Reorder the layers sent to HWC

Bug: 163076219
Test: manual
Test: I53fc851eca876d44ba7cb9347f1c62d659c38932

Remove OutputLayerCompositionState.z, LayerStateField::ZOrder, and
LayerState::mZOrder. Note that the layers are already stored in the
proper z-order (back to front). When sending them to HWC, specify order
with a local variable. The LayerState and -Field ZOrders were used to
treat layers with different z's as a differing field for comparison. But
in practice, a change in z order will change the geometry, resulting in
recreating all CachedSets. (Add a test to verify this changes the
NonBufferHash.)

Add peekThroughLayer to overrideInfo, which is used by Output to
reorder the layers and to change the blendMode so the peekThroughLayer
can be seen through it.

In Flattener::mergeWithCachedSets, update overrideInfo to include
peekThroughLayer, using a new accessor on CachedSet.

Add more info to CachedSet::dump().

Test updates:
- Remove tests that verify the state of OutputLayerCompositionState.z
and ZOrder.
- In LayerStackTest#getApproximateMatch_doesNotMatchManyDifferences, we
were setting kMaxDifferingFields + 1 fields to be different. Removing z
made these two stacks match, so replace with another (arbitrary) field.
- Fix OutputLayer tests to expect calling the new method
LayerFE::hasRoundedCorners

Latest patch set fixes a rebase error in includesOverrideInfoIfPresent.

Change-Id: I845a0f7016c57652045f6f5a082175304272347f

16 files changed, 180 insertions, 141 deletions

diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/OutputLayer.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/OutputLayer.h
index 3a843273b9..e67e7d1e8d 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/OutputLayer.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/OutputLayer.h
@@ -16,6 +16,7 @@
 
 #pragma once
 
+#include <cstdint>
 #include <optional>
 #include <string>
 
@@ -90,8 +91,10 @@ public:
     // Writes the geometry state to the HWC, or does nothing if this layer does
     // not use the HWC. If includeGeometry is false, the geometry state can be
     // skipped. If skipLayer is true, then the alpha of the layer is forced to
-    // 0 so that HWC will ignore it.
-    virtual void writeStateToHWC(bool includeGeometry, bool skipLayer) = 0;
+    // 0 so that HWC will ignore it. z specifies the order to draw the layer in
+    // (starting with 0 for the back layer, and increasing for each following
+    // layer).
+    virtual void writeStateToHWC(bool includeGeometry, bool skipLayer, uint32_t z) = 0;
 
     // Updates the cursor position with the HWC
     virtual void writeCursorPositionToHWC() const = 0;
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayer.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayer.h
index ae88e7839c..e40ea369d3 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayer.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayer.h
@@ -16,6 +16,7 @@
 
 #pragma once
 
+#include <cstdint>
 #include <memory>
 #include <string>
 
@@ -42,7 +43,7 @@ public:
 
     void updateCompositionState(bool includeGeometry, bool forceClientComposition,
                                 ui::Transform::RotationFlags) override;
-    void writeStateToHWC(bool includeGeometry, bool skipLayer) override;
+    void writeStateToHWC(bool includeGeometry, bool skipLayer, uint32_t z) override;
     void writeCursorPositionToHWC() const override;
 
     HWC2::Layer* getHwcLayer() const override;
@@ -66,7 +67,8 @@ protected:
 
 private:
     Rect calculateInitialCrop() const;
-    void writeOutputDependentGeometryStateToHWC(HWC2::Layer*, Hwc2::IComposerClient::Composition);
+    void writeOutputDependentGeometryStateToHWC(HWC2::Layer*, Hwc2::IComposerClient::Composition,
+                                                uint32_t z);
     void writeOutputIndependentGeometryStateToHWC(HWC2::Layer*, const LayerFECompositionState&,
                                                   bool skipLayer);
     void writeOutputDependentPerFrameStateToHWC(HWC2::Layer*);
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayerCompositionState.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayerCompositionState.h
index c61ec5991b..356965cf48 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayerCompositionState.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayerCompositionState.h
@@ -46,6 +46,10 @@ class Layer;
 
 class HWComposer;
 
+namespace compositionengine {
+class OutputLayer;
+} // namespace compositionengine
+
 namespace compositionengine::impl {
 
 // Note that fields that affect HW composer state may need to be mirrored into
@@ -84,9 +88,6 @@ struct OutputLayerCompositionState {
     // The dataspace for this layer
     ui::Dataspace dataspace{ui::Dataspace::UNKNOWN};
 
-    // The Z order index of this layer on this output
-    uint32_t z{0};
-
     // Overrides the buffer, acquire fence, and display frame stored in LayerFECompositionState
     struct {
         std::shared_ptr<renderengine::ExternalTexture> buffer = nullptr;
@@ -96,6 +97,12 @@ struct OutputLayerCompositionState {
         ProjectionSpace displaySpace;
         Region damageRegion = Region::INVALID_REGION;
         Region visibleRegion;
+
+        // The OutputLayer pointed to by this field will be rearranged to draw
+        // behind the OutputLayer represented by this CompositionState and will
+        // be visible through it. Unowned - the OutputLayer's lifetime will
+        // outlast this.)
+        OutputLayer* peekThroughLayer = nullptr;
     } overrideInfo;
 
     /*
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/CachedSet.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/CachedSet.h
index 7f068d421b..14c18ec1b3 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/CachedSet.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/CachedSet.h
@@ -115,12 +115,17 @@ public:
     // through. Must be called before ::render().
     void addHolePunchLayer(const LayerState*);
 
