michael@0: 
michael@0: /*
michael@0:  * Copyright 2012 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #include "GrClipMaskManager.h"
michael@0: #include "GrAAConvexPathRenderer.h"
michael@0: #include "GrAAHairLinePathRenderer.h"
michael@0: #include "GrAARectRenderer.h"
michael@0: #include "GrDrawTargetCaps.h"
michael@0: #include "GrGpu.h"
michael@0: #include "GrPaint.h"
michael@0: #include "GrPathRenderer.h"
michael@0: #include "GrRenderTarget.h"
michael@0: #include "GrStencilBuffer.h"
michael@0: #include "GrSWMaskHelper.h"
michael@0: #include "effects/GrTextureDomain.h"
michael@0: #include "effects/GrConvexPolyEffect.h"
michael@0: #include "effects/GrRRectEffect.h"
michael@0: #include "SkRasterClip.h"
michael@0: #include "SkStrokeRec.h"
michael@0: #include "SkTLazy.h"
michael@0: 
michael@0: #define GR_AA_CLIP 1
michael@0: 
michael@0: typedef SkClipStack::Element Element;
michael@0: 
michael@0: using namespace GrReducedClip;
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: namespace {
michael@0: // set up the draw state to enable the aa clipping mask. Besides setting up the
michael@0: // stage matrix this also alters the vertex layout
michael@0: void setup_drawstate_aaclip(GrGpu* gpu,
michael@0:                             GrTexture* result,
michael@0:                             const SkIRect &devBound) {
michael@0:     GrDrawState* drawState = gpu->drawState();
michael@0:     SkASSERT(drawState);
michael@0: 
michael@0:     SkMatrix mat;
michael@0:     // We want to use device coords to compute the texture coordinates. We set our matrix to be
michael@0:     // equal to the view matrix followed by an offset to the devBound, and then a scaling matrix to
michael@0:     // normalized coords. We apply this matrix to the vertex positions rather than local coords.
michael@0:     mat.setIDiv(result->width(), result->height());
michael@0:     mat.preTranslate(SkIntToScalar(-devBound.fLeft),
michael@0:                      SkIntToScalar(-devBound.fTop));
michael@0:     mat.preConcat(drawState->getViewMatrix());
michael@0: 
michael@0:     SkIRect domainTexels = SkIRect::MakeWH(devBound.width(), devBound.height());
michael@0:     // This could be a long-lived effect that is cached with the alpha-mask.
michael@0:     drawState->addCoverageEffect(
michael@0:         GrTextureDomainEffect::Create(result,
michael@0:                                       mat,
michael@0:                                       GrTextureDomain::MakeTexelDomain(result, domainTexels),
michael@0:                                       GrTextureDomain::kDecal_Mode,
michael@0:                                       GrTextureParams::kNone_FilterMode,
michael@0:                                       kPosition_GrCoordSet))->unref();
michael@0: }
michael@0: 
michael@0: bool path_needs_SW_renderer(GrContext* context,
michael@0:                             GrGpu* gpu,
michael@0:                             const SkPath& origPath,
michael@0:                             const SkStrokeRec& stroke,
michael@0:                             bool doAA) {
michael@0:     // the gpu alpha mask will draw the inverse paths as non-inverse to a temp buffer
michael@0:     SkTCopyOnFirstWrite<SkPath> path(origPath);
michael@0:     if (path->isInverseFillType()) {
michael@0:         path.writable()->toggleInverseFillType();
michael@0:     }
michael@0:     // last (false) parameter disallows use of the SW path renderer
michael@0:     GrPathRendererChain::DrawType type = doAA ?
michael@0:                                          GrPathRendererChain::kColorAntiAlias_DrawType :
michael@0:                                          GrPathRendererChain::kColor_DrawType;
michael@0: 
michael@0:     return NULL == context->getPathRenderer(*path, stroke, gpu, false, type);
michael@0: }
michael@0: 
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * This method traverses the clip stack to see if the GrSoftwarePathRenderer
michael@0:  * will be used on any element. If so, it returns true to indicate that the
michael@0:  * entire clip should be rendered in SW and then uploaded en masse to the gpu.
michael@0:  */
michael@0: bool GrClipMaskManager::useSWOnlyPath(const ElementList& elements) {
michael@0: 
michael@0:     // TODO: generalize this function so that when
michael@0:     // a clip gets complex enough it can just be done in SW regardless
michael@0:     // of whether it would invoke the GrSoftwarePathRenderer.
michael@0:     SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
michael@0: 
michael@0:     for (ElementList::Iter iter(elements.headIter()); iter.get(); iter.next()) {
michael@0:         const Element* element = iter.get();
michael@0:         // rects can always be drawn directly w/o using the software path
michael@0:         // Skip rrects once we're drawing them directly.
michael@0:         if (Element::kRect_Type != element->getType()) {
michael@0:             SkPath path;
michael@0:             element->asPath(&path);
michael@0:             if (path_needs_SW_renderer(this->getContext(), fGpu, path, stroke, element->isAA())) {
michael@0:                 return true;
michael@0:             }
michael@0:         }
michael@0:     }
michael@0:     return false;
michael@0: }
michael@0: 
michael@0: bool GrClipMaskManager::installClipEffects(const ElementList& elements,
michael@0:                                            GrDrawState::AutoRestoreEffects* are,
michael@0:                                            const SkVector& clipToRTOffset,
michael@0:                                            const SkRect* drawBounds) {
michael@0: 
michael@0:     GrDrawState* drawState = fGpu->drawState();
michael@0:     SkRect boundsInClipSpace;
michael@0:     if (NULL != drawBounds) {
michael@0:         boundsInClipSpace = *drawBounds;
michael@0:         boundsInClipSpace.offset(-clipToRTOffset.fX, -clipToRTOffset.fY);
michael@0:     }
michael@0: 
michael@0:     are->set(drawState);
michael@0:     GrRenderTarget* rt = drawState->getRenderTarget();
michael@0:     ElementList::Iter iter(elements);
michael@0: 
michael@0:     bool setARE = false;
michael@0:     bool failed = false;
michael@0: 
michael@0:     while (NULL != iter.get()) {
michael@0:         SkRegion::Op op = iter.get()->getOp();
michael@0:         bool invert;
michael@0:         bool skip = false;
michael@0:         switch (op) {
michael@0:             case SkRegion::kReplace_Op:
michael@0:                 SkASSERT(iter.get() == elements.head());
michael@0:                 // Fallthrough, handled same as intersect.
michael@0:             case SkRegion::kIntersect_Op:
michael@0:                 invert = false;
michael@0:                 if (NULL != drawBounds && iter.get()->contains(boundsInClipSpace)) {
michael@0:                     skip = true;
michael@0:                 }
michael@0:                 break;
michael@0:             case SkRegion::kDifference_Op:
michael@0:                 invert = true;
michael@0:                 // We don't currently have a cheap test for whether a rect is fully outside an
michael@0:                 // element's primitive, so don't attempt to set skip.
michael@0:                 break;
michael@0:             default:
michael@0:                 failed = true;
michael@0:                 break;
michael@0:         }
michael@0:         if (failed) {
michael@0:             break;
michael@0:         }
michael@0: 
michael@0:         if (!skip) {
michael@0:             GrEffectEdgeType edgeType;
michael@0:             if (GR_AA_CLIP && iter.get()->isAA()) {
michael@0:                 if (rt->isMultisampled()) {
michael@0:                     // Coverage based AA clips don't place nicely with MSAA.
