C++ GrDrawState::stencil方法代码示例

bool GrGpu::setupClipAndFlushState(GrPrimitiveType type) {
    const GrIRect* r = NULL;
    GrIRect clipRect;

    GrDrawState* drawState = this->drawState();
    const GrRenderTarget* rt = drawState->getRenderTarget();

    // GrDrawTarget should have filtered this for us
    GrAssert(NULL != rt);

    if (drawState->isClipState()) {

        GrRect bounds;
        GrRect rtRect;
        rtRect.setLTRB(0, 0,
                       GrIntToScalar(rt->width()), GrIntToScalar(rt->height()));
        if (fClip.hasConservativeBounds()) {
            bounds = fClip.getConservativeBounds();
            if (!bounds.intersect(rtRect)) {
                bounds.setEmpty();
            }
        } else {
            bounds = rtRect;
        }

        bounds.roundOut(&clipRect);
        if  (clipRect.isEmpty()) {
            clipRect.setLTRB(0,0,0,0);
        }
        r = &clipRect;

        // use the stencil clip if we can't represent the clip as a rectangle.
        fClipInStencil = !fClip.isRect() && !fClip.isEmpty() && 
                         !bounds.isEmpty();

        // TODO: dynamically attach a SB when needed.
        GrStencilBuffer* stencilBuffer = rt->getStencilBuffer();
        if (fClipInStencil && NULL == stencilBuffer) {
            return false;
        }

        if (fClipInStencil &&
            stencilBuffer->mustRenderClip(fClip, rt->width(), rt->height())) {

            stencilBuffer->setLastClip(fClip, rt->width(), rt->height());

            // we set the current clip to the bounds so that our recursive
            // draws are scissored to them. We use the copy of the complex clip
            // we just stashed on the SB to render from. We set it back after
            // we finish drawing it into the stencil.
            const GrClip& clip = stencilBuffer->getLastClip();
            fClip.setFromRect(bounds);

            AutoStateRestore asr(this);
            AutoGeometryPush agp(this);

            drawState->setViewMatrix(GrMatrix::I());
            this->flushScissor(NULL);
#if !VISUALIZE_COMPLEX_CLIP
            drawState->enableState(GrDrawState::kNoColorWrites_StateBit);
#else
            drawState->disableState(GrDrawState::kNoColorWrites_StateBit);
#endif
            int count = clip.getElementCount();
            int clipBit = stencilBuffer->bits();
            SkASSERT((clipBit <= 16) &&
                     "Ganesh only handles 16b or smaller stencil buffers");
            clipBit = (1 << (clipBit-1));
            
            bool clearToInside;
            GrSetOp startOp = kReplace_SetOp; // suppress warning
            int start = process_initial_clip_elements(clip,
                                                      rtRect,
                                                      &clearToInside,
                                                      &startOp);

            this->clearStencilClip(clipRect, clearToInside);

            // walk through each clip element and perform its set op
            // with the existing clip.
            for (int c = start; c < count; ++c) {
                GrPathFill fill;
                bool fillInverted;
                // enabled at bottom of loop
                drawState->disableState(kModifyStencilClip_StateBit);

                bool canRenderDirectToStencil; // can the clip element be drawn
                                               // directly to the stencil buffer
                                               // with a non-inverted fill rule
                                               // without extra passes to
                                               // resolve in/out status.

                GrPathRenderer* pr = NULL;
                const GrPath* clipPath = NULL;
                GrPathRenderer::AutoClearPath arp;
                if (kRect_ClipType == clip.getElementType(c)) {
                    canRenderDirectToStencil = true;
                    fill = kEvenOdd_PathFill;
                    fillInverted = false;
                    // there is no point in intersecting a screen filling
//.........这里部分代码省略.........

