CanvasContext.cpp revision 6a21ca5a4c6b62ae277ae6dcb14bc187460321a0 
1/*
2 * Copyright (C) 2014 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#include <GpuMemoryTracker.h>
18#include "CanvasContext.h"
19
20#include "AnimationContext.h"
21#include "Caches.h"
22#include "DeferredLayerUpdater.h"
23#include "EglManager.h"
24#include "LayerUpdateQueue.h"
25#include "Properties.h"
26#include "Readback.h"
27#include "RenderThread.h"
28#include "hwui/Canvas.h"
29#include "renderstate/RenderState.h"
30#include "renderstate/Stencil.h"
31#include "protos/hwui.pb.h"
32#include "OpenGLPipeline.h"
33#include "utils/GLUtils.h"
34#include "utils/TimeUtils.h"
35
36#include <cutils/properties.h>
37#include <google/protobuf/io/zero_copy_stream_impl.h>
38#include <private/hwui/DrawGlInfo.h>
39#include <strings.h>
40
41#include <algorithm>
42#include <fcntl.h>
43#include <sys/stat.h>
44
45#include <cstdlib>
46
47#define TRIM_MEMORY_COMPLETE 80
48#define TRIM_MEMORY_UI_HIDDEN 20
49
50#define ENABLE_RENDERNODE_SERIALIZATION false
51
52#define LOG_FRAMETIME_MMA 0
53
54#if LOG_FRAMETIME_MMA
55static float sBenchMma = 0;
56static int sFrameCount = 0;
57static const float NANOS_PER_MILLIS_F = 1000000.0f;
58#endif
59
60namespace android {
61namespace uirenderer {
62namespace renderthread {
63
64CanvasContext* CanvasContext::create(RenderThread& thread,
65        bool translucent, RenderNode* rootRenderNode, IContextFactory* contextFactory) {
66
67    auto renderType = Properties::getRenderPipelineType();
68
69    switch (renderType) {
70        case RenderPipelineType::OpenGL:
71            return new CanvasContext(thread, translucent, rootRenderNode, contextFactory,
72                    std::make_unique<OpenGLPipeline>(thread));
73        case RenderPipelineType::SkiaGL:
74            //TODO: implement SKIA GL
75            LOG_ALWAYS_FATAL("skiaGL canvas type not implemented.");
76            break;
77        case RenderPipelineType::SkiaVulkan:
78            //TODO: implement Vulkan
79            LOG_ALWAYS_FATAL("Vulkan canvas type not implemented.");
80            break;
81        default:
82            LOG_ALWAYS_FATAL("canvas context type %d not supported", (int32_t) renderType);
83            break;
84    }
85    return nullptr;
86}
87
88void CanvasContext::destroyLayer(RenderNode* node) {
89    auto renderType = Properties::getRenderPipelineType();
90    switch (renderType) {
91        case RenderPipelineType::OpenGL:
92            OpenGLPipeline::destroyLayer(node);
93            break;
94        default:
95            LOG_ALWAYS_FATAL("canvas context type %d not supported", (int32_t) renderType);
96            break;
97    }
98}
99
100CanvasContext::CanvasContext(RenderThread& thread, bool translucent,
101        RenderNode* rootRenderNode, IContextFactory* contextFactory,
102        std::unique_ptr<IRenderPipeline> renderPipeline)
103        : mRenderThread(thread)
104        , mOpaque(!translucent)
105        , mAnimationContext(contextFactory->createAnimationContext(mRenderThread.timeLord()))
106        , mJankTracker(thread.mainDisplayInfo())
107        , mProfiler(mFrames)
108        , mContentDrawBounds(0, 0, 0, 0)
109        , mRenderPipeline(std::move(renderPipeline)) {
110    mRenderNodes.emplace_back(rootRenderNode);
111    mRenderThread.renderState().registerCanvasContext(this);
112    mProfiler.setDensity(mRenderThread.mainDisplayInfo().density);
113}
114
115CanvasContext::~CanvasContext() {
116    destroy(nullptr);
117    mRenderThread.renderState().unregisterCanvasContext(this);
118}
119
120void CanvasContext::destroy(TreeObserver* observer) {
