C++ GrDrawState::getRenderTarget方法代码示例

////////////////////////////////////////////////////////////////////////////////
// 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.next()) {
            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()) {
                if (clip->fDoAA) {
                    drawState->enableState(GrDrawState::kHWAntialias_StateBit);
                } else {
                    drawState->disableState(GrDrawState::kHWAntialias_StateBit);
                }
            }

            // 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;
//.........这里部分代码省略.........

void GrGLPathRendering::drawPaths(const GrPathRange* pathRange, const uint32_t indices[], int count,
                                  const float transforms[], PathTransformType transformsType,
                                  SkPath::FillType fill) {
    SkASSERT(fGpu->caps()->pathRenderingSupport());
    SkASSERT(NULL != fGpu->drawState()->getRenderTarget());
    SkASSERT(NULL != fGpu->drawState()->getRenderTarget()->getStencilBuffer());

    GrGLuint baseID = static_cast<const GrGLPathRange*>(pathRange)->basePathID();

    this->flushPathStencilSettings(fill);
    SkASSERT(!fHWPathStencilSettings.isTwoSided());

    const SkStrokeRec& stroke = pathRange->getStroke();

    SkPath::FillType nonInvertedFill =
        SkPath::ConvertToNonInverseFillType(fill);

    GrGLenum fillMode =
        gr_stencil_op_to_gl_path_rendering_fill_mode(
            fHWPathStencilSettings.passOp(GrStencilSettings::kFront_Face));
    GrGLint writeMask =
        fHWPathStencilSettings.writeMask(GrStencilSettings::kFront_Face);

    if (nonInvertedFill == fill) {
        if (stroke.needToApply()) {
            if (SkStrokeRec::kStrokeAndFill_Style == stroke.getStyle()) {
                GL_CALL(StencilFillPathInstanced(
                                count, GR_GL_UNSIGNED_INT, indices, baseID, fillMode,
                                writeMask, gXformType2GLType[transformsType],
                                transforms));
            }
            this->stencilThenCoverStrokePathInstanced(
                                count, GR_GL_UNSIGNED_INT, indices, baseID, 0xffff, writeMask,
                                GR_GL_BOUNDING_BOX_OF_BOUNDING_BOXES,
                                gXformType2GLType[transformsType], transforms);
        } else {
            this->stencilThenCoverFillPathInstanced(
                                count, GR_GL_UNSIGNED_INT, indices, baseID, fillMode, writeMask,
                                GR_GL_BOUNDING_BOX_OF_BOUNDING_BOXES,
                                gXformType2GLType[transformsType], transforms);
        }
    } else {
        if (stroke.isFillStyle() || SkStrokeRec::kStrokeAndFill_Style == stroke.getStyle()) {
            GL_CALL(StencilFillPathInstanced(
                                count, GR_GL_UNSIGNED_INT, indices, baseID, fillMode,
                                writeMask, gXformType2GLType[transformsType],
                                transforms));
        }
        if (stroke.needToApply()) {
            GL_CALL(StencilStrokePathInstanced(
                                count, GR_GL_UNSIGNED_INT, indices, baseID, 0xffff,
                                writeMask, gXformType2GLType[transformsType],
                                transforms));
        }

        GrDrawState* drawState = fGpu->drawState();
        GrDrawState::AutoViewMatrixRestore avmr;
        SkRect bounds = SkRect::MakeLTRB(0, 0,
                                         SkIntToScalar(drawState->getRenderTarget()->width()),
                                         SkIntToScalar(drawState->getRenderTarget()->height()));
        SkMatrix vmi;
        // 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.
            SkScalar bloat = drawState->getViewMatrix().getMaxScale() * SK_ScalarHalf;
            bounds.outset(bloat, bloat);
        } else {
            avmr.setIdentity(drawState);
        }

        fGpu->drawSimpleRect(bounds);
    }
}

//.........这里部分代码省略.........
    } else if (defaultToUniformInputs && !requiresColorAttrib && inputColorIsUsed) {
        header->fColorInput = kUniform_ColorInput;
    } else {
        header->fColorInput = kAttribute_ColorInput;
        header->fRequiresVertexShader = true;
    }

    bool covIsSolidWhite = !requiresCoverageAttrib && 0xffffffff == drawState.getCoverageColor();

