src/pipe/SkGPipeRead.cpp

/*
    Copyright 2011 Google Inc.

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
 */


#include "SkCanvas.h"
#include "SkPaint.h"
#include "SkGPipe.h"
#include "SkGPipePriv.h"
#include "SkReader32.h"
#include "SkStream.h"

#include "SkColorFilter.h"
#include "SkDrawLooper.h"
#include "SkMaskFilter.h"
#include "SkPathEffect.h"
#include "SkRasterizer.h"
#include "SkShader.h"
#include "SkTypeface.h"
#include "SkXfermode.h"

static void set_paintflat(SkPaint* paint, SkFlattenable* obj, unsigned paintFlat) {
    SkASSERT(paintFlat < kCount_PaintFlats);
    switch (paintFlat) {
        case kColorFilter_PaintFlat:
            paint->setColorFilter((SkColorFilter*)obj);
            break;
        case kDrawLooper_PaintFlat:
            paint->setLooper((SkDrawLooper*)obj);
            break;
        case kMaskFilter_PaintFlat:
            paint->setMaskFilter((SkMaskFilter*)obj);
            break;
        case kPathEffect_PaintFlat:
            paint->setPathEffect((SkPathEffect*)obj);
            break;
        case kRasterizer_PaintFlat:
            paint->setRasterizer((SkRasterizer*)obj);
            break;
        case kShader_PaintFlat:
            paint->setShader((SkShader*)obj);
            break;
        case kXfermode_PaintFlat:
            paint->setXfermode((SkXfermode*)obj);
            break;
        default:
            SkASSERT(!"never gets here");
    }
}

template <typename T> class SkRefCntTDArray : public SkTDArray<T> {
public:
    ~SkRefCntTDArray() { this->unrefAll(); }
};

class SkGPipeState {
public:
    SkGPipeState();
    ~SkGPipeState();

    void setReader(SkFlattenableReadBuffer* reader) { fReader = reader; }

    const SkPaint& getPaint(uint32_t drawOp32) const;
    
    //  Extracts index from DrawOp_unpackData().
    //  Returns the specified paint from our list, or creates a new paint if
    //  index == count. If index > count, return NULL
    SkPaint* editPaint(uint32_t drawOp32);

    SkFlattenable* getFlat(unsigned index) const {
        if (0 == index) {
            return NULL;
        }
        return fFlatArray[index - 1];
    }

    void defFlattenable(PaintFlats pf, unsigned index) {
        SkFlattenable* obj = fReader->readFlattenable();
        *fFlatArray.append() = obj;
        SkASSERT(index == fFlatArray.count());
    }

    void addTypeface() {
        size_t size = fReader->readU32();
        const void* data = fReader->skip(SkAlign4(size));
        SkMemoryStream stream(data, size, false);
        *fTypefaces.append() = SkTypeface::Deserialize(&stream);
    }    
    void setTypeface(SkPaint* paint, unsigned id) {
        paint->setTypeface(id ? fTypefaces[id - 1] : NULL);
    }
    
    SkFlattenableReadBuffer* fReader;
    SkTDArray<SkFlattenable*> fFlatArray;

private:

    SkTDArray<SkPaint*> fPaints;

    SkRefCntTDArray<SkColorFilter*> fColorFilters;
    SkRefCntTDArray<SkDrawLooper*> fDrawLoopers;
    SkRefCntTDArray<SkMaskFilter*> fMaskFilters;
    SkRefCntTDArray<SkPathEffect*> fPathEffects;
    SkRefCntTDArray<SkRasterizer*> fRasterizers;
    SkRefCntTDArray<SkShader*> fShaders;
    SkRefCntTDArray<SkTypeface*> fTypefaces;
    SkRefCntTDArray<SkXfermode*> fXfermodes;
};

///////////////////////////////////////////////////////////////////////////////

template <typename T> const T* skip(SkReader32* reader, int count = 1) {
    SkASSERT(count >= 0);
    size_t size = sizeof(T) * count;
    SkASSERT(SkAlign4(size) == size);
    return reinterpret_cast<const T*>(reader->skip(size));
}

template <typename T> const T* skipAlign(SkReader32* reader, int count = 1) {
    SkASSERT(count >= 0);
    size_t size = SkAlign4(sizeof(T) * count);
    return reinterpret_cast<const T*>(reader->skip(size));
}

const SkPaint& SkGPipeState::getPaint(uint32_t op32) const {
    unsigned index = DrawOp_unpackData(op32);
    if (index >= fPaints.count()) {
        SkASSERT(!"paint index out of range");
        index = 0;  // we always have at least 1 paint
    }
    return *fPaints[index];
}

