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      1 /*
      2  * Copyright (C) 2013 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #define LOG_TAG "OpenGLRenderer"
     18 #define ATRACE_TAG ATRACE_TAG_VIEW
     19 
     20 #include <SkCanvas.h>
     21 
     22 #include <utils/Trace.h>
     23 #include <ui/Rect.h>
     24 #include <ui/Region.h>
     25 
     26 #include "Caches.h"
     27 #include "Debug.h"
     28 #include "DeferredDisplayList.h"
     29 #include "DisplayListOp.h"
     30 #include "OpenGLRenderer.h"
     31 #include "utils/MathUtils.h"
     32 
     33 #if DEBUG_DEFER
     34     #define DEFER_LOGD(...) ALOGD(__VA_ARGS__)
     35 #else
     36     #define DEFER_LOGD(...)
     37 #endif
     38 
     39 namespace android {
     40 namespace uirenderer {
     41 
     42 // Depth of the save stack at the beginning of batch playback at flush time
     43 #define FLUSH_SAVE_STACK_DEPTH 2
     44 
     45 #define DEBUG_COLOR_BARRIER          0x1f000000
     46 #define DEBUG_COLOR_MERGEDBATCH      0x5f7f7fff
     47 #define DEBUG_COLOR_MERGEDBATCH_SOLO 0x5f7fff7f
     48 
     49 /////////////////////////////////////////////////////////////////////////////////
     50 // Operation Batches
     51 /////////////////////////////////////////////////////////////////////////////////
     52 
     53 class Batch {
     54 public:
     55     virtual status_t replay(OpenGLRenderer& renderer, Rect& dirty, int index) = 0;
     56     virtual ~Batch() {}
     57     virtual bool purelyDrawBatch() { return false; }
     58     virtual bool coversBounds(const Rect& bounds) { return false; }
     59 };
     60 
     61 class DrawBatch : public Batch {
     62 public:
     63     DrawBatch(const DeferInfo& deferInfo) : mAllOpsOpaque(true),
     64             mBatchId(deferInfo.batchId), mMergeId(deferInfo.mergeId) {
     65         mOps.clear();
     66     }
     67 
     68     virtual ~DrawBatch() { mOps.clear(); }
     69 
     70     virtual void add(DrawOp* op, const DeferredDisplayState* state, bool opaqueOverBounds) {
     71         // NOTE: ignore empty bounds special case, since we don't merge across those ops
     72         mBounds.unionWith(state->mBounds);
     73         mAllOpsOpaque &= opaqueOverBounds;
     74         mOps.add(OpStatePair(op, state));
     75     }
     76 
     77     bool intersects(const Rect& rect) {
     78         if (!rect.intersects(mBounds)) return false;
     79 
     80         for (unsigned int i = 0; i < mOps.size(); i++) {
     81             if (rect.intersects(mOps[i].state->mBounds)) {
     82 #if DEBUG_DEFER
     83                 DEFER_LOGD("op intersects with op %p with bounds %f %f %f %f:", mOps[i].op,
     84                         mOps[i].state->mBounds.left, mOps[i].state->mBounds.top,
     85                         mOps[i].state->mBounds.right, mOps[i].state->mBounds.bottom);
     86                 mOps[i].op->output(2);
     87 #endif
     88                 return true;
     89             }
     90         }
     91         return false;
     92     }
     93 
     94     virtual status_t replay(OpenGLRenderer& renderer, Rect& dirty, int index) {
     95         DEFER_LOGD("%d  replaying DrawBatch %p, with %d ops (batch id %x, merge id %p)",
     96                 index, this, mOps.size(), getBatchId(), getMergeId());
     97 
     98         status_t status = DrawGlInfo::kStatusDone;
     99         DisplayListLogBuffer& logBuffer = DisplayListLogBuffer::getInstance();
    100         for (unsigned int i = 0; i < mOps.size(); i++) {
    101             DrawOp* op = mOps[i].op;
    102             const DeferredDisplayState* state = mOps[i].state;
    103             renderer.restoreDisplayState(*state);
    104 
    105 #if DEBUG_DISPLAY_LIST_OPS_AS_EVENTS
    106             renderer.eventMark(op->name());
    107 #endif
    108             logBuffer.writeCommand(0, op->name());
    109             status |= op->applyDraw(renderer, dirty);
    110 
    111 #if DEBUG_MERGE_BEHAVIOR
    112             const Rect& bounds = state->mBounds;
    113             int batchColor = 0x1f000000;
    114             if (getBatchId() & 0x1) batchColor |= 0x0000ff;