    if ((covIsSolidWhite || !inputCoverageIsUsed) && !skipCoverage) {
        header->fCoverageInput = kAllOnes_ColorInput;
    } else if (defaultToUniformInputs && !requiresCoverageAttrib && inputCoverageIsUsed) {
        header->fCoverageInput = kUniform_ColorInput;
    } else {
        header->fCoverageInput = kAttribute_ColorInput;
        header->fRequiresVertexShader = true;
    }

    if (readsDst) {
        SkASSERT(NULL != dstCopy || gpu->caps()->dstReadInShaderSupport());
        const GrTexture* dstCopyTexture = NULL;
        if (NULL != dstCopy) {
            dstCopyTexture = dstCopy->texture();
        }
        header->fDstReadKey = GrGLFragmentShaderBuilder::KeyForDstRead(dstCopyTexture,
                gpu->glCaps());
        SkASSERT(0 != header->fDstReadKey);
    } else {
        header->fDstReadKey = 0;
    }

    if (readFragPosition) {
        header->fFragPosKey = GrGLFragmentShaderBuilder::KeyForFragmentPosition(
                drawState.getRenderTarget(), gpu->glCaps());
    } else {
        header->fFragPosKey = 0;
    }

    // Record attribute indices
    header->fPositionAttributeIndex = drawState.positionAttributeIndex();
    header->fLocalCoordAttributeIndex = drawState.localCoordAttributeIndex();

    // For constant color and coverage we need an attribute with an index beyond those already set
    int availableAttributeIndex = drawState.getVertexAttribCount();
    if (requiresColorAttrib) {
        header->fColorAttributeIndex = drawState.colorVertexAttributeIndex();
    } else if (GrGLProgramDesc::kAttribute_ColorInput == header->fColorInput) {
        SkASSERT(availableAttributeIndex < GrDrawState::kMaxVertexAttribCnt);
        header->fColorAttributeIndex = availableAttributeIndex;
        availableAttributeIndex++;
    } else {
        header->fColorAttributeIndex = -1;
    }

    if (requiresCoverageAttrib) {
        header->fCoverageAttributeIndex = drawState.coverageVertexAttributeIndex();
    } else if (GrGLProgramDesc::kAttribute_ColorInput == header->fCoverageInput) {
        SkASSERT(availableAttributeIndex < GrDrawState::kMaxVertexAttribCnt);
        header->fCoverageAttributeIndex = availableAttributeIndex;
    } else {
        header->fCoverageAttributeIndex = -1;
    }

    // Here we deal with whether/how we handle color and coverage separately.

    // Set this default and then possibly change our mind if there is coverage.

////////////////////////////////////////////////////////////////////////////////
// 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;
    }

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

#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() &&
        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
//.........这里部分代码省略.........

//.........这里部分代码省略.........
    } else if (defaultToUniformInputs && !requiresColorAttrib) {
        header->fColorInput = kUniform_ColorInput;
    } else {
        header->fColorInput = kAttribute_ColorInput;
        header->fHasVertexCode = true;
    }

    bool covIsSolidWhite = !requiresCoverageAttrib && 0xffffffff == drawState.getCoverageColor();

    if (skipCoverage) {
        header->fCoverageInput = kTransBlack_ColorInput;
    } else if (covIsSolidWhite || !inputCoverageIsUsed) {
        header->fCoverageInput = kSolidWhite_ColorInput;
    } else if (defaultToUniformInputs && !requiresCoverageAttrib) {
        header->fCoverageInput = kUniform_ColorInput;
    } else {
        header->fCoverageInput = kAttribute_ColorInput;
        header->fHasVertexCode = true;
    }

    if (readsDst) {
        SkASSERT(NULL != dstCopy || gpu->caps()->dstReadInShaderSupport());
        const GrTexture* dstCopyTexture = NULL;
        if (NULL != dstCopy) {
            dstCopyTexture = dstCopy->texture();
        }
        header->fDstReadKey = GrGLShaderBuilder::KeyForDstRead(dstCopyTexture, gpu->glCaps());
        SkASSERT(0 != header->fDstReadKey);
    } else {
        header->fDstReadKey = 0;
    }

    if (readFragPosition) {
        header->fFragPosKey = GrGLShaderBuilder::KeyForFragmentPosition(drawState.getRenderTarget(),
                                                                      gpu->glCaps());
    } else {
        header->fFragPosKey = 0;
    }

    // Record attribute indices
    header->fPositionAttributeIndex = drawState.positionAttributeIndex();
    header->fLocalCoordAttributeIndex = drawState.localCoordAttributeIndex();

