Graphics: Adapt aspect ratio when SBS/TAB 3D is used

Adds support for choosing to present the full resolution
independently to each eye when using side-by-side or
top-and-bottom 3D.

1 files changed, 49 insertions, 21 deletions

diff --git a/Source/Core/VideoCommon/Present.cpp b/Source/Core/VideoCommon/Present.cpp
index 66d377acd7..c7ae018bbc 100644
--- a/Source/Core/VideoCommon/Present.cpp
+++ b/Source/Core/VideoCommon/Present.cpp
@@ -398,40 +398,68 @@ Presenter::ConvertStereoRectangle(const MathUtil::Rectangle<int>& rc) const
 float Presenter::CalculateDrawAspectRatio(bool allow_stretch) const
 {
   auto aspect_mode = g_ActiveConfig.aspect_mode;
+  float resulting_aspect_ratio;
 
   if (!allow_stretch && aspect_mode == AspectMode::Stretch)
     aspect_mode = AspectMode::Auto;
 
   // If stretch is enabled, we prefer the aspect ratio of the window.
   if (aspect_mode == AspectMode::Stretch)
-    return (static_cast<float>(m_backbuffer_width) / static_cast<float>(m_backbuffer_height));
-
-  // The actual aspect ratio of the XFB texture is irrelevant, the VI one is the one that matters
-  const auto& vi = Core::System::GetInstance().GetVideoInterface();
-  const float source_aspect_ratio = vi.GetAspectRatio();
-
-  // This will scale up the source ~4:3 resolution to its equivalent ~16:9 resolution
-  if (aspect_mode == AspectMode::ForceWide ||
-      (aspect_mode == AspectMode::Auto && g_widescreen->IsGameWidescreen()))
-  {
-    return SourceAspectRatioToWidescreen(source_aspect_ratio);
-  }
-  else if (aspect_mode == AspectMode::Custom)
   {
-    return source_aspect_ratio * (g_ActiveConfig.GetCustomAspectRatio() / (4.0f / 3.0f));
+    resulting_aspect_ratio =
+        (static_cast<float>(m_backbuffer_width) / static_cast<float>(m_backbuffer_height));
   }
-  // For the "custom stretch" mode, we force the exact target aspect ratio, without
-  // acknowleding the difference between the source aspect ratio and 4:3.
-  else if (aspect_mode == AspectMode::CustomStretch)
+  else
   {
-    return g_ActiveConfig.GetCustomAspectRatio();
+    // The actual aspect ratio of the XFB texture is irrelevant, the VI one is the one that matters
+    const auto& vi = Core::System::GetInstance().GetVideoInterface();
+    const float source_aspect_ratio = vi.GetAspectRatio();
+
+    // This will scale up the source ~4:3 resolution to its equivalent ~16:9 resolution
+    if (aspect_mode == AspectMode::ForceWide ||
+        (aspect_mode == AspectMode::Auto && g_widescreen->IsGameWidescreen()))
+    {
+      resulting_aspect_ratio = SourceAspectRatioToWidescreen(source_aspect_ratio);
+    }
+    else if (aspect_mode == AspectMode::Custom)
+    {
+      resulting_aspect_ratio =
+          source_aspect_ratio * (g_ActiveConfig.GetCustomAspectRatio() / (4.0f / 3.0f));
+    }
+    // For the "custom stretch" mode, we force the exact target aspect ratio, without
+    // acknowledging the difference between the source aspect ratio and 4:3.
+    else if (aspect_mode == AspectMode::CustomStretch)
+    {
+      resulting_aspect_ratio = g_ActiveConfig.GetCustomAspectRatio();
+    }
+    else if (aspect_mode == AspectMode::Raw)
+    {
+      resulting_aspect_ratio =
+          m_xfb_entry ? (static_cast<float>(m_last_xfb_width) / m_last_xfb_height) : 1.f;
+    }
+    else
+    {
+      resulting_aspect_ratio = source_aspect_ratio;
+    }
   }
-  else if (aspect_mode == AspectMode::Raw)
+
+  if (g_ActiveConfig.stereo_per_eye_resolution_full)
   {
-    return m_xfb_entry ? (static_cast<float>(m_last_xfb_width) / m_last_xfb_height) : 1.f;
+    if (g_ActiveConfig.stereo_mode == StereoMode::SBS)
+    {
+      // Render twice as wide if using side-by-side 3D, since the 3D will halve the horizontal
+      // resolution
+      resulting_aspect_ratio *= 2.0;
+    }
+    else if (g_ActiveConfig.stereo_mode == StereoMode::TAB)
+    {
+      // Render twice as tall if using top-and-bottom 3D, since the 3D will halve the vertical
+      // resolution
+      resulting_aspect_ratio /= 2.0;
+    }
   }
 
-  return source_aspect_ratio;
+  return resulting_aspect_ratio;
 }
 
 void Presenter::AdjustRectanglesToFitBounds(MathUtil::Rectangle<int>* target_rect,