Drawstate on stack

src/gpu/GrClipMaskManager.cpp

-
 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrClipMaskManager.h"
 #include "GrAAConvexPathRenderer.h"
 #include "GrAAHairLinePathRenderer.h"
 #include "GrAARectRenderer.h"
 #include "GrDrawTargetCaps.h"
 #include "GrPaint.h"
 #include "GrPathRenderer.h"
 #include "GrRenderTarget.h"
 #include "GrStencilBuffer.h"
 #include "GrSWMaskHelper.h"
 #include "SkRasterClip.h"
 #include "SkStrokeRec.h"
 #include "SkTLazy.h"
 #include "effects/GrTextureDomain.h"
 #include "effects/GrConvexPolyEffect.h"
 #include "effects/GrRRectEffect.h"
 
 #define GR_AA_CLIP 1
-
 typedef SkClipStack::Element Element;
 
 ////////////////////////////////////////////////////////////////////////////////
 namespace {
 // set up the draw state to enable the aa clipping mask. Besides setting up the
 // stage matrix this also alters the vertex layout
-void setup_drawstate_aaclip(GrDrawTarget* gpu,
-                            GrTexture* result,
-                            const SkIRect &devBound) {
-    GrDrawState* drawState = gpu->drawState();
+void setup_drawstate_aaclip(const SkIRect &devBound,
+                            GrDrawState* drawState,
+                            GrTexture* result) {
     SkASSERT(drawState);
 
     SkMatrix mat;
     // We want to use device coords to compute the texture coordinates. We set our matrix to be
     // equal to the view matrix followed by an offset to the devBound, and then a scaling matrix to
     // normalized coords. We apply this matrix to the vertex positions rather than local coords.
     mat.setIDiv(result->width(), result->height());
     mat.preTranslate(SkIntToScalar(-devBound.fLeft),
                      SkIntToScalar(-devBound.fTop));
     mat.preConcat(drawState->getViewMatrix());
 
     SkIRect domainTexels = SkIRect::MakeWH(devBound.width(), devBound.height());
     // This could be a long-lived effect that is cached with the alpha-mask.
     drawState->addCoverageProcessor(
         GrTextureDomainEffect::Create(result,
                                       mat,
                                       GrTextureDomain::MakeTexelDomain(result, domainTexels),
                                       GrTextureDomain::kDecal_Mode,
                                       GrTextureParams::kNone_FilterMode,
                                       kPosition_GrCoordSet))->unref();
 }
 
 bool path_needs_SW_renderer(GrContext* context,
-                            GrDrawTarget* gpu,
+                            const GrDrawTarget* gpu,
+                            const GrDrawState* drawState,
                             const SkPath& origPath,
                             const SkStrokeRec& stroke,
                             bool doAA) {
     // the gpu alpha mask will draw the inverse paths as non-inverse to a temp buffer
     SkTCopyOnFirstWrite<SkPath> path(origPath);
     if (path->isInverseFillType()) {
         path.writable()->toggleInverseFillType();
     }
     // last (false) parameter disallows use of the SW path renderer
     GrPathRendererChain::DrawType type = doAA ?
                                          GrPathRendererChain::kColorAntiAlias_DrawType :
                                          GrPathRendererChain::kColor_DrawType;
 
-    return NULL == context->getPathRenderer(*path, stroke, gpu, false, type);
+    return NULL == context->getPathRenderer(gpu, drawState, *path, stroke, false, type);
 }
-
 }
 
 /*
  * This method traverses the clip stack to see if the GrSoftwarePathRenderer
  * will be used on any element. If so, it returns true to indicate that the
  * entire clip should be rendered in SW and then uploaded en masse to the gpu.
  */
-bool GrClipMaskManager::useSWOnlyPath(const GrReducedClip::ElementList& elements) {
-
+bool GrClipMaskManager::useSWOnlyPath(const GrDrawState* drawState,
+                                      const GrReducedClip::ElementList& elements) {
     // TODO: generalize this function so that when
     // a clip gets complex enough it can just be done in SW regardless
     // of whether it would invoke the GrSoftwarePathRenderer.
     SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
 
     for (GrReducedClip::ElementList::Iter iter(elements.headIter()); iter.get(); iter.next()) {
         const Element* element = iter.get();
         // rects can always be drawn directly w/o using the software path
         // Skip rrects once we're drawing them directly.
         if (Element::kRect_Type != element->getType()) {
             SkPath path;
             element->asPath(&path);
-            if (path_needs_SW_renderer(this->getContext(), fClipTarget, path, stroke,
+            if (path_needs_SW_renderer(this->getContext(), fClipTarget, drawState, path, stroke,
                                        element->isAA())) {
                 return true;
             }
         }
     }
     return false;
 }
 
