C++ SkTDArray::setReserve方法代码示例

void SkRTree::insert(const SkRect boundsArray[], int N) {
    SkASSERT(0 == fCount);

    SkTDArray<Branch> branches;
    branches.setReserve(N);

    for (int i = 0; i < N; i++) {
        const SkRect& bounds = boundsArray[i];
        if (bounds.isEmpty()) {
            continue;
        }

        Branch* b = branches.push();
        b->fBounds = bounds;
        b->fOpIndex = i;
    }

    fCount = branches.count();
    if (fCount) {
        if (1 == fCount) {
            fNodes.setReserve(1);
            Node* n = this->allocateNodeAtLevel(0);
            n->fNumChildren = 1;
            n->fChildren[0] = branches[0];
            fRoot.fSubtree = n;
            fRoot.fBounds  = branches[0].fBounds;
        } else {
            fNodes.setReserve(CountNodes(fCount, fAspectRatio));
            fRoot = this->bulkLoad(&branches);
        }
    }
}

void SkTileGrid::reserve(int opCount) {
    if (fXTiles * fYTiles == 0) {
        return;  // A tileless tile grid is nonsensical, but happens in at least cc_unittests.
    }

    // If we assume every op we're about to try to insert() falls within our grid bounds,
    // then every op has to hit at least one tile.  In fact, a quick scan over our small
    // SKP set shows that in the average SKP, each op hits two 256x256 tiles.

    // If we take those observations and further assume the ops are distributed evenly
    // across the picture, we get this guess for number of ops per tile:
    const int opsPerTileGuess = (2 * opCount) / (fXTiles * fYTiles);

    for (SkTDArray<unsigned>* tile = fTiles; tile != fTiles + (fXTiles * fYTiles); tile++) {
        tile->setReserve(opsPerTileGuess);
    }

    // In practice, this heuristic means we'll temporarily allocate about 30% more bytes
    // than if we made no setReserve() calls, but time spent in insert() drops by about 50%.
}

// static
void SkPDFPage::GeneratePageTree(const SkTDArray<SkPDFPage*>& pages,
                                 SkPDFCatalog* catalog,
                                 SkTDArray<SkPDFDict*>* pageTree,
                                 SkPDFDict** rootNode) {
    // PDF wants a tree describing all the pages in the document.  We arbitrary
    // choose 8 (kNodeSize) as the number of allowed children.  The internal
    // nodes have type "Pages" with an array of children, a parent pointer, and
    // the number of leaves below the node as "Count."  The leaves are passed
    // into the method, have type "Page" and need a parent pointer. This method
    // builds the tree bottom up, skipping internal nodes that would have only
    // one child.
    static const int kNodeSize = 8;

    SkAutoTUnref<SkPDFName> kidsName(new SkPDFName("Kids"));
    SkAutoTUnref<SkPDFName> countName(new SkPDFName("Count"));
    SkAutoTUnref<SkPDFName> parentName(new SkPDFName("Parent"));

    // curNodes takes a reference to its items, which it passes to pageTree.
    SkTDArray<SkPDFDict*> curNodes;
    curNodes.setReserve(pages.count());
    for (int i = 0; i < pages.count(); i++) {
        SkSafeRef(pages[i]);
        curNodes.push(pages[i]);
    }

    // nextRoundNodes passes its references to nodes on to curNodes.
    SkTDArray<SkPDFDict*> nextRoundNodes;
    nextRoundNodes.setReserve((pages.count() + kNodeSize - 1)/kNodeSize);

    int treeCapacity = kNodeSize;
    do {
        for (int i = 0; i < curNodes.count(); ) {
            if (i > 0 && i + 1 == curNodes.count()) {
                nextRoundNodes.push(curNodes[i]);
                break;
            }

            SkPDFDict* newNode = new SkPDFDict("Pages");
            SkAutoTUnref<SkPDFObjRef> newNodeRef(new SkPDFObjRef(newNode));

