C++ GrDrawState::isClipState方法代码示例

////////////////////////////////////////////////////////////////////////////////
// Shared preamble between gpu and SW-only AA clip mask creation paths.
// Handles caching, determination of clip mask bound & allocation (if needed)
// of the result texture
// Returns true if there is no more work to be done (i.e., we got a cache hit)
bool GrClipMaskManager::clipMaskPreamble(const GrClipData& clipDataIn,
                                         GrTexture** result,
                                         GrIRect* devResultBounds) {
    GrDrawState* origDrawState = fGpu->drawState();
    GrAssert(origDrawState->isClipState());

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

    // unlike the stencil path the alpha path is not bound to the size of the
    // render target - determine the minimum size required for the mask
    // Note: intBounds is in device (as opposed to canvas) coordinates
    clipDataIn.getConservativeBounds(rt, devResultBounds);

    // need to outset a pixel since the standard bounding box computation
    // path doesn't leave any room for antialiasing (esp. w.r.t. rects)
    devResultBounds->outset(1, 1);

    // TODO: make sure we don't outset if bounds are still 0,0 @ min

    if (fAACache.canReuse(*clipDataIn.fClipStack, *devResultBounds)) {
        *result = fAACache.getLastMask();
        fAACache.getLastBound(devResultBounds);
        return true;
    }

    this->setupCache(*clipDataIn.fClipStack, *devResultBounds);
    return false;
}

////////////////////////////////////////////////////////////////////////////////
// Shared preamble between gpu and SW-only AA clip mask creation paths.
// Handles caching, determination of clip mask bound & allocation (if needed)
// of the result texture
// Returns true if there is no more work to be done (i.e., we got a cache hit)
bool GrClipMaskManager::clipMaskPreamble(GrGpu* gpu,
                                         const GrClip& clipIn,
                                         GrTexture** result,
                                         GrIRect *resultBounds) {
    GrDrawState* origDrawState = gpu->drawState();
    GrAssert(origDrawState->isClipState());

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

    GrRect rtRect;
    rtRect.setLTRB(0, 0,
                    GrIntToScalar(rt->width()), GrIntToScalar(rt->height()));

    // unlike the stencil path the alpha path is not bound to the size of the
    // render target - determine the minimum size required for the mask
    GrRect bounds;

    if (clipIn.hasConservativeBounds()) {
        bounds = clipIn.getConservativeBounds();
        if (!bounds.intersect(rtRect)) {
            // the mask will be empty in this case
            GrAssert(false);
            bounds.setEmpty();
        }
    } else {
        // still locked to the size of the render target
        bounds = rtRect;
    }

    GrIRect intBounds;
    bounds.roundOut(&intBounds);

    // need to outset a pixel since the standard bounding box computation
    // path doesn't leave any room for antialiasing (esp. w.r.t. rects)
    intBounds.outset(1, 1);

    // TODO: make sure we don't outset if bounds are still 0,0 @ min

    if (fAACache.canReuse(clipIn, 
                          intBounds.width(),
                          intBounds.height())) {
        *result = fAACache.getLastMask();
        fAACache.getLastBound(resultBounds);
        return true;
    }

    this->setupCache(clipIn, intBounds);

    *resultBounds = intBounds;
    return false;
}

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(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.........

////////////////////////////////////////////////////////////////////////////////
// sort out what kind of clip mask needs to be created: alpha, stencil,
// scissor, or entirely software
bool GrClipMaskManager::setupClipping(const GrClipData* clipDataIn) {
    fCurrClipMaskType = kNone_ClipMaskType;

    ElementList elements(16);
    InitialState initialState;
    SkIRect clipSpaceIBounds;
    bool requiresAA;
    bool isRect = false;