+    // Retrieve the layer that will be drawn behind this one.
+    OutputLayer* getHolePunchLayer() const;
+
 private:
     CachedSet() = default;
 
     const NonBufferHash mFingerprint;
     std::chrono::steady_clock::time_point mLastUpdate = std::chrono::steady_clock::now();
     std::vector<Layer> mLayers;
+
+    // Unowned.
     const LayerState* mHolePunchLayer = nullptr;
     Rect mBounds = Rect::EMPTY_RECT;
     Region mVisibleRegion;
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/LayerState.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/LayerState.h
index f2f6c0b912..3391273679 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/LayerState.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/LayerState.h
@@ -53,20 +53,19 @@ enum class LayerStateField : uint32_t {
     Name            = 1u << 1,
     DisplayFrame    = 1u << 2,
     SourceCrop      = 1u << 3,
-    ZOrder          = 1u << 4,
-    BufferTransform = 1u << 5,
-    BlendMode       = 1u << 6,
-    Alpha           = 1u << 7,
-    LayerMetadata   = 1u << 8,
-    VisibleRegion   = 1u << 9,
-    Dataspace       = 1u << 10,
-    PixelFormat     = 1u << 11,
-    ColorTransform  = 1u << 12,
-    SurfaceDamage   = 1u << 13,
-    CompositionType = 1u << 14,
-    SidebandStream  = 1u << 15,
-    Buffer          = 1u << 16,
-    SolidColor      = 1u << 17,
+    BufferTransform = 1u << 4,
+    BlendMode       = 1u << 5,
+    Alpha           = 1u << 6,
+    LayerMetadata   = 1u << 7,
+    VisibleRegion   = 1u << 8,
+    Dataspace       = 1u << 9,
+    PixelFormat     = 1u << 10,
+    ColorTransform  = 1u << 11,
+    SurfaceDamage   = 1u << 12,
+    CompositionType = 1u << 13,
+    SidebandStream  = 1u << 14,
+    Buffer          = 1u << 15,
+    SolidColor      = 1u << 16,
 };
 // clang-format on
 
@@ -271,9 +270,6 @@ private:
                                                        rect.top, rect.right, rect.bottom)};
                         }};
 
-    OutputLayerState<uint32_t, LayerStateField::ZOrder> mZOrder{
-            [](auto layer) { return layer->getState().z; }};
-
     using BufferTransformState = OutputLayerState<hardware::graphics::composer::hal::Transform,
                                                   LayerStateField::BufferTransform>;
     BufferTransformState mBufferTransform{[](auto layer) {
@@ -402,7 +398,7 @@ private:
                             return std::vector<std::string>{stream.str()};
                         }};
 
-    static const constexpr size_t kNumNonUniqueFields = 15;
+    static const constexpr size_t kNumNonUniqueFields = 14;
 
     std::array<StateInterface*, kNumNonUniqueFields> getNonUniqueFields() {
         std::array<const StateInterface*, kNumNonUniqueFields> constFields =
@@ -417,10 +413,10 @@ private:
 
     std::array<const StateInterface*, kNumNonUniqueFields> getNonUniqueFields() const {
         return {
-                &mDisplayFrame,    &mSourceCrop,     &mZOrder,         &mBufferTransform,
-                &mBlendMode,       &mAlpha,          &mLayerMetadata,  &mVisibleRegion,
-                &mOutputDataspace, &mPixelFormat,    &mColorTransform, &mCompositionType,
-                &mSidebandStream,  &mBuffer,         &mSolidColor,
+                &mDisplayFrame, &mSourceCrop,     &mBufferTransform, &mBlendMode,
+                &mAlpha,        &mLayerMetadata,  &mVisibleRegion,   &mOutputDataspace,
+                &mPixelFormat,  &mColorTransform, &mCompositionType, &mSidebandStream,
+                &mBuffer,       &mSolidColor,
         };
     }
 };
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/OutputLayer.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/OutputLayer.h
index 2454ff7188..63ada1b291 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/OutputLayer.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/OutputLayer.h
@@ -22,6 +22,7 @@
 #include <compositionengine/OutputLayer.h>
 #include <compositionengine/impl/OutputLayerCompositionState.h>
 #include <gmock/gmock.h>
+#include <cstdint>
 
 namespace android::compositionengine::mock {
 
@@ -39,7 +40,7 @@ public:
     MOCK_METHOD0(editState, impl::OutputLayerCompositionState&());
 
     MOCK_METHOD3(updateCompositionState, void(bool, bool, ui::Transform::RotationFlags));
-    MOCK_METHOD2(writeStateToHWC, void(bool, bool));
+    MOCK_METHOD3(writeStateToHWC, void(bool, bool, uint32_t));
     MOCK_CONST_METHOD0(writeCursorPositionToHWC, void());
 
     MOCK_CONST_METHOD0(getHwcLayer, HWC2::Layer*());
diff --git a/services/surfaceflinger/CompositionEngine/src/Output.cpp b/services/surfaceflinger/CompositionEngine/src/Output.cpp
index faa4b74c28..29534764d4 100644
--- a/services/surfaceflinger/CompositionEngine/src/Output.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/Output.cpp
@@ -455,12 +455,6 @@ void Output::collectVisibleLayers(const compositionengine::CompositionRefreshArg
     setReleasedLayers(refreshArgs);
 
     finalizePendingOutputLayers();
-
-    // Generate a simple Z-order values to each visible output layer
-    uint32_t zOrder = 0;
-    for (auto* outputLayer : getOutputLayersOrderedByZ()) {
-        outputLayer->editState().z = zOrder++;
-    }
 }
 
 void Output::ensureOutputLayerIfVisible(sp<compositionengine::LayerFE>& layerFE,
@@ -713,20 +707,39 @@ void Output::writeCompositionState(const compositionengine::CompositionRefreshAr
 
     editState().earliestPresentTime = refreshArgs.earliestPresentTime;
 