SkPaint* SkGPipeState::editPaint(uint32_t op32) {
    unsigned index = DrawOp_unpackData(op32);

    if (index > fPaints.count()) {
        SkASSERT(!"paint index out of range");
        return NULL;
    }

    if (index == fPaints.count()) {
        *fPaints.append() = SkNEW(SkPaint);
    }
    return fPaints[index];
}

///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////

static void clipPath_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                        SkGPipeState* state) {
    SkPath path;
    path.unflatten(*reader);
    canvas->clipPath(path, (SkRegion::Op)DrawOp_unpackData(op32));
}

static void clipRegion_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                          SkGPipeState* state) {
    SkRegion rgn;
    SkReadRegion(reader, &rgn);
    canvas->clipRegion(rgn, (SkRegion::Op)DrawOp_unpackData(op32));
}

static void clipRect_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                        SkGPipeState* state) {
    canvas->clipRect(*skip<SkRect>(reader), (SkRegion::Op)DrawOp_unpackData(op32));
}

///////////////////////////////////////////////////////////////////////////////

static void setMatrix_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                      SkGPipeState* state) {
    SkMatrix matrix;
    SkReadMatrix(reader, &matrix);
    canvas->setMatrix(matrix);
}

static void concat_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                      SkGPipeState* state) {
    SkMatrix matrix;
    SkReadMatrix(reader, &matrix);
    canvas->concat(matrix);
}

static void scale_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                      SkGPipeState* state) {
    const SkScalar* param = skip<SkScalar>(reader, 2);
    canvas->scale(param[0], param[1]);
}

static void skew_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                      SkGPipeState* state) {
    const SkScalar* param = skip<SkScalar>(reader, 2);
    canvas->skew(param[0], param[1]);
}

static void rotate_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                      SkGPipeState* state) {
    canvas->rotate(reader->readScalar());
}

static void translate_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                      SkGPipeState* state) {
    const SkScalar* param = skip<SkScalar>(reader, 2);
    canvas->translate(param[0], param[1]);
}

///////////////////////////////////////////////////////////////////////////////

static void save_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                    SkGPipeState* state) {
    canvas->save((SkCanvas::SaveFlags)DrawOp_unpackData(op32));
}

static void saveLayer_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                         SkGPipeState* state) {
    unsigned flags = DrawOp_unpackFlags(op32);
    SkCanvas::SaveFlags saveFlags = (SkCanvas::SaveFlags)DrawOp_unpackData(op32);

    const SkRect* bounds = NULL;
    if (flags & kSaveLayer_HasBounds_DrawOpFlag) {
        bounds = skip<SkRect>(reader);
    }
    const SkPaint* paint = NULL;
    if (flags & kSaveLayer_HasPaint_DrawOpFlag) {
        paint = &state->getPaint(reader->readU32());
    }
    canvas->saveLayer(bounds, paint, saveFlags);
}

static void restore_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                       SkGPipeState* state) {
    canvas->restore();
}

///////////////////////////////////////////////////////////////////////////////

static void drawClear_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                         SkGPipeState* state) {
    SkColor color = 0;
    if (DrawOp_unpackFlags(op32) & kClear_HasColor_DrawOpFlag) {
        color = reader->readU32();
    }
    canvas->clear(color);
}

static void drawPaint_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                         SkGPipeState* state) {
    canvas->drawPaint(state->getPaint(op32));
}

static void drawPoints_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                          SkGPipeState* state) {
    SkCanvas::PointMode mode = (SkCanvas::PointMode)DrawOp_unpackFlags(op32);
    size_t count = reader->readU32();
    const SkPoint* pts = skip<SkPoint>(reader, count);
    canvas->drawPoints(mode, count, pts, state->getPaint(op32));
}

static void drawRect_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                        SkGPipeState* state) {
    canvas->drawRect(*skip<SkRect>(reader), state->getPaint(op32));
}

static void drawPath_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                        SkGPipeState* state) {
    SkPath path;
    path.unflatten(*reader);
    canvas->drawPath(path, state->getPaint(op32));
}

static void drawVertices_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                            SkGPipeState* state) {
    unsigned flags = DrawOp_unpackFlags(op32);

    SkCanvas::VertexMode mode = (SkCanvas::VertexMode)reader->readU32();
    int vertexCount = reader->readU32();
    const SkPoint* verts = skip<SkPoint>(reader, vertexCount);

    const SkPoint* texs = NULL;
    if (flags & kDrawVertices_HasTexs_DrawOpFlag) {
        texs = skip<SkPoint>(reader, vertexCount);
    }

    const SkColor* colors = NULL;
    if (flags & kDrawVertices_HasColors_DrawOpFlag) {
        colors = skip<SkColor>(reader, vertexCount);
    }

