C++ SkPicture类代码示例

// Add several layers to the cache
static void create_layers(skiatest::Reporter* reporter,
                          GrLayerCache* cache,
                          const SkPicture& picture,
                          unsigned numToAdd,
                          unsigned idOffset) {

    for (unsigned i = 0; i < numToAdd; ++i) {
        unsigned indices[1] = { idOffset+i+1 };
        GrCachedLayer* layer = cache->findLayerOrCreate(picture.uniqueID(), 
                                                        idOffset+i+1, idOffset+i+2, 
                                                        SkIRect::MakeEmpty(),
                                                        SkIRect::MakeEmpty(),
                                                        SkMatrix::I(),
                                                        indices, 1,
                                                        NULL);
        REPORTER_ASSERT(reporter, layer);
        GrCachedLayer* temp = TestingAccess::Find(cache, picture.uniqueID(), SkMatrix::I(), 
                                                  indices, 1);
        REPORTER_ASSERT(reporter, temp == layer);

        REPORTER_ASSERT(reporter, TestingAccess::NumLayers(cache) == idOffset + i + 1);

        REPORTER_ASSERT(reporter, picture.uniqueID() == layer->pictureID());
        REPORTER_ASSERT(reporter, layer->start() == idOffset + i + 1);
        REPORTER_ASSERT(reporter, layer->stop() == idOffset + i + 2);
        REPORTER_ASSERT(reporter, NULL == layer->texture());
        REPORTER_ASSERT(reporter, NULL == layer->paint());
        REPORTER_ASSERT(reporter, !layer->isAtlased());
    }
}

static SkPicture* inspect(const char path[]) {
    SkFILEStream stream(path);
    if (!stream.isValid()) {
        printf("-- Can't open '%s'\n", path);
        return nullptr;
    }

    printf("Opening '%s'...\n", path);

    {
        int32_t header[3];
        if (stream.read(header, sizeof(header)) != sizeof(header)) {
            printf("-- Failed to read header (12 bytes)\n");
            return nullptr;
        }
        printf("version:%d width:%d height:%d\n", header[0], header[1], header[2]);
    }

    stream.rewind();
    SkPicture* pic = SkPicture::CreateFromStream(&stream);
    if (nullptr == pic) {
        SkDebugf("Could not create SkPicture: %s\n", path);
        return nullptr;
    }
    printf("picture cullRect: [%f %f %f %f]\n", 
           pic->cullRect().fLeft, pic->cullRect().fTop,
           pic->cullRect().fRight, pic->cullRect().fBottom);
    return pic;
}

void ImageBuffer::copyRecordingToCanvas(GraphicsContext* paintContext, const IntRect& r) const
{
    SkCanvas* paintCanvas = paintContext->platformContext()->mCanvas;
    SkPicture* canvasRecording = context()->platformContext()->getRecordingPicture();

    SkPaint paint;
    paint.setXfermodeMode(SkXfermode::kSrcOver_Mode);
	const SkIRect& clipBounds = paintCanvas->getTotalClip().getBounds();
	SkRect rect;
	int saveCount = 0; 
	if( (clipBounds.width() > r.width() * 2 ) || (clipBounds.height() > r.height() * 2))
	{
		rect.set(r.location().x(), r.location().y(),r.width(), r.height()); 
		saveCount = paintCanvas->saveLayer(&rect, &paint);
	}
	else
		saveCount = paintCanvas->saveLayer(0, &paint);
    paintCanvas->translate(r.location().x(), r.location().y());
    // Resize to the now known viewport.
    paintCanvas->scale(r.width() / width(), r.height() / height());
    // Draw the canvas recording into the layer recording canvas.
    canvasRecording->draw(paintCanvas);
    context()->platformContext()->clearRecording();
    paintCanvas->restoreToCount(saveCount);

}

    virtual void onDraw(SkCanvas* canvas) {
        this->drawBG(canvas);
        