121    stopDrawing();
122    setSurface(nullptr);
123    freePrefetchedLayers(observer);
124    destroyHardwareResources(observer);
125    mAnimationContext->destroy();
126}
127
128void CanvasContext::setSurface(Surface* surface) {
129    ATRACE_CALL();
130
131    mNativeSurface = surface;
132
133    bool hasSurface = mRenderPipeline->setSurface(surface, mSwapBehavior);
134
135    mFrameNumber = -1;
136
137    if (hasSurface) {
138         mHaveNewSurface = true;
139         mSwapHistory.clear();
140    } else {
141         mRenderThread.removeFrameCallback(this);
142    }
143}
144
145void CanvasContext::setSwapBehavior(SwapBehavior swapBehavior) {
146    mSwapBehavior = swapBehavior;
147}
148
149void CanvasContext::initialize(Surface* surface) {
150    setSurface(surface);
151}
152
153void CanvasContext::updateSurface(Surface* surface) {
154    setSurface(surface);
155}
156
157bool CanvasContext::pauseSurface(Surface* surface) {
158    return mRenderThread.removeFrameCallback(this);
159}
160
161void CanvasContext::setStopped(bool stopped) {
162    if (mStopped != stopped) {
163        mStopped = stopped;
164        if (mStopped) {
165            mRenderThread.removeFrameCallback(this);
166            mRenderPipeline->onStop();
167        } else if (mIsDirty && hasSurface()) {
168            mRenderThread.postFrameCallback(this);
169        }
170    }
171}
172
173void CanvasContext::setup(float lightRadius,
174        uint8_t ambientShadowAlpha, uint8_t spotShadowAlpha) {
175    mLightGeometry.radius = lightRadius;
176    mLightInfo.ambientShadowAlpha = ambientShadowAlpha;
177    mLightInfo.spotShadowAlpha = spotShadowAlpha;
178}
179
180void CanvasContext::setLightCenter(const Vector3& lightCenter) {
181    mLightGeometry.center = lightCenter;
182}
183
184void CanvasContext::setOpaque(bool opaque) {
185    mOpaque = opaque;
186}
187
188bool CanvasContext::makeCurrent() {
189    if (mStopped) return false;
190
191    auto result = mRenderPipeline->makeCurrent();
192    switch (result) {
193        case MakeCurrentResult::AlreadyCurrent:
194            return true;
195        case MakeCurrentResult::Failed:
196            mHaveNewSurface = true;
197            setSurface(nullptr);
198            return false;
199        case MakeCurrentResult::Succeeded:
200            mHaveNewSurface = true;
201            return true;
202        default:
203            LOG_ALWAYS_FATAL("unexpected result %d from IRenderPipeline::makeCurrent",
204                    (int32_t) result);
205    }
206
207    return true;
208}
209
210static bool wasSkipped(FrameInfo* info) {
211    return info && ((*info)[FrameInfoIndex::Flags] & FrameInfoFlags::SkippedFrame);
212}
213
214bool CanvasContext::isSwapChainStuffed() {
215    static const auto SLOW_THRESHOLD = 6_ms;
216
217    if (mSwapHistory.size() != mSwapHistory.capacity()) {
218        // We want at least 3 frames of history before attempting to
219        // guess if the queue is stuffed
220        return false;
221    }
222    nsecs_t frameInterval = mRenderThread.timeLord().frameIntervalNanos();
223    auto& swapA = mSwapHistory[0];
224
225    // Was there a happy queue & dequeue time? If so, don't
226    // consider it stuffed
227    if (swapA.dequeueDuration < SLOW_THRESHOLD
228            && swapA.queueDuration < SLOW_THRESHOLD) {
229        return false;
230    }
231
232    for (size_t i = 1; i < mSwapHistory.size(); i++) {
233        auto& swapB = mSwapHistory[i];
234
235        // If there's a multi-frameInterval gap we effectively already dropped a frame,
236        // so consider the queue healthy.
