From 8d1596286298e5e613c45957bc0f574ebdcad362 Mon Sep 17 00:00:00 2001
From: Brandon DeRosier <bdero@google.com>
Date: Mon, 27 Mar 2023 21:52:43 -0700
Subject: [PATCH] [Impeller] Fix EntityPass target flip

---
 impeller/aiks/aiks_unittests.cc                |  4 ----
 .../display_list/display_list_unittests.cc     |  4 ----
 impeller/entity/entity_pass_target.cc          | 18 ++++++++++++++----
 3 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/impeller/aiks/aiks_unittests.cc b/impeller/aiks/aiks_unittests.cc
index 2eba6cd0ef729..5d57191585d8a 100644
--- a/impeller/aiks/aiks_unittests.cc
+++ b/impeller/aiks/aiks_unittests.cc
@@ -1823,10 +1823,6 @@ TEST_P(AiksTest, SiblingSaveLayerBoundsAreRespected) {
 }
 
 TEST_P(AiksTest, CanRenderClippedLayers) {
-  if (GetBackend() == PlaygroundBackend::kVulkan) {
-    GTEST_SKIP_("Temporarily disabled.");
-  }
-
   Canvas canvas;
 
   canvas.DrawPaint({.color = Color::White()});
diff --git a/impeller/display_list/display_list_unittests.cc b/impeller/display_list/display_list_unittests.cc
index 03f176fab41d1..ca2930eaf7080 100644
--- a/impeller/display_list/display_list_unittests.cc
+++ b/impeller/display_list/display_list_unittests.cc
@@ -679,10 +679,6 @@ TEST_P(DisplayListTest, SaveLayerWithBlendFiltersAndAlphaDrawCorrectly) {
 }
 
 TEST_P(DisplayListTest, CanDrawBackdropFilter) {
-  if (GetBackend() == PlaygroundBackend::kVulkan) {
-    GTEST_SKIP_("Temporarily disabled.");
-  }
-
   auto texture = CreateTextureForFixture("embarcadero.jpg");
 
   auto callback = [&]() {
diff --git a/impeller/entity/entity_pass_target.cc b/impeller/entity/entity_pass_target.cc
index a67345ad50893..af6a042c1f024 100644
--- a/impeller/entity/entity_pass_target.cc
+++ b/impeller/entity/entity_pass_target.cc
@@ -4,6 +4,8 @@
 
 #include "impeller/entity/entity_pass_target.h"
 
+#include "impeller/base/validation.h"
+#include "impeller/renderer/formats.h"
 #include "impeller/renderer/texture.h"
 
 namespace impeller {
@@ -15,8 +17,16 @@ EntityPassTarget::EntityPassTarget(const RenderTarget& render_target,
 
 std::shared_ptr<Texture> EntityPassTarget::Flip(Allocator& allocator) {
   auto color0 = target_.GetColorAttachments().find(0)->second;
+  if (!color0.resolve_texture) {
+    VALIDATION_LOG << "EntityPassTarget Flip should never be called for a "
+                      "non-MSAA target.";
+    // ...because there is never a circumstance where doing so would be
+    // necessary. Unlike MSAA passes, non-MSAA passes can be trivially loaded
+    // with `LoadAction::kLoad`.
+    return color0.texture;
+  }
 
-  if (supports_read_from_resolve_ && color0.resolve_texture) {
+  if (supports_read_from_resolve_) {
     // Just return the current resolve texture, which is safe to read in the
     // next render pass that'll resolve to `target_`.
     //
@@ -26,7 +36,8 @@ std::shared_ptr<Texture> EntityPassTarget::Flip(Allocator& allocator) {
 
   if (!secondary_color_texture_) {
     // The second texture is allocated lazily to avoid unused allocations.
-    TextureDescriptor new_descriptor = color0.texture->GetTextureDescriptor();
+    TextureDescriptor new_descriptor =
+        color0.resolve_texture->GetTextureDescriptor();
     secondary_color_texture_ = allocator.CreateTexture(new_descriptor);
 
     if (!secondary_color_texture_) {
@@ -34,8 +45,7 @@ std::shared_ptr<Texture> EntityPassTarget::Flip(Allocator& allocator) {
     }
   }
 
-  std::swap(color0.resolve_texture ? color0.resolve_texture : color0.texture,
-            secondary_color_texture_);
+  std::swap(color0.resolve_texture, secondary_color_texture_);
 
   target_.SetColorAttachment(color0, 0);