    // TODO: flatten/unflatten xfermodes
    SkXfermode* xfer = NULL;

    int indexCount = 0;
    const uint16_t* indices = NULL;
    if (flags & kDrawVertices_HasIndices_DrawOpFlag) {
        indexCount = reader->readU32();
        indices = skipAlign<uint16_t>(reader, indexCount);
    }

    canvas->drawVertices(mode, vertexCount, verts, texs, colors, xfer,
                         indices, indexCount, state->getPaint(op32));
}

///////////////////////////////////////////////////////////////////////////////

static void drawText_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                        SkGPipeState* state) {
    size_t len = reader->readU32();
    const void* text = reader->skip(SkAlign4(len));
    const SkScalar* xy = skip<SkScalar>(reader, 2);
    canvas->drawText(text, len, xy[0], xy[1], state->getPaint(op32));
}

static void drawPosText_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                        SkGPipeState* state) {
    size_t len = reader->readU32();
    const void* text = reader->skip(SkAlign4(len));
    size_t posCount = reader->readU32();    // compute by our writer
    const SkPoint* pos = skip<SkPoint>(reader, posCount);
    canvas->drawPosText(text, len, pos, state->getPaint(op32));
}

static void drawPosTextH_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                        SkGPipeState* state) {
    size_t len = reader->readU32();
    const void* text = reader->skip(SkAlign4(len));
    size_t posCount = reader->readU32();    // compute by our writer
    const SkScalar* xpos = skip<SkScalar>(reader, posCount);
    SkScalar constY = reader->readScalar();
    canvas->drawPosTextH(text, len, xpos, constY, state->getPaint(op32));
}

static void drawTextOnPath_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                              SkGPipeState* state) {
    size_t len = reader->readU32();
    const void* text = reader->skip(SkAlign4(len));

    SkPath path;
    path.unflatten(*reader);

    SkMatrix matrixStorage;
    const SkMatrix* matrix = NULL;
    if (DrawOp_unpackFlags(op32) & kDrawTextOnPath_HasMatrix_DrawOpFlag) {
        SkReadMatrix(reader, &matrixStorage);
        matrix = &matrixStorage;
    }

    canvas->drawTextOnPath(text, len, path, matrix, state->getPaint(op32));
}

///////////////////////////////////////////////////////////////////////////////

static void drawBitmap_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                          SkGPipeState* state) {
    UNIMPLEMENTED
}

static void drawBitmapMatrix_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                                SkGPipeState* state) {
    UNIMPLEMENTED
}

static void drawBitmapRect_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                              SkGPipeState* state) {
    UNIMPLEMENTED
}

static void drawSprite_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                          SkGPipeState* state) {
    UNIMPLEMENTED
}

///////////////////////////////////////////////////////////////////////////////

static void drawData_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                        SkGPipeState* state) {
    // since we don't have a paint, we can use data for our (small) sizes
    size_t size = DrawOp_unpackData(op32);
    if (0 == size) {
        size = reader->readU32();
    }
    const void* data = reader->skip(SkAlign4(size));
    canvas->drawData(data, size);
}

static void drawShape_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                         SkGPipeState* state) {
    UNIMPLEMENTED
}

static void drawPicture_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                           SkGPipeState* state) {
    UNIMPLEMENTED
}

///////////////////////////////////////////////////////////////////////////////

static void paintOp_rp(SkCanvas*, SkReader32* reader, uint32_t op32,
                       SkGPipeState* state) {
    size_t offset = reader->offset();
    size_t stop = offset + PaintOp_unpackData(op32);
    SkPaint* p = state->editPaint(0);
    int done;

    do {
        uint32_t p32 = reader->readU32();
        unsigned op = PaintOp_unpackOp(p32);
        unsigned data = PaintOp_unpackData(p32);
        done = PaintOp_unpackFlags(p32) & kLastOp_PaintOpFlag;

//        SkDebugf(" read %08X op=%d flags=%d data=%d\n", p32, op, done, data);

        switch (op) {
            case kReset_PaintOp: p->reset(); break;
            case kFlags_PaintOp: p->setFlags(data); break;
            case kColor_PaintOp: p->setColor(reader->readU32()); break;
            case kStyle_PaintOp: p->setStyle((SkPaint::Style)data); break;
            case kJoin_PaintOp: p->setStrokeJoin((SkPaint::Join)data); break;
            case kCap_PaintOp: p->setStrokeCap((SkPaint::Cap)data); break;
            case kWidth_PaintOp: p->setStrokeWidth(reader->readScalar()); break;
            case kMiter_PaintOp: p->setStrokeMiter(reader->readScalar()); break;
            case kEncoding_PaintOp:
                p->setTextEncoding((SkPaint::TextEncoding)data);
                break;
            case kHinting_PaintOp: p->setHinting((SkPaint::Hinting)data); break;
            case kAlign_PaintOp: p->setTextAlign((SkPaint::Align)data); break;
            case kTextSize_PaintOp: p->setTextSize(reader->readScalar()); break;
            case kTextScaleX_PaintOp: p->setTextScaleX(reader->readScalar()); break;
            case kTextSkewX_PaintOp: p->setTextSkewX(reader->readScalar()); break;