237        if (swapA.swapCompletedTime - swapB.swapCompletedTime > frameInterval * 3) {
238            return false;
239        }
240
241        // Was there a happy queue & dequeue time? If so, don't
242        // consider it stuffed
243        if (swapB.dequeueDuration < SLOW_THRESHOLD
244                && swapB.queueDuration < SLOW_THRESHOLD) {
245            return false;
246        }
247
248        swapA = swapB;
249    }
250
251    // All signs point to a stuffed swap chain
252    ATRACE_NAME("swap chain stuffed");
253    return true;
254}
255
256void CanvasContext::prepareTree(TreeInfo& info, int64_t* uiFrameInfo,
257        int64_t syncQueued, RenderNode* target) {
258    mRenderThread.removeFrameCallback(this);
259
260    // If the previous frame was dropped we don't need to hold onto it, so
261    // just keep using the previous frame's structure instead
262    if (!wasSkipped(mCurrentFrameInfo)) {
263        mCurrentFrameInfo = &mFrames.next();
264    }
265    mCurrentFrameInfo->importUiThreadInfo(uiFrameInfo);
266    mCurrentFrameInfo->set(FrameInfoIndex::SyncQueued) = syncQueued;
267    mCurrentFrameInfo->markSyncStart();
268
269    info.damageAccumulator = &mDamageAccumulator;
270    info.layerUpdateQueue = &mLayerUpdateQueue;
271
272    mAnimationContext->startFrame(info.mode);
273    for (const sp<RenderNode>& node : mRenderNodes) {
274        // Only the primary target node will be drawn full - all other nodes would get drawn in
275        // real time mode. In case of a window, the primary node is the window content and the other
276        // node(s) are non client / filler nodes.
277        info.mode = (node.get() == target ? TreeInfo::MODE_FULL : TreeInfo::MODE_RT_ONLY);
278        node->prepareTree(info);
279        GL_CHECKPOINT(MODERATE);
280    }
281    mAnimationContext->runRemainingAnimations(info);
282    GL_CHECKPOINT(MODERATE);
283
284    freePrefetchedLayers(info.observer);
285    GL_CHECKPOINT(MODERATE);
286
287    mIsDirty = true;
288
289    if (CC_UNLIKELY(!mNativeSurface.get())) {
290        mCurrentFrameInfo->addFlag(FrameInfoFlags::SkippedFrame);
291        info.out.canDrawThisFrame = false;
292        return;
293    }
294
295    if (CC_LIKELY(mSwapHistory.size() && !Properties::forceDrawFrame)) {
296        nsecs_t latestVsync = mRenderThread.timeLord().latestVsync();
297        SwapHistory& lastSwap = mSwapHistory.back();
298        nsecs_t vsyncDelta = std::abs(lastSwap.vsyncTime - latestVsync);
299        // The slight fudge-factor is to deal with cases where
300        // the vsync was estimated due to being slow handling the signal.
301        // See the logic in TimeLord#computeFrameTimeNanos or in
302        // Choreographer.java for details on when this happens
303        if (vsyncDelta < 2_ms) {
304            // Already drew for this vsync pulse, UI draw request missed
305            // the deadline for RT animations
306            info.out.canDrawThisFrame = false;
307        } else if (vsyncDelta >= mRenderThread.timeLord().frameIntervalNanos() * 3
308                || (latestVsync - mLastDropVsync) < 500_ms) {
309            // It's been several frame intervals, assume the buffer queue is fine
310            // or the last drop was too recent
311            info.out.canDrawThisFrame = true;
312        } else {
313            info.out.canDrawThisFrame = !isSwapChainStuffed();
314            if (!info.out.canDrawThisFrame) {
315                // dropping frame
316                mLastDropVsync = mRenderThread.timeLord().latestVsync();
317            }
318        }
319    } else {
320        info.out.canDrawThisFrame = true;
321    }
322
323    if (!info.out.canDrawThisFrame) {
324        mCurrentFrameInfo->addFlag(FrameInfoFlags::SkippedFrame);
325    }
326
327    if (info.out.hasAnimations || !info.out.canDrawThisFrame) {
328        if (!info.out.requiresUiRedraw) {
329            // If animationsNeedsRedraw is set don't bother posting for an RT anim
330            // as we will just end up fighting the UI thread.