            SkAutoTUnref<SkPDFArray> kids(new SkPDFArray);
            kids->reserve(kNodeSize);

            int count = 0;
            for (; i < curNodes.count() && count < kNodeSize; i++, count++) {
                curNodes[i]->insert(parentName.get(), newNodeRef.get());
                kids->append(new SkPDFObjRef(curNodes[i]))->unref();

                // TODO(vandebo): put the objects in strict access order.
                // Probably doesn't matter because they are so small.
                if (curNodes[i] != pages[0]) {
                    pageTree->push(curNodes[i]);  // Transfer reference.
                    catalog->addObject(curNodes[i], false);
                } else {
                    SkSafeUnref(curNodes[i]);
                    catalog->addObject(curNodes[i], true);
                }
            }

            // treeCapacity is the number of leaf nodes possible for the
            // current set of subtrees being generated. (i.e. 8, 64, 512, ...).
            // It is hard to count the number of leaf nodes in the current
            // subtree. However, by construction, we know that unless it's the
            // last subtree for the current depth, the leaf count will be
            // treeCapacity, otherwise it's what ever is left over after
            // consuming treeCapacity chunks.
            int pageCount = treeCapacity;
            if (i == curNodes.count()) {
                pageCount = ((pages.count() - 1) % treeCapacity) + 1;
            }
            newNode->insert(countName.get(), new SkPDFInt(pageCount))->unref();
            newNode->insert(kidsName.get(), kids.get());
            nextRoundNodes.push(newNode);  // Transfer reference.
        }

        curNodes = nextRoundNodes;
        nextRoundNodes.rewind();
        treeCapacity *= kNodeSize;
    } while (curNodes.count() > 1);

    pageTree->push(curNodes[0]);  // Transfer reference.
    catalog->addObject(curNodes[0], false);
    if (rootNode) {
        *rootNode = curNodes[0];
    }
}

bool TiledPictureRenderer::render(SkBitmap** out) {
    SkASSERT(fPicture != NULL);
    if (NULL == fPicture) {
        return false;
    }

    SkBitmap bitmap;
    if (out) {
        *out = SkNEW(SkBitmap);
        setup_bitmap(*out, SkScalarCeilToInt(fPicture->cullRect().width()),
                           SkScalarCeilToInt(fPicture->cullRect().height()));
        setup_bitmap(&bitmap, fTileWidth, fTileHeight);
    }
    bool success = true;

    if (fUseMultiPictureDraw) {
        SkMultiPictureDraw mpd;
        SkTDArray<SkSurface*> surfaces;
        surfaces.setReserve(fTileRects.count());

        // Create a separate SkSurface/SkCanvas for each tile along with a
        // translated version of the skp (to mimic Chrome's behavior) and
        // feed all such pairs to the MultiPictureDraw.
        for (int i = 0; i < fTileRects.count(); ++i) {
            SkImageInfo ii = fCanvas->imageInfo().makeWH(fTileRects[i].width(),
                                                         fTileRects[i].height());
            *surfaces.append() = fCanvas->newSurface(ii);
            surfaces[i]->getCanvas()->setMatrix(fCanvas->getTotalMatrix());

            SkPictureRecorder recorder;
            SkRTreeFactory bbhFactory;

            SkCanvas* c = recorder.beginRecording(SkIntToScalar(fTileRects[i].width()),
                                                  SkIntToScalar(fTileRects[i].height()),
                                                  &bbhFactory,
                                                  SkPictureRecorder::kComputeSaveLayerInfo_RecordFlag);
            c->save();
            SkMatrix mat;
            mat.setTranslate(-SkIntToScalar(fTileRects[i].fLeft),
                             -SkIntToScalar(fTileRects[i].fTop));
            c->setMatrix(mat);
            c->drawPicture(fPicture);
            c->restore();

            SkAutoTUnref<SkPicture> xlatedPicture(recorder.endRecording());

            mpd.add(surfaces[i]->getCanvas(), xlatedPicture);
        }

        // Render all the buffered SkCanvases/SkPictures
        mpd.draw();