+    OutputLayer* peekThroughLayer = nullptr;
     sp<GraphicBuffer> previousOverride = nullptr;
+    uint32_t z = 0;
     for (auto* layer : getOutputLayersOrderedByZ()) {
+        if (layer == peekThroughLayer) {
+            // No longer needed, although it should not show up again, so
+            // resetting it is not truly needed either.
+            peekThroughLayer = nullptr;
+
+            // peekThroughLayer was already drawn ahead of its z order.
+            continue;
+        }
         bool skipLayer = false;
-        if (layer->getState().overrideInfo.buffer != nullptr) {
-            if (previousOverride != nullptr &&
-                layer->getState().overrideInfo.buffer->getBuffer() == previousOverride) {
+        auto& overrideInfo = layer->getState().overrideInfo;
+        if (overrideInfo.buffer != nullptr) {
+            if (previousOverride && overrideInfo.buffer->getBuffer() == previousOverride) {
                 ALOGV("Skipping redundant buffer");
                 skipLayer = true;
+            } else {
+                // First layer with the override buffer.
+                if (overrideInfo.peekThroughLayer) {
+                    peekThroughLayer = overrideInfo.peekThroughLayer;
+                    // Draw peekThroughLayer first.
+                    const bool includeGeometry = refreshArgs.updatingGeometryThisFrame;
+                    peekThroughLayer->writeStateToHWC(includeGeometry, false, z++);
+                }
+
+                previousOverride = overrideInfo.buffer->getBuffer();
             }
-            previousOverride = layer->getState().overrideInfo.buffer->getBuffer();
         }
 
         const bool includeGeometry = refreshArgs.updatingGeometryThisFrame;
-        layer->writeStateToHWC(includeGeometry, skipLayer);
+        layer->writeStateToHWC(includeGeometry, skipLayer, z++);
     }
 }
 
diff --git a/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp b/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
index 9ca8914deb..89d5a23293 100644
--- a/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
@@ -21,6 +21,7 @@
 #include <compositionengine/impl/OutputCompositionState.h>
 #include <compositionengine/impl/OutputLayer.h>
 #include <compositionengine/impl/OutputLayerCompositionState.h>
+#include <cstdint>
 
 // TODO(b/129481165): remove the #pragma below and fix conversion issues
 #pragma clang diagnostic push
@@ -312,7 +313,7 @@ void OutputLayer::updateCompositionState(
     }
 }
 
-void OutputLayer::writeStateToHWC(bool includeGeometry, bool skipLayer) {
+void OutputLayer::writeStateToHWC(bool includeGeometry, bool skipLayer, uint32_t z) {
     const auto& state = getState();
     // Skip doing this if there is no HWC interface
     if (!state.hwc) {
@@ -338,7 +339,7 @@ void OutputLayer::writeStateToHWC(bool includeGeometry, bool skipLayer) {
     const bool isOverridden = state.overrideInfo.buffer != nullptr;
     const bool prevOverridden = state.hwc->stateOverridden;
     if (isOverridden || prevOverridden || skipLayer || includeGeometry) {
-        writeOutputDependentGeometryStateToHWC(hwcLayer.get(), requestedCompositionType);
+        writeOutputDependentGeometryStateToHWC(hwcLayer.get(), requestedCompositionType, z);
         writeOutputIndependentGeometryStateToHWC(hwcLayer.get(), *outputIndependentState,
                                                  skipLayer);
     }
@@ -354,8 +355,9 @@ void OutputLayer::writeStateToHWC(bool includeGeometry, bool skipLayer) {
     editState().hwc->stateOverridden = isOverridden;
 }
 
-void OutputLayer::writeOutputDependentGeometryStateToHWC(
-        HWC2::Layer* hwcLayer, hal::Composition requestedCompositionType) {
+void OutputLayer::writeOutputDependentGeometryStateToHWC(HWC2::Layer* hwcLayer,
+                                                         hal::Composition requestedCompositionType,
+                                                         uint32_t z) {
     const auto& outputDependentState = getState();
 
     Rect displayFrame = outputDependentState.displayFrame;
@@ -382,9 +384,9 @@ void OutputLayer::writeOutputDependentGeometryStateToHWC(
               sourceCrop.bottom, to_string(error).c_str(), static_cast<int32_t>(error));
     }
 
-    if (auto error = hwcLayer->setZOrder(outputDependentState.z); error != hal::Error::NONE) {
-        ALOGE("[%s] Failed to set Z %u: %s (%d)", getLayerFE().getDebugName(),
-              outputDependentState.z, to_string(error).c_str(), static_cast<int32_t>(error));
+    if (auto error = hwcLayer->setZOrder(z); error != hal::Error::NONE) {
+        ALOGE("[%s] Failed to set Z %u: %s (%d)", getLayerFE().getDebugName(), z,
+              to_string(error).c_str(), static_cast<int32_t>(error));
     }
 
     // Solid-color layers and overridden buffers should always use an identity transform.
@@ -403,7 +405,10 @@ void OutputLayer::writeOutputDependentGeometryStateToHWC(
 void OutputLayer::writeOutputIndependentGeometryStateToHWC(
         HWC2::Layer* hwcLayer, const LayerFECompositionState& outputIndependentState,
         bool skipLayer) {
-    const auto blendMode = getState().overrideInfo.buffer
+    // If there is a peekThroughLayer, then this layer has a hole in it. We need to use
+    // PREMULTIPLIED so it will peek through.
+    const auto& overrideInfo = getState().overrideInfo;
+    const auto blendMode = overrideInfo.buffer || overrideInfo.peekThroughLayer
             ? hardware::graphics::composer::hal::BlendMode::PREMULTIPLIED
             : outputIndependentState.blendMode;
     if (auto error = hwcLayer->setBlendMode(blendMode); error != hal::Error::NONE) {
diff --git a/services/surfaceflinger/CompositionEngine/src/OutputLayerCompositionState.cpp b/services/surfaceflinger/CompositionEngine/src/OutputLayerCompositionState.cpp
index efd23dce98..b4c314c8d4 100644
--- a/services/surfaceflinger/CompositionEngine/src/OutputLayerCompositionState.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/OutputLayerCompositionState.cpp
@@ -67,7 +67,6 @@ void OutputLayerCompositionState::dump(std::string& out) const {
     dumpVal(out, "sourceCrop", sourceCrop);
     dumpVal(out, "bufferTransform", toString(bufferTransform), bufferTransform);
     dumpVal(out, "dataspace", toString(dataspace), dataspace);
-    dumpVal(out, "z-index", z);
     dumpVal(out, "override buffer", overrideInfo.buffer.get());
     dumpVal(out, "override acquire fence", overrideInfo.acquireFence.get());
     dumpVal(out, "override display frame", overrideInfo.displayFrame);
diff --git a/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp b/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
index 238282e6a6..6f6649924b 100644
--- a/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
@@ -278,6 +278,10 @@ void CachedSet::addHolePunchLayer(const LayerState* layerState) {
     mHolePunchLayer = layerState;
 }
 
