From a13f09433c87ace659d0e8edf713013d46e203e5 Mon Sep 17 00:00:00 2001
From: TellowKrinkle <tellowkrinkle@gmail.com>
Date: Sat, 30 Jul 2022 01:32:55 -0500
Subject: [PATCH] VideoBackends:Metal: Add config option to use presentDrawable

---
 Source/Core/Core/Config/GraphicsSettings.cpp   |  2 ++
 Source/Core/Core/Config/GraphicsSettings.h     |  1 +
 Source/Core/VideoBackends/Metal/MTLRenderer.mm | 11 +++++++++--
 Source/Core/VideoCommon/VideoConfig.cpp        |  1 +
 Source/Core/VideoCommon/VideoConfig.h          |  1 +
 5 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/Source/Core/Core/Config/GraphicsSettings.cpp b/Source/Core/Core/Config/GraphicsSettings.cpp
index 204a7fc82a..5bc9599784 100644
--- a/Source/Core/Core/Config/GraphicsSettings.cpp
+++ b/Source/Core/Core/Config/GraphicsSettings.cpp
@@ -94,6 +94,8 @@ const Info<bool> GFX_SAVE_TEXTURE_CACHE_TO_STATE{
 
 const Info<TriState> GFX_MTL_MANUALLY_UPLOAD_BUFFERS{
     {System::GFX, "Settings", "ManuallyUploadBuffers"}, TriState::Auto};
+const Info<bool> GFX_MTL_USE_PRESENT_DRAWABLE{{System::GFX, "Settings", "MTLUsePresentDrawable"},
+                                              false};
 
 const Info<bool> GFX_SW_DUMP_OBJECTS{{System::GFX, "Settings", "SWDumpObjects"}, false};
 const Info<bool> GFX_SW_DUMP_TEV_STAGES{{System::GFX, "Settings", "SWDumpTevStages"}, false};
diff --git a/Source/Core/Core/Config/GraphicsSettings.h b/Source/Core/Core/Config/GraphicsSettings.h
index b91f985289..4bdbb3b690 100644
--- a/Source/Core/Core/Config/GraphicsSettings.h
+++ b/Source/Core/Core/Config/GraphicsSettings.h
@@ -76,6 +76,7 @@ extern const Info<int> GFX_SHADER_PRECOMPILER_THREADS;
 extern const Info<bool> GFX_SAVE_TEXTURE_CACHE_TO_STATE;
 
 extern const Info<TriState> GFX_MTL_MANUALLY_UPLOAD_BUFFERS;
+extern const Info<bool> GFX_MTL_USE_PRESENT_DRAWABLE;
 
 extern const Info<bool> GFX_SW_DUMP_OBJECTS;
 extern const Info<bool> GFX_SW_DUMP_TEV_STAGES;
diff --git a/Source/Core/VideoBackends/Metal/MTLRenderer.mm b/Source/Core/VideoBackends/Metal/MTLRenderer.mm
index dba0c58d22..7d6c583599 100644
--- a/Source/Core/VideoBackends/Metal/MTLRenderer.mm
+++ b/Source/Core/VideoBackends/Metal/MTLRenderer.mm
@@ -455,8 +455,15 @@ void Metal::Renderer::PresentBackbuffer()
     g_state_tracker->EndRenderPass();
     if (m_drawable)
     {
-      [g_state_tracker->GetRenderCmdBuf()
-          addScheduledHandler:[drawable = std::move(m_drawable)](id) { [drawable present]; }];
+      // PresentDrawable refuses to allow Dolphin to present faster than the display's refresh rate
+      // when windowed (or fullscreen with vsync enabled, but that's more understandable).
+      // On the other hand, it helps Xcode's GPU captures start and stop on frame boundaries
+      // which is convenient.  Put it here as a default-off config, which we can override in Xcode.
+      if (g_ActiveConfig.bUsePresentDrawable)
+        [g_state_tracker->GetRenderCmdBuf() presentDrawable:m_drawable];
+      else
+        [g_state_tracker->GetRenderCmdBuf()
+            addScheduledHandler:[drawable = std::move(m_drawable)](id) { [drawable present]; }];
       m_bb_texture->SetMTLTexture(nullptr);
       m_drawable = nullptr;
     }
diff --git a/Source/Core/VideoCommon/VideoConfig.cpp b/Source/Core/VideoCommon/VideoConfig.cpp
index 845a59f05c..2411dca4f7 100644
--- a/Source/Core/VideoCommon/VideoConfig.cpp
+++ b/Source/Core/VideoCommon/VideoConfig.cpp
@@ -56,6 +56,7 @@ void VideoConfig::Refresh()
   bVSync = Config::Get(Config::GFX_VSYNC);
   iAdapter = Config::Get(Config::GFX_ADAPTER);
   iManuallyUploadBuffers = Config::Get(Config::GFX_MTL_MANUALLY_UPLOAD_BUFFERS);
+  bUsePresentDrawable = Config::Get(Config::GFX_MTL_USE_PRESENT_DRAWABLE);
 
   bWidescreenHack = Config::Get(Config::GFX_WIDESCREEN_HACK);
   aspect_mode = Config::Get(Config::GFX_ASPECT_RATIO);
diff --git a/Source/Core/VideoCommon/VideoConfig.h b/Source/Core/VideoCommon/VideoConfig.h
index f7477d6d3d..9664ad473c 100644
--- a/Source/Core/VideoCommon/VideoConfig.h
+++ b/Source/Core/VideoCommon/VideoConfig.h
@@ -157,6 +157,7 @@ struct VideoConfig final
 
   // Metal only config
   TriState iManuallyUploadBuffers = TriState::Auto;
+  bool bUsePresentDrawable = false;
 
   // Enable API validation layers, currently only supported with Vulkan.
   bool bEnableValidationLayer = false;