        // Sort out the results and cleanup the allocated surfaces
        for (int i = 0; i < fTileRects.count(); ++i) {
            success &= this->postRender(surfaces[i]->getCanvas(), fTileRects[i], &bitmap, out, i);
            surfaces[i]->unref();
        }
    } else {
        for (int i = 0; i < fTileRects.count(); ++i) {
            draw_tile_to_canvas(fCanvas, fTileRects[i], fPicture);
            success &= this->postRender(fCanvas, fTileRects[i], &bitmap, out, i);
        }
    }

    return success;
}

// static
void SkPDFPage::GeneratePageTree(const SkTDArray<SkPDFPage*>& pages,
                                 SkPDFCatalog* catalog,
                                 SkTDArray<SkPDFDict*>* pageTree,
                                 SkPDFDict** rootNode) {
    // PDF wants a tree describing all the pages in the document.  We arbitrary
    // choose 8 (kNodeSize) as the number of allowed children.  The internal
    // nodes have type "Pages" with an array of children, a parent pointer, and
    // the number of leaves below the node as "Count."  The leaves are passed
    // into the method, have type "Page" and need a parent pointer. This method
    // builds the tree bottom up, skipping internal nodes that would have only
    // one child.
    static const int kNodeSize = 8;

    SkRefPtr<SkPDFName> kidsName = new SkPDFName("Kids");
    kidsName->unref();  // SkRefPtr and new both took a reference.
    SkRefPtr<SkPDFName> countName = new SkPDFName("Count");
    countName->unref();  // SkRefPtr and new both took a reference.
    SkRefPtr<SkPDFName> parentName = new SkPDFName("Parent");
    parentName->unref();  // SkRefPtr and new both took a reference.

    // curNodes takes a reference to its items, which it passes to pageTree.
    SkTDArray<SkPDFDict*> curNodes;
    curNodes.setReserve(pages.count());
    for (int i = 0; i < pages.count(); i++) {
        SkSafeRef(pages[i]);
        curNodes.push(pages[i]);
    }

    // nextRoundNodes passes its references to nodes on to curNodes.
    SkTDArray<SkPDFDict*> nextRoundNodes;
    nextRoundNodes.setReserve((pages.count() + kNodeSize - 1)/kNodeSize);

    int treeCapacity = kNodeSize;
    do {
        for (int i = 0; i < curNodes.count(); ) {
            if (i > 0 && i + 1 == curNodes.count()) {
                nextRoundNodes.push(curNodes[i]);
                break;
            }

            SkPDFDict* newNode = new SkPDFDict("Pages");
            SkRefPtr<SkPDFObjRef> newNodeRef = new SkPDFObjRef(newNode);
            newNodeRef->unref();  // SkRefPtr and new both took a reference.

            SkRefPtr<SkPDFArray> kids = new SkPDFArray;
            kids->unref();  // SkRefPtr and new both took a reference.
            kids->reserve(kNodeSize);

            int count = 0;
            for (; i < curNodes.count() && count < kNodeSize; i++, count++) {
                curNodes[i]->insert(parentName.get(), newNodeRef.get());
                kids->append(new SkPDFObjRef(curNodes[i]))->unref();

                // TODO(vandebo): put the objects in strict access order.
                // Probably doesn't matter because they are so small.
                if (curNodes[i] != pages[0]) {
                    pageTree->push(curNodes[i]);  // Transfer reference.
                    catalog->addObject(curNodes[i], false);
                } else {
                    SkSafeUnref(curNodes[i]);
                    catalog->addObject(curNodes[i], true);
                }
            }

            newNode->insert(kidsName.get(), kids.get());
            int pageCount = treeCapacity;
            if (count < kNodeSize) {
                pageCount = pages.count() % treeCapacity;
            }
            newNode->insert(countName.get(), new SkPDFInt(pageCount))->unref();
            nextRoundNodes.push(newNode);  // Transfer reference.
        }

        curNodes = nextRoundNodes;
        nextRoundNodes.rewind();
        treeCapacity *= kNodeSize;
    } while (curNodes.count() > 1);

    pageTree->push(curNodes[0]);  // Transfer reference.
    catalog->addObject(curNodes[0], false);
    if (rootNode) {
        *rootNode = curNodes[0];
    }
}