SF: Introduce LayerSnapshot and LayerSnapshotBuilder
Create a builder that walks through the layer hierarchy
to build an ordered list of LayerSnapshots that can be
passed on to CompositionEngine.
This builder does a minimum amount of work to update
an existing set of snapshots based on hierarchy changes
and RequestedLayerState changes.
The builder also introduces a fast path to update
snapshots when there are only buffer updates.
Additionally, pull out LayerSnapshot class from LayerFE
and move it to frontend package.
Bug: 238781169
Test: presubmit
Change-Id: I3fbd6d60968950df2ee97d975c72f9e0aa31b007
diff --git a/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp b/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp
new file mode 100644
index 0000000..bff12d7
--- /dev/null
+++ b/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp
@@ -0,0 +1,833 @@
+/*
+ * Copyright 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// #define LOG_NDEBUG 0
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+#undef LOG_TAG
+#define LOG_TAG "LayerSnapshotBuilder"
+
+#include "LayerSnapshotBuilder.h"
+#include <gui/TraceUtils.h>
+#include <numeric>
+#include "DisplayHardware/HWC2.h"
+#include "DisplayHardware/Hal.h"
+#include "ftl/small_map.h"
+
+namespace android::surfaceflinger::frontend {
+
+using namespace ftl::flag_operators;
+
+namespace {
+FloatRect getMaxDisplayBounds(
+ const display::DisplayMap<ui::LayerStack, frontend::DisplayInfo>& displays) {
+ const ui::Size maxSize = [&displays] {
+ if (displays.empty()) return ui::Size{5000, 5000};
+
+ return std::accumulate(displays.begin(), displays.end(), ui::kEmptySize,
+ [](ui::Size size, const auto& pair) -> ui::Size {
+ const auto& display = pair.second;
+ return {std::max(size.getWidth(), display.info.logicalWidth),
+ std::max(size.getHeight(), display.info.logicalHeight)};
+ });
+ }();
+
+ // Ignore display bounds for now since they will be computed later. Use a large Rect bound
+ // to ensure it's bigger than an actual display will be.
+ const float xMax = static_cast<float>(maxSize.getWidth()) * 10.f;
+ const float yMax = static_cast<float>(maxSize.getHeight()) * 10.f;
+
+ return {-xMax, -yMax, xMax, yMax};
+}
+
+// Applies the given transform to the region, while protecting against overflows caused by any
+// offsets. If applying the offset in the transform to any of the Rects in the region would result
+// in an overflow, they are not added to the output Region.
+Region transformTouchableRegionSafely(const ui::Transform& t, const Region& r,
+ const std::string& debugWindowName) {
+ // Round the translation using the same rounding strategy used by ui::Transform.
+ const auto tx = static_cast<int32_t>(t.tx() + 0.5);
+ const auto ty = static_cast<int32_t>(t.ty() + 0.5);
+
+ ui::Transform transformWithoutOffset = t;
+ transformWithoutOffset.set(0.f, 0.f);
+
+ const Region transformed = transformWithoutOffset.transform(r);
+
+ // Apply the translation to each of the Rects in the region while discarding any that overflow.
+ Region ret;
+ for (const auto& rect : transformed) {
+ Rect newRect;
+ if (__builtin_add_overflow(rect.left, tx, &newRect.left) ||
+ __builtin_add_overflow(rect.top, ty, &newRect.top) ||
+ __builtin_add_overflow(rect.right, tx, &newRect.right) ||
+ __builtin_add_overflow(rect.bottom, ty, &newRect.bottom)) {
+ ALOGE("Applying transform to touchable region of window '%s' resulted in an overflow.",
+ debugWindowName.c_str());
+ continue;
+ }
+ ret.orSelf(newRect);
+ }
+ return ret;
+}
+
+/*
+ * We don't want to send the layer's transform to input, but rather the
+ * parent's transform. This is because Layer's transform is
+ * information about how the buffer is placed on screen. The parent's
+ * transform makes more sense to send since it's information about how the
+ * layer is placed on screen. This transform is used by input to determine
+ * how to go from screen space back to window space.
+ */
+ui::Transform getInputTransform(const LayerSnapshot& snapshot) {
+ if (!snapshot.hasBufferOrSidebandStream()) {
+ return snapshot.geomLayerTransform;
+ }
+ return snapshot.parentTransform;
+}
+
+/**
+ * Similar to getInputTransform, we need to update the bounds to include the transform.
+ * This is because bounds don't include the buffer transform, where the input assumes
+ * that's already included.
+ */
+Rect getInputBounds(const LayerSnapshot& snapshot) {
+ if (!snapshot.hasBufferOrSidebandStream()) {
+ return snapshot.croppedBufferSize;
+ }
+
+ if (snapshot.localTransform.getType() == ui::Transform::IDENTITY ||
+ !snapshot.croppedBufferSize.isValid()) {
+ return snapshot.croppedBufferSize;
+ }
+ return snapshot.localTransform.transform(snapshot.croppedBufferSize);
+}
+
+void fillInputFrameInfo(gui::WindowInfo& info, const ui::Transform& screenToDisplay,
+ const LayerSnapshot& snapshot) {
+ Rect tmpBounds = getInputBounds(snapshot);
+ if (!tmpBounds.isValid()) {
+ info.touchableRegion.clear();
+ // A layer could have invalid input bounds and still expect to receive touch input if it has
+ // replaceTouchableRegionWithCrop. For that case, the input transform needs to be calculated
+ // correctly to determine the coordinate space for input events. Use an empty rect so that
+ // the layer will receive input in its own layer space.
