libs/hwui/OpReorderer.cpp - platform/frameworks/base - Gitiles

 /*
  * Copyright (C) 2015 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.
  */

 #include "OpReorderer.h"

 #include "utils/PaintUtils.h"
 #include "RenderNode.h"

 #include "SkCanvas.h"
 #include "utils/Trace.h"

 namespace android {
 namespace uirenderer {

 class BatchBase {

 public:
     BatchBase(batchid_t batchId, BakedOpState* op, bool merging)
         : mBatchId(batchId)
         , mMerging(merging) {
         mBounds = op->computedState.clippedBounds;
         mOps.push_back(op);
     }

     bool intersects(const Rect& rect) const {
         if (!rect.intersects(mBounds)) return false;

         for (const BakedOpState* op : mOps) {
             if (rect.intersects(op->computedState.clippedBounds)) {
                 return true;
             }
         }
         return false;
     }

     batchid_t getBatchId() const { return mBatchId; }
     bool isMerging() const { return mMerging; }

     const std::vector<BakedOpState*>& getOps() const { return mOps; }

     void dump() const {
         ALOGD("    Batch %p, id %d, merging %d, count %d, bounds " RECT_STRING,
                 this, mBatchId, mMerging, mOps.size(), RECT_ARGS(mBounds));
     }
 protected:
     batchid_t mBatchId;
     Rect mBounds;
     std::vector<BakedOpState*> mOps;
     bool mMerging;
 };

 class OpBatch : public BatchBase {
 public:
     static void* operator new(size_t size, LinearAllocator& allocator) {
         return allocator.alloc(size);
     }

     OpBatch(batchid_t batchId, BakedOpState* op)
             : BatchBase(batchId, op, false) {
     }

     void batchOp(BakedOpState* op) {
         mBounds.unionWith(op->computedState.clippedBounds);
         mOps.push_back(op);
     }
 };

 class MergingOpBatch : public BatchBase {
 public:
     static void* operator new(size_t size, LinearAllocator& allocator) {
         return allocator.alloc(size);
     }

     MergingOpBatch(batchid_t batchId, BakedOpState* op)
             : BatchBase(batchId, op, true) {
     }

     /*
      * Helper for determining if a new op can merge with a MergingDrawBatch based on their bounds
      * and clip side flags. Positive bounds delta means new bounds fit in old.
      */
     static inline bool checkSide(const int currentFlags, const int newFlags, const int side,
             float boundsDelta) {
         bool currentClipExists = currentFlags & side;
         bool newClipExists = newFlags & side;

         // if current is clipped, we must be able to fit new bounds in current
         if (boundsDelta > 0 && currentClipExists) return false;

         // if new is clipped, we must be able to fit current bounds in new
         if (boundsDelta < 0 && newClipExists) return false;

         return true;
     }

     static bool paintIsDefault(const SkPaint& paint) {
         return paint.getAlpha() == 255
                 && paint.getColorFilter() == nullptr
                 && paint.getShader() == nullptr;
     }

     static bool paintsAreEquivalent(const SkPaint& a, const SkPaint& b) {
         return a.getAlpha() == b.getAlpha()
                 && a.getColorFilter() == b.getColorFilter()
                 && a.getShader() == b.getShader();
     }

     /*
      * Checks if a (mergeable) op can be merged into this batch
      *
      * If true, the op's multiDraw must be guaranteed to handle both ops simultaneously, so it is
      * important to consider all paint attributes used in the draw calls in deciding both a) if an
      * op tries to merge at all, and b) if the op can merge with another set of ops
      *
      * False positives can lead to information from the paints of subsequent merged operations being
      * dropped, so we make simplifying qualifications on the ops that can merge, per op type.
      */
     bool canMergeWith(BakedOpState* op) const {
         bool isTextBatch = getBatchId() == OpBatchType::Text
                 || getBatchId() == OpBatchType::ColorText;

         // Overlapping other operations is only allowed for text without shadow. For other ops,
         // multiDraw isn't guaranteed to overdraw correctly
         if (!isTextBatch || PaintUtils::hasTextShadow(op->op->paint)) {
             if (intersects(op->computedState.clippedBounds)) return false;
         }

         const BakedOpState* lhs = op;
         const BakedOpState* rhs = mOps[0];

         if (!MathUtils::areEqual(lhs->alpha, rhs->alpha)) return false;

