From e5c46a54b74bcdc8eb51618b8c2685ef0fb59a20 Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <stenzek@gmail.com>
Date: Thu, 6 Aug 2020 23:19:52 +1000
Subject: [PATCH] System: Restore/reset state on recreating GPU/updating
 settings

Fixes display corruption on RetroArch when switching renderers.
---
 src/core/host_interface.cpp | 6 ++++++
 src/core/system.cpp         | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/src/core/host_interface.cpp b/src/core/host_interface.cpp
index 6e945922c..2f9d6cdc6 100644
--- a/src/core/host_interface.cpp
+++ b/src/core/host_interface.cpp
@@ -487,7 +487,9 @@ void HostInterface::CheckForSettingsChanges(const Settings& old_settings)
         g_settings.display_crop_mode != old_settings.display_crop_mode ||
         g_settings.display_aspect_ratio != old_settings.display_aspect_ratio)
     {
+      g_gpu->RestoreGraphicsAPIState();
       g_gpu->UpdateSettings();
+      g_gpu->ResetGraphicsAPIState();
     }
 
     if (g_settings.gpu_pgxp_enable != old_settings.gpu_pgxp_enable ||
@@ -662,7 +664,11 @@ void HostInterface::ModifyResolutionScale(s32 increment)
                          GPU::VRAM_HEIGHT * g_settings.gpu_resolution_scale);
 
   if (!System::IsShutdown())
+  {
+    g_gpu->RestoreGraphicsAPIState();
     g_gpu->UpdateSettings();
+    g_gpu->ResetGraphicsAPIState();
+  }
 }
 
 void HostInterface::UpdateSoftwareCursor()
diff --git a/src/core/system.cpp b/src/core/system.cpp
index 661a26fa1..f1b40e436 100644
--- a/src/core/system.cpp
+++ b/src/core/system.cpp
@@ -222,6 +222,8 @@ ConsoleRegion GetConsoleRegionForDiscRegion(DiscRegion region)
 
 bool RecreateGPU(GPURenderer renderer)
 {
+  g_gpu->RestoreGraphicsAPIState();
+
   // save current state
   std::unique_ptr<ByteStream> state_stream = ByteStream_CreateGrowableMemoryStream();
   StateWrapper sw(state_stream.get(), StateWrapper::Mode::Write);
@@ -229,6 +231,8 @@ bool RecreateGPU(GPURenderer renderer)
   if (!state_valid)
     Log_ErrorPrintf("Failed to save old GPU state when switching renderers");
 
+  g_gpu->ResetGraphicsAPIState();
+
   // create new renderer
   g_gpu.reset();
   if (!CreateGPU(renderer))
@@ -241,8 +245,10 @@ bool RecreateGPU(GPURenderer renderer)
   {
     state_stream->SeekAbsolute(0);
     sw.SetMode(StateWrapper::Mode::Read);
+    g_gpu->RestoreGraphicsAPIState();
     g_gpu->DoState(sw);
     TimingEvents::DoState(sw, TimingEvents::GetGlobalTickCounter());
+    g_gpu->ResetGraphicsAPIState();
   }
 
   return true;