-bool GrClipMaskManager::installClipEffects(const GrReducedClip::ElementList& elements,
+bool GrClipMaskManager::installClipEffects(GrDrawState* drawState,
                                            GrDrawState::AutoRestoreEffects* are,
+                                           const GrReducedClip::ElementList& elements,
                                            const SkVector& clipToRTOffset,
                                            const SkRect* drawBounds) {
-
-    GrDrawState* drawState = fClipTarget->drawState();
     SkRect boundsInClipSpace;
     if (drawBounds) {
         boundsInClipSpace = *drawBounds;
         boundsInClipSpace.offset(-clipToRTOffset.fX, -clipToRTOffset.fY);
     }
 
     are->set(drawState);
     GrRenderTarget* rt = drawState->getRenderTarget();
     GrReducedClip::ElementList::Iter iter(elements);
-
-    bool setARE = false;
     bool failed = false;
-
     while (iter.get()) {
         SkRegion::Op op = iter.get()->getOp();
         bool invert;
         bool skip = false;
         switch (op) {
             case SkRegion::kReplace_Op:
                 SkASSERT(iter.get() == elements.head());
                 // Fallthrough, handled same as intersect.
             case SkRegion::kIntersect_Op:
                 invert = false;
@@ skipping 43 matching lines @@
                 case SkClipStack::Element::kRect_Type: {
                     SkRect rect = iter.get()->getRect();
                     rect.offset(clipToRTOffset.fX, clipToRTOffset.fY);
                     fp.reset(GrConvexPolyEffect::Create(edgeType, rect));
                     break;
                 }
                 default:
                     break;
             }
             if (fp) {
-                if (!setARE) {
-                    are->set(fClipTarget->drawState());
-                    setARE = true;
-                }
-                fClipTarget->drawState()->addCoverageProcessor(fp);
+                drawState->addCoverageProcessor(fp);
             } else {
                 failed = true;
                 break;
             }
         }
         iter.next();
     }
 
     if (failed) {
         are->set(NULL);
     }
-
     return !failed;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // sort out what kind of clip mask needs to be created: alpha, stencil,
 // scissor, or entirely software
-bool GrClipMaskManager::setupClipping(const GrClipData* clipDataIn,
-                                      const SkRect* devBounds,
+bool GrClipMaskManager::setupClipping(GrDrawState* drawState,
                                       GrDrawState::AutoRestoreEffects* are,
                                       GrDrawState::AutoRestoreStencil* ars,
-                                      ScissorState* scissorState) {
+                                      ScissorState* scissorState,
+                                      const GrClipData* clipDataIn,
+                                      const SkRect* devBounds) {
     fCurrClipMaskType = kNone_ClipMaskType;
     if (kRespectClip_StencilClipMode == fClipMode) {
         fClipMode = kIgnoreClip_StencilClipMode;
     }
 
     GrReducedClip::ElementList elements(16);
     int32_t genID;
     GrReducedClip::InitialState initialState;
     SkIRect clipSpaceIBounds;
     bool requiresAA;
+    GrRenderTarget* rt = drawState->getRenderTarget();
 
-    GrDrawState* drawState = fClipTarget->drawState();
-
-    const GrRenderTarget* rt = drawState->getRenderTarget();
     // GrDrawTarget should have filtered this for us
     SkASSERT(rt);
 
     bool ignoreClip = !drawState->isClipState() || clipDataIn->fClipStack->isWideOpen();
     if (!ignoreClip) {
         SkIRect clipSpaceRTIBounds = SkIRect::MakeWH(rt->width(), rt->height());
         clipSpaceRTIBounds.offset(clipDataIn->fOrigin);
         GrReducedClip::ReduceClipStack(*clipDataIn->fClipStack,
                                        clipSpaceRTIBounds,
                                        &elements,
                                        &genID,
                                        &initialState,
                                        &clipSpaceIBounds,
                                        &requiresAA);
         if (elements.isEmpty()) {
             if (GrReducedClip::kAllIn_InitialState == initialState) {
                 ignoreClip = clipSpaceIBounds == clipSpaceRTIBounds;
             } else {
                 return false;
             }
         }
     }
 
     if (ignoreClip) {
-        this->setDrawStateStencil(ars);
+        this->setDrawStateStencil(drawState, ars);
         return true;
     }
 