michael@0:                     failed = true;
michael@0:                     break;
michael@0:                 }
michael@0:                 edgeType = invert ? kInverseFillAA_GrEffectEdgeType : kFillAA_GrEffectEdgeType;
michael@0:             } else {
michael@0:                 edgeType = invert ? kInverseFillBW_GrEffectEdgeType : kFillBW_GrEffectEdgeType;
michael@0:             }
michael@0:             SkAutoTUnref<GrEffectRef> effect;
michael@0:             switch (iter.get()->getType()) {
michael@0:                 case SkClipStack::Element::kPath_Type:
michael@0:                     effect.reset(GrConvexPolyEffect::Create(edgeType, iter.get()->getPath(),
michael@0:                         &clipToRTOffset));
michael@0:                     break;
michael@0:                 case SkClipStack::Element::kRRect_Type: {
michael@0:                     SkRRect rrect = iter.get()->getRRect();
michael@0:                     rrect.offset(clipToRTOffset.fX, clipToRTOffset.fY);
michael@0:                     effect.reset(GrRRectEffect::Create(edgeType, rrect));
michael@0:                     break;
michael@0:                 }
michael@0:                 case SkClipStack::Element::kRect_Type: {
michael@0:                     SkRect rect = iter.get()->getRect();
michael@0:                     rect.offset(clipToRTOffset.fX, clipToRTOffset.fY);
michael@0:                     effect.reset(GrConvexPolyEffect::Create(edgeType, rect));
michael@0:                     break;
michael@0:                 }
michael@0:                 default:
michael@0:                     break;
michael@0:             }
michael@0:             if (effect) {
michael@0:                 if (!setARE) {
michael@0:                     are->set(fGpu->drawState());
michael@0:                     setARE = true;
michael@0:                 }
michael@0:                 fGpu->drawState()->addCoverageEffect(effect);
michael@0:             } else {
michael@0:                 failed = true;
michael@0:                 break;
michael@0:             }
michael@0:         }
michael@0:         iter.next();
michael@0:     }
michael@0: 
michael@0:     if (failed) {
michael@0:         are->set(NULL);
michael@0:     }
michael@0: 
michael@0:     return !failed;
michael@0: }
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: // sort out what kind of clip mask needs to be created: alpha, stencil,
michael@0: // scissor, or entirely software
michael@0: bool GrClipMaskManager::setupClipping(const GrClipData* clipDataIn,
michael@0:                                       GrDrawState::AutoRestoreEffects* are,
michael@0:                                       const SkRect* devBounds) {
michael@0:     fCurrClipMaskType = kNone_ClipMaskType;
michael@0: 
michael@0:     ElementList elements(16);
michael@0:     int32_t genID;
michael@0:     InitialState initialState;
michael@0:     SkIRect clipSpaceIBounds;
michael@0:     bool requiresAA;
michael@0:     bool isRect = false;
michael@0: 
michael@0:     GrDrawState* drawState = fGpu->drawState();
michael@0: 
michael@0:     const GrRenderTarget* rt = drawState->getRenderTarget();
michael@0:     // GrDrawTarget should have filtered this for us
michael@0:     SkASSERT(NULL != rt);
michael@0: 
michael@0:     bool ignoreClip = !drawState->isClipState() || clipDataIn->fClipStack->isWideOpen();
michael@0: 
michael@0:     if (!ignoreClip) {
michael@0:         SkIRect clipSpaceRTIBounds = SkIRect::MakeWH(rt->width(), rt->height());
michael@0:         clipSpaceRTIBounds.offset(clipDataIn->fOrigin);
michael@0:         ReduceClipStack(*clipDataIn->fClipStack,
michael@0:                         clipSpaceRTIBounds,
michael@0:                         &elements,
michael@0:                         &genID,
michael@0:                         &initialState,
michael@0:                         &clipSpaceIBounds,
michael@0:                         &requiresAA);
michael@0:         if (elements.isEmpty()) {
michael@0:             if (kAllIn_InitialState == initialState) {
michael@0:                 ignoreClip = clipSpaceIBounds == clipSpaceRTIBounds;
michael@0:                 isRect = true;
michael@0:             } else {
michael@0:                 return false;
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     if (ignoreClip) {
michael@0:         fGpu->disableScissor();
michael@0:         this->setGpuStencil();
michael@0:         return true;
michael@0:     }
michael@0: 
michael@0:     // An element count of 4 was chosen because of the common pattern in Blink of:
michael@0:     //   isect RR
michael@0:     //   diff  RR
michael@0:     //   isect convex_poly
michael@0:     //   isect convex_poly
michael@0:     // when drawing rounded div borders. This could probably be tuned based on a
michael@0:     // configuration's relative costs of switching RTs to generate a mask vs
michael@0:     // longer shaders.
michael@0:     if (elements.count() <= 4) {
michael@0:         SkVector clipToRTOffset = { SkIntToScalar(-clipDataIn->fOrigin.fX),
michael@0:                                     SkIntToScalar(-clipDataIn->fOrigin.fY) };
michael@0:         if (elements.isEmpty() ||
michael@0:             this->installClipEffects(elements, are, clipToRTOffset, devBounds)) {
michael@0:             SkIRect scissorSpaceIBounds(clipSpaceIBounds);
michael@0:             scissorSpaceIBounds.offset(-clipDataIn->fOrigin);
michael@0:             if (NULL == devBounds ||
michael@0:                 !SkRect::Make(scissorSpaceIBounds).contains(*devBounds)) {
michael@0:                 fGpu->enableScissor(scissorSpaceIBounds);
michael@0:             } else {
michael@0:                 fGpu->disableScissor();
michael@0:             }
michael@0:             this->setGpuStencil();
michael@0:             return true;
michael@0:         }
michael@0:     }
michael@0: 
michael@0: #if GR_AA_CLIP
michael@0:     // If MSAA is enabled we can do everything in the stencil buffer.
michael@0:     if (0 == rt->numSamples() && requiresAA) {
michael@0:         GrTexture* result = NULL;
michael@0: 
michael@0:         if (this->useSWOnlyPath(elements)) {
michael@0:             // The clip geometry is complex enough that it will be more efficient to create it
michael@0:             // entirely in software
michael@0:             result = this->createSoftwareClipMask(genID,
michael@0:                                                   initialState,
michael@0:                                                   elements,
michael@0:                                                   clipSpaceIBounds);
michael@0:         } else {
michael@0:             result = this->createAlphaClipMask(genID,
michael@0:                                                initialState,
michael@0:                                                elements,
michael@0:                                                clipSpaceIBounds);
michael@0:         }
michael@0: 
michael@0:         if (NULL != result) {
michael@0:             // The mask's top left coord should be pinned to the rounded-out top left corner of
michael@0:             // clipSpace bounds. We determine the mask's position WRT to the render target here.