        SkMatrix saveM = *fMatrixRefs[3];
        SkScalar c = SkIntToScalar(50);
        fMatrixRefs[3]->preRotate(SkIntToScalar(30), c, c);
        
        SkMatrix matrix;
     
        SkGroupShape* gs = new SkGroupShape;
        SkAutoUnref aur(gs);
        gs->appendShape(&fGroup);
        matrix.setScale(-SK_Scalar1, SK_Scalar1);
        matrix.postTranslate(SkIntToScalar(220), SkIntToScalar(240));
        gs->appendShape(&fGroup, matrix);
        matrix.setTranslate(SkIntToScalar(240), 0);
        matrix.preScale(SK_Scalar1*2, SK_Scalar1*2);
        gs->appendShape(&fGroup, matrix);
        
#if 0        
        canvas->drawShape(gs);
#else
        SkPicture pict;
        SkCanvas* cv = pict.beginRecording(1000, 1000);
        cv->scale(SK_ScalarHalf, SK_ScalarHalf);
        cv->drawShape(gs);
        cv->translate(SkIntToScalar(680), SkIntToScalar(480));
        cv->scale(-SK_Scalar1, SK_Scalar1);
        cv->drawShape(gs);
        pict.endRecording();
        canvas->drawPicture(pict);
#endif

        *fMatrixRefs[3] = saveM;
}

    virtual void onDraw(SkCanvas* canvas) {
        this->drawBG(canvas);

        SkMatrix matrix;

        SkGroupShape* gs = new SkGroupShape;
        SkAutoUnref aur(gs);
        gs->appendShape(&fGroup);
        matrix.setScale(-SK_Scalar1, SK_Scalar1);
        matrix.postTranslate(SkIntToScalar(220), SkIntToScalar(240));
        gs->appendShape(&fGroup, matrix);
        matrix.setTranslate(SkIntToScalar(240), 0);
        matrix.preScale(SK_Scalar1*2, SK_Scalar1*2);
        gs->appendShape(&fGroup, matrix);

#if 1
        SkPicture* pict = new SkPicture;
        SkCanvas* cv = pict->beginRecording(1000, 1000);
        cv->scale(SK_ScalarHalf, SK_ScalarHalf);
        gs->draw(cv);
        cv->translate(SkIntToScalar(680), SkIntToScalar(480));
        cv->scale(-SK_Scalar1, SK_Scalar1);
        gs->draw(cv);
        pict->endRecording();
        canvas->drawPicture(*pict);
        pict->unref();
#endif
}

static bool nativeSerializeViewState(JNIEnv* env, jobject, jint jbaseLayer,
                                     jobject jstream, jbyteArray jstorage)
{
    BaseLayerAndroid* baseLayer = (BaseLayerAndroid*) jbaseLayer;
    if (!baseLayer)
        return false;

    SkWStream *stream = CreateJavaOutputStreamAdaptor(env, jstream, jstorage);
#if USE(ACCELERATED_COMPOSITING)
// SAMSUNG CHANGE >> White flickering issue.
// WAS:stream->write32(baseLayer->getBackgroundColor().rgb());
    stream->write32(baseLayer->getBackgroundColor());
// SAMSUNG CHANGE <<
#else
    stream->write32(0);
#endif
    SkPicture picture;
    PictureSet* content = baseLayer->content();
    baseLayer->drawCanvas(picture.beginRecording(content->width(), content->height(),
            SkPicture::kUsePathBoundsForClip_RecordingFlag));
    picture.endRecording();
    if (!stream)
        return false;
    picture.serialize(stream);
    int childCount = baseLayer->countChildren();
    XLOG("BaseLayer has %d child(ren)", childCount);
    stream->write32(childCount);
    for (int i = 0; i < childCount; i++) {
        LayerAndroid* layer = static_cast<LayerAndroid*>(baseLayer->getChild(i));
        serializeLayer(layer, stream);
    }
    delete stream;
    return true;
}

static SkPicture* inspect(const char path[]) {
    SkFILEStream stream(path);
    if (!stream.isValid()) {
        printf("-- Can't open '%s'\n", path);
        return NULL;
    }

    printf("Opening '%s'...\n", path);