    115             if (getBatchId() & 0x2) batchColor |= 0x00ff00;
    116             if (getBatchId() & 0x4) batchColor |= 0xff0000;
    117             renderer.drawScreenSpaceColorRect(bounds.left, bounds.top, bounds.right, bounds.bottom,
    118                     batchColor);
    119 #endif
    120         }
    121         return status;
    122     }
    123 
    124     virtual bool purelyDrawBatch() { return true; }
    125 
    126     virtual bool coversBounds(const Rect& bounds) {
    127         if (CC_LIKELY(!mAllOpsOpaque || !mBounds.contains(bounds) || count() == 1)) return false;
    128 
    129         Region uncovered(android::Rect(bounds.left, bounds.top, bounds.right, bounds.bottom));
    130         for (unsigned int i = 0; i < mOps.size(); i++) {
    131             const Rect &r = mOps[i].state->mBounds;
    132             uncovered.subtractSelf(android::Rect(r.left, r.top, r.right, r.bottom));
    133         }
    134         return uncovered.isEmpty();
    135     }
    136 
    137     inline int getBatchId() const { return mBatchId; }
    138     inline mergeid_t getMergeId() const { return mMergeId; }
    139     inline int count() const { return mOps.size(); }
    140 
    141 protected:
    142     Vector<OpStatePair> mOps;
    143     Rect mBounds; // union of bounds of contained ops
    144 private:
    145     bool mAllOpsOpaque;
    146     int mBatchId;
    147     mergeid_t mMergeId;
    148 };
    149 
    150 class MergingDrawBatch : public DrawBatch {
    151 public:
    152     MergingDrawBatch(DeferInfo& deferInfo, int width, int height) :
    153             DrawBatch(deferInfo), mClipRect(width, height),
    154             mClipSideFlags(kClipSide_None) {}
    155 
    156     /*
    157      * Helper for determining if a new op can merge with a MergingDrawBatch based on their bounds
    158      * and clip side flags. Positive bounds delta means new bounds fit in old.
    159      */
    160     static inline bool checkSide(const int currentFlags, const int newFlags, const int side,
    161             float boundsDelta) {
    162         bool currentClipExists = currentFlags & side;
    163         bool newClipExists = newFlags & side;
    164 
    165         // if current is clipped, we must be able to fit new bounds in current
    166         if (boundsDelta > 0 && currentClipExists) return false;
    167 
    168         // if new is clipped, we must be able to fit current bounds in new
    169         if (boundsDelta < 0 && newClipExists) return false;
    170 
    171         return true;
    172     }
    173 
    174     /*
    175      * Checks if a (mergeable) op can be merged into this batch
    176      *
    177      * If true, the op's multiDraw must be guaranteed to handle both ops simultaneously, so it is
    178      * important to consider all paint attributes used in the draw calls in deciding both a) if an
    179      * op tries to merge at all, and b) if the op can merge with another set of ops
    180      *
    181      * False positives can lead to information from the paints of subsequent merged operations being
    182      * dropped, so we make simplifying qualifications on the ops that can merge, per op type.
    183      */
    184     bool canMergeWith(const DrawOp* op, const DeferredDisplayState* state) {
    185         bool isTextBatch = getBatchId() == DeferredDisplayList::kOpBatch_Text ||
    186                 getBatchId() == DeferredDisplayList::kOpBatch_ColorText;
    187 
    188         // Overlapping other operations is only allowed for text without shadow. For other ops,
    189         // multiDraw isn't guaranteed to overdraw correctly
    190         if (!isTextBatch || op->hasTextShadow()) {
    191             if (intersects(state->mBounds)) return false;
    192         }
    193         const DeferredDisplayState* lhs = state;
    194         const DeferredDisplayState* rhs = mOps[0].state;
    195 
    196         if (!MathUtils::areEqual(lhs->mAlpha, rhs->mAlpha)) return false;
    197 
    198         // Identical round rect clip state means both ops will clip in the same way, or not at all.