////////////////////////////////////////////////////////////////////////////////
// Create a 1-bit clip mask in the stencil buffer. 'devClipBounds' are in device
// (as opposed to canvas) coordinates
bool GrClipMaskManager::createStencilClipMask(const GrClipData& clipDataIn,
                                              const GrIRect& devClipBounds) {

    GrAssert(kNone_ClipMaskType == fCurrClipMaskType);

    GrDrawState* drawState = fGpu->drawState();
    GrAssert(drawState->isClipState());

    GrRenderTarget* rt = drawState->getRenderTarget();
    GrAssert(NULL != rt);

    // TODO: dynamically attach a SB when needed.
    GrStencilBuffer* stencilBuffer = rt->getStencilBuffer();
    if (NULL == stencilBuffer) {
        return false;
    }

    if (stencilBuffer->mustRenderClip(clipDataIn, rt->width(), rt->height())) {

        stencilBuffer->setLastClip(clipDataIn, rt->width(), rt->height());

        // we set the current clip to the bounds so that our recursive
        // draws are scissored to them. We use the copy of the complex clip
        // we just stashed on the SB to render from. We set it back after
        // we finish drawing it into the stencil.
        const GrClipData* oldClipData = fGpu->getClip();

        // The origin of 'newClipData' is (0, 0) so it is okay to place
        // a device-coordinate bound in 'newClipStack'
        SkClipStack newClipStack(devClipBounds);
        GrClipData newClipData;
        newClipData.fClipStack = &newClipStack;

        fGpu->setClip(&newClipData);

        GrDrawTarget::AutoStateRestore asr(fGpu, GrDrawTarget::kReset_ASRInit);
        drawState = fGpu->drawState();
        drawState->setRenderTarget(rt);
        GrDrawTarget::AutoGeometryPush agp(fGpu);

        if (0 != clipDataIn.fOrigin.fX || 0 != clipDataIn.fOrigin.fY) {
            // Add the saveLayer's offset to the view matrix rather than
            // offset each individual draw
            drawState->viewMatrix()->setTranslate(
                           SkIntToScalar(-clipDataIn.fOrigin.fX),
                           SkIntToScalar(-clipDataIn.fOrigin.fY));
        }

#if !VISUALIZE_COMPLEX_CLIP
        drawState->enableState(GrDrawState::kNoColorWrites_StateBit);
#endif

        int clipBit = stencilBuffer->bits();
        SkASSERT((clipBit <= 16) &&
                    "Ganesh only handles 16b or smaller stencil buffers");
        clipBit = (1 << (clipBit-1));

        GrIRect devRTRect = GrIRect::MakeWH(rt->width(), rt->height());

        bool clearToInside;
        SkRegion::Op firstOp = SkRegion::kReplace_Op; // suppress warning

        SkClipStack::Iter iter(*oldClipData->fClipStack,
                               SkClipStack::Iter::kBottom_IterStart);
        const SkClipStack::Iter::Clip* clip = process_initial_clip_elements(&iter,
                                                  devRTRect,
                                                  &clearToInside,
                                                  &firstOp,
                                                  clipDataIn);

        fGpu->clearStencilClip(devClipBounds, clearToInside);
        bool first = true;

        // walk through each clip element and perform its set op
        // with the existing clip.
        for ( ; NULL != clip; clip = iter.nextCombined()) {
            GrPathFill fill;
            bool fillInverted = false;
            // enabled at bottom of loop
            drawState->disableState(GrGpu::kModifyStencilClip_StateBit);
            // if the target is MSAA then we want MSAA enabled when the clip is soft
            if (rt->isMultisampled()) {
                drawState->setState(GrDrawState::kHWAntialias_StateBit, clip->fDoAA);
            }

            // Can the clip element be drawn directly to the stencil buffer
            // with a non-inverted fill rule without extra passes to
            // resolve in/out status?
            bool canRenderDirectToStencil = false;

            SkRegion::Op op = clip->fOp;
            if (first) {
                first = false;
                op = firstOp;
            }

            GrPathRenderer* pr = NULL;
//.........这里部分代码省略.........

////////////////////////////////////////////////////////////////////////////////
// Create a 1-bit clip mask in the stencil buffer. 'devClipBounds' are in device
// (as opposed to canvas) coordinates
bool GrClipMaskManager::createStencilClipMask(InitialState initialState,
                                              const ElementList& elements,
                                              const SkIRect& clipSpaceIBounds,
                                              const SkIPoint& clipSpaceToStencilOffset) {

    GrAssert(kNone_ClipMaskType == fCurrClipMaskType);

    GrDrawState* drawState = fGpu->drawState();
    GrAssert(drawState->isClipState());

    GrRenderTarget* rt = drawState->getRenderTarget();
    GrAssert(NULL != rt);

