From 8acca62755ccf0bdfed7370031251b449ced4fbc Mon Sep 17 00:00:00 2001
From: Jonah Williams <jonahwilliams@google.com>
Date: Wed, 28 Feb 2024 12:33:51 -0800
Subject: [PATCH] [Impeller] fix render pass depth descriptor.
 (flutter/engine#51031)

Depth+stencil should be treated as the same attachment. Adding more than one d/s attachment in the render pass descriptor seems to be confusing swiftshader.

@bdero

This fixes things for me locally, lets let CI take a spin
---
 .../src/flutter/impeller/entity/inline_pass_context.cc |  9 ++++++---
 .../impeller/renderer/backend/vulkan/context_vk.cc     |  6 ++----
 .../impeller/renderer/backend/vulkan/pipeline_vk.cc    |  4 +---
 .../impeller/renderer/backend/vulkan/render_pass_vk.cc | 10 +++-------
 4 files changed, 12 insertions(+), 17 deletions(-)

diff --git a/engine/src/flutter/impeller/entity/inline_pass_context.cc b/engine/src/flutter/impeller/entity/inline_pass_context.cc
index 7fcaf515ad3..d39d41394fe 100644
--- a/engine/src/flutter/impeller/entity/inline_pass_context.cc
+++ b/engine/src/flutter/impeller/entity/inline_pass_context.cc
@@ -158,15 +158,18 @@ InlinePassContext::RenderPassResult InlinePassContext::GetRenderPass(
     pass_target_.target_.SetDepthAttachment(depth.value());
   }
 
+  auto depth = pass_target_.GetRenderTarget().GetDepthAttachment();
   auto stencil = pass_target_.GetRenderTarget().GetStencilAttachment();
-  if (!stencil.has_value()) {
-    VALIDATION_LOG << "Stencil attachment unexpectedly missing from the "
+  if (!depth.has_value() || !stencil.has_value()) {
+    VALIDATION_LOG << "Stencil/Depth attachment unexpectedly missing from the "
                       "EntityPass render target.";
     return {};
   }
-
   stencil->load_action = LoadAction::kClear;
   stencil->store_action = StoreAction::kDontCare;
+  depth->load_action = LoadAction::kClear;
+  depth->store_action = StoreAction::kDontCare;
+  pass_target_.target_.SetDepthAttachment(depth);
   pass_target_.target_.SetStencilAttachment(stencil.value());
   pass_target_.target_.SetColorAttachment(color0, 0);
 
diff --git a/engine/src/flutter/impeller/renderer/backend/vulkan/context_vk.cc b/engine/src/flutter/impeller/renderer/backend/vulkan/context_vk.cc
index d8fde32f375..4fdde323fb3 100644
--- a/engine/src/flutter/impeller/renderer/backend/vulkan/context_vk.cc
+++ b/engine/src/flutter/impeller/renderer/backend/vulkan/context_vk.cc
@@ -600,10 +600,8 @@ void ContextVK::InitializeCommonlyUsedShadersIfNeeded() const {
         depth->load_action,                                   //
         depth->store_action                                   //
     );
-  }
-
-  if (auto stencil = render_target.GetStencilAttachment();
-      stencil.has_value()) {
+  } else if (auto stencil = render_target.GetStencilAttachment();
+             stencil.has_value()) {
     builder.SetStencilAttachment(
         stencil->texture->GetTextureDescriptor().format,        //
         stencil->texture->GetTextureDescriptor().sample_count,  //
diff --git a/engine/src/flutter/impeller/renderer/backend/vulkan/pipeline_vk.cc b/engine/src/flutter/impeller/renderer/backend/vulkan/pipeline_vk.cc
index 497fa2c3032..13c13ab337a 100644
--- a/engine/src/flutter/impeller/renderer/backend/vulkan/pipeline_vk.cc
+++ b/engine/src/flutter/impeller/renderer/backend/vulkan/pipeline_vk.cc
@@ -142,9 +142,7 @@ static vk::UniqueRenderPass CreateCompatRenderPassForPipeline(
                                       LoadAction::kDontCare,       //
                                       StoreAction::kDontCare       //
     );
-  }
-
-  if (desc.HasStencilAttachmentDescriptors()) {
+  } else if (desc.HasStencilAttachmentDescriptors()) {
     builder.SetStencilAttachment(desc.GetStencilPixelFormat(),  //
                                  desc.GetSampleCount(),         //
                                  LoadAction::kDontCare,         //
diff --git a/engine/src/flutter/impeller/renderer/backend/vulkan/render_pass_vk.cc b/engine/src/flutter/impeller/renderer/backend/vulkan/render_pass_vk.cc
index b2f8bde4c11..7c049814b21 100644
--- a/engine/src/flutter/impeller/renderer/backend/vulkan/render_pass_vk.cc
+++ b/engine/src/flutter/impeller/renderer/backend/vulkan/render_pass_vk.cc
@@ -68,9 +68,7 @@ static std::vector<vk::ClearValue> GetVKClearValues(
   if (depth.has_value()) {
     clears.emplace_back(VKClearValueFromDepthStencil(
         stencil ? stencil->clear_stencil : 0u, depth->clear_depth));
-  }
-
-  if (stencil.has_value()) {
+  } else if (stencil.has_value()) {
     clears.emplace_back(VKClearValueFromDepthStencil(
         stencil->clear_stencil, depth ? depth->clear_depth : 0.0f));
   }
@@ -116,10 +114,8 @@ SharedHandleVK<vk::RenderPass> RenderPassVK::CreateVKRenderPass(
         depth->store_action                                   //
     );
     TextureVK::Cast(*depth->texture).SetLayout(barrier);
-  }
-
-  if (auto stencil = render_target_.GetStencilAttachment();
-      stencil.has_value()) {
+  } else if (auto stencil = render_target_.GetStencilAttachment();
+             stencil.has_value()) {
     builder.SetStencilAttachment(
         stencil->texture->GetTextureDescriptor().format,        //
         stencil->texture->GetTextureDescriptor().sample_count,  //