+OutputLayer* CachedSet::getHolePunchLayer() const {
+    return mHolePunchLayer ? mHolePunchLayer->getOutputLayer() : nullptr;
+}
+
 void CachedSet::dump(std::string& result) const {
     const auto now = std::chrono::steady_clock::now();
 
@@ -285,6 +289,11 @@ void CachedSet::dump(std::string& result) const {
             std::chrono::duration_cast<std::chrono::milliseconds>(now - mLastUpdate);
     base::StringAppendF(&result, "  + Fingerprint %016zx, last update %sago, age %zd\n",
                         mFingerprint, durationString(lastUpdate).c_str(), mAge);
+    {
+        const auto b = mTexture ? mTexture->getBuffer().get() : nullptr;
+        base::StringAppendF(&result, "    Override buffer: %p\n", b);
+    }
+    base::StringAppendF(&result, "    HolePunchLayer: %p\n", mHolePunchLayer);
 
     if (mLayers.size() == 1) {
         base::StringAppendF(&result, "    Layer [%s]\n", mLayers[0].getName().c_str());
diff --git a/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp b/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp
index 960d8e16b9..a4b979ee10 100644
--- a/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp
@@ -209,6 +209,7 @@ bool Flattener::mergeWithCachedSets(const std::vector<const LayerState*>& layers
                 ALOGV("[%s] Found ready buffer", __func__);
                 size_t skipCount = mNewCachedSet->getLayerCount();
                 while (skipCount != 0) {
+                    auto* peekThroughLayer = mNewCachedSet->getHolePunchLayer();
                     const size_t layerCount = currentLayerIter->getLayerCount();
                     for (size_t i = 0; i < layerCount; ++i) {
                         OutputLayer::CompositionState& state =
@@ -221,6 +222,7 @@ bool Flattener::mergeWithCachedSets(const std::vector<const LayerState*>& layers
                                 .displaySpace = mNewCachedSet->getOutputSpace(),
                                 .damageRegion = Region::INVALID_REGION,
                                 .visibleRegion = mNewCachedSet->getVisibleRegion(),
+                                .peekThroughLayer = peekThroughLayer,
                         };
                         ++incomingLayerIter;
                     }
@@ -244,6 +246,7 @@ bool Flattener::mergeWithCachedSets(const std::vector<const LayerState*>& layers
 
             // Skip the incoming layers corresponding to this valid current layer
             const size_t layerCount = currentLayerIter->getLayerCount();
+            auto* peekThroughLayer = currentLayerIter->getHolePunchLayer();
             for (size_t i = 0; i < layerCount; ++i) {
                 OutputLayer::CompositionState& state =
                         (*incomingLayerIter)->getOutputLayer()->editState();
@@ -255,6 +258,7 @@ bool Flattener::mergeWithCachedSets(const std::vector<const LayerState*>& layers
                         .displaySpace = currentLayerIter->getOutputSpace(),
                         .damageRegion = Region(),
                         .visibleRegion = currentLayerIter->getVisibleRegion(),
+                        .peekThroughLayer = peekThroughLayer,
                 };
                 ++incomingLayerIter;
             }
diff --git a/services/surfaceflinger/CompositionEngine/src/planner/LayerState.cpp b/services/surfaceflinger/CompositionEngine/src/planner/LayerState.cpp
index ab8599796f..8423a124cf 100644
--- a/services/surfaceflinger/CompositionEngine/src/planner/LayerState.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/planner/LayerState.cpp
@@ -155,10 +155,9 @@ std::optional<std::string> LayerState::compare(const LayerState& other) const {
 
 bool operator==(const LayerState& lhs, const LayerState& rhs) {
     return lhs.mId == rhs.mId && lhs.mName == rhs.mName && lhs.mDisplayFrame == rhs.mDisplayFrame &&
-            lhs.mSourceCrop == rhs.mSourceCrop && lhs.mZOrder == rhs.mZOrder &&
-            lhs.mBufferTransform == rhs.mBufferTransform && lhs.mBlendMode == rhs.mBlendMode &&
-            lhs.mAlpha == rhs.mAlpha && lhs.mLayerMetadata == rhs.mLayerMetadata &&
-            lhs.mVisibleRegion == rhs.mVisibleRegion &&
+            lhs.mSourceCrop == rhs.mSourceCrop && lhs.mBufferTransform == rhs.mBufferTransform &&
+            lhs.mBlendMode == rhs.mBlendMode && lhs.mAlpha == rhs.mAlpha &&
+            lhs.mLayerMetadata == rhs.mLayerMetadata && lhs.mVisibleRegion == rhs.mVisibleRegion &&
             lhs.mOutputDataspace == rhs.mOutputDataspace && lhs.mPixelFormat == rhs.mPixelFormat &&
             lhs.mColorTransform == rhs.mColorTransform &&
             lhs.mCompositionType == rhs.mCompositionType &&
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
index 4c3f4940cc..4d5a8f5fc4 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
@@ -689,7 +689,6 @@ TEST_F(OutputLayerUpdateCompositionStateTest, clientCompositionForcedFromArgumen
 struct OutputLayerWriteStateToHWCTest : public OutputLayerTest {
     static constexpr hal::Error kError = hal::Error::UNSUPPORTED;
     static constexpr FloatRect kSourceCrop{11.f, 12.f, 13.f, 14.f};
-    static constexpr uint32_t kZOrder = 21u;
     static constexpr Hwc2::Transform kBufferTransform = static_cast<Hwc2::Transform>(31);
     static constexpr Hwc2::Transform kOverrideBufferTransform = static_cast<Hwc2::Transform>(0);
     static constexpr Hwc2::IComposerClient::BlendMode kBlendMode =
@@ -735,7 +734,6 @@ struct OutputLayerWriteStateToHWCTest : public OutputLayerTest {
 