    GrDrawState* drawState = fGpu->drawState();

    const GrRenderTarget* rt = drawState->getRenderTarget();
    // GrDrawTarget should have filtered this for us
    GrAssert(NULL != rt);

    bool ignoreClip = !drawState->isClipState() || clipDataIn->fClipStack->isWideOpen();

    if (!ignoreClip) {
        SkIRect clipSpaceRTIBounds = SkIRect::MakeWH(rt->width(), rt->height());
        clipSpaceRTIBounds.offset(clipDataIn->fOrigin);
        ReduceClipStack(*clipDataIn->fClipStack,
                        clipSpaceRTIBounds,
                        &elements,
                        &initialState,
                        &clipSpaceIBounds,
                        &requiresAA);
        if (elements.isEmpty()) {
            if (kAllIn_InitialState == initialState) {
                ignoreClip = clipSpaceIBounds == clipSpaceRTIBounds;
                isRect = true;
            } else {
                return false;
            }
        }
    }

    if (ignoreClip) {
        fGpu->disableScissor();
        this->setGpuStencil();
        return true;
    }

#if GR_AA_CLIP
    // TODO: catch isRect && requiresAA and use clip planes if available rather than a mask.

    // If MSAA is enabled we can do everything in the stencil buffer.
    if (0 == rt->numSamples() && requiresAA) {
        int32_t genID = clipDataIn->fClipStack->getTopmostGenID();
        GrTexture* result = NULL;

        if (this->useSWOnlyPath(elements)) {
            // The clip geometry is complex enough that it will be more efficient to create it
            // entirely in software
            result = this->createSoftwareClipMask(genID,
                                                  initialState,
                                                  elements,
                                                  clipSpaceIBounds);
        } else {
            result = this->createAlphaClipMask(genID,
                                               initialState,
                                               elements,
                                               clipSpaceIBounds);
        }

        if (NULL != result) {
            // The mask's top left coord should be pinned to the rounded-out top left corner of
            // clipSpace bounds. We determine the mask's position WRT to the render target here.
            SkIRect rtSpaceMaskBounds = clipSpaceIBounds;
            rtSpaceMaskBounds.offset(-clipDataIn->fOrigin);
            setup_drawstate_aaclip(fGpu, result, rtSpaceMaskBounds);
            fGpu->disableScissor();
            this->setGpuStencil();
            return true;
        }
        // if alpha clip mask creation fails fall through to the non-AA code paths
    }
#endif // GR_AA_CLIP

    // Either a hard (stencil buffer) clip was explicitly requested or an anti-aliased clip couldn't
    // be created. In either case, free up the texture in the anti-aliased mask cache.
    // TODO: this may require more investigation. Ganesh performs a lot of utility draws (e.g.,
    // clears, InOrderDrawBuffer playbacks) that hit the stencil buffer path. These may be
    // "incorrectly" clearing the AA cache.
    fAACache.reset();

    // If the clip is a rectangle then just set the scissor. Otherwise, create
    // a stencil mask.
    if (isRect) {
        SkIRect clipRect = clipSpaceIBounds;
        clipRect.offset(-clipDataIn->fOrigin);
        fGpu->enableScissor(clipRect);
        this->setGpuStencil();
        return true;
    }

    // use the stencil clip if we can't represent the clip as a rectangle.
    SkIPoint clipSpaceToStencilSpaceOffset = -clipDataIn->fOrigin;
//.........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.........

////////////////////////////////////////////////////////////////////////////////
// sort out what kind of clip mask needs to be created: alpha, stencil,
// scissor, or entirely software
bool GrClipMaskManager::setupClipping(const GrClipData* clipDataIn) {
    fCurrClipMaskType = kNone_ClipMaskType;

    GrDrawState* drawState = fGpu->drawState();
    if (!drawState->isClipState() || clipDataIn->fClipStack->isWideOpen()) {
        fGpu->disableScissor();
        this->setGpuStencil();
        return true;
    }

    GrRenderTarget* rt = drawState->getRenderTarget();
    // GrDrawTarget should have filtered this for us
    GrAssert(NULL != rt);

    GrIRect devClipBounds;
    bool isIntersectionOfRects = false;

    clipDataIn->getConservativeBounds(rt, &devClipBounds, &isIntersectionOfRects);
    if (devClipBounds.isEmpty()) {
        return false;
    }

#if GR_SW_CLIP
    bool requiresAA = requires_AA(*clipDataIn->fClipStack);