         // Identical round rect clip state means both ops will clip in the same way, or not at all.
         // As the state objects are const, we can compare their pointers to determine mergeability
         if (lhs->roundRectClipState != rhs->roundRectClipState) return false;
         if (lhs->projectionPathMask != rhs->projectionPathMask) return false;

         /* Clipping compatibility check
          *
          * Exploits the fact that if a op or batch is clipped on a side, its bounds will equal its
          * clip for that side.
          */
         const int currentFlags = mClipSideFlags;
         const int newFlags = op->computedState.clipSideFlags;
         if (currentFlags != OpClipSideFlags::None || newFlags != OpClipSideFlags::None) {
             const Rect& opBounds = op->computedState.clippedBounds;
             float boundsDelta = mBounds.left - opBounds.left;
             if (!checkSide(currentFlags, newFlags, OpClipSideFlags::Left, boundsDelta)) return false;
             boundsDelta = mBounds.top - opBounds.top;
             if (!checkSide(currentFlags, newFlags, OpClipSideFlags::Top, boundsDelta)) return false;

             // right and bottom delta calculation reversed to account for direction
             boundsDelta = opBounds.right - mBounds.right;
             if (!checkSide(currentFlags, newFlags, OpClipSideFlags::Right, boundsDelta)) return false;
             boundsDelta = opBounds.bottom - mBounds.bottom;
             if (!checkSide(currentFlags, newFlags, OpClipSideFlags::Bottom, boundsDelta)) return false;
         }

         const SkPaint* newPaint = op->op->paint;
         const SkPaint* oldPaint = mOps[0]->op->paint;

         if (newPaint == oldPaint) {
             // if paints are equal, then modifiers + paint attribs don't need to be compared
             return true;
         } else if (newPaint && !oldPaint) {
             return paintIsDefault(*newPaint);
         } else if (!newPaint && oldPaint) {
             return paintIsDefault(*oldPaint);
         }
         return paintsAreEquivalent(*newPaint, *oldPaint);
     }

     void mergeOp(BakedOpState* op) {
         mBounds.unionWith(op->computedState.clippedBounds);
         mOps.push_back(op);

         const int newClipSideFlags = op->computedState.clipSideFlags;
         mClipSideFlags |= newClipSideFlags;

         const Rect& opClip = op->computedState.clipRect;
         if (newClipSideFlags & OpClipSideFlags::Left) mClipRect.left = opClip.left;
         if (newClipSideFlags & OpClipSideFlags::Top) mClipRect.top = opClip.top;
         if (newClipSideFlags & OpClipSideFlags::Right) mClipRect.right = opClip.right;
         if (newClipSideFlags & OpClipSideFlags::Bottom) mClipRect.bottom = opClip.bottom;
     }

 private:
     int mClipSideFlags = 0;
     Rect mClipRect;
 };

 // iterate back toward target to see if anything drawn since should overlap the new op
 // if no target, merging ops still interate to find similar batch to insert after
 void OpReorderer::LayerReorderer::locateInsertIndex(int batchId, const Rect& clippedBounds,
         BatchBase** targetBatch, size_t* insertBatchIndex) const {
     for (int i = mBatches.size() - 1; i >= 0; i--) {
         BatchBase* overBatch = mBatches[i];

         if (overBatch == *targetBatch) break;

         // TODO: also consider shader shared between batch types
         if (batchId == overBatch->getBatchId()) {
             *insertBatchIndex = i + 1;
             if (!*targetBatch) break; // found insert position, quit
         }

         if (overBatch->intersects(clippedBounds)) {
             // NOTE: it may be possible to optimize for special cases where two operations
             // of the same batch/paint could swap order, such as with a non-mergeable
             // (clipped) and a mergeable text operation
             *targetBatch = nullptr;
             break;
         }
     }
 }

 void OpReorderer::LayerReorderer::deferUnmergeableOp(LinearAllocator& allocator,
         BakedOpState* op, batchid_t batchId) {
     OpBatch* targetBatch = mBatchLookup[batchId];

     size_t insertBatchIndex = mBatches.size();
     if (targetBatch) {
         locateInsertIndex(batchId, op->computedState.clippedBounds,
                 (BatchBase**)(&targetBatch), &insertBatchIndex);
     }

     if (targetBatch) {
         targetBatch->batchOp(op);
     } else  {
         // new non-merging batch
         targetBatch = new (allocator) OpBatch(batchId, op);
         mBatchLookup[batchId] = targetBatch;
         mBatches.insert(mBatches.begin() + insertBatchIndex, targetBatch);
     }
 }