    199         // As the state objects are const, we can compare their pointers to determine mergeability
    200         if (lhs->mRoundRectClipState != rhs->mRoundRectClipState) return false;
    201 
    202         /* Clipping compatibility check
    203          *
    204          * Exploits the fact that if a op or batch is clipped on a side, its bounds will equal its
    205          * clip for that side.
    206          */
    207         const int currentFlags = mClipSideFlags;
    208         const int newFlags = state->mClipSideFlags;
    209         if (currentFlags != kClipSide_None || newFlags != kClipSide_None) {
    210             const Rect& opBounds = state->mBounds;
    211             float boundsDelta = mBounds.left - opBounds.left;
    212             if (!checkSide(currentFlags, newFlags, kClipSide_Left, boundsDelta)) return false;
    213             boundsDelta = mBounds.top - opBounds.top;
    214             if (!checkSide(currentFlags, newFlags, kClipSide_Top, boundsDelta)) return false;
    215 
    216             // right and bottom delta calculation reversed to account for direction
    217             boundsDelta = opBounds.right - mBounds.right;
    218             if (!checkSide(currentFlags, newFlags, kClipSide_Right, boundsDelta)) return false;
    219             boundsDelta = opBounds.bottom - mBounds.bottom;
    220             if (!checkSide(currentFlags, newFlags, kClipSide_Bottom, boundsDelta)) return false;
    221         }
    222 
    223         // if paints are equal, then modifiers + paint attribs don't need to be compared
    224         if (op->mPaint == mOps[0].op->mPaint) return true;
    225 
    226         if (op->getPaintAlpha() != mOps[0].op->getPaintAlpha()) return false;
    227 
    228         if (op->mPaint && mOps[0].op->mPaint &&
    229             op->mPaint->getColorFilter() != mOps[0].op->mPaint->getColorFilter()) {
    230             return false;
    231         }
    232 
    233         if (op->mPaint && mOps[0].op->mPaint &&
    234             op->mPaint->getShader() != mOps[0].op->mPaint->getShader()) {
    235             return false;
    236         }
    237 
    238         /* Draw Modifiers compatibility check
    239          *
    240          * Shadows are ignored, as only text uses them, and in that case they are drawn
    241          * per-DrawTextOp, before the unified text draw. Because of this, it's always safe to merge
    242          * text UNLESS a later draw's shadow should overlays a previous draw's text. This is covered
    243          * above with the intersection check.
    244          *
    245          * OverrideLayerAlpha is also ignored, as it's only used for drawing layers, which are never
    246          * merged.
    247          *
    248          * These ignore cases prevent us from simply memcmp'ing the drawModifiers
    249          */
    250         const DrawModifiers& lhsMod = lhs->mDrawModifiers;
    251         const DrawModifiers& rhsMod = rhs->mDrawModifiers;
    252 
    253         // Draw filter testing expects bit fields to be clear if filter not set.