    // TODO: dynamically attach a SB when needed.
    GrStencilBuffer* stencilBuffer = rt->getStencilBuffer();
    if (NULL == stencilBuffer) {
        return false;
    }
    int32_t genID = elements.tail()->getGenID();

    if (stencilBuffer->mustRenderClip(genID, clipSpaceIBounds, clipSpaceToStencilOffset)) {

        stencilBuffer->setLastClip(genID, clipSpaceIBounds, clipSpaceToStencilOffset);

        GrDrawTarget::AutoGeometryAndStatePush agasp(fGpu, GrDrawTarget::kReset_ASRInit);
        drawState = fGpu->drawState();
        drawState->setRenderTarget(rt);

        // We set the current clip to the bounds so that our recursive draws are scissored to them.
        SkIRect stencilSpaceIBounds(clipSpaceIBounds);
        stencilSpaceIBounds.offset(clipSpaceToStencilOffset);
        GrDrawTarget::AutoClipRestore acr(fGpu, stencilSpaceIBounds);
        drawState->enableState(GrDrawState::kClip_StateBit);

        // Set the matrix so that rendered clip elements are transformed from clip to stencil space.
        SkVector translate = {
            SkIntToScalar(clipSpaceToStencilOffset.fX),
            SkIntToScalar(clipSpaceToStencilOffset.fY)
        };
        drawState->viewMatrix()->setTranslate(translate);

#if !VISUALIZE_COMPLEX_CLIP
        drawState->enableState(GrDrawState::kNoColorWrites_StateBit);
#endif

        int clipBit = stencilBuffer->bits();
        SkASSERT((clipBit <= 16) && "Ganesh only handles 16b or smaller stencil buffers");
        clipBit = (1 << (clipBit-1));

        fGpu->clearStencilClip(stencilSpaceIBounds, kAllIn_InitialState == initialState);

        // walk through each clip element and perform its set op
        // with the existing clip.
        for (ElementList::Iter iter(elements.headIter()); NULL != iter.get(); iter.next()) {
            const Element* element = iter.get();
            bool fillInverted = false;
            // enabled at bottom of loop
            drawState->disableState(GrGpu::kModifyStencilClip_StateBit);
            // if the target is MSAA then we want MSAA enabled when the clip is soft
            if (rt->isMultisampled()) {
                drawState->setState(GrDrawState::kHWAntialias_StateBit, element->isAA());
            }

            // This will be used to determine whether the clip shape can be rendered into the
            // stencil with arbitrary stencil settings.
            GrPathRenderer::StencilSupport stencilSupport;

            SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);

            SkRegion::Op op = element->getOp();

            GrPathRenderer* pr = NULL;
            SkTCopyOnFirstWrite<SkPath> clipPath;
            if (Element::kRect_Type == element->getType()) {
                stencilSupport = GrPathRenderer::kNoRestriction_StencilSupport;
                fillInverted = false;
            } else {
                GrAssert(Element::kPath_Type == element->getType());
                clipPath.init(element->getPath());
                fillInverted = clipPath->isInverseFillType();
                if (fillInverted) {
                    clipPath.writable()->toggleInverseFillType();
                }
                pr = this->getContext()->getPathRenderer(*clipPath,
                                                         stroke,
                                                         fGpu,
                                                         false,
                                                         GrPathRendererChain::kStencilOnly_DrawType,
                                                         &stencilSupport);
                if (NULL == pr) {
                    return false;
                }
            }

            int passes;
            GrStencilSettings stencilSettings[GrStencilSettings::kMaxStencilClipPasses];

//.........这里部分代码省略.........

////////////////////////////////////////////////////////////////////////////////
// Create a 1-bit clip mask in the stencil buffer
bool GrClipMaskManager::createStencilClipMask(GrGpu* gpu, 
                                              const GrClip& clipIn,
                                              const GrRect& bounds,
                                              ScissoringSettings* scissorSettings) {

    GrAssert(fClipMaskInStencil);

    GrDrawState* drawState = gpu->drawState();
    GrAssert(drawState->isClipState());

    GrRenderTarget* rt = drawState->getRenderTarget();
    GrAssert(NULL != rt);