 // insertion point of a new batch, will hopefully be immediately after similar batch
 // (generally, should be similar shader)
 void OpReorderer::LayerReorderer::deferMergeableOp(LinearAllocator& allocator,
         BakedOpState* op, batchid_t batchId, mergeid_t mergeId) {
     MergingOpBatch* targetBatch = nullptr;

     // Try to merge with any existing batch with same mergeId
     auto getResult = mMergingBatchLookup[batchId].find(mergeId);
     if (getResult != mMergingBatchLookup[batchId].end()) {
         targetBatch = getResult->second;
         if (!targetBatch->canMergeWith(op)) {
             targetBatch = nullptr;
         }
     }

     size_t insertBatchIndex = mBatches.size();
     locateInsertIndex(batchId, op->computedState.clippedBounds,
             (BatchBase**)(&targetBatch), &insertBatchIndex);

     if (targetBatch) {
         targetBatch->mergeOp(op);
     } else  {
         // new merging batch
         targetBatch = new (allocator) MergingOpBatch(batchId, op);
         mMergingBatchLookup[batchId].insert(std::make_pair(mergeId, targetBatch));

         mBatches.insert(mBatches.begin() + insertBatchIndex, targetBatch);
     }
 }

 void OpReorderer::LayerReorderer::replayBakedOpsImpl(void* arg, BakedOpReceiver* receivers) const {
     for (const BatchBase* batch : mBatches) {
         // TODO: different behavior based on batch->isMerging()
         for (const BakedOpState* op : batch->getOps()) {
             receivers[op->op->opId](arg, *op->op, *op);
         }
     }
 }

 void OpReorderer::LayerReorderer::dump() const {
     for (const BatchBase* batch : mBatches) {
         batch->dump();
     }
 }

 OpReorderer::OpReorderer()
         : mCanvasState(*this) {
     mLayerReorderers.emplace_back();
     mLayerStack.push_back(0);
 }

 void OpReorderer::onViewportInitialized() {}

 void OpReorderer::onSnapshotRestored(const Snapshot& removed, const Snapshot& restored) {}

 void OpReorderer::defer(const SkRect& clip, int viewportWidth, int viewportHeight,
         const std::vector< sp<RenderNode> >& nodes) {
     mCanvasState.initializeSaveStack(viewportWidth, viewportHeight,
             clip.fLeft, clip.fTop, clip.fRight, clip.fBottom,
             Vector3());
     for (const sp<RenderNode>& node : nodes) {
         if (node->nothingToDraw()) continue;

         // TODO: dedupe this code with onRenderNode()
         mCanvasState.save(SkCanvas::kClip_SaveFlag | SkCanvas::kMatrix_SaveFlag);
         if (node->applyViewProperties(mCanvasState)) {
             // not rejected do ops...
             const DisplayList& displayList = node->getDisplayList();
             deferImpl(displayList);
         }
         mCanvasState.restore();
     }
 }

 void OpReorderer::defer(int viewportWidth, int viewportHeight, const DisplayList& displayList) {
     ATRACE_NAME("prepare drawing commands");
     mCanvasState.initializeSaveStack(viewportWidth, viewportHeight,
             0, 0, viewportWidth, viewportHeight, Vector3());
     deferImpl(displayList);
 }

 /**
  * Used to define a list of lambdas referencing private OpReorderer::onXXXXOp() methods.
  *
  * This allows opIds embedded in the RecordedOps to be used for dispatching to these lambdas. E.g. a
  * BitmapOp op then would be dispatched to OpReorderer::onBitmapOp(const BitmapOp&)
  */
 #define OP_RECEIVER(Type) \
         [](OpReorderer& reorderer, const RecordedOp& op) { reorderer.on##Type(static_cast<const Type&>(op)); },
 void OpReorderer::deferImpl(const DisplayList& displayList) {
     static std::function<void(OpReorderer& reorderer, const RecordedOp&)> receivers[] = {
         MAP_OPS(OP_RECEIVER)
     };
     for (const DisplayList::Chunk& chunk : displayList.getChunks()) {
         for (size_t opIndex = chunk.beginOpIndex; opIndex < chunk.endOpIndex; opIndex++) {
             const RecordedOp* op = displayList.getOps()[opIndex];
             receivers[op->opId](*this, *op);
         }
     }
 }

 void OpReorderer::replayBakedOpsImpl(void* arg, BakedOpReceiver* receivers) {
     ATRACE_NAME("flush drawing commands");
     // Relay through layers in reverse order, since layers
     // later in the list will be drawn by earlier ones
     for (int i = mLayerReorderers.size() - 1; i >= 0; i--) {
         mLayerReorderers[i].replayBakedOpsImpl(arg, receivers);
     }
 }

 void OpReorderer::onRenderNodeOp(const RenderNodeOp& op) {
     if (op.renderNode->nothingToDraw()) {
         return;
     }
     int count = mCanvasState.save(SkCanvas::kClip_SaveFlag | SkCanvas::kMatrix_SaveFlag);

