
+    SideBySide,
+    Anaglyph,
+    Interlaced,
+    ReverseInterlaced,
+    CardboardVR
+};
 
 namespace NativeButton {
 enum Values {
@@ -190,6 +197,10 @@ 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;