    // If MSAA is enabled we can do everything in the stencil buffer.
    // Otherwise check if we should just create the entire clip mask
    // in software (this will only happen if the clip mask is anti-aliased
    // and too complex for the gpu to handle in its entirety)
    if (0 == rt->numSamples() &&
        requiresAA &&
        this->useSWOnlyPath(*clipDataIn->fClipStack)) {
        // The clip geometry is complex enough that it will be more
        // efficient to create it entirely in software
        GrTexture* result = NULL;
        GrIRect devBound;
        if (this->createSoftwareClipMask(*clipDataIn, &result, &devBound)) {
            setup_drawstate_aaclip(fGpu, result, devBound);
            fGpu->disableScissor();
            this->setGpuStencil();
            return true;
        }

        // if SW clip mask creation fails fall through to the other
        // two possible methods (bottoming out at stencil clipping)
    }
#endif // GR_SW_CLIP

#if GR_AA_CLIP
    // If MSAA is enabled use the (faster) stencil path for AA clipping
    // otherwise the alpha clip mask is our only option
    if (0 == rt->numSamples() && requiresAA) {
        // Since we are going to create a destination texture of the correct
        // size for the mask (rather than being bound by the size of the
        // render target) we aren't going to use scissoring like the stencil
        // path does (see scissorSettings below)
        GrTexture* result = NULL;
        GrIRect devBound;
        if (this->createAlphaClipMask(*clipDataIn, &result, &devBound)) {
            setup_drawstate_aaclip(fGpu, result, devBound);
            fGpu->disableScissor();
            this->setGpuStencil();
            return true;
        }

        // if alpha clip mask creation fails fall through to the stencil
        // buffer method
    }
#endif // GR_AA_CLIP

    // Either a hard (stencil buffer) clip was explicitly requested or
    // an antialiased clip couldn't be created. In either case, free up
    // the texture in the antialiased mask cache.
    // TODO: this may require more investigation. Ganesh performs a lot of
    // utility draws (e.g., clears, InOrderDrawBuffer playbacks) that hit
    // the stencil buffer path. These may be "incorrectly" clearing the
    // AA cache.
    fAACache.reset();

    // If the clip is a rectangle then just set the scissor. Otherwise, create
    // a stencil mask.
    if (isIntersectionOfRects) {
        fGpu->enableScissor(devClipBounds);
        this->setGpuStencil();
        return true;
    }

    // use the stencil clip if we can't represent the clip as a rectangle.
    bool useStencil = !clipDataIn->fClipStack->isWideOpen() &&
                      !devClipBounds.isEmpty();

    if (useStencil) {
        this->createStencilClipMask(*clipDataIn, devClipBounds);
    }
    // This must occur after createStencilClipMask. That function may change
    // the scissor. Also, it only guarantees that the stencil mask is correct
    // within the bounds it was passed, so we must use both stencil and scissor
//.........这里部分代码省略.........

////////////////////////////////////////////////////////////////////////////////
// sort out what kind of clip mask needs to be created: alpha, stencil,
// scissor, or entirely software
bool GrClipMaskManager::setupClipping(const GrClipData* clipDataIn,
                                      GrDrawState::AutoRestoreEffects* are,
                                      const SkRect* devBounds) {
    fCurrClipMaskType = kNone_ClipMaskType;

    ElementList elements(16);
    int32_t genID;
    InitialState initialState;
    SkIRect clipSpaceIBounds;
    bool requiresAA;

    GrDrawState* drawState = fGpu->drawState();

    const GrRenderTarget* rt = drawState->getRenderTarget();
    // GrDrawTarget should have filtered this for us
    SkASSERT(NULL != rt);

    bool ignoreClip = !drawState->isClipState() || clipDataIn->fClipStack->isWideOpen();

    if (!ignoreClip) {
        SkIRect clipSpaceRTIBounds = SkIRect::MakeWH(rt->width(), rt->height());
        clipSpaceRTIBounds.offset(clipDataIn->fOrigin);
        ReduceClipStack(*clipDataIn->fClipStack,
                        clipSpaceRTIBounds,
                        &elements,
                        &genID,
                        &initialState,
                        &clipSpaceIBounds,
                        &requiresAA);
        if (elements.isEmpty()) {
            if (kAllIn_InitialState == initialState) {
                ignoreClip = clipSpaceIBounds == clipSpaceRTIBounds;
            } else {
                return false;
            }
        }
    }

    if (ignoreClip) {
        fGpu->disableScissor();
        this->setGpuStencil();
        return true;
    }