    // TODO: dynamically attach a SB when needed.
    GrStencilBuffer* stencilBuffer = rt->getStencilBuffer();
    if (NULL == stencilBuffer) {
        return false;
    }

    if (stencilBuffer->mustRenderClip(clipIn, rt->width(), rt->height())) {

        stencilBuffer->setLastClip(clipIn, rt->width(), rt->height());

        // we set the current clip to the bounds so that our recursive
        // draws are scissored to them. We use the copy of the complex clip
        // we just stashed on the SB to render from. We set it back after
        // we finish drawing it into the stencil.
        const GrClip& clipCopy = stencilBuffer->getLastClip();
        gpu->setClip(GrClip(bounds));

        GrDrawTarget::AutoStateRestore asr(gpu, GrDrawTarget::kReset_ASRInit);
        drawState = gpu->drawState();
        drawState->setRenderTarget(rt);
        GrDrawTarget::AutoGeometryPush agp(gpu);

        gpu->disableScissor();
#if !VISUALIZE_COMPLEX_CLIP
        drawState->enableState(GrDrawState::kNoColorWrites_StateBit);
#endif

        int count = clipCopy.getElementCount();
        int clipBit = stencilBuffer->bits();
        SkASSERT((clipBit <= 16) &&
                    "Ganesh only handles 16b or smaller stencil buffers");
        clipBit = (1 << (clipBit-1));

        GrIRect rtRect = GrIRect::MakeWH(rt->width(), rt->height());

        bool clearToInside;
        SkRegion::Op startOp = SkRegion::kReplace_Op; // suppress warning
        int start = process_initial_clip_elements(clipCopy,
                                                    rtRect,
                                                    &clearToInside,
                                                    &startOp);

        gpu->clearStencilClip(scissorSettings->fScissorRect, clearToInside);

        // walk through each clip element and perform its set op
        // with the existing clip.
        for (int c = start; c < count; ++c) {
            GrPathFill fill;
            bool fillInverted;
            // enabled at bottom of loop
            drawState->disableState(GrGpu::kModifyStencilClip_StateBit);

            bool canRenderDirectToStencil; // can the clip element be drawn
                                           // directly to the stencil buffer
                                           // with a non-inverted fill rule
                                           // without extra passes to
                                           // resolve in/out status.

            SkRegion::Op op = (c == start) ? startOp : clipCopy.getOp(c);

            GrPathRenderer* pr = NULL;
            const SkPath* clipPath = NULL;
            if (kRect_ClipType == clipCopy.getElementType(c)) {
                canRenderDirectToStencil = true;
                fill = kEvenOdd_PathFill;
                fillInverted = false;
                // there is no point in intersecting a screen filling
                // rectangle.
                if (SkRegion::kIntersect_Op == op &&
                    contains(clipCopy.getRect(c), rtRect)) {
                    continue;
                }
            } else {
                fill = clipCopy.getPathFill(c);
                fillInverted = GrIsFillInverted(fill);
                fill = GrNonInvertedFill(fill);
                clipPath = &clipCopy.getPath(c);
                pr = this->getClipPathRenderer(gpu, *clipPath, fill, false);
                if (NULL == pr) {
                    fClipMaskInStencil = false;
                    gpu->setClip(clipCopy);     // restore to the original
                    return false;
                }
                canRenderDirectToStencil =
                    !pr->requiresStencilPass(*clipPath, fill, gpu);
//.........这里部分代码省略.........

bool GrStencilAndCoverPathRenderer::onDrawPath(const SkPath& path,
                                               GrPathFill fill,
                                               GrDrawTarget* target,
                                               bool antiAlias) {
    GrAssert(!antiAlias);
    GrAssert(kHairLine_GrPathFill != fill);

    GrDrawState* drawState = target->drawState();
    GrAssert(drawState->getStencil().isDisabled());

    SkAutoTUnref<GrPath> p(fGpu->createPath(path));

    GrPathFill nonInvertedFill = GrNonInvertedFill(fill);
    target->stencilPath(p, nonInvertedFill);

    // TODO: Use built in cover operation rather than a rect draw. This will require making our
    // fragment shaders be able to eat varyings generated by a matrix.