+ tmpBounds = Rect::EMPTY_RECT;
+ }
+
+ // InputDispatcher works in the display device's coordinate space. Here, we calculate the
+ // frame and transform used for the layer, which determines the bounds and the coordinate space
+ // within which the layer will receive input.
+ //
+ // The coordinate space within which each of the bounds are specified is explicitly documented
+ // in the variable name. For example "inputBoundsInLayer" is specified in layer space. A
+ // Transform converts one coordinate space to another, which is apparent in its naming. For
+ // example, "layerToDisplay" transforms layer space to display space.
+ //
+ // Coordinate space definitions:
+ // - display: The display device's coordinate space. Correlates to pixels on the display.
+ // - screen: The post-rotation coordinate space for the display, a.k.a. logical display space.
+ // - layer: The coordinate space of this layer.
+ // - input: The coordinate space in which this layer will receive input events. This could be
+ // different than layer space if a surfaceInset is used, which changes the origin
+ // of the input space.
+ const FloatRect inputBoundsInLayer = tmpBounds.toFloatRect();
+
+ // Clamp surface inset to the input bounds.
+ const auto surfaceInset = static_cast<float>(info.surfaceInset);
+ const float xSurfaceInset =
+ std::max(0.f, std::min(surfaceInset, inputBoundsInLayer.getWidth() / 2.f));
+ const float ySurfaceInset =
+ std::max(0.f, std::min(surfaceInset, inputBoundsInLayer.getHeight() / 2.f));
+
+ // Apply the insets to the input bounds.
+ const FloatRect insetBoundsInLayer(inputBoundsInLayer.left + xSurfaceInset,
+ inputBoundsInLayer.top + ySurfaceInset,
+ inputBoundsInLayer.right - xSurfaceInset,
+ inputBoundsInLayer.bottom - ySurfaceInset);
+
+ // Crop the input bounds to ensure it is within the parent's bounds.
+ const FloatRect croppedInsetBoundsInLayer =
+ snapshot.geomLayerBounds.intersect(insetBoundsInLayer);
+
+ const ui::Transform layerToScreen = getInputTransform(snapshot);
+ const ui::Transform layerToDisplay = screenToDisplay * layerToScreen;
+
+ const Rect roundedFrameInDisplay{layerToDisplay.transform(croppedInsetBoundsInLayer)};
+ info.frameLeft = roundedFrameInDisplay.left;
+ info.frameTop = roundedFrameInDisplay.top;
+ info.frameRight = roundedFrameInDisplay.right;
+ info.frameBottom = roundedFrameInDisplay.bottom;
+
+ ui::Transform inputToLayer;
+ inputToLayer.set(insetBoundsInLayer.left, insetBoundsInLayer.top);
+ const ui::Transform inputToDisplay = layerToDisplay * inputToLayer;
+
+ // InputDispatcher expects a display-to-input transform.
+ info.transform = inputToDisplay.inverse();
+
+ // The touchable region is specified in the input coordinate space. Change it to display space.
+ info.touchableRegion =
+ transformTouchableRegionSafely(inputToDisplay, info.touchableRegion, snapshot.name);
+}
+
+void handleDropInputMode(LayerSnapshot& snapshot, const LayerSnapshot& parentSnapshot) {
+ if (snapshot.inputInfo.inputConfig.test(gui::WindowInfo::InputConfig::NO_INPUT_CHANNEL)) {
+ return;
+ }
+
+ // Check if we need to drop input unconditionally
+ const gui::DropInputMode dropInputMode = snapshot.dropInputMode;
+ if (dropInputMode == gui::DropInputMode::ALL) {
+ snapshot.inputInfo.inputConfig |= gui::WindowInfo::InputConfig::DROP_INPUT;
+ ALOGV("Dropping input for %s as requested by policy.", snapshot.name.c_str());
+ return;
+ }
+
+ // Check if we need to check if the window is obscured by parent
+ if (dropInputMode != gui::DropInputMode::OBSCURED) {
+ return;
+ }
+
+ // Check if the parent has set an alpha on the layer
+ if (parentSnapshot.color.a != 1.0_hf) {
+ snapshot.inputInfo.inputConfig |= gui::WindowInfo::InputConfig::DROP_INPUT;
+ ALOGV("Dropping input for %s as requested by policy because alpha=%f",
+ snapshot.name.c_str(), static_cast<float>(parentSnapshot.color.a));
+ }
+
+ // Check if the parent has cropped the buffer
+ Rect bufferSize = snapshot.croppedBufferSize;
+ if (!bufferSize.isValid()) {
+ snapshot.inputInfo.inputConfig |= gui::WindowInfo::InputConfig::DROP_INPUT_IF_OBSCURED;
+ return;
+ }
+
+ // Screenbounds are the layer bounds cropped by parents, transformed to screenspace.
+ // To check if the layer has been cropped, we take the buffer bounds, apply the local
+ // layer crop and apply the same set of transforms to move to screenspace. If the bounds
+ // match then the layer has not been cropped by its parents.