    // An element count of 4 was chosen because of the common pattern in Blink of:
    //   isect RR
    //   diff  RR
    //   isect convex_poly
    //   isect convex_poly
    // when drawing rounded div borders. This could probably be tuned based on a
    // configuration's relative costs of switching RTs to generate a mask vs
    // longer shaders.
    if (elements.count() <= 4) {
        SkVector clipToRTOffset = { SkIntToScalar(-clipDataIn->fOrigin.fX),
                                    SkIntToScalar(-clipDataIn->fOrigin.fY) };
        if (elements.isEmpty() ||
            (requiresAA && this->installClipEffects(elements, are, clipToRTOffset, devBounds))) {
            SkIRect scissorSpaceIBounds(clipSpaceIBounds);
            scissorSpaceIBounds.offset(-clipDataIn->fOrigin);
            if (NULL == devBounds ||
                !SkRect::Make(scissorSpaceIBounds).contains(*devBounds)) {
                fGpu->enableScissor(scissorSpaceIBounds);
            } else {
                fGpu->disableScissor();
            }
            this->setGpuStencil();
            return true;
        }
    }

#if GR_AA_CLIP
    // If MSAA is enabled we can do everything in the stencil buffer.
    if (0 == rt->numSamples() && requiresAA) {
        GrTexture* result = NULL;

        if (this->useSWOnlyPath(elements)) {
            // The clip geometry is complex enough that it will be more efficient to create it
            // entirely in software
            result = this->createSoftwareClipMask(genID,
                                                  initialState,
                                                  elements,
                                                  clipSpaceIBounds);
        } else {
            result = this->createAlphaClipMask(genID,
                                               initialState,
                                               elements,
                                               clipSpaceIBounds);
        }

        if (NULL != result) {
            // The mask's top left coord should be pinned to the rounded-out top left corner of
            // clipSpace bounds. We determine the mask's position WRT to the render target here.
            SkIRect rtSpaceMaskBounds = clipSpaceIBounds;
            rtSpaceMaskBounds.offset(-clipDataIn->fOrigin);
            are->set(fGpu->drawState());
            setup_drawstate_aaclip(fGpu, result, rtSpaceMaskBounds);
            fGpu->disableScissor();
//.........这里部分代码省略.........

////////////////////////////////////////////////////////////////////////////////
// sort out what kind of clip mask needs to be created: alpha, stencil,
// scissor, or entirely software
bool GrClipMaskManager::createClipMask(GrGpu* gpu, 
                                       const GrClip& clipIn,
                                       ScissoringSettings* scissorSettings) {

    GrAssert(scissorSettings);

    scissorSettings->fEnableScissoring = false;
    fClipMaskInStencil = false;
    fClipMaskInAlpha = false;

    GrDrawState* drawState = gpu->drawState();
    if (!drawState->isClipState()) {
        return true;
    }

    GrRenderTarget* rt = drawState->getRenderTarget();

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

#if GR_SW_CLIP
    if (create_mask_in_sw()) {
        // The clip geometry is complex enough that it will be more
        // efficient to create it entirely in software
        GrTexture* result = NULL;
        GrIRect bound;
        if (this->createSoftwareClipMask(gpu, clipIn, &result, &bound)) {
            fClipMaskInAlpha = true;

            setup_drawstate_aaclip(gpu, result, bound);
            return true;
        }
    }
#endif

#if GR_AA_CLIP
    // If MSAA is enabled use the (faster) stencil path for AA clipping
    // otherwise the alpha clip mask is our only option
    if (clipIn.requiresAA() && 0 == rt->numSamples()) {
        // Since we are going to create a destination texture of the correct
        // size for the mask (rather than being bound by the size of the
        // render target) we aren't going to use scissoring like the stencil
        // path does (see scissorSettings below)
        GrTexture* result = NULL;
        GrIRect bound;
        if (this->createAlphaClipMask(gpu, clipIn, &result, &bound)) {
            fClipMaskInAlpha = true;

            setup_drawstate_aaclip(gpu, result, bound);
            return true;
        }

        // if alpha clip mask creation fails fall through to the stencil
        // buffer method
    }
#endif // GR_AA_CLIP

