From b674ebe6db8cc296f3cff9d291e096c24d8aa377 Mon Sep 17 00:00:00 2001
From: gaaclarke <30870216+gaaclarke@users.noreply.github.com>
Date: Fri, 29 Sep 2023 18:00:38 -0700
Subject: [PATCH] [Impeller] fixed subpass filter coverage with image filters
 (flutter/engine#46431)

fixes: https://github.com/flutter/flutter/issues/135777
fixes: https://github.com/flutter/flutter/issues/135766
fixes: https://github.com/flutter/flutter/issues/135212

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---
 .../flutter/impeller/aiks/aiks_unittests.cc   | 19 +++++++++++++++++++
 .../flutter/impeller/entity/entity_pass.cc    |  4 ++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/engine/src/flutter/impeller/aiks/aiks_unittests.cc b/engine/src/flutter/impeller/aiks/aiks_unittests.cc
index 849cf648b1f..a4d7cdaff2c 100644
--- a/engine/src/flutter/impeller/aiks/aiks_unittests.cc
+++ b/engine/src/flutter/impeller/aiks/aiks_unittests.cc
@@ -3590,6 +3590,25 @@ TEST_P(AiksTest, ClearBlend) {
   clear.blend_mode = BlendMode::kClear;
 
   canvas.DrawCircle(Point::MakeXY(300.0, 300.0), 200.0, clear);
+}
+
+TEST_P(AiksTest, MatrixImageFilterMagnify) {
+  Canvas canvas;
+  canvas.Scale(GetContentScale());
+  auto image = std::make_shared<Image>(CreateTextureForFixture("airplane.jpg"));
+  canvas.Translate({600, -200});
+  canvas.SaveLayer({
+      .image_filter = std::make_shared<MatrixImageFilter>(
+          Matrix{
+              2, 0, 0, 0,  //
+              0, 2, 0, 0,  //
+              0, 0, 2, 0,  //
+              0, 0, 0, 1   //
+          },
+          SamplerDescriptor{}),
+  });
+  canvas.DrawImage(image, {0, 0}, Paint{.color = Color(1.0, 1.0, 1.0, 0.5)});
+  canvas.Restore();
 
   ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
 }
diff --git a/engine/src/flutter/impeller/entity/entity_pass.cc b/engine/src/flutter/impeller/entity/entity_pass.cc
index 0d91112369a..bc312cd6bcb 100644
--- a/engine/src/flutter/impeller/entity/entity_pass.cc
+++ b/engine/src/flutter/impeller/entity/entity_pass.cc
@@ -202,8 +202,8 @@ std::optional<Rect> EntityPass::GetSubpassCoverage(
   // has deviated too much from the parent pass to safely intersect with the
   // pass coverage limit.
   coverage_limit =
-      (image_filter && image_filter->IsTranslationOnly() ? std::nullopt
-                                                         : coverage_limit);
+      (image_filter && !image_filter->IsTranslationOnly() ? std::nullopt
+                                                          : coverage_limit);
 
   auto entities_coverage = subpass.GetElementsCoverage(coverage_limit);
   // The entities don't cover anything. There is nothing to do.