331            mRenderThread.postFrameCallback(this);
332        }
333    }
334}
335
336void CanvasContext::stopDrawing() {
337    mRenderThread.removeFrameCallback(this);
338    mAnimationContext->pauseAnimators();
339}
340
341void CanvasContext::notifyFramePending() {
342    ATRACE_CALL();
343    mRenderThread.pushBackFrameCallback(this);
344}
345
346void CanvasContext::draw() {
347    SkRect dirty;
348    mDamageAccumulator.finish(&dirty);
349
350    // TODO: Re-enable after figuring out cause of b/22592975
351//    if (dirty.isEmpty() && Properties::skipEmptyFrames) {
352//        mCurrentFrameInfo->addFlag(FrameInfoFlags::SkippedFrame);
353//        return;
354//    }
355
356    mCurrentFrameInfo->markIssueDrawCommandsStart();
357
358    Frame frame = mRenderPipeline->getFrame();
359
360    SkRect windowDirty = computeDirtyRect(frame, &dirty);
361
362    bool drew = mRenderPipeline->draw(frame, windowDirty, dirty, mLightGeometry, &mLayerUpdateQueue,
363            mContentDrawBounds, mOpaque, mLightInfo, mRenderNodes, &(profiler()));
364
365    waitOnFences();
366
367    bool requireSwap = false;
368    bool didSwap = mRenderPipeline->swapBuffers(frame, drew, windowDirty, mCurrentFrameInfo,
369            &requireSwap);
370
371    mIsDirty = false;
372
373    if (requireSwap) {
374        if (!didSwap) { //some error happened
375            setSurface(nullptr);
376        }
377        SwapHistory& swap = mSwapHistory.next();
378        swap.damage = windowDirty;
379        swap.swapCompletedTime = systemTime(CLOCK_MONOTONIC);
380        swap.vsyncTime = mRenderThread.timeLord().latestVsync();
381        if (mNativeSurface.get()) {
382            int durationUs;
383            mNativeSurface->query(NATIVE_WINDOW_LAST_DEQUEUE_DURATION, &durationUs);
384            swap.dequeueDuration = us2ns(durationUs);
385            mNativeSurface->query(NATIVE_WINDOW_LAST_QUEUE_DURATION, &durationUs);
386            swap.queueDuration = us2ns(durationUs);
387        } else {
388            swap.dequeueDuration = 0;
389            swap.queueDuration = 0;
390        }
391        mCurrentFrameInfo->set(FrameInfoIndex::DequeueBufferDuration)
392                = swap.dequeueDuration;
393        mCurrentFrameInfo->set(FrameInfoIndex::QueueBufferDuration)
394                = swap.queueDuration;
395        mHaveNewSurface = false;
396        mFrameNumber = -1;
397    } else {
398        mCurrentFrameInfo->set(FrameInfoIndex::DequeueBufferDuration) = 0;
399        mCurrentFrameInfo->set(FrameInfoIndex::QueueBufferDuration) = 0;
400    }
401
402    // TODO: Use a fence for real completion?