+ Rect bufferInScreenSpace(snapshot.geomLayerTransform.transform(bufferSize));
+ bool croppedByParent = bufferInScreenSpace != Rect{snapshot.transformedBounds};
+
+ if (croppedByParent) {
+ snapshot.inputInfo.inputConfig |= gui::WindowInfo::InputConfig::DROP_INPUT;
+ ALOGV("Dropping input for %s as requested by policy because buffer is cropped by parent",
+ snapshot.name.c_str());
+ } else {
+ // If the layer is not obscured by its parents (by setting an alpha or crop), then only drop
+ // input if the window is obscured. This check should be done in surfaceflinger but the
+ // logic currently resides in inputflinger. So pass the if_obscured check to input to only
+ // drop input events if the window is obscured.
+ snapshot.inputInfo.inputConfig |= gui::WindowInfo::InputConfig::DROP_INPUT_IF_OBSCURED;
+ }
+}
+
+bool getBufferNeedsFiltering(const LayerSnapshot& snapshot, const ui::Size& unrotatedBufferSize) {
+ const int32_t layerWidth = static_cast<int32_t>(snapshot.geomLayerBounds.getWidth());
+ const int32_t layerHeight = static_cast<int32_t>(snapshot.geomLayerBounds.getHeight());
+ return layerWidth != unrotatedBufferSize.width || layerHeight != unrotatedBufferSize.height;
+}
+
+auto getBlendMode(const LayerSnapshot& snapshot, const RequestedLayerState& requested) {
+ auto blendMode = Hwc2::IComposerClient::BlendMode::NONE;
+ if (snapshot.alpha != 1.0f || !snapshot.isContentOpaque()) {
+ blendMode = requested.premultipliedAlpha ? Hwc2::IComposerClient::BlendMode::PREMULTIPLIED
+ : Hwc2::IComposerClient::BlendMode::COVERAGE;
+ }
+ return blendMode;
+}
+
+} // namespace
+
+LayerSnapshot LayerSnapshotBuilder::getRootSnapshot() {
+ LayerSnapshot snapshot;
+ snapshot.changes = ftl::Flags<RequestedLayerState::Changes>();
+ snapshot.isHiddenByPolicyFromParent = false;
+ snapshot.isHiddenByPolicyFromRelativeParent = false;
+ snapshot.parentTransform.reset();
+ snapshot.geomLayerTransform.reset();
+ snapshot.geomInverseLayerTransform.reset();
+ snapshot.geomLayerBounds = getMaxDisplayBounds({});
+ snapshot.roundedCorner = RoundedCornerState();
+ snapshot.stretchEffect = {};
+ snapshot.outputFilter.layerStack = ui::DEFAULT_LAYER_STACK;
+ snapshot.outputFilter.toInternalDisplay = false;
+ snapshot.isSecure = false;
+ snapshot.color.a = 1.0_hf;
+ snapshot.colorTransformIsIdentity = true;
+ snapshot.shadowRadius = 0.f;
+ snapshot.layerMetadata.mMap.clear();
+ snapshot.relativeLayerMetadata.mMap.clear();
+ snapshot.inputInfo.touchOcclusionMode = gui::TouchOcclusionMode::BLOCK_UNTRUSTED;
+ snapshot.dropInputMode = gui::DropInputMode::NONE;
+ snapshot.isTrustedOverlay = false;
+ return snapshot;
+}
+
+LayerSnapshotBuilder::LayerSnapshotBuilder() : mRootSnapshot(getRootSnapshot()) {}
+
+LayerSnapshotBuilder::LayerSnapshotBuilder(Args args) : LayerSnapshotBuilder() {
+ args.forceUpdate = true;
+ updateSnapshots(args);
+}
+
+bool LayerSnapshotBuilder::tryFastUpdate(const Args& args) {
+ if (args.forceUpdate) {
+ // force update requested, so skip the fast path
+ return false;
+ }
+
+ if (args.layerLifecycleManager.getGlobalChanges().get() == 0) {
+ // there are no changes, so just clear the change flags from before.
+ for (auto& snapshot : mSnapshots) {
+ snapshot->changes.clear();
+ snapshot->contentDirty = false;
+ }
+ return true;
+ }
+
+ if (args.layerLifecycleManager.getGlobalChanges() != RequestedLayerState::Changes::Content) {
+ // We have changes that require us to walk the hierarchy and update child layers.
+ // No fast path for you.
+ return false;
+ }
+
+ // There are only content changes which do not require any child layer snapshots to be updated.
+ ALOGV("%s", __func__);
+ ATRACE_NAME("FastPath");
+
+ // Collect layers with changes
+ ftl::SmallMap<uint32_t, RequestedLayerState*, 10> layersWithChanges;
+ for (auto& layer : args.layerLifecycleManager.getLayers()) {
+ if (layer->changes.test(RequestedLayerState::Changes::Content)) {
+ layersWithChanges.emplace_or_replace(layer->id, layer.get());
+ }
+ }
+
+ // Walk through the snapshots, clearing previous change flags and updating the snapshots
+ // if needed.