    254         if (lhsMod.mHasDrawFilter != rhsMod.mHasDrawFilter) return false;
    255         if (lhsMod.mPaintFilterClearBits != rhsMod.mPaintFilterClearBits) return false;
    256         if (lhsMod.mPaintFilterSetBits != rhsMod.mPaintFilterSetBits) return false;
    257 
    258         return true;
    259     }
    260 
    261     virtual void add(DrawOp* op, const DeferredDisplayState* state, bool opaqueOverBounds) {
    262         DrawBatch::add(op, state, opaqueOverBounds);
    263 
    264         const int newClipSideFlags = state->mClipSideFlags;
    265         mClipSideFlags |= newClipSideFlags;
    266         if (newClipSideFlags & kClipSide_Left) mClipRect.left = state->mClip.left;
    267         if (newClipSideFlags & kClipSide_Top) mClipRect.top = state->mClip.top;
    268         if (newClipSideFlags & kClipSide_Right) mClipRect.right = state->mClip.right;
    269         if (newClipSideFlags & kClipSide_Bottom) mClipRect.bottom = state->mClip.bottom;
    270     }
    271 
    272     virtual status_t replay(OpenGLRenderer& renderer, Rect& dirty, int index) {
    273         DEFER_LOGD("%d  replaying MergingDrawBatch %p, with %d ops,"
    274                 " clip flags %x (batch id %x, merge id %p)",
    275                 index, this, mOps.size(), mClipSideFlags, getBatchId(), getMergeId());
    276         if (mOps.size() == 1) {
    277             return DrawBatch::replay(renderer, dirty, -1);
    278         }
    279 
    280         // clipping in the merged case is done ahead of time since all ops share the clip (if any)
    281         renderer.setupMergedMultiDraw(mClipSideFlags ? &mClipRect : NULL);
    282 
    283         DrawOp* op = mOps[0].op;
    284         DisplayListLogBuffer& buffer = DisplayListLogBuffer::getInstance();
    285         buffer.writeCommand(0, "multiDraw");
    286         buffer.writeCommand(1, op->name());
    287 
    288 #if DEBUG_DISPLAY_LIST_OPS_AS_EVENTS
    289         renderer.eventMark("multiDraw");
    290         renderer.eventMark(op->name());
    291 #endif
    292         status_t status = op->multiDraw(renderer, dirty, mOps, mBounds);
    293 
    294 #if DEBUG_MERGE_BEHAVIOR
    295         renderer.drawScreenSpaceColorRect(mBounds.left, mBounds.top, mBounds.right, mBounds.bottom,
    296                 DEBUG_COLOR_MERGEDBATCH);
    297 #endif
    298         return status;
    299     }
    300 
    301 private:
    302     /*
    303      * Contains the effective clip rect shared by all merged ops. Initialized to the layer viewport,
    304      * it will shrink if an op must be clipped on a certain side. The clipped sides are reflected in
    305      * mClipSideFlags.
    306      */
    307     Rect mClipRect;
    308     int mClipSideFlags;
    309 };
    310 
    311 class StateOpBatch : public Batch {
    312 public:
    313     // creates a single operation batch
    314     StateOpBatch(const StateOp* op, const DeferredDisplayState* state) : mOp(op), mState(state) {}
    315 
    316     virtual status_t replay(OpenGLRenderer& renderer, Rect& dirty, int index) {
    317         DEFER_LOGD("replaying state op batch %p", this);
    318         renderer.restoreDisplayState(*mState);
    319 
    320         // use invalid save count because it won't be used at flush time - RestoreToCountOp is the
    321         // only one to use it, and we don't use that class at flush time, instead calling
    322         // renderer.restoreToCount directly
    323         int saveCount = -1;
    324         mOp->applyState(renderer, saveCount);
    325         return DrawGlInfo::kStatusDone;
    326     }
    327 
    328 private:
    329     const StateOp* mOp;
    330     const DeferredDisplayState* mState;
    331 };
    332 
    333 class RestoreToCountBatch : public Batch {
    334 public:
    335     RestoreToCountBatch(const StateOp* op, const DeferredDisplayState* state, int restoreCount) :
    336             mOp(op), mState(state), mRestoreCount(restoreCount) {}
    337 
    338     virtual status_t replay(OpenGLRenderer& renderer, Rect& dirty, int index) {
    339         DEFER_LOGD("batch %p restoring to count %d", this, mRestoreCount);
    340 
    341         renderer.restoreDisplayState(*mState);
    342         renderer.restoreToCount(mRestoreCount);
    343         return DrawGlInfo::kStatusDone;
    344     }
    345 
    346 private:
    347     // we use the state storage for the RestoreToCountOp, but don't replay the op itself
    348     const StateOp* mOp;
    349     const DeferredDisplayState* mState;
    350 
    351     /*
    352      * The count used here represents the flush() time saveCount. This is as opposed to the
    353      * DisplayList record time, or defer() time values (which are RestoreToCountOp's mCount, and
    354      * (saveCount + mCount) respectively). Since the count is different from the original
    355      * RestoreToCountOp, we don't store a pointer to the op, as elsewhere.