         outputLayerState.displayFrame = kDisplayFrame;
         outputLayerState.sourceCrop = kSourceCrop;
-        outputLayerState.z = kZOrder;
         outputLayerState.bufferTransform = static_cast<Hwc2::Transform>(kBufferTransform);
         outputLayerState.outputSpaceVisibleRegion = kOutputSpaceVisibleRegion;
         outputLayerState.dataspace = kDataspace;
@@ -785,7 +783,7 @@ struct OutputLayerWriteStateToHWCTest : public OutputLayerTest {
                                    float alpha = kAlpha) {
         EXPECT_CALL(*mHwcLayer, setDisplayFrame(displayFrame)).WillOnce(Return(kError));
         EXPECT_CALL(*mHwcLayer, setSourceCrop(sourceCrop)).WillOnce(Return(kError));
-        EXPECT_CALL(*mHwcLayer, setZOrder(kZOrder)).WillOnce(Return(kError));
+        EXPECT_CALL(*mHwcLayer, setZOrder(_)).WillOnce(Return(kError));
         EXPECT_CALL(*mHwcLayer, setTransform(bufferTransform)).WillOnce(Return(kError));
 
         EXPECT_CALL(*mHwcLayer, setBlendMode(blendMode)).WillOnce(Return(kError));
@@ -878,19 +876,19 @@ const std::vector<uint8_t> OutputLayerWriteStateToHWCTest::kLayerGenericMetadata
 TEST_F(OutputLayerWriteStateToHWCTest, doesNothingIfNoFECompositionState) {
     EXPECT_CALL(*mLayerFE, getCompositionState()).WillOnce(Return(nullptr));
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false);
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false, 0);
 }
 
 TEST_F(OutputLayerWriteStateToHWCTest, doesNothingIfNoHWCState) {
     mOutputLayer.editState().hwc.reset();
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false);
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false, 0);
 }
 
 TEST_F(OutputLayerWriteStateToHWCTest, doesNothingIfNoHWCLayer) {
     mOutputLayer.editState().hwc = impl::OutputLayerCompositionState::Hwc(nullptr);
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false);
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false, 0);
 }
 
 TEST_F(OutputLayerWriteStateToHWCTest, canSetAllState) {
@@ -898,8 +896,9 @@ TEST_F(OutputLayerWriteStateToHWCTest, canSetAllState) {
     expectPerFrameCommonCalls();
 
     expectNoSetCompositionTypeCall();
+    EXPECT_CALL(*mLayerFE, hasRoundedCorners()).WillOnce(Return(false));
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false);
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false, 0);
 }
 
 TEST_F(OutputLayerTest, displayInstallOrientationBufferTransformSetTo90) {
@@ -921,6 +920,7 @@ TEST_F(OutputLayerWriteStateToHWCTest, canSetPerFrameStateForSolidColor) {
     mLayerFEState.compositionType = Hwc2::IComposerClient::Composition::SOLID_COLOR;
 
     expectPerFrameCommonCalls();
+    EXPECT_CALL(*mLayerFE, hasRoundedCorners()).WillOnce(Return(false));
 
     // Setting the composition type should happen before setting the color. We
     // check this in this test only by setting up an testing::InSeqeuence
@@ -929,7 +929,7 @@ TEST_F(OutputLayerWriteStateToHWCTest, canSetPerFrameStateForSolidColor) {
     expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::SOLID_COLOR);
     expectSetColorCall();
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false);
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, 0);
 }
 
 TEST_F(OutputLayerWriteStateToHWCTest, canSetPerFrameStateForSideband) {
@@ -939,7 +939,9 @@ TEST_F(OutputLayerWriteStateToHWCTest, canSetPerFrameStateForSideband) {
     expectSetSidebandHandleCall();
     expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::SIDEBAND);
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false);
+    EXPECT_CALL(*mLayerFE, hasRoundedCorners()).WillOnce(Return(false));
+
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, 0);
 }
 
 TEST_F(OutputLayerWriteStateToHWCTest, canSetPerFrameStateForCursor) {
@@ -949,7 +951,9 @@ TEST_F(OutputLayerWriteStateToHWCTest, canSetPerFrameStateForCursor) {
     expectSetHdrMetadataAndBufferCalls();
     expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::CURSOR);
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false);
+    EXPECT_CALL(*mLayerFE, hasRoundedCorners()).WillOnce(Return(false));
+
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, 0);
 }
 
 TEST_F(OutputLayerWriteStateToHWCTest, canSetPerFrameStateForDevice) {
@@ -959,7 +963,9 @@ TEST_F(OutputLayerWriteStateToHWCTest, canSetPerFrameStateForDevice) {
     expectSetHdrMetadataAndBufferCalls();
     expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::DEVICE);
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false);
+    EXPECT_CALL(*mLayerFE, hasRoundedCorners()).WillOnce(Return(false));
+
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, 0);
 }
 
 TEST_F(OutputLayerWriteStateToHWCTest, compositionTypeIsNotSetIfUnchanged) {
@@ -972,7 +978,9 @@ TEST_F(OutputLayerWriteStateToHWCTest, compositionTypeIsNotSetIfUnchanged) {
     expectSetColorCall();
     expectNoSetCompositionTypeCall();
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false);
+    EXPECT_CALL(*mLayerFE, hasRoundedCorners()).WillOnce(Return(false));
+
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, 0);
 }
 