    // fill the path, zero out the stencil
    GrRect bounds = p->getBounds();
    GrScalar bloat = drawState->getViewMatrix().getMaxStretch() * GR_ScalarHalf;
    GrDrawState::AutoDeviceCoordDraw adcd;

    if (nonInvertedFill == fill) {
        GR_STATIC_CONST_SAME_STENCIL(kStencilPass,
            kZero_StencilOp,
            kZero_StencilOp,
            kNotEqual_StencilFunc,
            0xffff,
            0x0000,
            0xffff);
        *drawState->stencil() = kStencilPass;
    } else {
        GR_STATIC_CONST_SAME_STENCIL(kInvertedStencilPass,
            kZero_StencilOp,
            kZero_StencilOp,
            // We know our rect will hit pixels outside the clip and the user bits will be 0
            // outside the clip. So we can't just fill where the user bits are 0. We also need to
            // check that the clip bit is set.
            kEqualIfInClip_StencilFunc,
            0xffff,
            0x0000,
            0xffff);
        GrMatrix vmi;
        bounds.setLTRB(0, 0,
                       GrIntToScalar(drawState->getRenderTarget()->width()),
                       GrIntToScalar(drawState->getRenderTarget()->height()));
        // mapRect through persp matrix may not be correct
        if (!drawState->getViewMatrix().hasPerspective() && drawState->getViewInverse(&vmi)) {
            vmi.mapRect(&bounds);
            // theoretically could set bloat = 0, instead leave it because of matrix inversion
            // precision.
        } else {
            adcd.set(drawState);
            bloat = 0;
        }
        *drawState->stencil() = kInvertedStencilPass;
    }
    bounds.outset(bloat, bloat);
    target->drawSimpleRect(bounds, NULL);
    target->drawState()->stencil()->setDisabled();
    return true;
}

bool GrDefaultPathRenderer::internalDrawPath(const SkPath& path,
                                             const SkStrokeRec& origStroke,
                                             GrDrawTarget* target,
                                             bool stencilOnly) {

    SkMatrix viewM = target->getDrawState().getViewMatrix();
    SkTCopyOnFirstWrite<SkStrokeRec> stroke(origStroke);

    SkScalar hairlineCoverage;
    if (IsStrokeHairlineOrEquivalent(*stroke, target->getDrawState().getViewMatrix(),
                                     &hairlineCoverage)) {
        uint8_t newCoverage = SkScalarRoundToInt(hairlineCoverage *
                                                 target->getDrawState().getCoverage());
        target->drawState()->setCoverage(newCoverage);

        if (!stroke->isHairlineStyle()) {
            stroke.writable()->setHairlineStyle();
        }
    }

    SkScalar tol = SK_Scalar1;
    tol = GrPathUtils::scaleToleranceToSrc(tol, viewM, path.getBounds());

    int vertexCnt;
    int indexCnt;
    GrPrimitiveType primType;
    GrDrawTarget::AutoReleaseGeometry arg;
    if (!this->createGeom(path,
                          *stroke,
                          tol,
                          target,
                          &primType,
                          &vertexCnt,
                          &indexCnt,
                          &arg)) {
        return false;
    }

    SkASSERT(NULL != target);
    GrDrawTarget::AutoStateRestore asr(target, GrDrawTarget::kPreserve_ASRInit);
    GrDrawState* drawState = target->drawState();
    bool colorWritesWereDisabled = drawState->isColorWriteDisabled();
    // face culling doesn't make sense here
    SkASSERT(GrDrawState::kBoth_DrawFace == drawState->getDrawFace());

    int                         passCount = 0;
    const GrStencilSettings*    passes[3];
    GrDrawState::DrawFace       drawFace[3];
    bool                        reverse = false;
    bool                        lastPassIsBounds;

    if (stroke->isHairlineStyle()) {
        passCount = 1;
        if (stencilOnly) {
            passes[0] = &gDirectToStencil;
        } else {
            passes[0] = NULL;
        }
        lastPassIsBounds = false;
        drawFace[0] = GrDrawState::kBoth_DrawFace;
    } else {
        if (single_pass_path(path, *stroke)) {
            passCount = 1;
            if (stencilOnly) {
                passes[0] = &gDirectToStencil;
            } else {
                passes[0] = NULL;
            }
            drawFace[0] = GrDrawState::kBoth_DrawFace;
            lastPassIsBounds = false;
        } else {
            switch (path.getFillType()) {
                case SkPath::kInverseEvenOdd_FillType:
                    reverse = true;
                    // fallthrough
                case SkPath::kEvenOdd_FillType:
                    passes[0] = &gEOStencilPass;
                    if (stencilOnly) {
                        passCount = 1;
                        lastPassIsBounds = false;
                    } else {
                        passCount = 2;
                        lastPassIsBounds = true;
                        if (reverse) {
                            passes[1] = &gInvEOColorPass;
                        } else {
                            passes[1] = &gEOColorPass;
                        }
                    }
                    drawFace[0] = drawFace[1] = GrDrawState::kBoth_DrawFace;
                    break;