     // apply state from RecordedOp
     mCanvasState.concatMatrix(op.localMatrix);
     mCanvasState.clipRect(op.localClipRect.left, op.localClipRect.top,
             op.localClipRect.right, op.localClipRect.bottom, SkRegion::kIntersect_Op);

     // apply RenderProperties state
     if (op.renderNode->applyViewProperties(mCanvasState)) {
         // if node not rejected based on properties, do ops...
         deferImpl(op.renderNode->getDisplayList());
     }
     mCanvasState.restoreToCount(count);
 }

 static batchid_t tessellatedBatchId(const SkPaint& paint) {
     return paint.getPathEffect()
             ? OpBatchType::AlphaMaskTexture
             : (paint.isAntiAlias() ? OpBatchType::AlphaVertices : OpBatchType::Vertices);
 }

 void OpReorderer::onBitmapOp(const BitmapOp& op) {
     BakedOpState* bakedStateOp = tryBakeOpState(op);
     if (!bakedStateOp) return; // quick rejected

     mergeid_t mergeId = (mergeid_t) op.bitmap->getGenerationID();
     // TODO: AssetAtlas
     currentLayer().deferMergeableOp(mAllocator, bakedStateOp, OpBatchType::Bitmap, mergeId);
 }

 void OpReorderer::onRectOp(const RectOp& op) {
     BakedOpState* bakedStateOp = tryBakeOpState(op);
     if (!bakedStateOp) return; // quick rejected
     currentLayer().deferUnmergeableOp(mAllocator, bakedStateOp, tessellatedBatchId(*op.paint));
 }

 void OpReorderer::onSimpleRectsOp(const SimpleRectsOp& op) {
     BakedOpState* bakedStateOp = tryBakeOpState(op);
     if (!bakedStateOp) return; // quick rejected
     currentLayer().deferUnmergeableOp(mAllocator, bakedStateOp, OpBatchType::Vertices);
 }

 // TODO: test rejection at defer time, where the bounds become empty
 void OpReorderer::onBeginLayerOp(const BeginLayerOp& op) {
     mCanvasState.save(SkCanvas::kClip_SaveFlag | SkCanvas::kMatrix_SaveFlag);
     mCanvasState.writableSnapshot()->transform->loadIdentity();
     mCanvasState.writableSnapshot()->initializeViewport(
             (int) op.unmappedBounds.getWidth(), (int) op.unmappedBounds.getHeight());
     mCanvasState.writableSnapshot()->roundRectClipState = nullptr;

     // create a new layer, and push its index on the stack
     mLayerStack.push_back(mLayerReorderers.size());
     mLayerReorderers.emplace_back();
     mLayerReorderers.back().beginLayerOp = &op;
 }

 void OpReorderer::onEndLayerOp(const EndLayerOp& /* ignored */) {
     mCanvasState.restore();

     const BeginLayerOp& beginLayerOp = *currentLayer().beginLayerOp;

     // pop finished layer off of the stack
     int finishedLayerIndex = mLayerStack.back();
     mLayerStack.pop_back();

     // record the draw operation into the previous layer's list of draw commands
     // uses state from the associated beginLayerOp, since it has all the state needed for drawing
     LayerOp* drawLayerOp = new (mAllocator) LayerOp(
             beginLayerOp.unmappedBounds,
             beginLayerOp.localMatrix,
             beginLayerOp.localClipRect,
             beginLayerOp.paint);
     BakedOpState* bakedOpState = tryBakeOpState(*drawLayerOp);

     if (bakedOpState) {
         // Layer will be drawn into parent layer (which is now current, since we popped mLayerStack)
         currentLayer().deferUnmergeableOp(mAllocator, bakedOpState, OpBatchType::Bitmap);
     } else {
         // Layer won't be drawn - delete its drawing batches to prevent it from doing any work
         mLayerReorderers[finishedLayerIndex].clear();
         return;
     }
 }

 void OpReorderer::onLayerOp(const LayerOp& op) {
     LOG_ALWAYS_FATAL("unsupported");
 }

