From 28a1dd6fab2b33b0f875bdd7e7b5c2331a271a40 Mon Sep 17 00:00:00 2001
From: Chris Bracken <chris@bracken.jp>
Date: Wed, 31 Mar 2021 19:14:04 -0700
Subject: [PATCH 1/2] Fix texture corruption on Windows

Notify Skia that we've updated texture handles within the current
binding such that Skia invalidates any assumptions about previous
context modifications that it had made.

This fixes a texture corruption issue reported in
https://github.com/flutter/flutter/issues/78648
---
 shell/platform/embedder/embedder.cc           | 25 ++++++++++++++++---
 .../embedder/embedder_external_texture_gl.cc  |  2 ++
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/shell/platform/embedder/embedder.cc b/shell/platform/embedder/embedder.cc
index 9c0b7ee2c3732..f1f9d3994a52f 100644
--- a/shell/platform/embedder/embedder.cc
+++ b/shell/platform/embedder/embedder.cc
@@ -446,6 +446,26 @@ static sk_sp<SkSurface> MakeSkSurfaceFromBackingStore(
   texture_info.fID = texture->name;
   texture_info.fFormat = texture->format;
 
+  struct Captures {
+    VoidCallback destruction_callback;
+    void* user_data;
+    GrDirectContext* gr_direct_context;
+  };
+  auto captures = std::make_unique<Captures>();
+  captures->destruction_callback = texture->destruction_callback;
+  captures->user_data = texture->user_data;
+  captures->gr_direct_context = context;
+  auto release_proc = [](void* context) {
+    auto captures = reinterpret_cast<Captures*>(context);
+    if (captures->gr_direct_context) {
+      captures->gr_direct_context->flushAndSubmit();
+      captures->gr_direct_context->resetContext(kAll_GrBackendState);
+    }
+    if (captures->destruction_callback) {
+      captures->destruction_callback(captures->user_data);
+    }
+  };
+
   GrBackendTexture backend_texture(config.size.width,   //
                                    config.size.height,  //
                                    GrMipMapped::kNo,    //
@@ -462,9 +482,8 @@ static sk_sp<SkSurface> MakeSkSurfaceFromBackingStore(
       kN32_SkColorType,             // color type
       SkColorSpace::MakeSRGB(),     // color space
       &surface_properties,          // surface properties
-      static_cast<SkSurface::TextureReleaseProc>(
-          texture->destruction_callback),  // release proc
-      texture->user_data                   // release context
+      release_proc,                 // release proc
+      captures.release()            // release context
   );
 
   if (!surface) {
diff --git a/shell/platform/embedder/embedder_external_texture_gl.cc b/shell/platform/embedder/embedder_external_texture_gl.cc
index 0b5ed43c78028..45996a40d5792 100644
--- a/shell/platform/embedder/embedder_external_texture_gl.cc
+++ b/shell/platform/embedder/embedder_external_texture_gl.cc
@@ -48,6 +48,8 @@ sk_sp<SkImage> EmbedderExternalTextureGL::ResolveTexture(
     int64_t texture_id,
     GrDirectContext* context,
     const SkISize& size) {
+  context->flushAndSubmit();
+  context->resetContext(kAll_GrBackendState);
   std::unique_ptr<FlutterOpenGLTexture> texture =
       external_texture_callback_(texture_id, size.width(), size.height());
 

From 41c966ca0f7f0b16c57d1bc38ef13b59f5bd2900 Mon Sep 17 00:00:00 2001
From: Chris Bracken <chris@bracken.jp>
Date: Mon, 5 Apr 2021 11:44:37 -0700
Subject: [PATCH 2/2] Revert changes to destruction_callback

Out of concerns with GrDirectContext lifetime, reverting this bit.
---
 shell/platform/embedder/embedder.cc | 25 +++----------------------
 1 file changed, 3 insertions(+), 22 deletions(-)

diff --git a/shell/platform/embedder/embedder.cc b/shell/platform/embedder/embedder.cc
index f1f9d3994a52f..9c0b7ee2c3732 100644
--- a/shell/platform/embedder/embedder.cc
+++ b/shell/platform/embedder/embedder.cc
@@ -446,26 +446,6 @@ static sk_sp<SkSurface> MakeSkSurfaceFromBackingStore(
   texture_info.fID = texture->name;
   texture_info.fFormat = texture->format;
 
-  struct Captures {
-    VoidCallback destruction_callback;
-    void* user_data;
-    GrDirectContext* gr_direct_context;
-  };
-  auto captures = std::make_unique<Captures>();
-  captures->destruction_callback = texture->destruction_callback;
-  captures->user_data = texture->user_data;
-  captures->gr_direct_context = context;
-  auto release_proc = [](void* context) {
-    auto captures = reinterpret_cast<Captures*>(context);
-    if (captures->gr_direct_context) {
-      captures->gr_direct_context->flushAndSubmit();
-      captures->gr_direct_context->resetContext(kAll_GrBackendState);
-    }
-    if (captures->destruction_callback) {
-      captures->destruction_callback(captures->user_data);
-    }
-  };
-
   GrBackendTexture backend_texture(config.size.width,   //
                                    config.size.height,  //
                                    GrMipMapped::kNo,    //
@@ -482,8 +462,9 @@ static sk_sp<SkSurface> MakeSkSurfaceFromBackingStore(
       kN32_SkColorType,             // color type
       SkColorSpace::MakeSRGB(),     // color space
       &surface_properties,          // surface properties
-      release_proc,                 // release proc
-      captures.release()            // release context
+      static_cast<SkSurface::TextureReleaseProc>(
+          texture->destruction_callback),  // release proc
+      texture->user_data                   // release context
   );
 
   if (!surface) {