michael@0:             SkIRect rtSpaceMaskBounds = clipSpaceIBounds;
michael@0:             rtSpaceMaskBounds.offset(-clipDataIn->fOrigin);
michael@0:             are->set(fGpu->drawState());
michael@0:             setup_drawstate_aaclip(fGpu, result, rtSpaceMaskBounds);
michael@0:             fGpu->disableScissor();
michael@0:             this->setGpuStencil();
michael@0:             return true;
michael@0:         }
michael@0:         // if alpha clip mask creation fails fall through to the non-AA code paths
michael@0:     }
michael@0: #endif // GR_AA_CLIP
michael@0: 
michael@0:     // Either a hard (stencil buffer) clip was explicitly requested or an anti-aliased clip couldn't
michael@0:     // be created. In either case, free up the texture in the anti-aliased mask cache.
michael@0:     // TODO: this may require more investigation. Ganesh performs a lot of utility draws (e.g.,
michael@0:     // clears, InOrderDrawBuffer playbacks) that hit the stencil buffer path. These may be
michael@0:     // "incorrectly" clearing the AA cache.
michael@0:     fAACache.reset();
michael@0: 
michael@0:     // If the clip is a rectangle then just set the scissor. Otherwise, create
michael@0:     // a stencil mask.
michael@0:     if (isRect) {
michael@0:         SkIRect clipRect = clipSpaceIBounds;
michael@0:         clipRect.offset(-clipDataIn->fOrigin);
michael@0:         fGpu->enableScissor(clipRect);
michael@0:         this->setGpuStencil();
michael@0:         return true;
michael@0:     }
michael@0: 
michael@0:     // use the stencil clip if we can't represent the clip as a rectangle.
michael@0:     SkIPoint clipSpaceToStencilSpaceOffset = -clipDataIn->fOrigin;
michael@0:     this->createStencilClipMask(genID,
michael@0:                                 initialState,
michael@0:                                 elements,
michael@0:                                 clipSpaceIBounds,
michael@0:                                 clipSpaceToStencilSpaceOffset);
michael@0: 
michael@0:     // This must occur after createStencilClipMask. That function may change the scissor. Also, it
michael@0:     // only guarantees that the stencil mask is correct within the bounds it was passed, so we must
michael@0:     // use both stencil and scissor test to the bounds for the final draw.
michael@0:     SkIRect scissorSpaceIBounds(clipSpaceIBounds);
michael@0:     scissorSpaceIBounds.offset(clipSpaceToStencilSpaceOffset);
michael@0:     fGpu->enableScissor(scissorSpaceIBounds);
michael@0:     this->setGpuStencil();
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: #define VISUALIZE_COMPLEX_CLIP 0
michael@0: 
michael@0: #if VISUALIZE_COMPLEX_CLIP
michael@0:     #include "SkRandom.h"
michael@0:     SkRandom gRandom;
michael@0:     #define SET_RANDOM_COLOR drawState->setColor(0xff000000 | gRandom.nextU());
michael@0: #else
michael@0:     #define SET_RANDOM_COLOR
michael@0: #endif
michael@0: 
michael@0: namespace {
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: // set up the OpenGL blend function to perform the specified
michael@0: // boolean operation for alpha clip mask creation
michael@0: void setup_boolean_blendcoeffs(GrDrawState* drawState, SkRegion::Op op) {
michael@0: 
michael@0:     switch (op) {
michael@0:         case SkRegion::kReplace_Op:
michael@0:             drawState->setBlendFunc(kOne_GrBlendCoeff, kZero_GrBlendCoeff);
michael@0:             break;
michael@0:         case SkRegion::kIntersect_Op:
michael@0:             drawState->setBlendFunc(kDC_GrBlendCoeff, kZero_GrBlendCoeff);
michael@0:             break;
michael@0:         case SkRegion::kUnion_Op:
michael@0:             drawState->setBlendFunc(kOne_GrBlendCoeff, kISC_GrBlendCoeff);
michael@0:             break;
michael@0:         case SkRegion::kXOR_Op:
michael@0:             drawState->setBlendFunc(kIDC_GrBlendCoeff, kISC_GrBlendCoeff);
michael@0:             break;
michael@0:         case SkRegion::kDifference_Op:
michael@0:             drawState->setBlendFunc(kZero_GrBlendCoeff, kISC_GrBlendCoeff);
michael@0:             break;
michael@0:         case SkRegion::kReverseDifference_Op:
michael@0:             drawState->setBlendFunc(kIDC_GrBlendCoeff, kZero_GrBlendCoeff);
michael@0:             break;
michael@0:         default:
michael@0:             SkASSERT(false);
michael@0:             break;
michael@0:     }
michael@0: }
michael@0: 
michael@0: }
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: bool GrClipMaskManager::drawElement(GrTexture* target,
michael@0:                                     const SkClipStack::Element* element,
michael@0:                                     GrPathRenderer* pr) {
michael@0:     GrDrawState* drawState = fGpu->drawState();
michael@0: 
michael@0:     drawState->setRenderTarget(target->asRenderTarget());
michael@0: 
michael@0:     // TODO: Draw rrects directly here.
michael@0:     switch (element->getType()) {
michael@0:         case Element::kEmpty_Type:
michael@0:             SkDEBUGFAIL("Should never get here with an empty element.");
michael@0:             break;
michael@0:         case Element::kRect_Type:
michael@0:             // TODO: Do rects directly to the accumulator using a aa-rect GrEffect that covers the
michael@0:             // entire mask bounds and writes 0 outside the rect.
michael@0:             if (element->isAA()) {
michael@0:                 getContext()->getAARectRenderer()->fillAARect(fGpu,
michael@0:                                                               fGpu,
michael@0:                                                               element->getRect(),
michael@0:                                                               SkMatrix::I(),
michael@0:                                                               element->getRect(),
michael@0:                                                               false);
michael@0:             } else {
michael@0:                 fGpu->drawSimpleRect(element->getRect(), NULL);
michael@0:             }
michael@0:             return true;
michael@0:         default: {
michael@0:             SkPath path;
michael@0:             element->asPath(&path);
michael@0:             if (path.isInverseFillType()) {
michael@0:                 path.toggleInverseFillType();
michael@0:             }
michael@0:             SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
michael@0:             if (NULL == pr) {
michael@0:                 GrPathRendererChain::DrawType type;
michael@0:                 type = element->isAA() ? GrPathRendererChain::kColorAntiAlias_DrawType :
michael@0:                                          GrPathRendererChain::kColor_DrawType;
michael@0:                 pr = this->getContext()->getPathRenderer(path, stroke, fGpu, false, type);
michael@0:             }
michael@0:             if (NULL == pr) {
michael@0:                 return false;
michael@0:             }
michael@0:             pr->drawPath(path, stroke, fGpu, element->isAA());
michael@0:             break;
michael@0:         }
michael@0:     }
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool GrClipMaskManager::canStencilAndDrawElement(GrTexture* target,
michael@0:                                                  const SkClipStack::Element* element,
michael@0:                                                  GrPathRenderer** pr) {
michael@0:     GrDrawState* drawState = fGpu->drawState();
michael@0:     drawState->setRenderTarget(target->asRenderTarget());
michael@0: 
michael@0:     if (Element::kRect_Type == element->getType()) {
michael@0:         return true;
michael@0:     } else {
michael@0:         // We shouldn't get here with an empty clip element.