 } // namespace uirenderer
 } // namespace android
	/*
	* Copyright (C) 2015 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.
	*/

	#include "OpReorderer.h"

	#include "utils/PaintUtils.h"
	#include "RenderNode.h"

	#include "SkCanvas.h"
	#include "utils/Trace.h"

	namespace android {
	namespace uirenderer {

	class BatchBase {

	public:
	BatchBase(batchid_t batchId, BakedOpState* op, bool merging)
	: mBatchId(batchId)
	, mMerging(merging) {
	mBounds = op->computedState.clippedBounds;
	mOps.push_back(op);
	}

	bool intersects(const Rect& rect) const {
	if (!rect.intersects(mBounds)) return false;

	for (const BakedOpState* op : mOps) {
	if (rect.intersects(op->computedState.clippedBounds)) {
	return true;
	}
	}
	return false;
	}

	batchid_t getBatchId() const { return mBatchId; }
	bool isMerging() const { return mMerging; }

	const std::vector<BakedOpState*>& getOps() const { return mOps; }

	void dump() const {
	ALOGD(" Batch %p, id %d, merging %d, count %d, bounds " RECT_STRING,
	this, mBatchId, mMerging, mOps.size(), RECT_ARGS(mBounds));
	}
	protected:
	batchid_t mBatchId;
	Rect mBounds;
	std::vector<BakedOpState*> mOps;
	bool mMerging;
	};

	class OpBatch : public BatchBase {
	public:
	static void* operator new(size_t size, LinearAllocator& allocator) {
	return allocator.alloc(size);
	}

	OpBatch(batchid_t batchId, BakedOpState* op)
	: BatchBase(batchId, op, false) {
	}

	void batchOp(BakedOpState* op) {
	mBounds.unionWith(op->computedState.clippedBounds);
	mOps.push_back(op);
	}
	};

	class MergingOpBatch : public BatchBase {
	public:
	static void* operator new(size_t size, LinearAllocator& allocator) {
	return allocator.alloc(size);
	}

	MergingOpBatch(batchid_t batchId, BakedOpState* op)
	: BatchBase(batchId, op, true) {
	}

	/*
	* Helper for determining if a new op can merge with a MergingDrawBatch based on their bounds
	* and clip side flags. Positive bounds delta means new bounds fit in old.
	*/
	static inline bool checkSide(const int currentFlags, const int newFlags, const int side,
	float boundsDelta) {
	bool currentClipExists = currentFlags & side;
	bool newClipExists = newFlags & side;

	// if current is clipped, we must be able to fit new bounds in current
	if (boundsDelta > 0 && currentClipExists) return false;

	// if new is clipped, we must be able to fit current bounds in new
	if (boundsDelta < 0 && newClipExists) return false;

	return true;
	}

	static bool paintIsDefault(const SkPaint& paint) {
	return paint.getAlpha() == 255
	&& paint.getColorFilter() == nullptr
	&& paint.getShader() == nullptr;
	}

	static bool paintsAreEquivalent(const SkPaint& a, const SkPaint& b) {
	return a.getAlpha() == b.getAlpha()
	&& a.getColorFilter() == b.getColorFilter()
	&& a.getShader() == b.getShader();
	}

	/*
	* Checks if a (mergeable) op can be merged into this batch
	*
	* If true, the op's multiDraw must be guaranteed to handle both ops simultaneously, so it is
	* important to consider all paint attributes used in the draw calls in deciding both a) if an
	* op tries to merge at all, and b) if the op can merge with another set of ops
	*
	* False positives can lead to information from the paints of subsequent merged operations being
	* dropped, so we make simplifying qualifications on the ops that can merge, per op type.
	*/
	bool canMergeWith(BakedOpState* op) const {
	bool isTextBatch = getBatchId() == OpBatchType::Text
	\|\| getBatchId() == OpBatchType::ColorText;

	// Overlapping other operations is only allowed for text without shadow. For other ops,
	// multiDraw isn't guaranteed to overdraw correctly
	if (!isTextBatch \|\| PaintUtils::hasTextShadow(op->op->paint)) {
	if (intersects(op->computedState.clippedBounds)) return false;
	}

	const BakedOpState* lhs = op;
	const BakedOpState* rhs = mOps[0];

	if (!MathUtils::areEqual(lhs->alpha, rhs->alpha)) return false;

	// Identical round rect clip state means both ops will clip in the same way, or not at all.
	// As the state objects are const, we can compare their pointers to determine mergeability
	if (lhs->roundRectClipState != rhs->roundRectClipState) return false;
	if (lhs->projectionPathMask != rhs->projectionPathMask) return false;