                case SkPath::kInverseWinding_FillType:
                    reverse = true;
                    // fallthrough
                case SkPath::kWinding_FillType:
                    if (fSeparateStencil) {
                        if (fStencilWrapOps) {
                            passes[0] = &gWindStencilSeparateWithWrap;
                        } else {
//.........这里部分代码省略.........

bool GrDefaultPathRenderer::internalDrawPath(const SkPath& path,
                                             GrPathFill fill,
                                             GrDrawTarget* target,
                                             bool stencilOnly) {

    GrMatrix viewM = target->getDrawState().getViewMatrix();
    GrScalar tol = GR_Scalar1;
    tol = GrPathUtils::scaleToleranceToSrc(tol, viewM, path.getBounds());

    int vertexCnt;
    int indexCnt;
    GrPrimitiveType primType;
    GrDrawTarget::AutoReleaseGeometry arg;
    if (!this->createGeom(path,
                          fill,
                          tol,
                          target,
                          &primType,
                          &vertexCnt,
                          &indexCnt,
                          &arg)) {
        return false;
    }

    GrAssert(NULL != target);
    GrDrawTarget::AutoStateRestore asr(target, GrDrawTarget::kPreserve_ASRInit);
    GrDrawState* drawState = target->drawState();
    bool colorWritesWereDisabled = drawState->isColorWriteDisabled();
    // face culling doesn't make sense here
    GrAssert(GrDrawState::kBoth_DrawFace == drawState->getDrawFace());

    int                         passCount = 0;
    const GrStencilSettings*    passes[3];
    GrDrawState::DrawFace       drawFace[3];
    bool                        reverse = false;
    bool                        lastPassIsBounds;

    if (kHairLine_GrPathFill == fill) {
        passCount = 1;
        if (stencilOnly) {
            passes[0] = &gDirectToStencil;
        } else {
            passes[0] = NULL;
        }
        lastPassIsBounds = false;
        drawFace[0] = GrDrawState::kBoth_DrawFace;
    } else {
        if (single_pass_path(path, fill)) {
            passCount = 1;
            if (stencilOnly) {
                passes[0] = &gDirectToStencil;
            } else {
                passes[0] = NULL;
            }
            drawFace[0] = GrDrawState::kBoth_DrawFace;
            lastPassIsBounds = false;
        } else {
            switch (fill) {
                case kInverseEvenOdd_GrPathFill:
                    reverse = true;
                    // fallthrough
                case kEvenOdd_GrPathFill:
                    passes[0] = &gEOStencilPass;
                    if (stencilOnly) {
                        passCount = 1;
                        lastPassIsBounds = false;
                    } else {
                        passCount = 2;
                        lastPassIsBounds = true;
                        if (reverse) {
                            passes[1] = &gInvEOColorPass;
                        } else {
                            passes[1] = &gEOColorPass;
                        }
                    }
                    drawFace[0] = drawFace[1] = GrDrawState::kBoth_DrawFace;
                    break;

                case kInverseWinding_GrPathFill:
                    reverse = true;
                    // fallthrough
                case kWinding_GrPathFill:
                    if (fSeparateStencil) {
                        if (fStencilWrapOps) {
                            passes[0] = &gWindStencilSeparateWithWrap;
                        } else {
                            passes[0] = &gWindStencilSeparateNoWrap;
                        }
                        passCount = 2;
                        drawFace[0] = GrDrawState::kBoth_DrawFace;
                    } else {
                        if (fStencilWrapOps) {
                            passes[0] = &gWindSingleStencilWithWrapInc;
                            passes[1] = &gWindSingleStencilWithWrapDec;
                        } else {
                            passes[0] = &gWindSingleStencilNoWrapInc;
                            passes[1] = &gWindSingleStencilNoWrapDec;
                        }
                        // which is cw and which is ccw is arbitrary.
                        drawFace[0] = GrDrawState::kCW_DrawFace;
//.........这里部分代码省略.........

