From 76600f8cb3efeb001e8d44164ed4e08925913c96 Mon Sep 17 00:00:00 2001
From: Brandon DeRosier <bdero@google.com>
Date: Sun, 19 Mar 2023 23:37:45 -0700
Subject: [PATCH] [Impeller] Load instead of restore drawing for non-MSAA
 passes (flutter/engine#40436)

[Impeller] Load instead of restore drawing for non-MSAA passes
---
 .../flutter/impeller/entity/inline_pass_context.cc  | 13 ++++++++++---
 .../flutter/impeller/entity/inline_pass_context.h   |  1 +
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/engine/src/flutter/impeller/entity/inline_pass_context.cc b/engine/src/flutter/impeller/entity/inline_pass_context.cc
index c29bb2b4ea8..b4437a7bd64 100644
--- a/engine/src/flutter/impeller/entity/inline_pass_context.cc
+++ b/engine/src/flutter/impeller/entity/inline_pass_context.cc
@@ -100,7 +100,10 @@ InlinePassContext::RenderPassResult InlinePassContext::GetRenderPass(
 
   RenderPassResult result;
 
-  if (pass_count_ > 0) {
+  if (pass_count_ > 0 && pass_target_.GetRenderTarget()
+                             .GetColorAttachments()
+                             .find(0)
+                             ->second.resolve_texture) {
     result.backdrop_texture =
         pass_target_.Flip(*context_->GetResourceAllocator());
     if (!result.backdrop_texture) {
@@ -111,8 +114,12 @@ InlinePassContext::RenderPassResult InlinePassContext::GetRenderPass(
   auto color0 =
       pass_target_.GetRenderTarget().GetColorAttachments().find(0)->second;
 
-  color0.load_action =
-      pass_count_ > 0 ? LoadAction::kDontCare : LoadAction::kClear;
+  if (pass_count_ > 0) {
+    color0.load_action =
+        color0.resolve_texture ? LoadAction::kDontCare : LoadAction::kLoad;
+  } else {
+    color0.load_action = LoadAction::kClear;
+  }
 
   color0.store_action = color0.resolve_texture
                             ? StoreAction::kMultisampleResolve
diff --git a/engine/src/flutter/impeller/entity/inline_pass_context.h b/engine/src/flutter/impeller/entity/inline_pass_context.h
index f35c1fc4477..00ce649204b 100644
--- a/engine/src/flutter/impeller/entity/inline_pass_context.h
+++ b/engine/src/flutter/impeller/entity/inline_pass_context.h
@@ -15,6 +15,7 @@ class InlinePassContext {
  public:
   struct RenderPassResult {
     std::shared_ptr<RenderPass> pass;
+
     std::shared_ptr<Texture> backdrop_texture;
   };