michael@0:         SkASSERT(Element::kEmpty_Type != element->getType());
michael@0:         SkPath path;
michael@0:         element->asPath(&path);
michael@0:         if (path.isInverseFillType()) {
michael@0:             path.toggleInverseFillType();
michael@0:         }
michael@0:         SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
michael@0:         GrPathRendererChain::DrawType type = element->isAA() ?
michael@0:             GrPathRendererChain::kStencilAndColorAntiAlias_DrawType :
michael@0:             GrPathRendererChain::kStencilAndColor_DrawType;
michael@0:         *pr = this->getContext()->getPathRenderer(path, stroke, fGpu, false, type);
michael@0:         return NULL != *pr;
michael@0:     }
michael@0: }
michael@0: 
michael@0: void GrClipMaskManager::mergeMask(GrTexture* dstMask,
michael@0:                                   GrTexture* srcMask,
michael@0:                                   SkRegion::Op op,
michael@0:                                   const SkIRect& dstBound,
michael@0:                                   const SkIRect& srcBound) {
michael@0:     GrDrawState::AutoViewMatrixRestore avmr;
michael@0:     GrDrawState* drawState = fGpu->drawState();
michael@0:     SkAssertResult(avmr.setIdentity(drawState));
michael@0:     GrDrawState::AutoRestoreEffects are(drawState);
michael@0: 
michael@0:     drawState->setRenderTarget(dstMask->asRenderTarget());
michael@0: 
michael@0:     setup_boolean_blendcoeffs(drawState, op);
michael@0: 
michael@0:     SkMatrix sampleM;
michael@0:     sampleM.setIDiv(srcMask->width(), srcMask->height());
michael@0: 
michael@0:     drawState->addColorEffect(
michael@0:         GrTextureDomainEffect::Create(srcMask,
michael@0:                                       sampleM,
michael@0:                                       GrTextureDomain::MakeTexelDomain(srcMask, srcBound),
michael@0:                                       GrTextureDomain::kDecal_Mode,
michael@0:                                       GrTextureParams::kNone_FilterMode))->unref();
michael@0:     fGpu->drawSimpleRect(SkRect::Make(dstBound), NULL);
michael@0: }
michael@0: 
michael@0: // get a texture to act as a temporary buffer for AA clip boolean operations
michael@0: // TODO: given the expense of createTexture we may want to just cache this too
michael@0: void GrClipMaskManager::getTemp(int width, int height, GrAutoScratchTexture* temp) {
michael@0:     if (NULL != temp->texture()) {
michael@0:         // we've already allocated the temp texture
michael@0:         return;
michael@0:     }
michael@0: 
michael@0:     GrTextureDesc desc;
michael@0:     desc.fFlags = kRenderTarget_GrTextureFlagBit|kNoStencil_GrTextureFlagBit;
michael@0:     desc.fWidth = width;
michael@0:     desc.fHeight = height;
michael@0:     desc.fConfig = kAlpha_8_GrPixelConfig;
michael@0: 
michael@0:     temp->set(this->getContext(), desc);
michael@0: }
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: // Handles caching & allocation (if needed) of a clip alpha-mask texture for both the sw-upload
michael@0: // or gpu-rendered cases. Returns true if there is no more work to be done (i.e., we got a cache
michael@0: // hit)
michael@0: bool GrClipMaskManager::getMaskTexture(int32_t elementsGenID,
michael@0:                                        const SkIRect& clipSpaceIBounds,
michael@0:                                        GrTexture** result,
michael@0:                                        bool willUpload) {
michael@0:     bool cached = fAACache.canReuse(elementsGenID, clipSpaceIBounds);
michael@0:     if (!cached) {
michael@0: 
michael@0:         // There isn't a suitable entry in the cache so we create a new texture to store the mask.
michael@0:         // Since we are setting up the cache we know the last lookup was a miss. Free up the
michael@0:         // currently cached mask so it can be reused.
michael@0:         fAACache.reset();
michael@0: 
michael@0:         GrTextureDesc desc;
michael@0:         desc.fFlags = willUpload ? kNone_GrTextureFlags : kRenderTarget_GrTextureFlagBit;
michael@0:         desc.fWidth = clipSpaceIBounds.width();
michael@0:         desc.fHeight = clipSpaceIBounds.height();
michael@0:         desc.fConfig = kRGBA_8888_GrPixelConfig;
michael@0:         if (willUpload || this->getContext()->isConfigRenderable(kAlpha_8_GrPixelConfig, false)) {
michael@0:             // We would always like A8 but it isn't supported on all platforms
michael@0:             desc.fConfig = kAlpha_8_GrPixelConfig;
michael@0:         }
michael@0: 
michael@0:         fAACache.acquireMask(elementsGenID, desc, clipSpaceIBounds);
michael@0:     }
michael@0: 
michael@0:     *result = fAACache.getLastMask();
michael@0:     return cached;
michael@0: }
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: // Create a 8-bit clip mask in alpha
michael@0: GrTexture* GrClipMaskManager::createAlphaClipMask(int32_t elementsGenID,
michael@0:                                                   InitialState initialState,
michael@0:                                                   const ElementList& elements,
michael@0:                                                   const SkIRect& clipSpaceIBounds) {
michael@0:     SkASSERT(kNone_ClipMaskType == fCurrClipMaskType);
michael@0: 
michael@0:     GrTexture* result;
michael@0:     if (this->getMaskTexture(elementsGenID, clipSpaceIBounds, &result, false)) {
michael@0:         fCurrClipMaskType = kAlpha_ClipMaskType;
michael@0:         return result;
michael@0:     }
michael@0: 
michael@0:     if (NULL == result) {
michael@0:         fAACache.reset();
michael@0:         return NULL;
michael@0:     }
michael@0: 
michael@0:     // The top-left of the mask corresponds to the top-left corner of the bounds.
michael@0:     SkVector clipToMaskOffset = {
michael@0:         SkIntToScalar(-clipSpaceIBounds.fLeft),
michael@0:         SkIntToScalar(-clipSpaceIBounds.fTop)
michael@0:     };
michael@0:     // The texture may be larger than necessary, this rect represents the part of the texture
michael@0:     // we populate with a rasterization of the clip.
michael@0:     SkIRect maskSpaceIBounds = SkIRect::MakeWH(clipSpaceIBounds.width(), clipSpaceIBounds.height());
michael@0: 
michael@0:     // Set the matrix so that rendered clip elements are transformed to mask space from clip space.
michael@0:     SkMatrix translate;
michael@0:     translate.setTranslate(clipToMaskOffset);
michael@0:     GrDrawTarget::AutoGeometryAndStatePush agasp(fGpu, GrDrawTarget::kReset_ASRInit, &translate);
michael@0: 
michael@0:     GrDrawState* drawState = fGpu->drawState();
michael@0: 
michael@0:     // We're drawing a coverage mask and want coverage to be run through the blend function.
michael@0:     drawState->enableState(GrDrawState::kCoverageDrawing_StateBit);
michael@0: 
michael@0:     // The scratch texture that we are drawing into can be substantially larger than the mask. Only
michael@0:     // clear the part that we care about.
michael@0:     fGpu->clear(&maskSpaceIBounds,
michael@0:                 kAllIn_InitialState == initialState ? 0xffffffff : 0x00000000,
michael@0:                 true,
michael@0:                 result->asRenderTarget());
michael@0: 
michael@0:     // When we use the stencil in the below loop it is important to have this clip installed.