    356      */
    357     const int mRestoreCount;
    358 };
    359 
    360 #if DEBUG_MERGE_BEHAVIOR
    361 class BarrierDebugBatch : public Batch {
    362     virtual status_t replay(OpenGLRenderer& renderer, Rect& dirty, int index) {
    363         renderer.drawScreenSpaceColorRect(0, 0, 10000, 10000, DEBUG_COLOR_BARRIER);
    364         return DrawGlInfo::kStatusDrew;
    365     }
    366 };
    367 #endif
    368 
    369 /////////////////////////////////////////////////////////////////////////////////
    370 // DeferredDisplayList
    371 /////////////////////////////////////////////////////////////////////////////////
    372 
    373 void DeferredDisplayList::resetBatchingState() {
    374     for (int i = 0; i < kOpBatch_Count; i++) {
    375         mBatchLookup[i] = NULL;
    376         mMergingBatches[i].clear();
    377     }
    378 #if DEBUG_MERGE_BEHAVIOR
    379     if (mBatches.size() != 0) {
    380         mBatches.add(new BarrierDebugBatch());
    381     }
    382 #endif
    383     mEarliestBatchIndex = mBatches.size();
    384 }
    385 
    386 void DeferredDisplayList::clear() {
    387     resetBatchingState();
    388     mComplexClipStackStart = -1;
    389 
    390     for (unsigned int i = 0; i < mBatches.size(); i++) {
    391         delete mBatches[i];
    392     }
    393     mBatches.clear();
    394     mSaveStack.clear();
    395     mEarliestBatchIndex = 0;
    396     mEarliestUnclearedIndex = 0;
    397 }
    398 
    399 /////////////////////////////////////////////////////////////////////////////////
    400 // Operation adding
    401 /////////////////////////////////////////////////////////////////////////////////
    402 
    403 int DeferredDisplayList::getStateOpDeferFlags() const {
    404     // For both clipOp and save(Layer)Op, we don't want to save drawing info, and only want to save
    405     // the clip if we aren't recording a complex clip (and can thus trust it to be a rect)
    406     return recordingComplexClip() ? 0 : kStateDeferFlag_Clip;
    407 }
    408 
    409 int DeferredDisplayList::getDrawOpDeferFlags() const {
    410     return kStateDeferFlag_Draw | getStateOpDeferFlags();
    411 }
    412 
    413 /**
    414  * When an clipping operation occurs that could cause a complex clip, record the operation and all
    415  * subsequent clipOps, save/restores (if the clip flag is set). During a flush, instead of loading
    416  * the clip from deferred state, we play back all of the relevant state operations that generated
    417  * the complex clip.
    418  *
    419  * Note that we don't need to record the associated restore operation, since operations at defer
    420  * time record whether they should store the renderer's current clip
    421  */
    422 void DeferredDisplayList::addClip(OpenGLRenderer& renderer, ClipOp* op) {
    423     if (recordingComplexClip() || op->canCauseComplexClip() || !renderer.hasRectToRectTransform()) {
    424         DEFER_LOGD("%p Received complex clip operation %p", this, op);
    425 
    426         // NOTE: defer clip op before setting mComplexClipStackStart so previous clip is recorded
    427         storeStateOpBarrier(renderer, op);
    428 
    429         if (!recordingComplexClip()) {
    430             mComplexClipStackStart = renderer.getSaveCount() - 1;
    431             DEFER_LOGD("    Starting complex clip region, start is %d", mComplexClipStackStart);
    432         }
    433     }
    434 }
    435 
    436 /**
    437  * For now, we record save layer operations as barriers in the batch list, preventing drawing
    438  * operations from reordering around the saveLayer and it's associated restore()
    439  *
    440  * In the future, we should send saveLayer commands (if they can be played out of order) and their
    441  * contained drawing operations to a seperate list of batches, so that they may draw at the
    442  * beginning of the frame. This would avoid targetting and removing an FBO in the middle of a frame.
    443  *
    444  * saveLayer operations should be pulled to the beginning of the frame if the canvas doesn't have a
    445  * complex clip, and if the flags (kClip_SaveFlag & kClipToLayer_SaveFlag) are set.