 TEST_F(OutputLayerWriteStateToHWCTest, compositionTypeIsSetToClientIfColorTransformNotSupported) {
@@ -982,7 +990,7 @@ TEST_F(OutputLayerWriteStateToHWCTest, compositionTypeIsSetToClientIfColorTransf
     expectSetColorCall();
     expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::CLIENT);
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false);
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, 0);
 }
 
 TEST_F(OutputLayerWriteStateToHWCTest, compositionTypeIsSetToClientIfClientCompositionForced) {
@@ -994,7 +1002,7 @@ TEST_F(OutputLayerWriteStateToHWCTest, compositionTypeIsSetToClientIfClientCompo
     expectSetColorCall();
     expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::CLIENT);
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false);
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, 0);
 }
 
 TEST_F(OutputLayerWriteStateToHWCTest, allStateIncludesMetadataIfPresent) {
@@ -1007,7 +1015,9 @@ TEST_F(OutputLayerWriteStateToHWCTest, allStateIncludesMetadataIfPresent) {
     expectGenericLayerMetadataCalls();
     expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::DEVICE);
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false);
+    EXPECT_CALL(*mLayerFE, hasRoundedCorners()).WillOnce(Return(false));
+
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false, 0);
 }
 
 TEST_F(OutputLayerWriteStateToHWCTest, perFrameStateDoesNotIncludeMetadataIfPresent) {
@@ -1018,7 +1028,9 @@ TEST_F(OutputLayerWriteStateToHWCTest, perFrameStateDoesNotIncludeMetadataIfPres
     expectSetHdrMetadataAndBufferCalls();
     expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::DEVICE);
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false);
+    EXPECT_CALL(*mLayerFE, hasRoundedCorners()).WillOnce(Return(false));
+
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, 0);
 }
 
 TEST_F(OutputLayerWriteStateToHWCTest, includesOverrideInfoIfPresent) {
@@ -1032,7 +1044,9 @@ TEST_F(OutputLayerWriteStateToHWCTest, includesOverrideInfoIfPresent) {
     expectSetHdrMetadataAndBufferCalls(kOverrideBuffer->getBuffer(), kOverrideFence);
     expectSetCompositionTypeCall(Hwc2::IComposerClient::Composition::DEVICE);
 
-    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false);
+    EXPECT_CALL(*mLayerFE, hasRoundedCorners()).WillOnce(Return(false));
+
+    mOutputLayer.writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false, 0);
 }
 
 /*
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
index e80100cc6e..8754984d95 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
@@ -30,6 +30,7 @@
 #include <ui/Region.h>
 
 #include <cmath>
+#include <cstdint>
 
 #include "CallOrderStateMachineHelper.h"
 #include "MockHWC2.h"
@@ -783,15 +784,16 @@ TEST_F(OutputUpdateAndWriteCompositionStateTest, updatesLayerContentForAllLayers
     InjectedLayer layer2;
     InjectedLayer layer3;
 
+    uint32_t z = 0;
     EXPECT_CALL(*layer1.outputLayer, updateCompositionState(false, false, ui::Transform::ROT_180));
     EXPECT_CALL(*layer1.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, z++));
     EXPECT_CALL(*layer2.outputLayer, updateCompositionState(false, false, ui::Transform::ROT_180));
     EXPECT_CALL(*layer2.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, z++));
     EXPECT_CALL(*layer3.outputLayer, updateCompositionState(false, false, ui::Transform::ROT_180));
     EXPECT_CALL(*layer3.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, z++));
 
     injectOutputLayer(layer1);
     injectOutputLayer(layer2);
@@ -813,15 +815,16 @@ TEST_F(OutputUpdateAndWriteCompositionStateTest, updatesLayerGeometryAndContentF
     InjectedLayer layer2;
     InjectedLayer layer3;
 
+    uint32_t z = 0;
     EXPECT_CALL(*layer1.outputLayer, updateCompositionState(true, false, ui::Transform::ROT_0));
     EXPECT_CALL(*layer1.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false, z++));
     EXPECT_CALL(*layer2.outputLayer, updateCompositionState(true, false, ui::Transform::ROT_0));
     EXPECT_CALL(*layer2.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false, z++));
     EXPECT_CALL(*layer3.outputLayer, updateCompositionState(true, false, ui::Transform::ROT_0));
     EXPECT_CALL(*layer3.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ true, /*skipLayer*/ false, z++));
 
     injectOutputLayer(layer1);
     injectOutputLayer(layer2);
@@ -842,15 +845,16 @@ TEST_F(OutputUpdateAndWriteCompositionStateTest, forcesClientCompositionForAllLa
     InjectedLayer layer2;
     InjectedLayer layer3;
 
+    uint32_t z = 0;
     EXPECT_CALL(*layer1.outputLayer, updateCompositionState(false, true, ui::Transform::ROT_0));
     EXPECT_CALL(*layer1.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, z++));
     EXPECT_CALL(*layer2.outputLayer, updateCompositionState(false, true, ui::Transform::ROT_0));
     EXPECT_CALL(*layer2.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, z++));
     EXPECT_CALL(*layer3.outputLayer, updateCompositionState(false, true, ui::Transform::ROT_0));
     EXPECT_CALL(*layer3.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, z++));
 
     injectOutputLayer(layer1);
     injectOutputLayer(layer2);
@@ -1144,11 +1148,6 @@ TEST_F(OutputCollectVisibleLayersTest, processesCandidateLayersReversedAndSetsOu
     EXPECT_CALL(mOutput, finalizePendingOutputLayers());
 
     mOutput.collectVisibleLayers(mRefreshArgs, mCoverageState);
-
-    // Ensure all output layers have been assigned a simple/flattened z-order.
-    EXPECT_EQ(0u, mLayer1.outputLayerState.z);
-    EXPECT_EQ(1u, mLayer2.outputLayerState.z);
-    EXPECT_EQ(2u, mLayer3.outputLayerState.z);
 }
 