	/* Clipping compatibility check
	*
	* Exploits the fact that if a op or batch is clipped on a side, its bounds will equal its
	* clip for that side.
	*/
	const int currentFlags = mClipSideFlags;
	const int newFlags = op->computedState.clipSideFlags;
	if (currentFlags != OpClipSideFlags::None \|\| newFlags != OpClipSideFlags::None) {
	const Rect& opBounds = op->computedState.clippedBounds;
	float boundsDelta = mBounds.left - opBounds.left;
	if (!checkSide(currentFlags, newFlags, OpClipSideFlags::Left, boundsDelta)) return false;
	boundsDelta = mBounds.top - opBounds.top;
	if (!checkSide(currentFlags, newFlags, OpClipSideFlags::Top, boundsDelta)) return false;

	// right and bottom delta calculation reversed to account for direction
	boundsDelta = opBounds.right - mBounds.right;
	if (!checkSide(currentFlags, newFlags, OpClipSideFlags::Right, boundsDelta)) return false;
	boundsDelta = opBounds.bottom - mBounds.bottom;
	if (!checkSide(currentFlags, newFlags, OpClipSideFlags::Bottom, boundsDelta)) return false;
	}

	const SkPaint* newPaint = op->op->paint;
	const SkPaint* oldPaint = mOps[0]->op->paint;

	if (newPaint == oldPaint) {
	// if paints are equal, then modifiers + paint attribs don't need to be compared
	return true;
	} else if (newPaint && !oldPaint) {
	return paintIsDefault(*newPaint);
	} else if (!newPaint && oldPaint) {
	return paintIsDefault(*oldPaint);
	}
	return paintsAreEquivalent(newPaint, oldPaint);
	}

	void mergeOp(BakedOpState* op) {
	mBounds.unionWith(op->computedState.clippedBounds);
	mOps.push_back(op);

	const int newClipSideFlags = op->computedState.clipSideFlags;
	mClipSideFlags \|= newClipSideFlags;

	const Rect& opClip = op->computedState.clipRect;
	if (newClipSideFlags & OpClipSideFlags::Left) mClipRect.left = opClip.left;
	if (newClipSideFlags & OpClipSideFlags::Top) mClipRect.top = opClip.top;
	if (newClipSideFlags & OpClipSideFlags::Right) mClipRect.right = opClip.right;
	if (newClipSideFlags & OpClipSideFlags::Bottom) mClipRect.bottom = opClip.bottom;
	}

	private:
	int mClipSideFlags = 0;
	Rect mClipRect;
	};

	// iterate back toward target to see if anything drawn since should overlap the new op
	// if no target, merging ops still interate to find similar batch to insert after
	void OpReorderer::LayerReorderer::locateInsertIndex(int batchId, const Rect& clippedBounds,
	BatchBase** targetBatch, size_t* insertBatchIndex) const {
	for (int i = mBatches.size() - 1; i >= 0; i--) {
	BatchBase* overBatch = mBatches[i];

	if (overBatch == *targetBatch) break;

	// TODO: also consider shader shared between batch types
	if (batchId == overBatch->getBatchId()) {
	*insertBatchIndex = i + 1;
	if (!*targetBatch) break; // found insert position, quit
	}

	if (overBatch->intersects(clippedBounds)) {
	// NOTE: it may be possible to optimize for special cases where two operations
	// of the same batch/paint could swap order, such as with a non-mergeable
	// (clipped) and a mergeable text operation
	*targetBatch = nullptr;
	break;
	}
	}
	}

	void OpReorderer::LayerReorderer::deferUnmergeableOp(LinearAllocator& allocator,
	BakedOpState* op, batchid_t batchId) {
	OpBatch* targetBatch = mBatchLookup[batchId];

	size_t insertBatchIndex = mBatches.size();
	if (targetBatch) {
	locateInsertIndex(batchId, op->computedState.clippedBounds,
	(BatchBase**)(&targetBatch), &insertBatchIndex);
	}

	if (targetBatch) {
	targetBatch->batchOp(op);
	} else {
	// new non-merging batch
	targetBatch = new (allocator) OpBatch(batchId, op);
	mBatchLookup[batchId] = targetBatch;
	mBatches.insert(mBatches.begin() + insertBatchIndex, targetBatch);
	}
	}