+ for (auto& snapshot : mSnapshots) {
+ snapshot->changes.clear();
+ snapshot->contentDirty = false;
+ auto it = layersWithChanges.find(snapshot->path.id);
+ if (it != layersWithChanges.end()) {
+ ALOGV("%s fast path snapshot changes = %s", __func__,
+ mRootSnapshot.changes.string().c_str());
+ LayerHierarchy::TraversalPath root = LayerHierarchy::TraversalPath::ROOT;
+ updateSnapshot(*snapshot, args, *it->second, mRootSnapshot, root);
+ }
+ }
+ return true;
+}
+
+void LayerSnapshotBuilder::updateSnapshots(const Args& args) {
+ ATRACE_NAME("UpdateSnapshots");
+ ALOGV("%s updateSnapshots force = %s", __func__, std::to_string(args.forceUpdate).c_str());
+ if (args.forceUpdate || args.displayChanges) {
+ mRootSnapshot.geomLayerBounds = getMaxDisplayBounds(args.displays);
+ }
+ if (args.displayChanges) {
+ mRootSnapshot.changes = RequestedLayerState::Changes::AffectsChildren |
+ RequestedLayerState::Changes::Geometry;
+ }
+ LayerHierarchy::TraversalPath root = LayerHierarchy::TraversalPath::ROOT;
+ for (auto& [childHierarchy, variant] : args.root.mChildren) {
+ LayerHierarchy::ScopedAddToTraversalPath addChildToPath(root,
+ childHierarchy->getLayer()->id,
+ variant);
+ updateSnapshotsInHierarchy(args, *childHierarchy, root, mRootSnapshot);
+ }
+
+ sortSnapshotsByZ(args);
+ mRootSnapshot.changes.clear();
+
+ // Destroy unreachable snapshots
+ if (args.layerLifecycleManager.getDestroyedLayers().empty()) {
+ return;
+ }
+
+ std::unordered_set<uint32_t> destroyedLayerIds;
+ for (auto& destroyedLayer : args.layerLifecycleManager.getDestroyedLayers()) {
+ destroyedLayerIds.emplace(destroyedLayer->id);
+ }
+ auto it = mSnapshots.begin();
+ while (it < mSnapshots.end()) {
+ auto& traversalPath = it->get()->path;
+ if (destroyedLayerIds.find(traversalPath.id) == destroyedLayerIds.end()) {
+ it++;
+ continue;
+ }
+
+ mIdToSnapshot.erase(traversalPath);
+ std::iter_swap(it, mSnapshots.end() - 1);
+ mSnapshots.erase(mSnapshots.end() - 1);
+ }
+}
+
+void LayerSnapshotBuilder::update(const Args& args) {
+ if (tryFastUpdate(args)) {
+ return;
+ }
+ updateSnapshots(args);
+}
+
+void LayerSnapshotBuilder::updateSnapshotsInHierarchy(const Args& args,
+ const LayerHierarchy& hierarchy,
+ LayerHierarchy::TraversalPath& traversalPath,
+ const LayerSnapshot& parentSnapshot) {
+ const RequestedLayerState* layer = hierarchy.getLayer();
+ LayerSnapshot* snapshot = getOrCreateSnapshot(traversalPath, *layer);
+ if (traversalPath.isRelative()) {
+ bool parentIsRelative = traversalPath.variant == LayerHierarchy::Variant::Relative;
+ updateRelativeState(*snapshot, parentSnapshot, parentIsRelative, args);
+ } else {
+ if (traversalPath.isAttached()) {
+ resetRelativeState(*snapshot);
+ }
+ updateSnapshot(*snapshot, args, *layer, parentSnapshot, traversalPath);
+ }
+
+ // If layer is hidden by policy we can avoid update its children. If the visibility
+ // changed this update, then we still need to set the visibility on all the children.
+ if (snapshot->isHiddenByPolicy() &&
+ (!snapshot->changes.any(RequestedLayerState::Changes::Visibility |
+ RequestedLayerState::Changes::Hierarchy))) {
+ return;
+ }
+
+ for (auto& [childHierarchy, variant] : hierarchy.mChildren) {
+ LayerHierarchy::ScopedAddToTraversalPath addChildToPath(traversalPath,
+ childHierarchy->getLayer()->id,
+ variant);
+ updateSnapshotsInHierarchy(args, *childHierarchy, traversalPath, *snapshot);
+ }
+}
+
+LayerSnapshot* LayerSnapshotBuilder::getSnapshot(uint32_t layerId) const {
+ if (layerId == UNASSIGNED_LAYER_ID) {
+ return nullptr;
+ }
+ LayerHierarchy::TraversalPath path{.id = layerId};
+ return getSnapshot(path);
+}
+
+LayerSnapshot* LayerSnapshotBuilder::getSnapshot(const LayerHierarchy::TraversalPath& id) const {
+ auto it = mIdToSnapshot.find(id);
+ return it == mIdToSnapshot.end() ? nullptr : it->second;
+}
+
+LayerSnapshot* LayerSnapshotBuilder::getOrCreateSnapshot(const LayerHierarchy::TraversalPath& id,
+ const RequestedLayerState& layer) {
+ auto snapshot = getSnapshot(id);
+ if (snapshot) {
+ return snapshot;
+ }
+
+ mSnapshots.emplace_back(std::make_unique<LayerSnapshot>(layer, id));
+ snapshot = mSnapshots.back().get();
+ snapshot->globalZ = static_cast<size_t>(mSnapshots.size()) - 1;
+ mIdToSnapshot[id] = snapshot;
+ return snapshot;
+}
+
+void LayerSnapshotBuilder::sortSnapshotsByZ(const Args& args) {
+ if (!args.forceUpdate &&
+ !args.layerLifecycleManager.getGlobalChanges().any(
+ RequestedLayerState::Changes::Hierarchy |
+ RequestedLayerState::Changes::Visibility)) {
+ // We are not force updating and there are no hierarchy or visibility changes. Avoid sorting
+ // the snapshots.
