src/core/SkRecordDraw.cpp

/*
 * Copyright 2014 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "SkRecordDraw.h"
#include "SkTSort.h"

void SkRecordDraw(const SkRecord& record,
                  SkCanvas* canvas,
                  const SkBBoxHierarchy* bbh,
                  SkDrawPictureCallback* callback) {
    SkAutoCanvasRestore saveRestore(canvas, true /*save now, restore at exit*/);

    if (NULL != bbh) {
        SkASSERT(bbh->getCount() == SkToInt(record.count()));

        // Draw only ops that affect pixels in the canvas's current clip.
        SkIRect devBounds;
        canvas->getClipDeviceBounds(&devBounds);
        SkTDArray<void*> ops;
        bbh->search(devBounds, &ops);

        // Until we start filling in real bounds, we should get every op back.
        SkASSERT(ops.count() == SkToInt(record.count()));

        // FIXME: QuadTree doesn't send these back in the order we inserted them.  :(
        // Also remove the sort in SkPictureData::getActiveOps()?
        if (ops.count() > 0) {
            SkTQSort(ops.begin(), ops.end() - 1, SkTCompareLT<void*>());
        }

        SkRecords::Draw draw(canvas);
        for (int i = 0; i < ops.count(); i++) {
            if (NULL != callback && callback->abortDrawing()) {
                return;
            }
            record.visit<void>((uintptr_t)ops[i], draw);  // See FillBounds below.
        }
    } else {
        // Draw all ops.
        for (SkRecords::Draw draw(canvas); draw.index() < record.count(); draw.next()) {
            if (NULL != callback && callback->abortDrawing()) {
                return;
            }
            record.visit<void>(draw.index(), draw);
        }
    }
}

namespace SkRecords {

// FIXME: SkBitmaps are stateful, so we need to copy them to play back in multiple threads.
static SkBitmap shallow_copy(const SkBitmap& bitmap) {
    return bitmap;
}

// NoOps draw nothing.
template <> void Draw::draw(const NoOp&) {}

#define DRAW(T, call) template <> void Draw::draw(const T& r) { fCanvas->call; }
DRAW(Restore, restore());
DRAW(Save, save());
DRAW(SaveLayer, saveLayer(r.bounds, r.paint, r.flags));
DRAW(PopCull, popCull());
DRAW(PushCull, pushCull(r.rect));
DRAW(Clear, clear(r.color));
DRAW(Concat, concat(r.matrix));
DRAW(SetMatrix, setMatrix(SkMatrix::Concat(fInitialCTM, r.matrix)));

DRAW(ClipPath, clipPath(r.path, r.op, r.doAA));
DRAW(ClipRRect, clipRRect(r.rrect, r.op, r.doAA));
DRAW(ClipRect, clipRect(r.rect, r.op, r.doAA));
DRAW(ClipRegion, clipRegion(r.region, r.op));

DRAW(DrawBitmap, drawBitmap(shallow_copy(r.bitmap), r.left, r.top, r.paint));
DRAW(DrawBitmapMatrix, drawBitmapMatrix(shallow_copy(r.bitmap), r.matrix, r.paint));
DRAW(DrawBitmapNine, drawBitmapNine(shallow_copy(r.bitmap), r.center, r.dst, r.paint));
DRAW(DrawBitmapRectToRect,
        drawBitmapRectToRect(shallow_copy(r.bitmap), r.src, r.dst, r.paint, r.flags));
DRAW(DrawDRRect, drawDRRect(r.outer, r.inner, r.paint));
DRAW(DrawOval, drawOval(r.oval, r.paint));
DRAW(DrawPaint, drawPaint(r.paint));
DRAW(DrawPath, drawPath(r.path, r.paint));
DRAW(DrawPatch, drawPatch(r.cubics, r.colors, r.texCoords, r.xmode.get(), r.paint));
DRAW(DrawPicture, drawPicture(r.picture, r.matrix, r.paint));
DRAW(DrawPoints, drawPoints(r.mode, r.count, r.pts, r.paint));
DRAW(DrawPosText, drawPosText(r.text, r.byteLength, r.pos, r.paint));
DRAW(DrawPosTextH, drawPosTextH(r.text, r.byteLength, r.xpos, r.y, r.paint));
DRAW(DrawRRect, drawRRect(r.rrect, r.paint));
DRAW(DrawRect, drawRect(r.rect, r.paint));
DRAW(DrawSprite, drawSprite(shallow_copy(r.bitmap), r.left, r.top, r.paint));
DRAW(DrawText, drawText(r.text, r.byteLength, r.x, r.y, r.paint));
DRAW(DrawTextOnPath, drawTextOnPath(r.text, r.byteLength, r.path, r.matrix, r.paint));
DRAW(DrawVertices, drawVertices(r.vmode, r.vertexCount, r.vertices, r.texs, r.colors,
                                r.xmode.get(), r.indices, r.indexCount, r.paint));
#undef DRAW


// This is an SkRecord visitor that fills an SkBBoxHierarchy.
class FillBounds : SkNoncopyable {
public:
    explicit FillBounds(SkBBoxHierarchy* bbh) : fBBH(bbh), fIndex(0) {}
    ~FillBounds() { fBBH->flushDeferredInserts(); }

    uintptr_t index() const { return fIndex; }
    void next() { ++fIndex; }

    template <typename T> void operator()(const T& r) {
        // MakeLargest() is a trivially safe default for ops that haven't been bounded yet.
        this->insert(this->index(), SkIRect::MakeLargest());
    }

private:
    void insert(uintptr_t opIndex, const SkIRect& bounds) {
        fBBH->insert((void*)opIndex, bounds, true/*ok to defer*/);
    }

    SkBBoxHierarchy* fBBH;  // Unowned. The BBH is guaranteed to be ref'd for our lifetime.
    uintptr_t fIndex;
};

}  // namespace SkRecords

void SkRecordFillBounds(const SkRecord& record, SkBBoxHierarchy* bbh) {
    SkASSERT(NULL != bbh);
    for(SkRecords::FillBounds fb(bbh); fb.index() < record.count(); fb.next()) {
        record.visit<void>(fb.index(), fb);
    }
}