            case kFlatIndex_PaintOp: {
                PaintFlats pf = (PaintFlats)PaintOp_unpackFlags(p32);
                unsigned index = data;
                set_paintflat(p, state->getFlat(index), pf);
                break;
            }

            case kTypeface_PaintOp: state->setTypeface(p, data); break;
            default: SkASSERT(!"bad paintop"); return;
        }
        SkASSERT(reader->offset() <= stop);
        done = (reader->offset() >= stop);
    } while (!done);
}

///////////////////////////////////////////////////////////////////////////////

static void def_Typeface_rp(SkCanvas*, SkReader32*, uint32_t, SkGPipeState* state) {
    state->addTypeface();
}

static void def_PaintFlat_rp(SkCanvas*, SkReader32*, uint32_t op32,
                             SkGPipeState* state) {
    PaintFlats pf = (PaintFlats)DrawOp_unpackFlags(op32);
    unsigned index = DrawOp_unpackData(op32);
    state->defFlattenable(pf, index);
}

///////////////////////////////////////////////////////////////////////////////

static void skip_rp(SkCanvas*, SkReader32* reader, uint32_t op32, SkGPipeState*) {
    size_t bytes = DrawOp_unpackData(op32);
    (void)reader->skip(bytes);
}

static void done_rp(SkCanvas*, SkReader32*, uint32_t, SkGPipeState*) {}

typedef void (*ReadProc)(SkCanvas*, SkReader32*, uint32_t op32, SkGPipeState*);

static const ReadProc gReadTable[] = {
    skip_rp,
    clipPath_rp,
    clipRegion_rp,
    clipRect_rp,
    concat_rp,
    drawBitmap_rp,
    drawBitmapMatrix_rp,
    drawBitmapRect_rp,
    drawClear_rp,
    drawData_rp,
    drawPaint_rp,
    drawPath_rp,
    drawPicture_rp,
    drawPoints_rp,
    drawPosText_rp,
    drawPosTextH_rp,
    drawRect_rp,
    drawShape_rp,
    drawSprite_rp,
    drawText_rp,
    drawTextOnPath_rp,
    drawVertices_rp,
    restore_rp,
    rotate_rp,
    save_rp,
    saveLayer_rp,
    scale_rp,
    setMatrix_rp,
    skew_rp,
    translate_rp,

    paintOp_rp,
    def_Typeface_rp,
    def_PaintFlat_rp,

    done_rp
};

///////////////////////////////////////////////////////////////////////////////

SkGPipeState::SkGPipeState() {
    // start out with one paint in default state
    *fPaints.append() = SkNEW(SkPaint);
}

SkGPipeState::~SkGPipeState() {
    fFlatArray.unrefAll();
    fPaints.deleteAll();
}

///////////////////////////////////////////////////////////////////////////////

#include "SkGPipe.h"

SkGPipeReader::SkGPipeReader(SkCanvas* target) {
    SkSafeRef(target);
    fCanvas = target;
    fState = NULL;
}

SkGPipeReader::~SkGPipeReader() {
    SkSafeUnref(fCanvas);
    delete fState;
}

SkGPipeReader::Status SkGPipeReader::playback(const void* data, size_t length) {
    if (NULL == fCanvas) {
        return kError_Status;
    }

    if (NULL == fState) {
        fState = new SkGPipeState;
    }

    SkASSERT(SK_ARRAY_COUNT(gReadTable) == (kDone_DrawOp + 1));

    const ReadProc* table = gReadTable;
    SkFlattenableReadBuffer reader(data, length);
    SkCanvas* canvas = fCanvas;

    fState->setReader(&reader);
    while (!reader.eof()) {
        uint32_t op32 = reader.readU32();
        unsigned op = DrawOp_unpackOp(op32);
        SkDEBUGCODE(DrawOps drawOp = (DrawOps)op;)
        
        if (op >= SK_ARRAY_COUNT(gReadTable)) {
            SkDebugf("---- bad op during GPipeState::playback\n");
            return kError_Status;
        }
        if (kDone_DrawOp == op) {
            return kDone_Status;
        }
        table[op](canvas, &reader, op32, fState);
    }
    return kEOF_Status;
}