Initial commit of new Canvas operation recording / replay

Done:
- drawRect, drawBitmap, drawColor, drawPaint, drawRenderNode, drawRegion
- Recording with new DisplayList format
- batching & reordering
- Stateless op reorder
- Stateless op rendering
- Frame lifecycle (clear, geterror, cleanup)

Not done:
- SaveLayer (clipped and unclipped)
- HW layers
- Complex clipping
- Ripple projection
- Z reordering
- Z shadows
- onDefer prefetching (text + task kickoff)
- round rect clip
- linear allocation for std collections
- AssetAtlas support

Change-Id: Iaf98c1a3aeab5fa47cc8f9c6d964420abc0e7691
diff --git a/libs/hwui/OpReorderer.cpp b/libs/hwui/OpReorderer.cpp
new file mode 100644
index 0000000..1d8be2b
--- /dev/null
+++ b/libs/hwui/OpReorderer.cpp
@@ -0,0 +1,404 @@
+/*
+ * 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, merging %d, bounds " RECT_STRING, this, mMerging, 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;
+};
+
+class NullClient: public CanvasStateClient {
+    void onViewportInitialized() override {}
+    void onSnapshotRestored(const Snapshot& removed, const Snapshot& restored) {}
+    GLuint getTargetFbo() const override { return 0; }
+};
+static NullClient sNullClient;
+
+OpReorderer::OpReorderer()
+        : mCanvasState(sNullClient) {
+}
+
+void OpReorderer::defer(int viewportWidth, int viewportHeight,
+        const std::vector< sp<RenderNode> >& nodes) {
+    mCanvasState.initializeSaveStack(viewportWidth, viewportHeight,
+            0, 0, viewportWidth, viewportHeight, 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 DisplayListData& data = node->getDisplayListData();
+            deferImpl(data.getChunks(), data.getOps());
+        }
+        mCanvasState.restore();
+    }
+}
+
+void OpReorderer::defer(int viewportWidth, int viewportHeight,
+        const std::vector<DisplayListData::Chunk>& chunks, const std::vector<RecordedOp*>& ops) {
+    ATRACE_NAME("prepare drawing commands");
+    mCanvasState.initializeSaveStack(viewportWidth, viewportHeight,
+            0, 0, viewportWidth, viewportHeight, Vector3());
+    deferImpl(chunks, ops);
+}
+
+/**
+ * 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_RECIEVER(Type) \
+        [](OpReorderer& reorderer, const RecordedOp& op) { reorderer.on##Type(static_cast<const Type&>(op)); },
+void OpReorderer::deferImpl(const std::vector<DisplayListData::Chunk>& chunks,
+        const std::vector<RecordedOp*>& ops) {
+    static std::function<void(OpReorderer& reorderer, const RecordedOp&)> receivers[] = {
+        MAP_OPS(OP_RECIEVER)
+    };
+    for (const DisplayListData::Chunk& chunk : chunks) {
+        for (size_t opIndex = chunk.beginOpIndex; opIndex < chunk.endOpIndex; opIndex++) {
+            const RecordedOp* op = ops[opIndex];
+            receivers[op->opId](*this, *op);
+        }
+    }
+}
+
+void OpReorderer::replayBakedOpsImpl(void* arg, BakedOpReceiver* receivers) {
+    ATRACE_NAME("flush drawing commands");
+    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);
+        }
+    }
+}
+
+BakedOpState* OpReorderer::bakeOpState(const RecordedOp& recordedOp) {
+    return BakedOpState::tryConstruct(mAllocator, *mCanvasState.currentSnapshot(), recordedOp);
+}
+
+void OpReorderer::onRenderNodeOp(const RenderNodeOp& op) {
+    if (op.renderNode->nothingToDraw()) {
+        return;
+    }
+    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)) {
+        // not rejected do ops...
+        const DisplayListData& data = op.renderNode->getDisplayListData();
+        deferImpl(data.getChunks(), data.getOps());
+    }
+    mCanvasState.restore();
+}
+
+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 = bakeOpState(op);
+    if (!bakedStateOp) return; // quick rejected
+
+    mergeid_t mergeId = (mergeid_t) op.bitmap->getGenerationID();
+    // TODO: AssetAtlas
+
+    deferMergeableOp(bakedStateOp, OpBatchType::Bitmap, mergeId);
+}
+
+void OpReorderer::onRectOp(const RectOp& op) {
+    BakedOpState* bakedStateOp = bakeOpState(op);
+    if (!bakedStateOp) return; // quick rejected
+    deferUnmergeableOp(bakedStateOp, tessellatedBatchId(*op.paint));
+}
+
+void OpReorderer::onSimpleRectsOp(const SimpleRectsOp& op) {
+    BakedOpState* bakedStateOp = bakeOpState(op);
+    if (!bakedStateOp) return; // quick rejected
+    deferUnmergeableOp(bakedStateOp, OpBatchType::Vertices);
+}
+
+// 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::locateInsertIndex(int batchId, const Rect& clippedBounds,
+        BatchBase** targetBatch, size_t* insertBatchIndex) const {
+    for (size_t i = mBatches.size() - 1; i >= mEarliestBatchIndex; 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::deferUnmergeableOp(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 (mAllocator) 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::deferMergeableOp(BakedOpState* op, batchid_t batchId, mergeid_t mergeId) {
+    MergingOpBatch* targetBatch = nullptr;
+
+    // Try to merge with any existing batch with same mergeId
+    auto getResult = mMergingBatches[batchId].find(mergeId);
+    if (getResult != mMergingBatches[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 (mAllocator) MergingOpBatch(batchId, op);
+        mMergingBatches[batchId].insert(std::make_pair(mergeId, targetBatch));
+
+        mBatches.insert(mBatches.begin() + insertBatchIndex, targetBatch);
+    }
+}
+
+void OpReorderer::dump() {
+    for (const BatchBase* batch : mBatches) {
+        batch->dump();
+    }
+}
+
+} // namespace uirenderer
+} // namespace android