michael@0:     // The second pass that zeros the stencil buffer renders the rect maskSpaceIBounds so the first
michael@0:     // pass must not set values outside of this bounds or stencil values outside the rect won't be
michael@0:     // cleared.
michael@0:     GrDrawTarget::AutoClipRestore acr(fGpu, maskSpaceIBounds);
michael@0:     drawState->enableState(GrDrawState::kClip_StateBit);
michael@0: 
michael@0:     GrAutoScratchTexture temp;
michael@0:     // walk through each clip element and perform its set op
michael@0:     for (ElementList::Iter iter = elements.headIter(); iter.get(); iter.next()) {
michael@0:         const Element* element = iter.get();
michael@0:         SkRegion::Op op = element->getOp();
michael@0:         bool invert = element->isInverseFilled();
michael@0: 
michael@0:         if (invert || SkRegion::kIntersect_Op == op || SkRegion::kReverseDifference_Op == op) {
michael@0:             GrPathRenderer* pr = NULL;
michael@0:             bool useTemp = !this->canStencilAndDrawElement(result, element, &pr);
michael@0:             GrTexture* dst;
michael@0:             // This is the bounds of the clip element in the space of the alpha-mask. The temporary
michael@0:             // mask buffer can be substantially larger than the actually clip stack element. We
michael@0:             // touch the minimum number of pixels necessary and use decal mode to combine it with
michael@0:             // the accumulator.
michael@0:             SkIRect maskSpaceElementIBounds;
michael@0: 
michael@0:             if (useTemp) {
michael@0:                 if (invert) {
michael@0:                     maskSpaceElementIBounds = maskSpaceIBounds;
michael@0:                 } else {
michael@0:                     SkRect elementBounds = element->getBounds();
michael@0:                     elementBounds.offset(clipToMaskOffset);
michael@0:                     elementBounds.roundOut(&maskSpaceElementIBounds);
michael@0:                 }
michael@0: 
michael@0:                 this->getTemp(maskSpaceIBounds.fRight, maskSpaceIBounds.fBottom, &temp);
michael@0:                 if (NULL == temp.texture()) {
michael@0:                     fAACache.reset();
michael@0:                     return NULL;
michael@0:                 }
michael@0:                 dst = temp.texture();
michael@0:                 // clear the temp target and set blend to replace
michael@0:                 fGpu->clear(&maskSpaceElementIBounds,
michael@0:                             invert ? 0xffffffff : 0x00000000,
michael@0:                             true,
michael@0:                             dst->asRenderTarget());
michael@0:                 setup_boolean_blendcoeffs(drawState, SkRegion::kReplace_Op);
michael@0: 
michael@0:             } else {
michael@0:                 // draw directly into the result with the stencil set to make the pixels affected
michael@0:                 // by the clip shape be non-zero.
michael@0:                 dst = result;
michael@0:                 GR_STATIC_CONST_SAME_STENCIL(kStencilInElement,
michael@0:                                              kReplace_StencilOp,
michael@0:                                              kReplace_StencilOp,
michael@0:                                              kAlways_StencilFunc,
michael@0:                                              0xffff,
michael@0:                                              0xffff,
michael@0:                                              0xffff);
michael@0:                 drawState->setStencil(kStencilInElement);
michael@0:                 setup_boolean_blendcoeffs(drawState, op);
michael@0:             }
michael@0: 
michael@0:             drawState->setAlpha(invert ? 0x00 : 0xff);
michael@0: 
michael@0:             if (!this->drawElement(dst, element, pr)) {
michael@0:                 fAACache.reset();
michael@0:                 return NULL;
michael@0:             }
michael@0: 
michael@0:             if (useTemp) {
michael@0:                 // Now draw into the accumulator using the real operation and the temp buffer as a
michael@0:                 // texture
michael@0:                 this->mergeMask(result,
michael@0:                                 temp.texture(),
michael@0:                                 op,
michael@0:                                 maskSpaceIBounds,
michael@0:                                 maskSpaceElementIBounds);
michael@0:             } else {
michael@0:                 // Draw to the exterior pixels (those with a zero stencil value).
michael@0:                 drawState->setAlpha(invert ? 0xff : 0x00);
michael@0:                 GR_STATIC_CONST_SAME_STENCIL(kDrawOutsideElement,
michael@0:                                              kZero_StencilOp,
michael@0:                                              kZero_StencilOp,
michael@0:                                              kEqual_StencilFunc,
michael@0:                                              0xffff,
michael@0:                                              0x0000,
michael@0:                                              0xffff);
michael@0:                 drawState->setStencil(kDrawOutsideElement);
michael@0:                 fGpu->drawSimpleRect(clipSpaceIBounds);
michael@0:                 drawState->disableStencil();
michael@0:             }
michael@0:         } else {
michael@0:             // all the remaining ops can just be directly draw into the accumulation buffer
michael@0:             drawState->setAlpha(0xff);
michael@0:             setup_boolean_blendcoeffs(drawState, op);
michael@0:             this->drawElement(result, element);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     fCurrClipMaskType = kAlpha_ClipMaskType;
michael@0:     return result;
michael@0: }
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: // Create a 1-bit clip mask in the stencil buffer. 'devClipBounds' are in device
michael@0: // (as opposed to canvas) coordinates
michael@0: bool GrClipMaskManager::createStencilClipMask(int32_t elementsGenID,
michael@0:                                               InitialState initialState,
michael@0:                                               const ElementList& elements,
michael@0:                                               const SkIRect& clipSpaceIBounds,
michael@0:                                               const SkIPoint& clipSpaceToStencilOffset) {
michael@0: 
michael@0:     SkASSERT(kNone_ClipMaskType == fCurrClipMaskType);
michael@0: 
michael@0:     GrDrawState* drawState = fGpu->drawState();
michael@0:     SkASSERT(drawState->isClipState());
michael@0: 
michael@0:     GrRenderTarget* rt = drawState->getRenderTarget();
michael@0:     SkASSERT(NULL != rt);
michael@0: 
michael@0:     // TODO: dynamically attach a SB when needed.
michael@0:     GrStencilBuffer* stencilBuffer = rt->getStencilBuffer();
michael@0:     if (NULL == stencilBuffer) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     if (stencilBuffer->mustRenderClip(elementsGenID, clipSpaceIBounds, clipSpaceToStencilOffset)) {
michael@0: 
michael@0:         stencilBuffer->setLastClip(elementsGenID, clipSpaceIBounds, clipSpaceToStencilOffset);
michael@0: 
michael@0:         // Set the matrix so that rendered clip elements are transformed from clip to stencil space.
michael@0:         SkVector translate = {
michael@0:             SkIntToScalar(clipSpaceToStencilOffset.fX),
michael@0:             SkIntToScalar(clipSpaceToStencilOffset.fY)
michael@0:         };
michael@0:         SkMatrix matrix;
michael@0:         matrix.setTranslate(translate);
michael@0:         GrDrawTarget::AutoGeometryAndStatePush agasp(fGpu, GrDrawTarget::kReset_ASRInit, &matrix);
michael@0:         drawState = fGpu->drawState();
michael@0: 
michael@0:         drawState->setRenderTarget(rt);
michael@0: 
michael@0:         // We set the current clip to the bounds so that our recursive draws are scissored to them.