    446  */
    447 void DeferredDisplayList::addSaveLayer(OpenGLRenderer& renderer,
    448         SaveLayerOp* op, int newSaveCount) {
    449     DEFER_LOGD("%p adding saveLayerOp %p, flags %x, new count %d",
    450             this, op, op->getFlags(), newSaveCount);
    451 
    452     storeStateOpBarrier(renderer, op);
    453     mSaveStack.push(newSaveCount);
    454 }
    455 
    456 /**
    457  * Takes save op and it's return value - the new save count - and stores it into the stream as a
    458  * barrier if it's needed to properly modify a complex clip
    459  */
    460 void DeferredDisplayList::addSave(OpenGLRenderer& renderer, SaveOp* op, int newSaveCount) {
    461     int saveFlags = op->getFlags();
    462     DEFER_LOGD("%p adding saveOp %p, flags %x, new count %d", this, op, saveFlags, newSaveCount);
    463 
    464     if (recordingComplexClip() && (saveFlags & SkCanvas::kClip_SaveFlag)) {
    465         // store and replay the save operation, as it may be needed to correctly playback the clip
    466         DEFER_LOGD("    adding save barrier with new save count %d", newSaveCount);
    467         storeStateOpBarrier(renderer, op);
    468         mSaveStack.push(newSaveCount);
    469     }
    470 }
    471 
    472 /**
    473  * saveLayer() commands must be associated with a restoreToCount batch that will clean up and draw
    474  * the layer in the deferred list
    475  *
    476  * other save() commands which occur as children of a snapshot with complex clip will be deferred,
    477  * and must be restored
    478  *
    479  * Either will act as a barrier to draw operation reordering, as we want to play back layer
    480  * save/restore and complex canvas modifications (including save/restore) in order.
    481  */
    482 void DeferredDisplayList::addRestoreToCount(OpenGLRenderer& renderer, StateOp* op,
    483         int newSaveCount) {
    484     DEFER_LOGD("%p addRestoreToCount %d", this, newSaveCount);
    485 
    486     if (recordingComplexClip() && newSaveCount <= mComplexClipStackStart) {
    487         mComplexClipStackStart = -1;
    488         resetBatchingState();
    489     }
    490 
    491     if (mSaveStack.isEmpty() || newSaveCount > mSaveStack.top()) {
    492         return;
    493     }
    494 
    495     while (!mSaveStack.isEmpty() && mSaveStack.top() >= newSaveCount) mSaveStack.pop();
    496 
    497     storeRestoreToCountBarrier(renderer, op, mSaveStack.size() + FLUSH_SAVE_STACK_DEPTH);
    498 }
    499 
    500 void DeferredDisplayList::addDrawOp(OpenGLRenderer& renderer, DrawOp* op) {
    501     /* 1: op calculates local bounds */
    502     DeferredDisplayState* const state = createState();
    503     if (op->getLocalBounds(state->mBounds)) {
    504         if (state->mBounds.isEmpty()) {
    505             // valid empty bounds, don't bother deferring
    506             tryRecycleState(state);
    507             return;
    508         }
    509     } else {
    510         state->mBounds.setEmpty();
    511     }
    512 
    513     /* 2: renderer calculates global bounds + stores state */
    514     if (renderer.storeDisplayState(*state, getDrawOpDeferFlags())) {
    515         tryRecycleState(state);
    516         return; // quick rejected
    517     }
    518 
    519     /* 3: ask op for defer info, given renderer state */
    520     DeferInfo deferInfo;
    521     op->onDefer(renderer, deferInfo, *state);
    522 
    523     // complex clip has a complex set of expectations on the renderer state - for now, avoid taking
    524     // the merge path in those cases
    525     deferInfo.mergeable &= !recordingComplexClip();
    526     deferInfo.opaqueOverBounds &= !recordingComplexClip() && mSaveStack.isEmpty();
    527 
    528     if (CC_LIKELY(mAvoidOverdraw) && mBatches.size() &&
    529             state->mClipSideFlags != kClipSide_ConservativeFull &&
    530             deferInfo.opaqueOverBounds && state->mBounds.contains(mBounds)) {
    531         // avoid overdraw by resetting drawing state + discarding drawing ops
    532         discardDrawingBatches(mBatches.size() - 1);
    533         resetBatchingState();
    534     }
    535 
    536     if (CC_UNLIKELY(renderer.getCaches().drawReorderDisabled)) {
    537         // TODO: elegant way to reuse batches?