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

    bounds.roundOut(&scissorSettings->fScissorRect);
    if  (scissorSettings->fScissorRect.isEmpty()) {
        scissorSettings->fScissorRect.setLTRB(0,0,0,0);
        // TODO: I think we can do an early exit here - after refactoring try:
        //  set fEnableScissoring to true but leave fClipMaskInStencil false
        //  and return - everything is going to be scissored away anyway!
    }
    scissorSettings->fEnableScissoring = true;

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

    if (fClipMaskInStencil) {
        return this->createStencilClipMask(gpu, clipIn, bounds, scissorSettings);
    }

    return true;
}

////////////////////////////////////////////////////////////////////////////////
// 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.........

void GrInOrderDrawBuffer::drawRect(const GrRect& rect,
                                   const GrMatrix* matrix,
                                   StageMask stageMask,
                                   const GrRect* srcRects[],
                                   const GrMatrix* srcMatrices[]) {

    GrAssert(!(NULL == fQuadIndexBuffer && fCurrQuad));
    GrAssert(!(fDraws.empty() && fCurrQuad));
    GrAssert(!(0 != fMaxQuads && NULL == fQuadIndexBuffer));

    GrDrawState* drawState = this->drawState();

    // if we have a quad IB then either append to the previous run of
    // rects or start a new run
    if (fMaxQuads) {

        bool appendToPreviousDraw = false;
        GrVertexLayout layout = GetRectVertexLayout(stageMask, srcRects);
        AutoReleaseGeometry geo(this, layout, 4, 0);
        if (!geo.succeeded()) {
            GrPrintf("Failed to get space for vertices!\n");
            return;
        }
        GrMatrix combinedMatrix = drawState->getViewMatrix();
        // We go to device space so that matrix changes allow us to concat
        // rect draws. When the caller has provided explicit source rects
        // then we don't want to modify the sampler matrices. Otherwise we do
        // we have to account for the view matrix change in the sampler
        // matrices.
        StageMask devCoordMask = (NULL == srcRects) ? stageMask : 0;
        GrDrawTarget::AutoDeviceCoordDraw adcd(this, devCoordMask);
        if (NULL != matrix) {
            combinedMatrix.preConcat(*matrix);
        }

        SetRectVertices(rect, &combinedMatrix, srcRects, srcMatrices, layout, geo.vertices());

        // we don't want to miss an opportunity to batch rects together
        // simply because the clip has changed if the clip doesn't affect
        // the rect.
        bool disabledClip = false;
        if (drawState->isClipState() && fClip.isRect()) {

            GrRect clipRect = fClip.getRect(0);
            // If the clip rect touches the edge of the viewport, extended it
            // out (close) to infinity to avoid bogus intersections.
            // We might consider a more exact clip to viewport if this
            // conservative test fails.
            const GrRenderTarget* target = drawState->getRenderTarget();
            if (0 >= clipRect.fLeft) {
                clipRect.fLeft = GR_ScalarMin;
            }
            if (target->width() <= clipRect.fRight) {
                clipRect.fRight = GR_ScalarMax;
            }
            if (0 >= clipRect.top()) {
                clipRect.fTop = GR_ScalarMin;
            }
            if (target->height() <= clipRect.fBottom) {
                clipRect.fBottom = GR_ScalarMax;
            }
            int stride = VertexSize(layout);
            bool insideClip = true;
            for (int v = 0; v < 4; ++v) {
                const GrPoint& p = *GetVertexPoint(geo.vertices(), v, stride);
                if (!clipRect.contains(p)) {
                    insideClip = false;
                    break;
                }
            }
            if (insideClip) {
                drawState->disableState(GrDrawState::kClip_StateBit);
                disabledClip = true;
            }
        }
        if (!needsNewClip() && !needsNewState() && fCurrQuad > 0 &&
            fCurrQuad < fMaxQuads && layout == fLastRectVertexLayout) {

            int vsize = VertexSize(layout);

            Draw& lastDraw = fDraws.back();