403    mCurrentFrameInfo->markFrameCompleted();
404
405#if LOG_FRAMETIME_MMA
406    float thisFrame = mCurrentFrameInfo->duration(
407            FrameInfoIndex::IssueDrawCommandsStart,
408            FrameInfoIndex::FrameCompleted) / NANOS_PER_MILLIS_F;
409    if (sFrameCount) {
410        sBenchMma = ((9 * sBenchMma) + thisFrame) / 10;
411    } else {
412        sBenchMma = thisFrame;
413    }
414    if (++sFrameCount == 10) {
415        sFrameCount = 1;
416        ALOGD("Average frame time: %.4f", sBenchMma);
417    }
418#endif
419
420    mJankTracker.addFrame(*mCurrentFrameInfo);
421    mRenderThread.jankTracker().addFrame(*mCurrentFrameInfo);
422    if (CC_UNLIKELY(mFrameMetricsReporter.get() != nullptr)) {
423        mFrameMetricsReporter->reportFrameMetrics(mCurrentFrameInfo->data());
424    }
425
426    GpuMemoryTracker::onFrameCompleted();
427#ifdef BUGREPORT_FONT_CACHE_USAGE
428    Caches& caches = Caches::getInstance();
429    caches.fontRenderer.getFontRenderer().historyTracker().frameCompleted();
430#endif
431
432}
433
434// Called by choreographer to do an RT-driven animation
435void CanvasContext::doFrame() {
436    if (!mRenderPipeline->isSurfaceReady()) return;
437    prepareAndDraw(nullptr);
438}
439
440void CanvasContext::prepareAndDraw(RenderNode* node) {
441    ATRACE_CALL();
442
443    nsecs_t vsync = mRenderThread.timeLord().computeFrameTimeNanos();
444    int64_t frameInfo[UI_THREAD_FRAME_INFO_SIZE];
445    UiFrameInfoBuilder(frameInfo)
446        .addFlag(FrameInfoFlags::RTAnimation)
447        .setVsync(vsync, vsync);
448
449    TreeInfo info(TreeInfo::MODE_RT_ONLY, *this);
450    prepareTree(info, frameInfo, systemTime(CLOCK_MONOTONIC), node);
451    if (info.out.canDrawThisFrame) {
452        draw();
453    } else {
454        // wait on fences so tasks don't overlap next frame
455        waitOnFences();
456    }
457}
458
459void CanvasContext::invokeFunctor(RenderThread& thread, Functor* functor) {
460    ATRACE_CALL();
461    DrawGlInfo::Mode mode = DrawGlInfo::kModeProcessNoContext;
462    if (thread.eglManager().hasEglContext()) {
463        mode = DrawGlInfo::kModeProcess;
464    }
465
466    thread.renderState().invokeFunctor(functor, mode, nullptr);
467}
468
469void CanvasContext::markLayerInUse(RenderNode* node) {
470    if (mPrefetchedLayers.erase(node)) {
471        node->decStrong(nullptr);
472    }
473}
474
475void CanvasContext::freePrefetchedLayers(TreeObserver* observer) {
476    if (mPrefetchedLayers.size()) {
477        for (auto& node : mPrefetchedLayers) {
478            ALOGW("Incorrectly called buildLayer on View: %s, destroying layer...",
479                    node->getName());
480            node->destroyHardwareResources(observer);
481            node->decStrong(observer);
482        }
483        mPrefetchedLayers.clear();
484    }
485}
486
487void CanvasContext::buildLayer(RenderNode* node, TreeObserver* observer) {
488    ATRACE_CALL();
489    if (!mRenderPipeline->isContextReady()) return;
490
491    // buildLayer() will leave the tree in an unknown state, so we must stop drawing
492    stopDrawing();
493
494    TreeInfo info(TreeInfo::MODE_FULL, *this);
495    info.damageAccumulator = &mDamageAccumulator;
496    info.observer = observer;
497    info.layerUpdateQueue = &mLayerUpdateQueue;
498    info.runAnimations = false;
499    node->prepareTree(info);
500    SkRect ignore;
501    mDamageAccumulator.finish(&ignore);
502    // Tickle the GENERIC property on node to mark it as dirty for damaging
503    // purposes when the frame is actually drawn
504    node->setPropertyFieldsDirty(RenderNode::GENERIC);
505