    {
        int32_t header[3];
        if (stream.read(header, sizeof(header)) != sizeof(header)) {
            printf("-- Failed to read header (12 bytes)\n");
            return NULL;
        }
        printf("version:%d width:%d height:%d\n", header[0], header[1], header[2]);
    }

    stream.rewind();
    SkPicture* pic = SkPicture::CreateFromStream(&stream, &sk_tools::LazyDecodeBitmap);
    if (NULL == pic) {
        SkDebugf("Could not create SkPicture: %s\n", path);
        return NULL;
    }
    printf("picture size:[%d %d]\n", pic->width(), pic->height());
    return pic;
}

// Ensure that serializing an empty picture does not assert. Likewise only runs in debug mode.
static void test_serializing_empty_picture() {
    SkPicture picture;
    picture.beginRecording(0, 0);
    picture.endRecording();
    SkDynamicMemoryWStream stream;
    picture.serialize(&stream);
}

static SkData* serialized_picture_from_bitmap(const SkBitmap& bitmap) {
    SkPicture picture;
    SkCanvas* canvas = picture.beginRecording(bitmap.width(), bitmap.height());
    canvas->drawBitmap(bitmap, 0, 0);
    SkDynamicMemoryWStream wStream;
    picture.serialize(&wStream, &encode_bitmap_to_data);
    return wStream.copyToData();
}

static SkBitmap draw_picture(SkPicture& picture) {
     SkBitmap bitmap;
     bitmap.allocN32Pixels(SkScalarCeilToInt(picture.cullRect().width()),
                           SkScalarCeilToInt(picture.cullRect().height()));
     SkCanvas canvas(bitmap);
     picture.playback(&canvas);
     return bitmap;
}

 static void draw(JNIEnv* env, jobject, jlong canvasHandle,
                         jlong pictureHandle) {
     SkCanvas* canvas = reinterpret_cast<SkCanvas*>(canvasHandle);
     SkPicture* picture = reinterpret_cast<SkPicture*>(pictureHandle);
     SkASSERT(canvas);
     SkASSERT(picture);
     picture->draw(canvas);
 }

void SkDumpCanvas::drawPicture(SkPicture& picture) {
    this->dump(kDrawPicture_Verb, NULL, "drawPicture(%p) %d:%d", &picture,
               picture.width(), picture.height());
    fNestLevel += 1;
    this->INHERITED::drawPicture(picture);
    fNestLevel -= 1;
    this->dump(kDrawPicture_Verb, NULL, "endPicture(%p) %d:%d", &picture,
               picture.width(), picture.height());
}

// Ensure that deleting SkPicturePlayback does not assert. Asserts only fire in debug mode, so only
// run in debug mode.
static void test_deleting_empty_playback() {
    SkPicture picture;
    // Creates an SkPictureRecord
    picture.beginRecording(0, 0);
    // Turns that into an SkPicturePlayback
    picture.endRecording();
    // Deletes the old SkPicturePlayback, and creates a new SkPictureRecord
    picture.beginRecording(0, 0);
}

void PicturePileLayerContent::serialize(SkWStream* stream)
{
    if (!stream)
       return;
    SkPicture picture;
    draw(picture.beginRecording(width(), height(),
                                SkPicture::kUsePathBoundsForClip_RecordingFlag));
    picture.endRecording();
    picture.serialize(stream);
}

// Extract the command ops from the input SkPicture
static void gets_ops(SkPicture& input, SkTDArray<DrawType>* ops) {
    SkDebugCanvas debugCanvas(input.width(), input.height());
    debugCanvas.setBounds(input.width(), input.height());
    input.draw(&debugCanvas);

    ops->setCount(debugCanvas.getSize());
    for (int i = 0; i < debugCanvas.getSize(); ++i) {
        (*ops)[i] = debugCanvas.getDrawCommandAt(i)->getType();
    }
}