    538         DrawBatch* b = new DrawBatch(deferInfo);
    539         b->add(op, state, deferInfo.opaqueOverBounds);
    540         mBatches.add(b);
    541         return;
    542     }
    543 
    544     // find the latest batch of the new op's type, and try to merge the new op into it
    545     DrawBatch* targetBatch = NULL;
    546 
    547     // insertion point of a new batch, will hopefully be immediately after similar batch
    548     // (eventually, should be similar shader)
    549     int insertBatchIndex = mBatches.size();
    550     if (!mBatches.isEmpty()) {
    551         if (state->mBounds.isEmpty()) {
    552             // don't know the bounds for op, so add to last batch and start from scratch on next op
    553             DrawBatch* b = new DrawBatch(deferInfo);
    554             b->add(op, state, deferInfo.opaqueOverBounds);
    555             mBatches.add(b);
    556             resetBatchingState();
    557 #if DEBUG_DEFER
    558             DEFER_LOGD("Warning: Encountered op with empty bounds, resetting batches");
    559             op->output(2);
    560 #endif
    561             return;
    562         }
    563 
    564         if (deferInfo.mergeable) {
    565             // Try to merge with any existing batch with same mergeId.
    566             if (mMergingBatches[deferInfo.batchId].get(deferInfo.mergeId, targetBatch)) {
    567                 if (!((MergingDrawBatch*) targetBatch)->canMergeWith(op, state)) {
    568                     targetBatch = NULL;
    569                 }
    570             }
    571         } else {
    572             // join with similar, non-merging batch
    573             targetBatch = (DrawBatch*)mBatchLookup[deferInfo.batchId];
    574         }
    575 
    576         if (targetBatch || deferInfo.mergeable) {
    577             // iterate back toward target to see if anything drawn since should overlap the new op
    578             // if no target, merging ops still interate to find similar batch to insert after
    579             for (int i = mBatches.size() - 1; i >= mEarliestBatchIndex; i--) {
    580                 DrawBatch* overBatch = (DrawBatch*)mBatches[i];
    581 
    582                 if (overBatch == targetBatch) break;
    583 
    584                 // TODO: also consider shader shared between batch types
    585                 if (deferInfo.batchId == overBatch->getBatchId()) {
    586                     insertBatchIndex = i + 1;
    587                     if (!targetBatch) break; // found insert position, quit
    588                 }
    589 
    590                 if (overBatch->intersects(state->mBounds)) {
    591                     // NOTE: it may be possible to optimize for special cases where two operations
    592                     // of the same batch/paint could swap order, such as with a non-mergeable
    593                     // (clipped) and a mergeable text operation
    594                     targetBatch = NULL;
    595 #if DEBUG_DEFER
    596                     DEFER_LOGD("op couldn't join batch %p, was intersected by batch %d",
    597                             targetBatch, i);
    598                     op->output(2);
    599 #endif
    600                     break;
    601                 }
    602             }
    603         }
    604     }
    605 
    606     if (!targetBatch) {
    607         if (deferInfo.mergeable) {
    608             targetBatch = new MergingDrawBatch(deferInfo,
    609                     renderer.getViewportWidth(), renderer.getViewportHeight());
    610             mMergingBatches[deferInfo.batchId].put(deferInfo.mergeId, targetBatch);
    611         } else {
    612             targetBatch = new DrawBatch(deferInfo);
    613             mBatchLookup[deferInfo.batchId] = targetBatch;
    614         }
    615 
    616         DEFER_LOGD("creating %singBatch %p, bid %x, at %d",
    617                 deferInfo.mergeable ? "Merg" : "Draw",
    618                 targetBatch, deferInfo.batchId, insertBatchIndex);
    619         mBatches.insertAt(targetBatch, insertBatchIndex);
    620     }