506    mRenderPipeline->renderLayers(mLightGeometry, &mLayerUpdateQueue, mOpaque, mLightInfo);
507
508    node->incStrong(nullptr);
509    mPrefetchedLayers.insert(node);
510}
511
512bool CanvasContext::copyLayerInto(DeferredLayerUpdater* layer, SkBitmap* bitmap) {
513    return mRenderPipeline->copyLayerInto(layer, bitmap);
514}
515
516void CanvasContext::destroyHardwareResources(TreeObserver* observer) {
517    stopDrawing();
518    if (mRenderPipeline->isContextReady()) {
519        freePrefetchedLayers(observer);
520        for (const sp<RenderNode>& node : mRenderNodes) {
521            node->destroyHardwareResources(observer);
522        }
523        Caches& caches = Caches::getInstance();
524        // Make sure to release all the textures we were owning as there won't
525        // be another draw
526        caches.textureCache.resetMarkInUse(this);
527        mRenderPipeline->onDestroyHardwareResources();
528    }
529}
530
531void CanvasContext::trimMemory(RenderThread& thread, int level) {
532    // No context means nothing to free
533    if (!thread.eglManager().hasEglContext()) return;
534
535    ATRACE_CALL();
536    if (level >= TRIM_MEMORY_COMPLETE) {
537        thread.renderState().flush(Caches::FlushMode::Full);
538        thread.eglManager().destroy();
539    } else if (level >= TRIM_MEMORY_UI_HIDDEN) {
540        thread.renderState().flush(Caches::FlushMode::Moderate);
541    }
542}
543
544DeferredLayerUpdater* CanvasContext::createTextureLayer() {
545    return mRenderPipeline->createTextureLayer();
546}
547
548void CanvasContext::setTextureAtlas(RenderThread& thread,
549        const sp<GraphicBuffer>& buffer, int64_t* map, size_t mapSize) {
550    thread.eglManager().setTextureAtlas(buffer, map, mapSize);
551}
552
553void CanvasContext::dumpFrames(int fd) {
554    FILE* file = fdopen(fd, "a");
555    fprintf(file, "\n\n---PROFILEDATA---\n");
556    for (size_t i = 0; i < static_cast<size_t>(FrameInfoIndex::NumIndexes); i++) {
557        fprintf(file, "%s", FrameInfoNames[i].c_str());
558        fprintf(file, ",");
559    }
560    for (size_t i = 0; i < mFrames.size(); i++) {
561        FrameInfo& frame = mFrames[i];
562        if (frame[FrameInfoIndex::SyncStart] == 0) {
563            continue;
564        }
565        fprintf(file, "\n");
566        for (int i = 0; i < static_cast<int>(FrameInfoIndex::NumIndexes); i++) {
567            fprintf(file, "%" PRId64 ",", frame[i]);
568        }
569    }
570    fprintf(file, "\n---PROFILEDATA---\n\n");
571    fflush(file);
572}
573
574void CanvasContext::resetFrameStats() {
575    mFrames.clear();
576    mRenderThread.jankTracker().reset();
577}
578
579void CanvasContext::serializeDisplayListTree() {
580#if ENABLE_RENDERNODE_SERIALIZATION
581    using namespace google::protobuf::io;
582    char package[128];
583    // Check whether tracing is enabled for this process.
584    FILE * file = fopen("/proc/self/cmdline", "r");
585    if (file) {
586        if (!fgets(package, 128, file)) {
587            ALOGE("Error reading cmdline: %s (%d)", strerror(errno), errno);
588            fclose(file);
589            return;
590        }
591        fclose(file);
592    } else {
593        ALOGE("Error opening /proc/self/cmdline: %s (%d)", strerror(errno),
594                errno);
595        return;
596    }
597    char path[1024];
598    snprintf(path, 1024, "/data/data/%s/cache/rendertree_dump", package);
599    int fd = open(path, O_CREAT | O_WRONLY, S_IRWXU | S_IRGRP | S_IROTH);
600    if (fd == -1) {
601        ALOGD("Failed to open '%s'", path);
602        return;
603    }
604    proto::RenderNode tree;
605    // TODO: Streaming writes?