     // An element count of 4 was chosen because of the common pattern in Blink of:
     //   isect RR
     //   diff  RR
     //   isect convex_poly
     //   isect convex_poly
     // when drawing rounded div borders. This could probably be tuned based on a
     // configuration's relative costs of switching RTs to generate a mask vs
     // longer shaders.
     if (elements.count() <= 4) {
         SkVector clipToRTOffset = { SkIntToScalar(-clipDataIn->fOrigin.fX),
                                     SkIntToScalar(-clipDataIn->fOrigin.fY) };
         if (elements.isEmpty() ||
-            (requiresAA && this->installClipEffects(elements, are, clipToRTOffset, devBounds))) {
+            (requiresAA && this->installClipEffects(drawState, are, elements, clipToRTOffset, devBounds))) {
             SkIRect scissorSpaceIBounds(clipSpaceIBounds);
             scissorSpaceIBounds.offset(-clipDataIn->fOrigin);
             if (NULL == devBounds ||
                 !SkRect::Make(scissorSpaceIBounds).contains(*devBounds)) {
                 scissorState->set(scissorSpaceIBounds);
             }
-            this->setDrawStateStencil(ars);
+            this->setDrawStateStencil(drawState, ars);
             return true;
         }
     }
 
 #if GR_AA_CLIP
     // If MSAA is enabled we can do everything in the stencil buffer.
     if (0 == rt->numSamples() && requiresAA) {
         GrTexture* result = NULL;
 
-        if (this->useSWOnlyPath(elements)) {
+        if (this->useSWOnlyPath(drawState, elements)) {
             // The clip geometry is complex enough that it will be more efficient to create it
             // entirely in software
             result = this->createSoftwareClipMask(genID,
                                                   initialState,
                                                   elements,
                                                   clipSpaceIBounds);
         } else {
             result = this->createAlphaClipMask(genID,
                                                initialState,
                                                elements,
                                                clipSpaceIBounds);
         }
 
         if (result) {
             // The mask's top left coord should be pinned to the rounded-out top left corner of
             // clipSpace bounds. We determine the mask's position WRT to the render target here.
             SkIRect rtSpaceMaskBounds = clipSpaceIBounds;
             rtSpaceMaskBounds.offset(-clipDataIn->fOrigin);
-            are->set(fClipTarget->drawState());
-            setup_drawstate_aaclip(fClipTarget, result, rtSpaceMaskBounds);
-            this->setDrawStateStencil(ars);
+            setup_drawstate_aaclip(rtSpaceMaskBounds, drawState, result);
+            this->setDrawStateStencil(drawState, ars);
             return true;
         }
         // if alpha clip mask creation fails fall through to the non-AA code paths
     }
 #endif // GR_AA_CLIP
 
     // Either a hard (stencil buffer) clip was explicitly requested or an anti-aliased clip couldn't
     // be created. In either case, free up the texture in the anti-aliased mask cache.
     // TODO: this may require more investigation. Ganesh performs a lot of utility draws (e.g.,
     // clears, InOrderDrawBuffer playbacks) that hit the stencil buffer path. These may be
     // "incorrectly" clearing the AA cache.
     fAACache.reset();
 
     // use the stencil clip if we can't represent the clip as a rectangle.
     SkIPoint clipSpaceToStencilSpaceOffset = -clipDataIn->fOrigin;
-    this->createStencilClipMask(genID,
+    this->createStencilClipMask(rt,
+                                genID,
                                 initialState,
                                 elements,
                                 clipSpaceIBounds,
                                 clipSpaceToStencilSpaceOffset);
 