            GrAssert(lastDraw.fIndexBuffer == fQuadIndexBuffer);
            GrAssert(kTriangles_PrimitiveType == lastDraw.fPrimitiveType);
            GrAssert(0 == lastDraw.fVertexCount % 4);
            GrAssert(0 == lastDraw.fIndexCount % 6);
            GrAssert(0 == lastDraw.fStartIndex);

            GeometryPoolState& poolState = fGeoPoolStateStack.back();
            bool clearSinceLastDraw =
                            fClears.count() && 
                            fClears.back().fBeforeDrawIdx == fDraws.count();

            appendToPreviousDraw =  
                !clearSinceLastDraw &&
                lastDraw.fVertexBuffer == poolState.fPoolVertexBuffer &&
                (fCurrQuad * 4 + lastDraw.fStartVertex) == poolState.fPoolStartVertex;

            if (appendToPreviousDraw) {
                lastDraw.fVertexCount += 4;
//.........这里部分代码省略.........

void GrInOrderDrawBuffer::drawRect(const GrRect& rect,
                                   const SkMatrix* matrix,
                                   const GrRect* srcRects[],
                                   const SkMatrix* srcMatrices[]) {

    GrAssert(!(NULL == fQuadIndexBuffer && fCurrQuad));
    GrAssert(!(fDraws.empty() && fCurrQuad));
    GrAssert(!(0 != fMaxQuads && NULL == fQuadIndexBuffer));

    GrDrawState* drawState = this->drawState();

    // if we have a quad IB then either append to the previous run of
    // rects or start a new run
    if (fMaxQuads) {

        bool appendToPreviousDraw = false;
        GrVertexLayout layout = GetRectVertexLayout(srcRects);

        // Batching across colors means we move the draw color into the
        // rect's vertex colors to allow greater batching (a lot of rects
        // in a row differing only in color is a common occurence in tables).
        bool batchAcrossColors = true;
        if (!this->getCaps().dualSourceBlendingSupport()) {
            for (int s = 0; s < GrDrawState::kNumStages; ++s) {
                if (this->getDrawState().isStageEnabled(s)) {
                    // We disable batching across colors when there is a texture
                    // present because (by pushing the the color to the vertices)
                    // Ganesh loses track of the rect's opacity. This, in turn, can
                    // cause some of the blending optimizations to be disabled. This
                    // becomes a huge problem on some of the smaller devices where
                    // shader derivatives and dual source blending aren't supported.
                    // In those cases paths are often drawn to a texture and then
                    // drawn as a texture (using this method). Because dual source
                    // blending is disabled (and the blend optimizations are short
                    // circuited) some of the more esoteric blend modes can no longer
                    // be supported.
                    // TODO: add tracking of batchAcrossColors's opacity
                    batchAcrossColors = false;
                    break;
                }
            }
        }

        if (batchAcrossColors) {
            layout |= GrDrawState::kColor_VertexLayoutBit;
        }

        AutoReleaseGeometry geo(this, layout, 4, 0);
        if (!geo.succeeded()) {
            GrPrintf("Failed to get space for vertices!\n");
            return;
        }
        SkMatrix combinedMatrix = drawState->getViewMatrix();
        // We go to device space so that matrix changes allow us to concat
        // rect draws. When the caller has provided explicit source rects
        // then we don't want to modify the stages' matrices. Otherwise
        // we have to account for the view matrix change in the stage
        // matrices.
        uint32_t explicitCoordMask = 0;
        if (srcRects) {
            for (int s = 0; s < GrDrawState::kNumStages; ++s) {
                if (srcRects[s]) {
                    explicitCoordMask |= (1 << s);
                }
            }
        }
        GrDrawState::AutoDeviceCoordDraw adcd(this->drawState(), explicitCoordMask);
        if (!adcd.succeeded()) {
            return;
        }
        if (NULL != matrix) {
            combinedMatrix.preConcat(*matrix);
        }

        SetRectVertices(rect, &combinedMatrix, srcRects, srcMatrices,
                        this->getDrawState().getColor(), layout, geo.vertices());

        // Now that the paint's color is stored in the vertices set it to
        // white so that the following code can batch all the rects regardless
        // of paint color
        GrDrawState::AutoColorRestore acr(this->drawState(),
                                          batchAcrossColors ? SK_ColorWHITE
                                                            : this->getDrawState().getColor());