	// insertion point of a new batch, will hopefully be immediately after similar batch
	// (generally, should be similar shader)
	void OpReorderer::LayerReorderer::deferMergeableOp(LinearAllocator& allocator,
	BakedOpState* op, batchid_t batchId, mergeid_t mergeId) {
	MergingOpBatch* targetBatch = nullptr;

	// Try to merge with any existing batch with same mergeId
	auto getResult = mMergingBatchLookup[batchId].find(mergeId);
	if (getResult != mMergingBatchLookup[batchId].end()) {
	targetBatch = getResult->second;
	if (!targetBatch->canMergeWith(op)) {
	targetBatch = nullptr;
	}
	}

	size_t insertBatchIndex = mBatches.size();
	locateInsertIndex(batchId, op->computedState.clippedBounds,
	(BatchBase**)(&targetBatch), &insertBatchIndex);

	if (targetBatch) {
	targetBatch->mergeOp(op);
	} else {
	// new merging batch
	targetBatch = new (allocator) MergingOpBatch(batchId, op);
	mMergingBatchLookup[batchId].insert(std::make_pair(mergeId, targetBatch));

	mBatches.insert(mBatches.begin() + insertBatchIndex, targetBatch);
	}
	}

	void OpReorderer::LayerReorderer::replayBakedOpsImpl(void* arg, BakedOpReceiver* receivers) const {
	for (const BatchBase* batch : mBatches) {
	// TODO: different behavior based on batch->isMerging()
	for (const BakedOpState* op : batch->getOps()) {
	receivers[op->op->opId](arg, op->op, op);
	}
	}
	}

	void OpReorderer::LayerReorderer::dump() const {
	for (const BatchBase* batch : mBatches) {
	batch->dump();
	}
	}

	OpReorderer::OpReorderer()
	: mCanvasState(*this) {
	mLayerReorderers.emplace_back();
	mLayerStack.push_back(0);
	}

	void OpReorderer::onViewportInitialized() {}

	void OpReorderer::onSnapshotRestored(const Snapshot& removed, const Snapshot& restored) {}

	void OpReorderer::defer(const SkRect& clip, int viewportWidth, int viewportHeight,
	const std::vector< sp<RenderNode> >& nodes) {
	mCanvasState.initializeSaveStack(viewportWidth, viewportHeight,
	clip.fLeft, clip.fTop, clip.fRight, clip.fBottom,
	Vector3());
	for (const sp<RenderNode>& node : nodes) {
	if (node->nothingToDraw()) continue;

	// TODO: dedupe this code with onRenderNode()
	mCanvasState.save(SkCanvas::kClip_SaveFlag \| SkCanvas::kMatrix_SaveFlag);
	if (node->applyViewProperties(mCanvasState)) {
	// not rejected do ops...
	const DisplayList& displayList = node->getDisplayList();
	deferImpl(displayList);
	}
	mCanvasState.restore();
	}
	}

	void OpReorderer::defer(int viewportWidth, int viewportHeight, const DisplayList& displayList) {
	ATRACE_NAME("prepare drawing commands");
	mCanvasState.initializeSaveStack(viewportWidth, viewportHeight,
	0, 0, viewportWidth, viewportHeight, Vector3());
	deferImpl(displayList);
	}

	/**
	* Used to define a list of lambdas referencing private OpReorderer::onXXXXOp() methods.
	*
	* This allows opIds embedded in the RecordedOps to be used for dispatching to these lambdas. E.g. a
	* BitmapOp op then would be dispatched to OpReorderer::onBitmapOp(const BitmapOp&)
	*/
	#define OP_RECEIVER(Type) \
	[](OpReorderer& reorderer, const RecordedOp& op) { reorderer.on##Type(static_cast<const Type&>(op)); },
	void OpReorderer::deferImpl(const DisplayList& displayList) {
	static std::function<void(OpReorderer& reorderer, const RecordedOp&)> receivers[] = {
	MAP_OPS(OP_RECEIVER)
	};
	for (const DisplayList::Chunk& chunk : displayList.getChunks()) {
	for (size_t opIndex = chunk.beginOpIndex; opIndex < chunk.endOpIndex; opIndex++) {
	const RecordedOp* op = displayList.getOps()[opIndex];
	receivers[op->opId](this, op);
	}
	}
	}

	void OpReorderer::replayBakedOpsImpl(void* arg, BakedOpReceiver* receivers) {
	ATRACE_NAME("flush drawing commands");
	// Relay through layers in reverse order, since layers
	// later in the list will be drawn by earlier ones
	for (int i = mLayerReorderers.size() - 1; i >= 0; i--) {
	mLayerReorderers[i].replayBakedOpsImpl(arg, receivers);
	}
	}

	void OpReorderer::onRenderNodeOp(const RenderNodeOp& op) {
	if (op.renderNode->nothingToDraw()) {
	return;
	}
	int count = mCanvasState.save(SkCanvas::kClip_SaveFlag \| SkCanvas::kMatrix_SaveFlag);