michael@0:         SkIRect stencilSpaceIBounds(clipSpaceIBounds);
michael@0:         stencilSpaceIBounds.offset(clipSpaceToStencilOffset);
michael@0:         GrDrawTarget::AutoClipRestore acr(fGpu, stencilSpaceIBounds);
michael@0:         drawState->enableState(GrDrawState::kClip_StateBit);
michael@0: 
michael@0: #if !VISUALIZE_COMPLEX_CLIP
michael@0:         drawState->enableState(GrDrawState::kNoColorWrites_StateBit);
michael@0: #endif
michael@0: 
michael@0:         int clipBit = stencilBuffer->bits();
michael@0:         SkASSERT((clipBit <= 16) && "Ganesh only handles 16b or smaller stencil buffers");
michael@0:         clipBit = (1 << (clipBit-1));
michael@0: 
michael@0:         fGpu->clearStencilClip(stencilSpaceIBounds, kAllIn_InitialState == initialState);
michael@0: 
michael@0:         // walk through each clip element and perform its set op
michael@0:         // with the existing clip.
michael@0:         for (ElementList::Iter iter(elements.headIter()); NULL != iter.get(); iter.next()) {
michael@0:             const Element* element = iter.get();
michael@0:             bool fillInverted = false;
michael@0:             // enabled at bottom of loop
michael@0:             drawState->disableState(GrGpu::kModifyStencilClip_StateBit);
michael@0:             // if the target is MSAA then we want MSAA enabled when the clip is soft
michael@0:             if (rt->isMultisampled()) {
michael@0:                 drawState->setState(GrDrawState::kHWAntialias_StateBit, element->isAA());
michael@0:             }
michael@0: 
michael@0:             // This will be used to determine whether the clip shape can be rendered into the
michael@0:             // stencil with arbitrary stencil settings.
michael@0:             GrPathRenderer::StencilSupport stencilSupport;
michael@0: 
michael@0:             SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
michael@0: 
michael@0:             SkRegion::Op op = element->getOp();
michael@0: 
michael@0:             GrPathRenderer* pr = NULL;
michael@0:             SkPath clipPath;
michael@0:             if (Element::kRect_Type == element->getType()) {
michael@0:                 stencilSupport = GrPathRenderer::kNoRestriction_StencilSupport;
michael@0:                 fillInverted = false;
michael@0:             } else {
michael@0:                 element->asPath(&clipPath);
michael@0:                 fillInverted = clipPath.isInverseFillType();
michael@0:                 if (fillInverted) {
michael@0:                     clipPath.toggleInverseFillType();
michael@0:                 }
michael@0:                 pr = this->getContext()->getPathRenderer(clipPath,
michael@0:                                                          stroke,
michael@0:                                                          fGpu,
michael@0:                                                          false,
michael@0:                                                          GrPathRendererChain::kStencilOnly_DrawType,
michael@0:                                                          &stencilSupport);
michael@0:                 if (NULL == pr) {
michael@0:                     return false;
michael@0:                 }
michael@0:             }
michael@0: 
michael@0:             int passes;
michael@0:             GrStencilSettings stencilSettings[GrStencilSettings::kMaxStencilClipPasses];
michael@0: 
michael@0:             bool canRenderDirectToStencil =
michael@0:                 GrPathRenderer::kNoRestriction_StencilSupport == stencilSupport;
michael@0:             bool canDrawDirectToClip; // Given the renderer, the element,
michael@0:                                       // fill rule, and set operation can
michael@0:                                       // we render the element directly to
michael@0:                                       // stencil bit used for clipping.
michael@0:             canDrawDirectToClip = GrStencilSettings::GetClipPasses(op,
michael@0:                                                                    canRenderDirectToStencil,
michael@0:                                                                    clipBit,
michael@0:                                                                    fillInverted,
michael@0:                                                                    &passes,
michael@0:                                                                    stencilSettings);
michael@0: 
michael@0:             // draw the element to the client stencil bits if necessary
michael@0:             if (!canDrawDirectToClip) {
michael@0:                 GR_STATIC_CONST_SAME_STENCIL(gDrawToStencil,
michael@0:                                              kIncClamp_StencilOp,
michael@0:                                              kIncClamp_StencilOp,
michael@0:                                              kAlways_StencilFunc,
michael@0:                                              0xffff,
michael@0:                                              0x0000,
michael@0:                                              0xffff);
michael@0:                 SET_RANDOM_COLOR
michael@0:                 if (Element::kRect_Type == element->getType()) {
michael@0:                     *drawState->stencil() = gDrawToStencil;
michael@0:                     fGpu->drawSimpleRect(element->getRect(), NULL);
michael@0:                 } else {
michael@0:                     if (!clipPath.isEmpty()) {
michael@0:                         if (canRenderDirectToStencil) {
michael@0:                             *drawState->stencil() = gDrawToStencil;
michael@0:                             pr->drawPath(clipPath, stroke, fGpu, false);
michael@0:                         } else {
michael@0:                             pr->stencilPath(clipPath, stroke, fGpu);
michael@0:                         }
michael@0:                     }
michael@0:                 }
michael@0:             }
michael@0: 
michael@0:             // now we modify the clip bit by rendering either the clip
michael@0:             // element directly or a bounding rect of the entire clip.
michael@0:             drawState->enableState(GrGpu::kModifyStencilClip_StateBit);
michael@0:             for (int p = 0; p < passes; ++p) {
michael@0:                 *drawState->stencil() = stencilSettings[p];
michael@0:                 if (canDrawDirectToClip) {
michael@0:                     if (Element::kRect_Type == element->getType()) {
michael@0:                         SET_RANDOM_COLOR
michael@0:                         fGpu->drawSimpleRect(element->getRect(), NULL);
michael@0:                     } else {
michael@0:                         SET_RANDOM_COLOR
michael@0:                         pr->drawPath(clipPath, stroke, fGpu, false);
michael@0:                     }
michael@0:                 } else {
michael@0:                     SET_RANDOM_COLOR
michael@0:                     // The view matrix is setup to do clip space -> stencil space translation, so
michael@0:                     // draw rect in clip space.
michael@0:                     fGpu->drawSimpleRect(SkRect::Make(clipSpaceIBounds), NULL);
michael@0:                 }
michael@0:             }
michael@0:         }
michael@0:     }
michael@0:     // set this last because recursive draws may overwrite it back to kNone.
michael@0:     SkASSERT(kNone_ClipMaskType == fCurrClipMaskType);
michael@0:     fCurrClipMaskType = kStencil_ClipMaskType;
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: 
michael@0: // mapping of clip-respecting stencil funcs to normal stencil funcs
michael@0: // mapping depends on whether stencil-clipping is in effect.
michael@0: static const GrStencilFunc
michael@0:     gSpecialToBasicStencilFunc[2][kClipStencilFuncCount] = {
michael@0:     {// Stencil-Clipping is DISABLED,  we are effectively always inside the clip
michael@0:         // In the Clip Funcs
michael@0:         kAlways_StencilFunc,          // kAlwaysIfInClip_StencilFunc
michael@0:         kEqual_StencilFunc,           // kEqualIfInClip_StencilFunc
michael@0:         kLess_StencilFunc,            // kLessIfInClip_StencilFunc
michael@0:         kLEqual_StencilFunc,          // kLEqualIfInClip_StencilFunc
michael@0:         // Special in the clip func that forces user's ref to be 0.