 /*
@@ -3501,7 +3500,7 @@ struct OutputComposeSurfacesTest_SetsExpensiveRendering_ForBlur
 
         EXPECT_CALL(mLayer.outputLayer, updateCompositionState(false, true, ui::Transform::ROT_0));
         EXPECT_CALL(mLayer.outputLayer,
-                    writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false));
+                    writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, 0));
         EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
                 .WillOnce(Return(std::vector<LayerFE::LayerSettings>{}));
         EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, false, _, _)).WillOnce(Return(NO_ERROR));
@@ -4080,16 +4079,17 @@ TEST_F(OutputUpdateAndWriteCompositionStateTest, handlesBackgroundBlurRequests)
     InjectedLayer layer2;
     InjectedLayer layer3;
 
+    uint32_t z = 0;
     // Layer requesting blur, or below, should request client composition.
     EXPECT_CALL(*layer1.outputLayer, updateCompositionState(false, true, ui::Transform::ROT_0));
     EXPECT_CALL(*layer1.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, z++));
     EXPECT_CALL(*layer2.outputLayer, updateCompositionState(false, true, ui::Transform::ROT_0));
     EXPECT_CALL(*layer2.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, z++));
     EXPECT_CALL(*layer3.outputLayer, updateCompositionState(false, false, ui::Transform::ROT_0));
     EXPECT_CALL(*layer3.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, z++));
 
     layer2.layerFEState.backgroundBlurRadius = 10;
 
@@ -4112,16 +4112,17 @@ TEST_F(OutputUpdateAndWriteCompositionStateTest, handlesBlurRegionRequests) {
     InjectedLayer layer2;
     InjectedLayer layer3;
 
+    uint32_t z = 0;
     // Layer requesting blur, or below, should request client composition.
     EXPECT_CALL(*layer1.outputLayer, updateCompositionState(false, true, ui::Transform::ROT_0));
     EXPECT_CALL(*layer1.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, z++));
     EXPECT_CALL(*layer2.outputLayer, updateCompositionState(false, true, ui::Transform::ROT_0));
     EXPECT_CALL(*layer2.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, z++));
     EXPECT_CALL(*layer3.outputLayer, updateCompositionState(false, false, ui::Transform::ROT_0));
     EXPECT_CALL(*layer3.outputLayer,
-                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false));
+                writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, z++));
 
     BlurRegion region;
     layer2.layerFEState.blurRegions.push_back(region);
diff --git a/services/surfaceflinger/CompositionEngine/tests/planner/LayerStateTest.cpp b/services/surfaceflinger/CompositionEngine/tests/planner/LayerStateTest.cpp
index 83cc19b014..948c850735 100644
--- a/services/surfaceflinger/CompositionEngine/tests/planner/LayerStateTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/planner/LayerStateTest.cpp
@@ -41,8 +41,6 @@ const Rect sRectOne = Rect(10, 20, 30, 40);
 const Rect sRectTwo = Rect(40, 30, 20, 10);
 const FloatRect sFloatRectOne = FloatRect(100.f, 200.f, 300.f, 400.f);
 const FloatRect sFloatRectTwo = FloatRect(400.f, 300.f, 200.f, 100.f);
-const constexpr int32_t sZOne = 100;
-const constexpr int32_t sZTwo = 101;
 const constexpr float sAlphaOne = 0.25f;
 const constexpr float sAlphaTwo = 0.5f;
 const Region sRegionOne = Region(sRectOne);
@@ -408,45 +406,6 @@ TEST_F(LayerStateTest, compareSourceCrop) {
     EXPECT_TRUE(otherLayerState->compare(*mLayerState));
 }
 
-TEST_F(LayerStateTest, updateZOrder) {
-    OutputLayerCompositionState outputLayerCompositionState;
-    outputLayerCompositionState.z = sZOne;
-    LayerFECompositionState layerFECompositionState;
-    setupMocksForLayer(mOutputLayer, mLayerFE, outputLayerCompositionState,
-                       layerFECompositionState);
-    mLayerState = std::make_unique<LayerState>(&mOutputLayer);
-
-    mock::OutputLayer newOutputLayer;
-    mock::LayerFE newLayerFE;
-    OutputLayerCompositionState outputLayerCompositionStateTwo;
-    outputLayerCompositionStateTwo.z = sZTwo;
-    setupMocksForLayer(newOutputLayer, newLayerFE, outputLayerCompositionStateTwo,
-                       layerFECompositionState);
-    Flags<LayerStateField> updates = mLayerState->update(&newOutputLayer);
-    EXPECT_EQ(Flags<LayerStateField>(LayerStateField::ZOrder), updates);
-}
-
-TEST_F(LayerStateTest, compareZOrder) {
-    OutputLayerCompositionState outputLayerCompositionState;
-    outputLayerCompositionState.z = sZOne;
-    LayerFECompositionState layerFECompositionState;
-    setupMocksForLayer(mOutputLayer, mLayerFE, outputLayerCompositionState,
-                       layerFECompositionState);
-    mLayerState = std::make_unique<LayerState>(&mOutputLayer);
-    mock::OutputLayer newOutputLayer;
-    mock::LayerFE newLayerFE;
-    OutputLayerCompositionState outputLayerCompositionStateTwo;
-    outputLayerCompositionStateTwo.z = sZTwo;
-    setupMocksForLayer(newOutputLayer, newLayerFE, outputLayerCompositionStateTwo,
-                       layerFECompositionState);
-    auto otherLayerState = std::make_unique<LayerState>(&newOutputLayer);
-
-    verifyNonUniqueDifferingFields(*mLayerState, *otherLayerState, LayerStateField::ZOrder);
-
-    EXPECT_TRUE(mLayerState->compare(*otherLayerState));
-    EXPECT_TRUE(otherLayerState->compare(*mLayerState));
-}
-
 TEST_F(LayerStateTest, updateBufferTransform) {
     OutputLayerCompositionState outputLayerCompositionState;
     outputLayerCompositionState.bufferTransform = Hwc2::Transform::FLIP_H;
@@ -954,4 +913,4 @@ TEST_F(LayerStateTest, getNonBufferHash_filtersOutBuffers) {
 }
 