    // For constant color and coverage we need an attribute with an index beyond those already set
    int availableAttributeIndex = drawState.getVertexAttribCount();
    if (requiresColorAttrib) {
        header->fColorAttributeIndex = drawState.colorVertexAttributeIndex();
    } else if (GrGLProgramDesc::kAttribute_ColorInput == header->fColorInput) {
        SkASSERT(availableAttributeIndex < GrDrawState::kMaxVertexAttribCnt);
        header->fColorAttributeIndex = availableAttributeIndex;
        availableAttributeIndex++;
    } else {
        header->fColorAttributeIndex = -1;
    }

    if (requiresCoverageAttrib) {
        header->fCoverageAttributeIndex = drawState.coverageVertexAttributeIndex();
    } else if (GrGLProgramDesc::kAttribute_ColorInput == header->fCoverageInput) {
        SkASSERT(availableAttributeIndex < GrDrawState::kMaxVertexAttribCnt);
        header->fCoverageAttributeIndex = availableAttributeIndex;
    } else {
        header->fCoverageAttributeIndex = -1;
    }

    // Here we deal with whether/how we handle color and coverage separately.

bool GrStencilAndCoverPathRenderer::onDrawPath(const SkPath& path,
                                               const SkStroke& stroke,
                                               GrDrawTarget* target,
                                               bool antiAlias) {
    GrAssert(!antiAlias);
    GrAssert(0 != stroke.getWidthIfStroked());

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

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

    SkPath::FillType nonInvertedFill = SkPath::NonInverseFill(path.getFillType());
    target->stencilPath(p, stroke, 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();
    SkScalar bloat = drawState->getViewMatrix().getMaxStretch() * SK_ScalarHalf;
    GrDrawState::AutoDeviceCoordDraw adcd;

    if (nonInvertedFill == path.getFillType()) {
        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);
        SkMatrix vmi;
        bounds.setLTRB(0, 0,
                       SkIntToScalar(drawState->getRenderTarget()->width()),
                       SkIntToScalar(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;
}

//.........这里部分代码省略.........
                            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;
                        drawFace[1] = GrDrawState::kCCW_DrawFace;
                        passCount = 3;
                    }
                    if (stencilOnly) {
                        lastPassIsBounds = false;
                        --passCount;
                    } else {
                        lastPassIsBounds = true;
                        drawFace[passCount-1] = GrDrawState::kBoth_DrawFace;
                        if (reverse) {
                            passes[passCount-1] = &gInvWindColorPass;
                        } else {
                            passes[passCount-1] = &gWindColorPass;
                        }
                    }
                    break;
                default:
                    GrAssert(!"Unknown path fFill!");
                    return false;
            }
        }
    }

    {
    for (int p = 0; p < passCount; ++p) {
        drawState->setDrawFace(drawFace[p]);
        if (NULL != passes[p]) {
            *drawState->stencil() = *passes[p];
        }

        if (lastPassIsBounds && (p == passCount-1)) {
            if (!colorWritesWereDisabled) {
                drawState->disableState(GrDrawState::kNoColorWrites_StateBit);
            }
            GrRect bounds;
            GrDrawState::AutoDeviceCoordDraw adcd;
            if (reverse) {
                GrAssert(NULL != drawState->getRenderTarget());
                // draw over the whole world.
                bounds.setLTRB(0, 0,
                               GrIntToScalar(drawState->getRenderTarget()->width()),
                               GrIntToScalar(drawState->getRenderTarget()->height()));
                GrMatrix vmi;
                // mapRect through persp matrix may not be correct
                if (!drawState->getViewMatrix().hasPerspective() &&
                    drawState->getViewInverse(&vmi)) {
                    vmi.mapRect(&bounds);
                } else {
                    adcd.set(drawState);
                }
            } else {
                bounds = path.getBounds();
            }
            GrDrawTarget::AutoGeometryPush agp(target);
            target->drawSimpleRect(bounds, NULL);
        } else {
            if (passCount > 1) {
                drawState->enableState(GrDrawState::kNoColorWrites_StateBit);
            }
            if (indexCnt) {
                target->drawIndexed(primType, 0, 0,
                                    vertexCnt, indexCnt);
            } else {
                target->drawNonIndexed(primType, 0, vertexCnt);
            }
        }
    }
    }
    return true;
}

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.........

bool GrStencilAndCoverPathRenderer::onDrawPath(const SkPath& path,
                                               const SkStrokeRec& stroke,
                                               GrDrawTarget* target,
                                               bool antiAlias) {
    SkASSERT(!antiAlias);
    SkASSERT(!stroke.isHairlineStyle());