	// apply state from RecordedOp
	mCanvasState.concatMatrix(op.localMatrix);
	mCanvasState.clipRect(op.localClipRect.left, op.localClipRect.top,
	op.localClipRect.right, op.localClipRect.bottom, SkRegion::kIntersect_Op);

	// apply RenderProperties state
	if (op.renderNode->applyViewProperties(mCanvasState)) {
	// if node not rejected based on properties, do ops...
	deferImpl(op.renderNode->getDisplayList());
	}
	mCanvasState.restoreToCount(count);
	}

	static batchid_t tessellatedBatchId(const SkPaint& paint) {
	return paint.getPathEffect()
	? OpBatchType::AlphaMaskTexture
	: (paint.isAntiAlias() ? OpBatchType::AlphaVertices : OpBatchType::Vertices);
	}

	void OpReorderer::onBitmapOp(const BitmapOp& op) {
	BakedOpState* bakedStateOp = tryBakeOpState(op);
	if (!bakedStateOp) return; // quick rejected

	mergeid_t mergeId = (mergeid_t) op.bitmap->getGenerationID();
	// TODO: AssetAtlas
	currentLayer().deferMergeableOp(mAllocator, bakedStateOp, OpBatchType::Bitmap, mergeId);
	}

	void OpReorderer::onRectOp(const RectOp& op) {
	BakedOpState* bakedStateOp = tryBakeOpState(op);
	if (!bakedStateOp) return; // quick rejected
	currentLayer().deferUnmergeableOp(mAllocator, bakedStateOp, tessellatedBatchId(*op.paint));
	}

	void OpReorderer::onSimpleRectsOp(const SimpleRectsOp& op) {
	BakedOpState* bakedStateOp = tryBakeOpState(op);
	if (!bakedStateOp) return; // quick rejected
	currentLayer().deferUnmergeableOp(mAllocator, bakedStateOp, OpBatchType::Vertices);
	}

	// TODO: test rejection at defer time, where the bounds become empty
	void OpReorderer::onBeginLayerOp(const BeginLayerOp& op) {
	mCanvasState.save(SkCanvas::kClip_SaveFlag \| SkCanvas::kMatrix_SaveFlag);
	mCanvasState.writableSnapshot()->transform->loadIdentity();
	mCanvasState.writableSnapshot()->initializeViewport(
	(int) op.unmappedBounds.getWidth(), (int) op.unmappedBounds.getHeight());
	mCanvasState.writableSnapshot()->roundRectClipState = nullptr;

	// create a new layer, and push its index on the stack
	mLayerStack.push_back(mLayerReorderers.size());
	mLayerReorderers.emplace_back();
	mLayerReorderers.back().beginLayerOp = &op;
	}

	void OpReorderer::onEndLayerOp(const EndLayerOp& /* ignored */) {
	mCanvasState.restore();

	const BeginLayerOp& beginLayerOp = *currentLayer().beginLayerOp;

	// pop finished layer off of the stack
	int finishedLayerIndex = mLayerStack.back();
	mLayerStack.pop_back();

	// record the draw operation into the previous layer's list of draw commands
	// uses state from the associated beginLayerOp, since it has all the state needed for drawing
	LayerOp* drawLayerOp = new (mAllocator) LayerOp(
	beginLayerOp.unmappedBounds,
	beginLayerOp.localMatrix,
	beginLayerOp.localClipRect,
	beginLayerOp.paint);
	BakedOpState* bakedOpState = tryBakeOpState(*drawLayerOp);

	if (bakedOpState) {
	// Layer will be drawn into parent layer (which is now current, since we popped mLayerStack)
	currentLayer().deferUnmergeableOp(mAllocator, bakedOpState, OpBatchType::Bitmap);
	} else {
	// Layer won't be drawn - delete its drawing batches to prevent it from doing any work
	mLayerReorderers[finishedLayerIndex].clear();
	return;
	}
	}

	void OpReorderer::onLayerOp(const LayerOp& op) {
	LOG_ALWAYS_FATAL("unsupported");
	}

	} // namespace uirenderer
	} // namespace android