606    mRootRenderNode->copyTo(&tree);
607    std::string data = tree.SerializeAsString();
608    write(fd, data.c_str(), data.length());
609    close(fd);
610#endif
611}
612
613void CanvasContext::waitOnFences() {
614    if (mFrameFences.size()) {
615        ATRACE_CALL();
616        for (auto& fence : mFrameFences) {
617            fence->getResult();
618        }
619        mFrameFences.clear();
620    }
621}
622
623class CanvasContext::FuncTaskProcessor : public TaskProcessor<bool> {
624public:
625    explicit FuncTaskProcessor(TaskManager* taskManager)
626            : TaskProcessor<bool>(taskManager) {}
627
628    virtual void onProcess(const sp<Task<bool> >& task) override {
629        FuncTask* t = static_cast<FuncTask*>(task.get());
630        t->func();
631        task->setResult(true);
632    }
633};
634
635void CanvasContext::enqueueFrameWork(std::function<void()>&& func) {
636    if (!mFrameWorkProcessor.get()) {
637        mFrameWorkProcessor = new FuncTaskProcessor(mRenderPipeline->getTaskManager());
638    }
639    sp<FuncTask> task(new FuncTask());
640    task->func = func;
641    mFrameFences.push_back(task);
642    mFrameWorkProcessor->add(task);
643}
644
645int64_t CanvasContext::getFrameNumber() {
646    // mFrameNumber is reset to -1 when the surface changes or we swap buffers
647    if (mFrameNumber == -1 && mNativeSurface.get()) {
648        mFrameNumber = static_cast<int64_t>(mNativeSurface->getNextFrameNumber());
649    }
650    return mFrameNumber;
651}
652
653SkRect CanvasContext::computeDirtyRect(const Frame& frame, SkRect* dirty) {
654    if (frame.width() != mLastFrameWidth || frame.height() != mLastFrameHeight) {
655        // can't rely on prior content of window if viewport size changes
656        dirty->setEmpty();
657        mLastFrameWidth = frame.width();
658        mLastFrameHeight = frame.height();
659    } else if (mHaveNewSurface || frame.bufferAge() == 0) {
660        // New surface needs a full draw
661        dirty->setEmpty();
662    } else {
663        if (!dirty->isEmpty() && !dirty->intersect(0, 0, frame.width(), frame.height())) {
664            ALOGW("Dirty " RECT_STRING " doesn't intersect with 0 0 %d %d ?",
665                    SK_RECT_ARGS(*dirty), frame.width(), frame.height());
666            dirty->setEmpty();
667        }
668        profiler().unionDirty(dirty);
669    }
670
671    if (dirty->isEmpty()) {
672        dirty->set(0, 0, frame.width(), frame.height());
673    }
674
675    // At this point dirty is the area of the window to update. However,
676    // the area of the frame we need to repaint is potentially different, so
677    // stash the screen area for later
678    SkRect windowDirty(*dirty);
679
680    // If the buffer age is 0 we do a full-screen repaint (handled above)
681    // If the buffer age is 1 the buffer contents are the same as they were
682    // last frame so there's nothing to union() against
683    // Therefore we only care about the > 1 case.
684    if (frame.bufferAge() > 1) {
685        if (frame.bufferAge() > (int) mSwapHistory.size()) {
686            // We don't have enough history to handle this old of a buffer
687            // Just do a full-draw
688            dirty->set(0, 0, frame.width(), frame.height());
689        } else {
690            // At this point we haven't yet added the latest frame
691            // to the damage history (happens below)
692            // So we need to damage
693            for (int i = mSwapHistory.size() - 1;
694                    i > ((int) mSwapHistory.size()) - frame.bufferAge(); i--) {
695                dirty->join(mSwapHistory[i].damage);
696            }
697        }
698    }
699
700    return windowDirty;
701}
702
703} /* namespace renderthread */
704} /* namespace uirenderer */
705} /* namespace android */
706