    621 
    622     targetBatch->add(op, state, deferInfo.opaqueOverBounds);
    623 }
    624 
    625 void DeferredDisplayList::storeStateOpBarrier(OpenGLRenderer& renderer, StateOp* op) {
    626     DEFER_LOGD("%p adding state op barrier at pos %d", this, mBatches.size());
    627 
    628     DeferredDisplayState* state = createState();
    629     renderer.storeDisplayState(*state, getStateOpDeferFlags());
    630     mBatches.add(new StateOpBatch(op, state));
    631     resetBatchingState();
    632 }
    633 
    634 void DeferredDisplayList::storeRestoreToCountBarrier(OpenGLRenderer& renderer, StateOp* op,
    635         int newSaveCount) {
    636     DEFER_LOGD("%p adding restore to count %d barrier, pos %d",
    637             this, newSaveCount, mBatches.size());
    638 
    639     // store displayState for the restore operation, as it may be associated with a saveLayer that
    640     // doesn't have kClip_SaveFlag set
    641     DeferredDisplayState* state = createState();
    642     renderer.storeDisplayState(*state, getStateOpDeferFlags());
    643     mBatches.add(new RestoreToCountBatch(op, state, newSaveCount));
    644     resetBatchingState();
    645 }
    646 
    647 /////////////////////////////////////////////////////////////////////////////////
    648 // Replay / flush
    649 /////////////////////////////////////////////////////////////////////////////////
    650 
    651 static status_t replayBatchList(const Vector<Batch*>& batchList,
    652         OpenGLRenderer& renderer, Rect& dirty) {
    653     status_t status = DrawGlInfo::kStatusDone;
    654 
    655     for (unsigned int i = 0; i < batchList.size(); i++) {
    656         if (batchList[i]) {
    657             status |= batchList[i]->replay(renderer, dirty, i);
    658         }
    659     }
    660     DEFER_LOGD("--flushed, drew %d batches", batchList.size());
    661     return status;
    662 }
    663 
    664 status_t DeferredDisplayList::flush(OpenGLRenderer& renderer, Rect& dirty) {
    665     ATRACE_NAME("flush drawing commands");
    666     Caches::getInstance().fontRenderer->endPrecaching();
    667 
    668     status_t status = DrawGlInfo::kStatusDone;
    669 
    670     if (isEmpty()) return status; // nothing to flush
    671     renderer.restoreToCount(1);
    672 
    673     DEFER_LOGD("--flushing");
    674     renderer.eventMark("Flush");
    675 
    676     // save and restore (with draw modifiers) so that reordering doesn't affect final state
    677     DrawModifiers restoreDrawModifiers = renderer.getDrawModifiers();
    678     renderer.save(SkCanvas::kMatrix_SaveFlag | SkCanvas::kClip_SaveFlag);
    679 
    680     if (CC_LIKELY(mAvoidOverdraw)) {
    681         for (unsigned int i = 1; i < mBatches.size(); i++) {
    682             if (mBatches[i] && mBatches[i]->coversBounds(mBounds)) {
    683                 discardDrawingBatches(i - 1);
    684             }
    685         }
    686     }
    687     // NOTE: depth of the save stack at this point, before playback, should be reflected in
    688     // FLUSH_SAVE_STACK_DEPTH, so that save/restores match up correctly
    689     status |= replayBatchList(mBatches, renderer, dirty);
    690 
    691     renderer.restoreToCount(1);
    692     renderer.setDrawModifiers(restoreDrawModifiers);
    693 
    694     DEFER_LOGD("--flush complete, returning %x", status);
    695     clear();
    696     return status;
    697 }
    698 
    699 void DeferredDisplayList::discardDrawingBatches(const unsigned int maxIndex) {
    700     for (unsigned int i = mEarliestUnclearedIndex; i <= maxIndex; i++) {
    701         // leave deferred state ops alone for simplicity (empty save restore pairs may now exist)
    702         if (mBatches[i] && mBatches[i]->purelyDrawBatch()) {
    703             DrawBatch* b = (DrawBatch*) mBatches[i];
    704             delete mBatches[i];
    705             mBatches.replaceAt(NULL, i);
    706         }
    707     }
    708     mEarliestUnclearedIndex = maxIndex + 1;
    709 }
    710 
    711 }; // namespace uirenderer
    712 }; // namespace android
    713