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

    SkAutoTUnref<GrPath> p(get_gr_path(fGpu, path, stroke));

    if (path.isInverseFillType()) {
        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);

        drawState->setStencil(kInvertedStencilPass);

        // fake inverse with a stencil and cover
        target->stencilPath(p, convert_skpath_filltype(path.getFillType()));

        GrDrawState::AutoViewMatrixRestore avmr;
        SkRect bounds = SkRect::MakeLTRB(0, 0,
                                         SkIntToScalar(drawState->getRenderTarget()->width()),
                                         SkIntToScalar(drawState->getRenderTarget()->height()));
        SkMatrix vmi;
        // 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.
            SkScalar bloat = drawState->getViewMatrix().getMaxScale() * SK_ScalarHalf;
            bounds.outset(bloat, bloat);
        } else {
            avmr.setIdentity(drawState);
        }
        target->drawSimpleRect(bounds);
    } else {
        GR_STATIC_CONST_SAME_STENCIL(kStencilPass,
            kZero_StencilOp,
            kZero_StencilOp,
            kNotEqual_StencilFunc,
            0xffff,
            0x0000,
            0xffff);

        drawState->setStencil(kStencilPass);
        target->drawPath(p, convert_skpath_filltype(path.getFillType()));
    }

    target->drawState()->stencil()->setDisabled();
    return true;
}

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.........

//.........这里部分代码省略.........
                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;
                    }
                    if (stencilOnly) {
                        lastPassIsBounds = false;
                        --passCount;
                    } else {
                        lastPassIsBounds = true;
                        drawFace[passCount-1] = GrDrawState::kBoth_DrawFace;
                        if (reverse) {
                            passes[passCount-1] = &gInvWindColorPass;
                        } else {
                            passes[passCount-1] = &gWindColorPass;
                        }
                    }
                    break;
                default:
                    GrAssert(!"Unknown path fFill!");
                    return;
            }
        }
    }

    {
    for (int p = 0; p < passCount; ++p) {
        drawState->setDrawFace(drawFace[p]);
        if (NULL != passes[p]) {
            *drawState->stencil() = *passes[p];
        }

        if (lastPassIsBounds && (p == passCount-1)) {
            if (!colorWritesWereDisabled) {
                drawState->disableState(GrDrawState::kNoColorWrites_StateBit);
            }
            GrRect bounds;
            if (reverse) {
                GrAssert(NULL != drawState->getRenderTarget());
                // draw over the whole world.
                bounds.setLTRB(0, 0,
                               GrIntToScalar(drawState->getRenderTarget()->width()),
                               GrIntToScalar(drawState->getRenderTarget()->height()));
                GrMatrix vmi;
                // mapRect through persp matrix may not be correct
                if (!drawState->getViewMatrix().hasPerspective() &&
                    drawState->getViewInverse(&vmi)) {
                    vmi.mapRect(&bounds);
                } else {
                    if (stageMask) {
                        if (!drawState->getViewInverse(&vmi)) {
                            GrPrintf("Could not invert matrix.");
                            return;
                        }
                        drawState->preConcatSamplerMatrices(stageMask, vmi);
                    }
                    drawState->setViewMatrix(GrMatrix::I());
                }
            } else {
                bounds = fPath->getBounds();
                bounds.offset(fTranslate);
            }
            GrDrawTarget::AutoGeometryPush agp(fTarget);
            fTarget->drawSimpleRect(bounds, NULL, stageMask);
        } else {
            if (passCount > 1) {
                drawState->enableState(GrDrawState::kNoColorWrites_StateBit);
            }
            if (fUseIndexedDraw) {
                fTarget->drawIndexed(fPrimitiveType, 0, 0, 
                                     fVertexCnt, fIndexCnt);
            } else {
                int baseVertex = 0;
                for (int sp = 0; sp < fSubpathCount; ++sp) {
                    fTarget->drawNonIndexed(fPrimitiveType, baseVertex,
                                            fSubpathVertCount[sp]);
                    baseVertex += fSubpathVertCount[sp];
                }
            }
        }
    }
    }
}

////////////////////////////////////////////////////////////////////////////////
// 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->getContext()->getPathRenderer(*clipPath,
                                                         fill, gpu, false,
                                                         true);
                if (NULL == pr) {
                    fClipMaskInStencil = false;
                    gpu->setClip(clipCopy);     // restore to the original
                    return false;
                }
//.........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.........