void GrDefaultPathRenderer::onDrawPath(GrDrawState::StageMask stageMask,
                                       bool stencilOnly) {

    GrMatrix viewM = fTarget->getDrawState().getViewMatrix();
    GrScalar tol = GR_Scalar1;
    tol = GrPathUtils::scaleToleranceToSrc(tol, viewM, fPath->getBounds());
    GrDrawState* drawState = fTarget->drawState();

    // FIXME: It's really dumb that we recreate the verts for a new vertex
    // layout. We only do that because the GrDrawTarget API doesn't allow
    // us to change the vertex layout after reserveVertexSpace(). We won't
    // actually change the vertex data when the layout changes since all the
    // stages reference the positions (rather than having separate tex coords)
    // and we don't ever have per-vert colors. In practice our call sites
    // won't change the stages in use inside a setPath / removePath pair. But
    // it is a silly limitation of the GrDrawTarget design that should be fixed.
    if (tol != fPreviousSrcTol ||
        stageMask != fPreviousStages) {
        if (!this->createGeom(tol, stageMask)) {
            return;
        }
    }

    GrAssert(NULL != fTarget);
    GrDrawTarget::AutoStateRestore asr(fTarget);
    bool colorWritesWereDisabled = drawState->isColorWriteDisabled();
    // face culling doesn't make sense here
    GrAssert(GrDrawState::kBoth_DrawFace == drawState->getDrawFace());

    int                         passCount = 0;
    const GrStencilSettings*    passes[3];
    GrDrawState::DrawFace       drawFace[3];
    bool                        reverse = false;
    bool                        lastPassIsBounds;

    if (kHairLine_PathFill == fFill) {
        passCount = 1;
        if (stencilOnly) {
            passes[0] = &gDirectToStencil;
        } else {
            passes[0] = NULL;
        }
        lastPassIsBounds = false;
        drawFace[0] = GrDrawState::kBoth_DrawFace;
    } else {
        if (single_pass_path(*fTarget, *fPath, fFill)) {
            passCount = 1;
            if (stencilOnly) {
                passes[0] = &gDirectToStencil;
            } else {
                passes[0] = NULL;
            }
            drawFace[0] = GrDrawState::kBoth_DrawFace;
            lastPassIsBounds = false;
        } else {
            switch (fFill) {
                case kInverseEvenOdd_PathFill:
                    reverse = true;
                    // fallthrough
                case kEvenOdd_PathFill:
                    passes[0] = &gEOStencilPass;
                    if (stencilOnly) {
                        passCount = 1;
                        lastPassIsBounds = false;
                    } else {
                        passCount = 2;
                        lastPassIsBounds = true;
                        if (reverse) {
                            passes[1] = &gInvEOColorPass;
                        } else {
                            passes[1] = &gEOColorPass;
                        }
                    }
                    drawFace[0] = drawFace[1] = GrDrawState::kBoth_DrawFace;
                    break;

                case kInverseWinding_PathFill:
                    reverse = true;
                    // fallthrough
                case kWinding_PathFill:
                    if (fSeparateStencil) {
                        if (fStencilWrapOps) {
                            passes[0] = &gWindStencilSeparateWithWrap;
                        } else {
                            passes[0] = &gWindStencilSeparateNoWrap;
                        }
                        passCount = 2;
                        drawFace[0] = GrDrawState::kBoth_DrawFace;
                    } else {
                        if (fStencilWrapOps) {
                            passes[0] = &gWindSingleStencilWithWrapInc;
                            passes[1] = &gWindSingleStencilWithWrapDec;
                        } else {
                            passes[0] = &gWindSingleStencilNoWrapInc;
                            passes[1] = &gWindSingleStencilNoWrapDec;
                        }
                        // which is cw and which is ccw is arbitrary.
                        drawFace[0] = GrDrawState::kCW_DrawFace;
                        drawFace[1] = GrDrawState::kCCW_DrawFace;
                        passCount = 3;
//.........这里部分代码省略.........