michael@0:         kNotEqual_StencilFunc,        // kNonZeroIfInClip_StencilFunc
michael@0:                                       // make ref 0 and do normal nequal.
michael@0:     },
michael@0:     {// Stencil-Clipping is ENABLED
michael@0:         // In the Clip Funcs
michael@0:         kEqual_StencilFunc,           // kAlwaysIfInClip_StencilFunc
michael@0:                                       // eq stencil clip bit, mask
michael@0:                                       // out user bits.
michael@0: 
michael@0:         kEqual_StencilFunc,           // kEqualIfInClip_StencilFunc
michael@0:                                       // add stencil bit to mask and ref
michael@0: 
michael@0:         kLess_StencilFunc,            // kLessIfInClip_StencilFunc
michael@0:         kLEqual_StencilFunc,          // kLEqualIfInClip_StencilFunc
michael@0:                                       // for both of these we can add
michael@0:                                       // the clip bit to the mask and
michael@0:                                       // ref and compare as normal
michael@0:         // Special in the clip func that forces user's ref to be 0.
michael@0:         kLess_StencilFunc,            // kNonZeroIfInClip_StencilFunc
michael@0:                                       // make ref have only the clip bit set
michael@0:                                       // and make comparison be less
michael@0:                                       // 10..0 < 1..user_bits..
michael@0:     }
michael@0: };
michael@0: 
michael@0: namespace {
michael@0: // Sets the settings to clip against the stencil buffer clip while ignoring the
michael@0: // client bits.
michael@0: const GrStencilSettings& basic_apply_stencil_clip_settings() {
michael@0:     // stencil settings to use when clip is in stencil
michael@0:     GR_STATIC_CONST_SAME_STENCIL_STRUCT(gSettings,
michael@0:         kKeep_StencilOp,
michael@0:         kKeep_StencilOp,
michael@0:         kAlwaysIfInClip_StencilFunc,
michael@0:         0x0000,
michael@0:         0x0000,
michael@0:         0x0000);
michael@0:     return *GR_CONST_STENCIL_SETTINGS_PTR_FROM_STRUCT_PTR(&gSettings);
michael@0: }
michael@0: }
michael@0: 
michael@0: void GrClipMaskManager::setGpuStencil() {
michael@0:     // We make two copies of the StencilSettings here (except in the early
michael@0:     // exit scenario. One copy from draw state to the stack var. Then another
michael@0:     // from the stack var to the gpu. We could make this class hold a ptr to
michael@0:     // GrGpu's fStencilSettings and eliminate the stack copy here.
michael@0: 
michael@0:     const GrDrawState& drawState = fGpu->getDrawState();
michael@0: 
michael@0:     // use stencil for clipping if clipping is enabled and the clip
michael@0:     // has been written into the stencil.
michael@0:     GrClipMaskManager::StencilClipMode clipMode;
michael@0:     if (this->isClipInStencil() && drawState.isClipState()) {
michael@0:         clipMode = GrClipMaskManager::kRespectClip_StencilClipMode;
michael@0:         // We can't be modifying the clip and respecting it at the same time.
michael@0:         SkASSERT(!drawState.isStateFlagEnabled(
michael@0:                     GrGpu::kModifyStencilClip_StateBit));
michael@0:     } else if (drawState.isStateFlagEnabled(
michael@0:                     GrGpu::kModifyStencilClip_StateBit)) {
michael@0:         clipMode = GrClipMaskManager::kModifyClip_StencilClipMode;
michael@0:     } else {
michael@0:         clipMode = GrClipMaskManager::kIgnoreClip_StencilClipMode;
michael@0:     }
michael@0: 
michael@0:     GrStencilSettings settings;
michael@0:     // The GrGpu client may not be using the stencil buffer but we may need to
michael@0:     // enable it in order to respect a stencil clip.
michael@0:     if (drawState.getStencil().isDisabled()) {
michael@0:         if (GrClipMaskManager::kRespectClip_StencilClipMode == clipMode) {
michael@0:             settings = basic_apply_stencil_clip_settings();
michael@0:         } else {
michael@0:             fGpu->disableStencil();
michael@0:             return;
michael@0:         }
michael@0:     } else {
michael@0:         settings = drawState.getStencil();
michael@0:     }
michael@0: 
michael@0:     // TODO: dynamically attach a stencil buffer
michael@0:     int stencilBits = 0;
michael@0:     GrStencilBuffer* stencilBuffer =
michael@0:         drawState.getRenderTarget()->getStencilBuffer();
michael@0:     if (NULL != stencilBuffer) {
michael@0:         stencilBits = stencilBuffer->bits();
michael@0:     }
michael@0: 
michael@0:     SkASSERT(fGpu->caps()->stencilWrapOpsSupport() || !settings.usesWrapOp());
michael@0:     SkASSERT(fGpu->caps()->twoSidedStencilSupport() || !settings.isTwoSided());
michael@0:     this->adjustStencilParams(&settings, clipMode, stencilBits);
michael@0:     fGpu->setStencilSettings(settings);
michael@0: }
michael@0: 
michael@0: void GrClipMaskManager::adjustStencilParams(GrStencilSettings* settings,
michael@0:                                             StencilClipMode mode,
michael@0:                                             int stencilBitCnt) {
michael@0:     SkASSERT(stencilBitCnt > 0);
michael@0: 
michael@0:     if (kModifyClip_StencilClipMode == mode) {
michael@0:         // We assume that this clip manager itself is drawing to the GrGpu and
michael@0:         // has already setup the correct values.