+ return;
+ }
+
+ size_t globalZ = 0;
+ args.root.traverseInZOrder(
+ [this, &globalZ](const LayerHierarchy&,
+ const LayerHierarchy::TraversalPath& traversalPath) -> bool {
+ LayerSnapshot* snapshot = getSnapshot(traversalPath);
+ if (!snapshot) {
+ return false;
+ }
+
+ if (snapshot->isHiddenByPolicy() &&
+ !snapshot->changes.test(RequestedLayerState::Changes::Visibility)) {
+ return false;
+ }
+
+ if (snapshot->isVisible) {
+ size_t oldZ = snapshot->globalZ;
+ size_t newZ = globalZ++;
+ snapshot->globalZ = newZ;
+ if (oldZ == newZ) {
+ return true;
+ }
+ mSnapshots[newZ]->globalZ = oldZ;
+ std::iter_swap(mSnapshots.begin() + static_cast<ssize_t>(oldZ),
+ mSnapshots.begin() + static_cast<ssize_t>(newZ));
+ }
+
+ return true;
+ });
+
+ while (globalZ < mSnapshots.size()) {
+ mSnapshots[globalZ]->globalZ = globalZ;
+ mSnapshots[globalZ]->isVisible = false;
+ globalZ++;
+ }
+}
+
+void LayerSnapshotBuilder::updateRelativeState(LayerSnapshot& snapshot,
+ const LayerSnapshot& parentSnapshot,
+ bool parentIsRelative, const Args& args) {
+ if (parentIsRelative) {
+ snapshot.isHiddenByPolicyFromRelativeParent = parentSnapshot.isHiddenByPolicyFromParent;
+ if (args.includeMetadata) {
+ snapshot.relativeLayerMetadata = parentSnapshot.layerMetadata;
+ }
+ } else {
+ snapshot.isHiddenByPolicyFromRelativeParent =
+ parentSnapshot.isHiddenByPolicyFromRelativeParent;
+ if (args.includeMetadata) {
+ snapshot.relativeLayerMetadata = parentSnapshot.relativeLayerMetadata;
+ }
+ }
+ snapshot.isVisible = snapshot.getIsVisible();
+}
+
+void LayerSnapshotBuilder::resetRelativeState(LayerSnapshot& snapshot) {
+ snapshot.isHiddenByPolicyFromRelativeParent = false;
+ snapshot.relativeLayerMetadata.mMap.clear();
+}
+
+uint32_t getDisplayRotationFlags(
+ const display::DisplayMap<ui::LayerStack, frontend::DisplayInfo>& displays,
+ const ui::LayerStack& layerStack) {
+ static frontend::DisplayInfo sDefaultDisplayInfo = {.isPrimary = false};
+ auto display = displays.get(layerStack).value_or(sDefaultDisplayInfo).get();
+ return display.isPrimary ? display.rotationFlags : 0;
+}
+
+void LayerSnapshotBuilder::updateSnapshot(LayerSnapshot& snapshot, const Args& args,
+ const RequestedLayerState& requested,
+ const LayerSnapshot& parentSnapshot,
+ const LayerHierarchy::TraversalPath& path) {
+ // Always update flags and visibility
+ ftl::Flags<RequestedLayerState::Changes> parentChanges = parentSnapshot.changes &
+ (RequestedLayerState::Changes::Hierarchy | RequestedLayerState::Changes::Geometry |
+ RequestedLayerState::Changes::Visibility | RequestedLayerState::Changes::Metadata |
+ RequestedLayerState::Changes::AffectsChildren);
+ snapshot.changes = parentChanges | requested.changes;
+ snapshot.isHiddenByPolicyFromParent =
+ parentSnapshot.isHiddenByPolicyFromParent || requested.isHiddenByPolicy();
+ snapshot.contentDirty = requested.what & layer_state_t::CONTENT_DIRTY;
+ if (snapshot.isHiddenByPolicyFromParent) {
+ snapshot.isVisible = false;
+ return;
+ }
+
+ uint32_t displayRotationFlags =
+ getDisplayRotationFlags(args.displays, snapshot.outputFilter.layerStack);
+
+ const bool forceUpdate = args.forceUpdate ||
+ snapshot.changes.any(RequestedLayerState::Changes::Visibility |
+ RequestedLayerState::Changes::Created);
+
+ if (forceUpdate || snapshot.changes.any(RequestedLayerState::Changes::AffectsChildren)) {
+ // If root layer, use the layer stack otherwise get the parent's layer stack.
