Merge "Revert "Skip a step when blurring"" into main

Author: LeonScroggins

libs/renderengine/skia/SkiaRenderEngine.cpp

@@ -764,10 +764,11 @@ void SkiaRenderEngine::drawLayersInternal(
             // save a snapshot of the activeSurface to use as input to the blur shaders
             blurInput = activeSurface->makeImageSnapshot();
 
-            // blit the offscreen framebuffer into the destination AHB, but only
-            // if there are blur regions. backgroundBlurRadius blurs the entire
-            // image below, so it can skip this step.
-            if (layer.blurRegions.size()) {
+            // blit the offscreen framebuffer into the destination AHB. This ensures that
+            // even if the blurred image does not cover the screen (for example, during
+            // a rotation animation, or if blur regions are used), the entire screen is
+            // initialized.
+            if (layer.blurRegions.size() || FlagManager::getInstance().restore_blur_step()) {
                 SkPaint paint;
                 paint.setBlendMode(SkBlendMode::kSrc);
                 if (CC_UNLIKELY(mCapture->isCaptureRunning())) {

services/surfaceflinger/common/FlagManager.cpp

@@ -131,6 +131,7 @@ void FlagManager::dump(std::string& result) const {
     DUMP_READ_ONLY_FLAG(screenshot_fence_preservation);
     DUMP_READ_ONLY_FLAG(vulkan_renderengine);
     DUMP_READ_ONLY_FLAG(renderable_buffer_usage);
+    DUMP_READ_ONLY_FLAG(restore_blur_step);
 #undef DUMP_READ_ONLY_FLAG
 #undef DUMP_SERVER_FLAG
 #undef DUMP_FLAG_INTERVAL
@@ -208,6 +209,7 @@ FLAG_MANAGER_READ_ONLY_FLAG(enable_layer_command_batching, "")
 FLAG_MANAGER_READ_ONLY_FLAG(screenshot_fence_preservation, "debug.sf.screenshot_fence_preservation")
 FLAG_MANAGER_READ_ONLY_FLAG(vulkan_renderengine, "debug.renderengine.vulkan")
 FLAG_MANAGER_READ_ONLY_FLAG(renderable_buffer_usage, "")
+FLAG_MANAGER_READ_ONLY_FLAG(restore_blur_step, "debug.renderengine.restore_blur_step")
 
 /// Trunk stable server flags ///
 FLAG_MANAGER_SERVER_FLAG(late_boot_misc2, "")

services/surfaceflinger/common/include/common/FlagManager.h

@@ -71,6 +71,7 @@ class FlagManager {
     bool screenshot_fence_preservation() const;
     bool vulkan_renderengine() const;
     bool renderable_buffer_usage() const;
+    bool restore_blur_step() const;
 
 protected:
     // overridden for unit tests

services/surfaceflinger/surfaceflinger_flags.aconfig

@@ -185,3 +185,14 @@ flag {
     purpose: PURPOSE_BUGFIX
   }
 }
+
+flag {
+  name: "restore_blur_step"
+  namespace: "core_graphics"
+  description: "Restore drawing the blur input prior to drawing blurred content."
+  bug: "255921628"
+  is_fixed_read_only: true
+  metadata {
+    purpose: PURPOSE_BUGFIX
+  }
+}