michael@0:         return;
michael@0:     }
michael@0: 
michael@0:     unsigned int clipBit = (1 << (stencilBitCnt - 1));
michael@0:     unsigned int userBits = clipBit - 1;
michael@0: 
michael@0:     GrStencilSettings::Face face = GrStencilSettings::kFront_Face;
michael@0:     bool twoSided = fGpu->caps()->twoSidedStencilSupport();
michael@0: 
michael@0:     bool finished = false;
michael@0:     while (!finished) {
michael@0:         GrStencilFunc func = settings->func(face);
michael@0:         uint16_t writeMask = settings->writeMask(face);
michael@0:         uint16_t funcMask = settings->funcMask(face);
michael@0:         uint16_t funcRef = settings->funcRef(face);
michael@0: 
michael@0:         SkASSERT((unsigned) func < kStencilFuncCount);
michael@0: 
michael@0:         writeMask &= userBits;
michael@0: 
michael@0:         if (func >= kBasicStencilFuncCount) {
michael@0:             int respectClip = kRespectClip_StencilClipMode == mode;
michael@0:             if (respectClip) {
michael@0:                 // The GrGpu class should have checked this
michael@0:                 SkASSERT(this->isClipInStencil());
michael@0:                 switch (func) {
michael@0:                     case kAlwaysIfInClip_StencilFunc:
michael@0:                         funcMask = clipBit;
michael@0:                         funcRef = clipBit;
michael@0:                         break;
michael@0:                     case kEqualIfInClip_StencilFunc:
michael@0:                     case kLessIfInClip_StencilFunc:
michael@0:                     case kLEqualIfInClip_StencilFunc:
michael@0:                         funcMask = (funcMask & userBits) | clipBit;
michael@0:                         funcRef  = (funcRef  & userBits) | clipBit;
michael@0:                         break;
michael@0:                     case kNonZeroIfInClip_StencilFunc:
michael@0:                         funcMask = (funcMask & userBits) | clipBit;
michael@0:                         funcRef = clipBit;
michael@0:                         break;
michael@0:                     default:
michael@0:                         GrCrash("Unknown stencil func");
michael@0:                 }
michael@0:             } else {
michael@0:                 funcMask &= userBits;
michael@0:                 funcRef &= userBits;
michael@0:             }
michael@0:             const GrStencilFunc* table =
michael@0:                 gSpecialToBasicStencilFunc[respectClip];
michael@0:             func = table[func - kBasicStencilFuncCount];
michael@0:             SkASSERT(func >= 0 && func < kBasicStencilFuncCount);
michael@0:         } else {
michael@0:             funcMask &= userBits;
michael@0:             funcRef &= userBits;
michael@0:         }
michael@0: 
michael@0:         settings->setFunc(face, func);
michael@0:         settings->setWriteMask(face, writeMask);
michael@0:         settings->setFuncMask(face, funcMask);
michael@0:         settings->setFuncRef(face, funcRef);
michael@0: 
michael@0:         if (GrStencilSettings::kFront_Face == face) {
michael@0:             face = GrStencilSettings::kBack_Face;
michael@0:             finished = !twoSided;
michael@0:         } else {
michael@0:             finished = true;
michael@0:         }
michael@0:     }
michael@0:     if (!twoSided) {
michael@0:         settings->copyFrontSettingsToBack();
michael@0:     }
michael@0: }
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: GrTexture* GrClipMaskManager::createSoftwareClipMask(int32_t elementsGenID,
michael@0:                                                      GrReducedClip::InitialState initialState,
michael@0:                                                      const GrReducedClip::ElementList& elements,
michael@0:                                                      const SkIRect& clipSpaceIBounds) {
michael@0:     SkASSERT(kNone_ClipMaskType == fCurrClipMaskType);
michael@0: 
michael@0:     GrTexture* result;
michael@0:     if (this->getMaskTexture(elementsGenID, clipSpaceIBounds, &result, true)) {
michael@0:         return result;
michael@0:     }
michael@0: 
michael@0:     if (NULL == result) {
michael@0:         fAACache.reset();
michael@0:         return NULL;
michael@0:     }
michael@0: 
michael@0:     // The mask texture may be larger than necessary. We round out the clip space bounds and pin
michael@0:     // the top left corner of the resulting rect to the top left of the texture.
michael@0:     SkIRect maskSpaceIBounds = SkIRect::MakeWH(clipSpaceIBounds.width(), clipSpaceIBounds.height());
michael@0: 
michael@0:     GrSWMaskHelper helper(this->getContext());
michael@0: 
michael@0:     SkMatrix matrix;
michael@0:     matrix.setTranslate(SkIntToScalar(-clipSpaceIBounds.fLeft),
michael@0:                         SkIntToScalar(-clipSpaceIBounds.fTop));
michael@0:     helper.init(maskSpaceIBounds, &matrix);
michael@0: 
michael@0:     helper.clear(kAllIn_InitialState == initialState ? 0xFF : 0x00);
michael@0: 
michael@0:     SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
michael@0: 
michael@0:     for (ElementList::Iter iter(elements.headIter()) ; NULL != iter.get(); iter.next()) {
michael@0: 
michael@0:         const Element* element = iter.get();
michael@0:         SkRegion::Op op = element->getOp();
michael@0: 
michael@0:         if (SkRegion::kIntersect_Op == op || SkRegion::kReverseDifference_Op == op) {
michael@0:             // Intersect and reverse difference require modifying pixels outside of the geometry
michael@0:             // that is being "drawn". In both cases we erase all the pixels outside of the geometry
michael@0:             // but leave the pixels inside the geometry alone. For reverse difference we invert all
michael@0:             // the pixels before clearing the ones outside the geometry.
michael@0:             if (SkRegion::kReverseDifference_Op == op) {
michael@0:                 SkRect temp = SkRect::Make(clipSpaceIBounds);
michael@0:                 // invert the entire scene
michael@0:                 helper.draw(temp, SkRegion::kXOR_Op, false, 0xFF);
michael@0:             }
michael@0: 
michael@0:             SkPath clipPath;
michael@0:             element->asPath(&clipPath);
michael@0:             clipPath.toggleInverseFillType();
michael@0:             helper.draw(clipPath, stroke, SkRegion::kReplace_Op, element->isAA(), 0x00);
michael@0: 
michael@0:             continue;
michael@0:         }
michael@0: 
michael@0:         // The other ops (union, xor, diff) only affect pixels inside
michael@0:         // the geometry so they can just be drawn normally
michael@0:         if (Element::kRect_Type == element->getType()) {
michael@0:             helper.draw(element->getRect(), op, element->isAA(), 0xFF);
michael@0:         } else {
michael@0:             SkPath path;
michael@0:             element->asPath(&path);
michael@0:             helper.draw(path, stroke, op, element->isAA(), 0xFF);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     helper.toTexture(result);
michael@0: 
michael@0:     fCurrClipMaskType = kAlpha_ClipMaskType;
michael@0:     return result;
michael@0: }
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: void GrClipMaskManager::releaseResources() {
michael@0:     fAACache.releaseResources();
michael@0: }
michael@0: 
michael@0: void GrClipMaskManager::setGpu(GrGpu* gpu) {
michael@0:     fGpu = gpu;
michael@0:     fAACache.setContext(gpu->getContext());
michael@0: }
michael@0: 
michael@0: void GrClipMaskManager::adjustPathStencilParams(GrStencilSettings* settings) {
michael@0:     const GrDrawState& drawState = fGpu->getDrawState();
michael@0:     GrClipMaskManager::StencilClipMode clipMode;
michael@0:     if (this->isClipInStencil() && drawState.isClipState()) {
michael@0:         clipMode = GrClipMaskManager::kRespectClip_StencilClipMode;
michael@0:         // We can't be modifying the clip and respecting it at the same time.
michael@0:         SkASSERT(!drawState.isStateFlagEnabled(
michael@0:                     GrGpu::kModifyStencilClip_StateBit));
michael@0:     } else if (drawState.isStateFlagEnabled(
michael@0:                     GrGpu::kModifyStencilClip_StateBit)) {
michael@0:         clipMode = GrClipMaskManager::kModifyClip_StencilClipMode;
michael@0:     } else {
michael@0:         clipMode = GrClipMaskManager::kIgnoreClip_StencilClipMode;
michael@0:     }
michael@0: 
michael@0:     // TODO: dynamically attach a stencil buffer
michael@0:     int stencilBits = 0;
michael@0:     GrStencilBuffer* stencilBuffer =
michael@0:         drawState.getRenderTarget()->getStencilBuffer();
michael@0:     if (NULL != stencilBuffer) {
michael@0:         stencilBits = stencilBuffer->bits();
michael@0:         this->adjustStencilParams(settings, clipMode, stencilBits);
michael@0:     }
michael@0: }