+ snapshot.color.a = parentSnapshot.color.a * requested.color.a;
+ snapshot.alpha = snapshot.color.a;
+ snapshot.isSecure =
+ parentSnapshot.isSecure || (requested.flags & layer_state_t::eLayerSecure);
+ snapshot.isTrustedOverlay = parentSnapshot.isTrustedOverlay || requested.isTrustedOverlay;
+ snapshot.outputFilter.layerStack = requested.parentId != UNASSIGNED_LAYER_ID
+ ? parentSnapshot.outputFilter.layerStack
+ : requested.layerStack;
+ snapshot.outputFilter.toInternalDisplay = parentSnapshot.outputFilter.toInternalDisplay ||
+ (requested.flags & layer_state_t::eLayerSkipScreenshot);
+ snapshot.stretchEffect = (requested.stretchEffect.hasEffect())
+ ? requested.stretchEffect
+ : parentSnapshot.stretchEffect;
+ if (!parentSnapshot.colorTransformIsIdentity) {
+ snapshot.colorTransform = parentSnapshot.colorTransform * requested.colorTransform;
+ snapshot.colorTransformIsIdentity = false;
+ } else {
+ snapshot.colorTransform = requested.colorTransform;
+ snapshot.colorTransformIsIdentity = !requested.hasColorTransform;
+ }
+ }
+
+ if (forceUpdate || requested.changes.get() != 0) {
+ snapshot.compositionType = requested.getCompositionType();
+ snapshot.dimmingEnabled = requested.dimmingEnabled;
+ snapshot.layerOpaqueFlagSet =
+ (requested.flags & layer_state_t::eLayerOpaque) == layer_state_t::eLayerOpaque;
+ }
+
+ if (forceUpdate || requested.what & layer_state_t::BUFFER_CHANGES) {
+ snapshot.acquireFence =
+ (requested.bufferData) ? requested.bufferData->acquireFence : Fence::NO_FENCE;
+ snapshot.buffer =
+ requested.externalTexture ? requested.externalTexture->getBuffer() : nullptr;
+ snapshot.bufferSize = requested.getBufferSize(displayRotationFlags);
+ snapshot.geomBufferSize = snapshot.bufferSize;
+ snapshot.croppedBufferSize = requested.getCroppedBufferSize(snapshot.bufferSize);
+ snapshot.dataspace = requested.dataspace;
+ snapshot.externalTexture = requested.externalTexture;
+ snapshot.frameNumber = (requested.bufferData) ? requested.bufferData->frameNumber : 0;
+ snapshot.geomBufferTransform = requested.bufferTransform;
+ snapshot.geomBufferUsesDisplayInverseTransform = requested.transformToDisplayInverse;
+ snapshot.geomContentCrop = requested.getBufferCrop();
+ snapshot.geomUsesSourceCrop = snapshot.hasBufferOrSidebandStream();
+ snapshot.hasProtectedContent = requested.externalTexture &&
+ requested.externalTexture->getUsage() & GRALLOC_USAGE_PROTECTED;
+ snapshot.isHdrY410 = requested.dataspace == ui::Dataspace::BT2020_ITU_PQ &&
+ requested.api == NATIVE_WINDOW_API_MEDIA &&
+ requested.bufferData->getPixelFormat() == HAL_PIXEL_FORMAT_RGBA_1010102;
+ snapshot.sidebandStream = requested.sidebandStream;
+ snapshot.surfaceDamage = requested.surfaceDamageRegion;
+ snapshot.transparentRegionHint = requested.transparentRegion;
+ }
+
+ if (forceUpdate || snapshot.changes.any(RequestedLayerState::Changes::Content)) {
+ snapshot.color.rgb = requested.getColor().rgb;
+ snapshot.isColorspaceAgnostic = requested.colorSpaceAgnostic;
+ snapshot.backgroundBlurRadius = static_cast<int>(requested.backgroundBlurRadius);
+ snapshot.blurRegions = requested.blurRegions;
+ snapshot.hdrMetadata = requested.hdrMetadata;
+ }
+
+ if (forceUpdate ||
+ snapshot.changes.any(RequestedLayerState::Changes::Hierarchy |
+ RequestedLayerState::Changes::Geometry)) {
+ updateLayerBounds(snapshot, requested, parentSnapshot, displayRotationFlags);
+ updateRoundedCorner(snapshot, requested, parentSnapshot);
+ }
+
+ if (forceUpdate ||
+ snapshot.changes.any(RequestedLayerState::Changes::Hierarchy |
+ RequestedLayerState::Changes::Geometry |
+ RequestedLayerState::Changes::Input)) {
+ static frontend::DisplayInfo sDefaultInfo = {.isSecure = false};
+ const std::optional<frontend::DisplayInfo> displayInfo =
+ args.displays.get(snapshot.outputFilter.layerStack);
+ bool noValidDisplay = !displayInfo.has_value();
+ updateInput(snapshot, requested, parentSnapshot, displayInfo.value_or(sDefaultInfo),
+ noValidDisplay, path);
+ }
+
+ // computed snapshot properties
+ updateShadows(snapshot, requested, args.globalShadowSettings);
+ if (args.includeMetadata) {
+ snapshot.layerMetadata = parentSnapshot.layerMetadata;
+ snapshot.layerMetadata.merge(requested.metadata);
+ }
+ snapshot.forceClientComposition = snapshot.isHdrY410 || snapshot.shadowSettings.length > 0 ||
+ requested.blurRegions.size() > 0 || snapshot.stretchEffect.hasEffect();
+ snapshot.isVisible = snapshot.getIsVisible();
+ snapshot.isOpaque = snapshot.isContentOpaque() && !snapshot.roundedCorner.hasRoundedCorners() &&
+ snapshot.color.a == 1.f;
+ snapshot.blendMode = getBlendMode(snapshot, requested);
+
+ ALOGV("%supdated [%d]%s changes parent:%s global:%s local:%s requested:%s %s from parent %s",