 } // namespace
-} // namespace android::compositionengine::impl::planner
\ No newline at end of file
+} // namespace android::compositionengine::impl::planner
diff --git a/services/surfaceflinger/CompositionEngine/tests/planner/PredictorTest.cpp b/services/surfaceflinger/CompositionEngine/tests/planner/PredictorTest.cpp
index 43e119fc11..1492707ad2 100644
--- a/services/surfaceflinger/CompositionEngine/tests/planner/PredictorTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/planner/PredictorTest.cpp
@@ -31,8 +31,6 @@ const FloatRect sFloatRectOne = FloatRect(100.f, 200.f, 300.f, 400.f);
 const FloatRect sFloatRectTwo = FloatRect(400.f, 300.f, 200.f, 100.f);
 const Rect sRectOne = Rect(1, 2, 3, 4);
 const Rect sRectTwo = Rect(4, 3, 2, 1);
-const constexpr int32_t sZOne = 100;
-const constexpr int32_t sZTwo = 101;
 const constexpr float sAlphaOne = 0.25f;
 const constexpr float sAlphaTwo = 0.5f;
 const Region sRegionOne = Region(sRectOne);
@@ -194,11 +192,11 @@ TEST_F(LayerStackTest, getApproximateMatch_doesNotMatchManyDifferences) {
             .displayFrame = sRectOne,
             .sourceCrop = sFloatRectOne,
             .dataspace = ui::Dataspace::SRGB,
-            .z = sZOne,
     };
     LayerFECompositionState layerFECompositionStateOne;
     layerFECompositionStateOne.alpha = sAlphaOne;
     layerFECompositionStateOne.colorTransformIsIdentity = true;
+    layerFECompositionStateOne.blendMode = hal::BlendMode::NONE;
     setupMocksForLayer(outputLayerOne, layerFEOne, outputLayerCompositionStateOne,
                        layerFECompositionStateOne);
     LayerState layerStateOne(&outputLayerOne);
@@ -210,12 +208,12 @@ TEST_F(LayerStackTest, getApproximateMatch_doesNotMatchManyDifferences) {
             .displayFrame = sRectTwo,
             .sourceCrop = sFloatRectTwo,
             .dataspace = ui::Dataspace::DISPLAY_P3,
-            .z = sZTwo,
     };
     LayerFECompositionState layerFECompositionStateTwo;
     layerFECompositionStateTwo.alpha = sAlphaTwo;
     layerFECompositionStateTwo.colorTransformIsIdentity = false;
     layerFECompositionStateTwo.colorTransform = sMat4One;
+    layerFECompositionStateTwo.blendMode = hal::BlendMode::PREMULTIPLIED;
     setupMocksForLayer(outputLayerTwo, layerFETwo, outputLayerCompositionStateTwo,
                        layerFECompositionStateTwo);
     LayerState layerStateTwo(&outputLayerTwo);
@@ -264,7 +262,6 @@ TEST_F(LayerStackTest, getApproximateMatch_alwaysMatchesClientComposition) {
             .displayFrame = sRectOne,
             .sourceCrop = sFloatRectOne,
             .dataspace = ui::Dataspace::SRGB,
-            .z = sZOne,
     };
     LayerFECompositionState layerFECompositionStateOne;
     layerFECompositionStateOne.buffer = new GraphicBuffer();
@@ -282,7 +279,6 @@ TEST_F(LayerStackTest, getApproximateMatch_alwaysMatchesClientComposition) {
             .displayFrame = sRectTwo,
             .sourceCrop = sFloatRectTwo,
             .dataspace = ui::Dataspace::DISPLAY_P3,
-            .z = sZTwo,
     };
     LayerFECompositionState layerFECompositionStateTwo;
     layerFECompositionStateTwo.buffer = new GraphicBuffer();
@@ -346,6 +342,32 @@ struct PredictionTest : public testing::Test {
     }
 };
 
+TEST_F(LayerStackTest, reorderingChangesNonBufferHash) {
+    mock::OutputLayer outputLayerOne;
+    mock::LayerFE layerFEOne;
+    OutputLayerCompositionState outputLayerCompositionStateOne{
+            .sourceCrop = sFloatRectOne,
+    };
+    LayerFECompositionState layerFECompositionStateOne;
+    setupMocksForLayer(outputLayerOne, layerFEOne, outputLayerCompositionStateOne,
+                       layerFECompositionStateOne);
+    LayerState layerStateOne(&outputLayerOne);
+
+    mock::OutputLayer outputLayerTwo;
+    mock::LayerFE layerFETwo;
+    OutputLayerCompositionState outputLayerCompositionStateTwo{
+            .sourceCrop = sFloatRectTwo,
+    };
+    LayerFECompositionState layerFECompositionStateTwo;
+    setupMocksForLayer(outputLayerTwo, layerFETwo, outputLayerCompositionStateTwo,
+                       layerFECompositionStateTwo);
+    LayerState layerStateTwo(&outputLayerTwo);
+
+    NonBufferHash hash = getNonBufferHash({&layerStateOne, &layerStateTwo});
+    NonBufferHash hashReverse = getNonBufferHash({&layerStateTwo, &layerStateOne});
+    EXPECT_NE(hash, hashReverse);
+}
+
 TEST_F(PredictionTest, constructPrediction) {
     Plan plan;
     plan.addLayerType(hal::Composition::DEVICE);
@@ -525,4 +547,4 @@ TEST_F(PredictorTest, recordMissedPlan_skipsApproximateMatch) {
 }
 
 } // namespace
-} // namespace android::compositionengine::impl::planner
\ No newline at end of file
+} // namespace android::compositionengine::impl::planner