     // This must occur after createStencilClipMask. That function may change the scissor. Also, it
     // only guarantees that the stencil mask is correct within the bounds it was passed, so we must
     // use both stencil and scissor test to the bounds for the final draw.
     SkIRect scissorSpaceIBounds(clipSpaceIBounds);
     scissorSpaceIBounds.offset(clipSpaceToStencilSpaceOffset);
     scissorState->set(scissorSpaceIBounds);
-    this->setDrawStateStencil(ars);
+    this->setDrawStateStencil(drawState, ars);
     return true;
 }
 
 #define VISUALIZE_COMPLEX_CLIP 0
 
 #if VISUALIZE_COMPLEX_CLIP
     #include "SkRandom.h"
     SkRandom gRandom;
     #define SET_RANDOM_COLOR drawState->setColor(0xff000000 | gRandom.nextU());
 #else
     #define SET_RANDOM_COLOR
 #endif
 
 namespace {
-
 ////////////////////////////////////////////////////////////////////////////////
 // set up the OpenGL blend function to perform the specified
 // boolean operation for alpha clip mask creation
-void setup_boolean_blendcoeffs(GrDrawState* drawState, SkRegion::Op op) {
-
+void setup_boolean_blendcoeffs(SkRegion::Op op, GrDrawState* drawState) {
     switch (op) {
         case SkRegion::kReplace_Op:
             drawState->setBlendFunc(kOne_GrBlendCoeff, kZero_GrBlendCoeff);
             break;
         case SkRegion::kIntersect_Op:
             drawState->setBlendFunc(kDC_GrBlendCoeff, kZero_GrBlendCoeff);
             break;
         case SkRegion::kUnion_Op:
             drawState->setBlendFunc(kOne_GrBlendCoeff, kISC_GrBlendCoeff);
             break;
         case SkRegion::kXOR_Op:
             drawState->setBlendFunc(kIDC_GrBlendCoeff, kISC_GrBlendCoeff);
             break;
         case SkRegion::kDifference_Op:
             drawState->setBlendFunc(kZero_GrBlendCoeff, kISC_GrBlendCoeff);
             break;
         case SkRegion::kReverseDifference_Op:
             drawState->setBlendFunc(kIDC_GrBlendCoeff, kZero_GrBlendCoeff);
             break;
         default:
             SkASSERT(false);
             break;
     }
 }
-
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-bool GrClipMaskManager::drawElement(GrTexture* target,
+bool GrClipMaskManager::drawElement(GrDrawState* drawState,
+                                    GrTexture* target,
                                     const SkClipStack::Element* element,
                                     GrPathRenderer* pr) {
-    GrDrawState* drawState = fClipTarget->drawState();
+    GrDrawTarget::AutoGeometryPush agp(fClipTarget);
 
     drawState->setRenderTarget(target->asRenderTarget());
 
     // TODO: Draw rrects directly here.
     switch (element->getType()) {
         case Element::kEmpty_Type:
             SkDEBUGFAIL("Should never get here with an empty element.");
             break;
         case Element::kRect_Type:
             // TODO: Do rects directly to the accumulator using a aa-rect GrProcessor that covers
             // the entire mask bounds and writes 0 outside the rect.
             if (element->isAA()) {
                 this->getContext()->getAARectRenderer()->fillAARect(fClipTarget,
+                                                                    drawState,
                                                                     element->getRect(),
                                                                     SkMatrix::I(),
                                                                     element->getRect());
             } else {
-                fClipTarget->drawSimpleRect(element->getRect());
+                fClipTarget->drawSimpleRect(drawState, element->getRect());
             }
             return true;
         default: {
             SkPath path;
             element->asPath(&path);
             path.setIsVolatile(true);
             if (path.isInverseFillType()) {
                 path.toggleInverseFillType();
             }
             SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
             if (NULL == pr) {
                 GrPathRendererChain::DrawType type;
                 type = element->isAA() ? GrPathRendererChain::kColorAntiAlias_DrawType :
                                          GrPathRendererChain::kColor_DrawType;
-                pr = this->getContext()->getPathRenderer(path, stroke, fClipTarget, false, type);
+                pr = this->getContext()->getPathRenderer(fClipTarget, drawState, path, stroke,
+                                                         false, type);
             }
             if (NULL == pr) {
                 return false;
             }
-            pr->drawPath(path, stroke, fClipTarget, element->isAA());
+
+            pr->drawPath(fClipTarget, drawState, path, stroke, element->isAA());
             break;
         }
     }
     return true;
 }
 