+ args.forceUpdate ? "Force " : "", requested.id, requested.name.c_str(),
+ parentSnapshot.changes.string().c_str(), snapshot.changes.string().c_str(),
+ requested.changes.string().c_str(), std::to_string(requested.what).c_str(),
+ snapshot.getDebugString().c_str(), parentSnapshot.getDebugString().c_str());
+}
+
+void LayerSnapshotBuilder::updateRoundedCorner(LayerSnapshot& snapshot,
+ const RequestedLayerState& requested,
+ const LayerSnapshot& parentSnapshot) {
+ snapshot.roundedCorner = RoundedCornerState();
+ RoundedCornerState parentRoundedCorner;
+ if (parentSnapshot.roundedCorner.hasRoundedCorners()) {
+ parentRoundedCorner = parentSnapshot.roundedCorner;
+ ui::Transform t = snapshot.localTransform.inverse();
+ parentRoundedCorner.cropRect = t.transform(parentRoundedCorner.cropRect);
+ parentRoundedCorner.radius.x *= t.getScaleX();
+ parentRoundedCorner.radius.y *= t.getScaleY();
+ }
+
+ FloatRect layerCropRect = snapshot.croppedBufferSize.toFloatRect();
+ const vec2 radius(requested.cornerRadius, requested.cornerRadius);
+ RoundedCornerState layerSettings(layerCropRect, radius);
+ const bool layerSettingsValid = layerSettings.hasRoundedCorners() && !layerCropRect.isEmpty();
+ const bool parentRoundedCornerValid = parentRoundedCorner.hasRoundedCorners();
+ if (layerSettingsValid && parentRoundedCornerValid) {
+ // If the parent and the layer have rounded corner settings, use the parent settings if
+ // the parent crop is entirely inside the layer crop. This has limitations and cause
+ // rendering artifacts. See b/200300845 for correct fix.
+ if (parentRoundedCorner.cropRect.left > layerCropRect.left &&
+ parentRoundedCorner.cropRect.top > layerCropRect.top &&
+ parentRoundedCorner.cropRect.right < layerCropRect.right &&
+ parentRoundedCorner.cropRect.bottom < layerCropRect.bottom) {
+ snapshot.roundedCorner = parentRoundedCorner;
+ } else {
+ snapshot.roundedCorner = layerSettings;
+ }
+ } else if (layerSettingsValid) {
+ snapshot.roundedCorner = layerSettings;
+ } else if (parentRoundedCornerValid) {
+ snapshot.roundedCorner = parentRoundedCorner;
+ }
+}
+
+void LayerSnapshotBuilder::updateLayerBounds(LayerSnapshot& snapshot,
+ const RequestedLayerState& requested,
+ const LayerSnapshot& parentSnapshot,
+ uint32_t displayRotationFlags) {
+ snapshot.croppedBufferSize = requested.getCroppedBufferSize(snapshot.bufferSize);
+ snapshot.geomCrop = requested.crop;
+ snapshot.localTransform = requested.getTransform(displayRotationFlags);
+ snapshot.localTransformInverse = snapshot.localTransform.inverse();
+ snapshot.geomLayerTransform = parentSnapshot.geomLayerTransform * snapshot.localTransform;
+ snapshot.invalidTransform = !LayerSnapshot::isTransformValid(snapshot.geomLayerTransform);
+ if (snapshot.invalidTransform) {
+ ALOGW("Resetting transform for %s because it has an invalid transformation.",
+ requested.getDebugStringShort().c_str());
+ snapshot.geomLayerTransform.reset();
+ }
+ snapshot.geomInverseLayerTransform = snapshot.geomLayerTransform.inverse();
+
+ FloatRect parentBounds = parentSnapshot.geomLayerBounds;
+ parentBounds = snapshot.localTransform.inverse().transform(parentBounds);
+ snapshot.geomLayerBounds =
+ (requested.externalTexture) ? snapshot.bufferSize.toFloatRect() : parentBounds;
+ if (!requested.crop.isEmpty()) {
+ snapshot.geomLayerBounds = snapshot.geomLayerBounds.intersect(requested.crop.toFloatRect());
+ }
+ snapshot.geomLayerBounds = snapshot.geomLayerBounds.intersect(parentBounds);
+ snapshot.transformedBounds = snapshot.geomLayerTransform.transform(snapshot.geomLayerBounds);
+ snapshot.parentTransform = parentSnapshot.geomLayerTransform;
+
+ // Subtract the transparent region and snap to the bounds
+ Rect bounds =
+ RequestedLayerState::reduce(snapshot.croppedBufferSize, requested.transparentRegion);
+ snapshot.cursorFrame = snapshot.geomLayerTransform.transform(bounds);
+
+ // TODO(b/238781169) use dest vs src
+ snapshot.bufferNeedsFiltering = snapshot.externalTexture &&
+ getBufferNeedsFiltering(snapshot,
+ requested.getUnrotatedBufferSize(displayRotationFlags));
+}
+
+void LayerSnapshotBuilder::updateShadows(LayerSnapshot& snapshot,
+ const RequestedLayerState& requested,
+ const renderengine::ShadowSettings& globalShadowSettings) {
+ snapshot.shadowRadius = requested.shadowRadius;
+ snapshot.shadowSettings.length = requested.shadowRadius;
+ if (snapshot.shadowRadius > 0.f) {
+ snapshot.shadowSettings = globalShadowSettings;
+
+ // Note: this preserves existing behavior of shadowing the entire layer and not cropping
+ // it if transparent regions are present. This may not be necessary since shadows are
+ // typically cast by layers without transparent regions.