        // we don't want to miss an opportunity to batch rects together
        // simply because the clip has changed if the clip doesn't affect
        // the rect.
        bool disabledClip = false;

        if (drawState->isClipState()) {

            GrRect devClipRect;
            bool isIntersectionOfRects = false;
            const GrClipData* clip = this->getClip();
            clip->fClipStack->getConservativeBounds(-clip->fOrigin.fX,
                                                    -clip->fOrigin.fY,
                                                    drawState->getRenderTarget()->width(),
                                                    drawState->getRenderTarget()->height(),
                                                    &devClipRect,
                                                    &isIntersectionOfRects);
//.........这里部分代码省略.........

////////////////////////////////////////////////////////////////////////////////
// sort out what kind of clip mask needs to be created: alpha, stencil,
// scissor, or entirely software
bool GrClipMaskManager::createClipMask(GrGpu* gpu, 
                                       const GrClip& clipIn,
                                       ScissoringSettings* scissorSettings) {

    GrAssert(scissorSettings);

    scissorSettings->fEnableScissoring = false;
    fClipMaskInStencil = false;
    fClipMaskInAlpha = false;

    GrDrawState* drawState = gpu->drawState();
    if (!drawState->isClipState()) {
        return true;
    }

    GrRenderTarget* rt = drawState->getRenderTarget();

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

#if GR_SW_CLIP
    // If MSAA is enabled we can do everything in the stencil buffer.
    // Otherwise check if we should just create the entire clip mask 
    // in software (this will only happen if the clip mask is anti-aliased
    // and too complex for the gpu to handle in its entirety)
    if (0 == rt->numSamples() && useSWOnlyPath(gpu, clipIn)) {
        // The clip geometry is complex enough that it will be more
        // efficient to create it entirely in software
        GrTexture* result = NULL;
        GrIRect bound;
        if (this->createSoftwareClipMask(gpu, clipIn, &result, &bound)) {
            fClipMaskInAlpha = true;

            setup_drawstate_aaclip(gpu, result, bound);
            return true;
        }

        // if SW clip mask creation fails fall through to the other
        // two possible methods (bottoming out at stencil clipping)
    }
#endif // GR_SW_CLIP

#if GR_AA_CLIP
    // If MSAA is enabled use the (faster) stencil path for AA clipping
    // otherwise the alpha clip mask is our only option
    if (0 == rt->numSamples() && clipIn.requiresAA()) {
        // Since we are going to create a destination texture of the correct
        // size for the mask (rather than being bound by the size of the
        // render target) we aren't going to use scissoring like the stencil
        // path does (see scissorSettings below)
        GrTexture* result = NULL;
        GrIRect bound;
        if (this->createAlphaClipMask(gpu, clipIn, &result, &bound)) {
            fClipMaskInAlpha = true;

            setup_drawstate_aaclip(gpu, result, bound);
            return true;
        }

        // if alpha clip mask creation fails fall through to the stencil
        // buffer method
    }
#endif // GR_AA_CLIP

    // Either a hard (stencil buffer) clip was explicitly requested or 
    // an antialiased clip couldn't be created. In either case, free up
    // the texture in the antialiased mask cache.
    // TODO: this may require more investigation. Ganesh performs a lot of
    // utility draws (e.g., clears, InOrderDrawBuffer playbacks) that hit
    // the stencil buffer path. These may be "incorrectly" clearing the 
    // AA cache.
    fAACache.reset();

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

    bounds.roundOut(&scissorSettings->fScissorRect);
    if  (scissorSettings->fScissorRect.isEmpty()) {
        scissorSettings->fScissorRect.setLTRB(0,0,0,0);
        // TODO: I think we can do an early exit here - after refactoring try:
        //  set fEnableScissoring to true but leave fClipMaskInStencil false
        //  and return - everything is going to be scissored away anyway!
    }
    scissorSettings->fEnableScissoring = true;

    // use the stencil clip if we can't represent the clip as a rectangle.
    fClipMaskInStencil = !clipIn.isRect() && !clipIn.isEmpty() &&
//.........这里部分代码省略.........