+ snapshot.shadowSettings.boundaries = snapshot.geomLayerBounds;
+
+ // If the casting layer is translucent, we need to fill in the shadow underneath the
+ // layer. Otherwise the generated shadow will only be shown around the casting layer.
+ snapshot.shadowSettings.casterIsTranslucent =
+ !snapshot.isContentOpaque() || (snapshot.alpha < 1.0f);
+ snapshot.shadowSettings.ambientColor *= snapshot.alpha;
+ snapshot.shadowSettings.spotColor *= snapshot.alpha;
+ }
+}
+
+void LayerSnapshotBuilder::updateInput(LayerSnapshot& snapshot,
+ const RequestedLayerState& requested,
+ const LayerSnapshot& parentSnapshot,
+ const frontend::DisplayInfo& displayInfo,
+ bool noValidDisplay,
+ const LayerHierarchy::TraversalPath& path) {
+ snapshot.inputInfo.displayId = static_cast<int32_t>(snapshot.outputFilter.layerStack.id);
+ if (!requested.hasInputInfo()) {
+ snapshot.inputInfo.inputConfig = gui::WindowInfo::InputConfig::NO_INPUT_CHANNEL;
+ return;
+ }
+
+ fillInputFrameInfo(snapshot.inputInfo, displayInfo.transform, snapshot);
+
+ if (noValidDisplay) {
+ // Do not let the window receive touches if it is not associated with a valid display
+ // transform. We still allow the window to receive keys and prevent ANRs.
+ snapshot.inputInfo.inputConfig |= gui::WindowInfo::InputConfig::NOT_TOUCHABLE;
+ }
+
+ // For compatibility reasons we let layers which can receive input
+ // receive input before they have actually submitted a buffer. Because
+ // of this we use canReceiveInput instead of isVisible to check the
+ // policy-visibility, ignoring the buffer state. However for layers with
+ // hasInputInfo()==false we can use the real visibility state.
+ // We are just using these layers for occlusion detection in
+ // InputDispatcher, and obviously if they aren't visible they can't occlude
+ // anything.
+ const bool visible = requested.hasInputInfo() ? snapshot.canReceiveInput() : snapshot.isVisible;
+ snapshot.inputInfo.setInputConfig(gui::WindowInfo::InputConfig::NOT_VISIBLE, !visible);
+
+ snapshot.inputInfo.alpha = snapshot.color.a;
+ snapshot.inputInfo.touchOcclusionMode = parentSnapshot.inputInfo.touchOcclusionMode;
+ if (requested.dropInputMode == gui::DropInputMode::ALL ||
+ parentSnapshot.dropInputMode == gui::DropInputMode::ALL) {
+ snapshot.dropInputMode = gui::DropInputMode::ALL;
+ } else if (requested.dropInputMode == gui::DropInputMode::OBSCURED ||
+ parentSnapshot.dropInputMode == gui::DropInputMode::OBSCURED) {
+ snapshot.dropInputMode = gui::DropInputMode::OBSCURED;
+ } else {
+ snapshot.dropInputMode = gui::DropInputMode::NONE;
+ }
+
+ handleDropInputMode(snapshot, parentSnapshot);
+
+ // If the window will be blacked out on a display because the display does not have the secure
+ // flag and the layer has the secure flag set, then drop input.
+ if (!displayInfo.isSecure && snapshot.isSecure) {
+ snapshot.inputInfo.inputConfig |= gui::WindowInfo::InputConfig::DROP_INPUT;
+ }
+
+ auto cropLayerSnapshot = getSnapshot(requested.touchCropId);
+ if (snapshot.inputInfo.replaceTouchableRegionWithCrop) {
+ const Rect bounds(cropLayerSnapshot ? cropLayerSnapshot->transformedBounds
+ : snapshot.transformedBounds);
+ snapshot.inputInfo.touchableRegion = Region(displayInfo.transform.transform(bounds));
+ } else if (cropLayerSnapshot) {
+ snapshot.inputInfo.touchableRegion = snapshot.inputInfo.touchableRegion.intersect(
+ displayInfo.transform.transform(Rect{cropLayerSnapshot->transformedBounds}));
+ }
+
+ // Inherit the trusted state from the parent hierarchy, but don't clobber the trusted state
+ // if it was set by WM for a known system overlay
+ if (snapshot.isTrustedOverlay) {
+ snapshot.inputInfo.inputConfig |= gui::WindowInfo::InputConfig::TRUSTED_OVERLAY;
+ }
+
+ // If the layer is a clone, we need to crop the input region to cloned root to prevent
+ // touches from going outside the cloned area.
+ if (path.isClone()) {
+ snapshot.inputInfo.inputConfig |= gui::WindowInfo::InputConfig::CLONE;
+ auto clonedRootSnapshot = getSnapshot(path.mirrorRootIds.back());
+ if (clonedRootSnapshot) {
+ const Rect rect =
+ displayInfo.transform.transform(Rect{clonedRootSnapshot->transformedBounds});
+ snapshot.inputInfo.touchableRegion = snapshot.inputInfo.touchableRegion.intersect(rect);
+ }
+ }
+}
+
+std::vector<std::unique_ptr<LayerSnapshot>>& LayerSnapshotBuilder::getSnapshots() {
+ return mSnapshots;
+}
+
+} // namespace android::surfaceflinger::frontend