-bool GrClipMaskManager::canStencilAndDrawElement(GrTexture* target,
-                                                 const SkClipStack::Element* element,
-                                                 GrPathRenderer** pr) {
-    GrDrawState* drawState = fClipTarget->drawState();
+bool GrClipMaskManager::canStencilAndDrawElement(GrDrawState* drawState,
+                                                 GrTexture* target,
+                                                 GrPathRenderer** pr,
+                                                 const SkClipStack::Element* element) {
     drawState->setRenderTarget(target->asRenderTarget());
 
     if (Element::kRect_Type == element->getType()) {
         return true;
     } else {
         // We shouldn't get here with an empty clip element.
         SkASSERT(Element::kEmpty_Type != element->getType());
         SkPath path;
         element->asPath(&path);
         if (path.isInverseFillType()) {
             path.toggleInverseFillType();
         }
         SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
         GrPathRendererChain::DrawType type = element->isAA() ?
             GrPathRendererChain::kStencilAndColorAntiAlias_DrawType :
             GrPathRendererChain::kStencilAndColor_DrawType;
-        *pr = this->getContext()->getPathRenderer(path, stroke, fClipTarget, false, type);
+        *pr = this->getContext()->getPathRenderer(fClipTarget, drawState, path, stroke, false, type);
         return SkToBool(*pr);
     }
 }
 
-void GrClipMaskManager::mergeMask(GrTexture* dstMask,
+void GrClipMaskManager::mergeMask(GrDrawState* drawState,
+                                  GrTexture* dstMask,
                                   GrTexture* srcMask,
                                   SkRegion::Op op,
                                   const SkIRect& dstBound,
                                   const SkIRect& srcBound) {
     GrDrawState::AutoViewMatrixRestore avmr;
-    GrDrawState* drawState = fClipTarget->drawState();
     SkAssertResult(avmr.setIdentity(drawState));
     GrDrawState::AutoRestoreEffects are(drawState);
 
     drawState->setRenderTarget(dstMask->asRenderTarget());
 
-    setup_boolean_blendcoeffs(drawState, op);
+    setup_boolean_blendcoeffs(op, drawState);
 
     SkMatrix sampleM;
     sampleM.setIDiv(srcMask->width(), srcMask->height());
 
     drawState->addColorProcessor(
         GrTextureDomainEffect::Create(srcMask,
                                       sampleM,
                                       GrTextureDomain::MakeTexelDomain(srcMask, srcBound),
                                       GrTextureDomain::kDecal_Mode,
                                       GrTextureParams::kNone_FilterMode))->unref();
-    fClipTarget->drawSimpleRect(SkRect::Make(dstBound));
+    fClipTarget->drawSimpleRect(drawState, SkRect::Make(dstBound));
 }
 
 GrTexture* GrClipMaskManager::createTempMask(int width, int height) {
     GrSurfaceDesc desc;
     desc.fFlags = kRenderTarget_GrSurfaceFlag|kNoStencil_GrSurfaceFlag;
     desc.fWidth = width;
     desc.fHeight = height;
     desc.fConfig = kAlpha_8_GrPixelConfig;
 
     return this->getContext()->refScratchTexture(desc, GrContext::kApprox_ScratchTexMatch);
@@ skipping 62 matching lines @@
         SkIntToScalar(-clipSpaceIBounds.fLeft),
         SkIntToScalar(-clipSpaceIBounds.fTop)
     };
     // The texture may be larger than necessary, this rect represents the part of the texture
     // we populate with a rasterization of the clip.
     SkIRect maskSpaceIBounds = SkIRect::MakeWH(clipSpaceIBounds.width(), clipSpaceIBounds.height());
 
     // Set the matrix so that rendered clip elements are transformed to mask space from clip space.
     SkMatrix translate;
     translate.setTranslate(clipToMaskOffset);
-    GrDrawTarget::AutoGeometryAndStatePush agasp(fClipTarget, GrDrawTarget::kReset_ASRInit,
-                                                 &translate);
-
-    GrDrawState* drawState = fClipTarget->drawState();
-
-    // We're drawing a coverage mask and want coverage to be run through the blend function.
-    drawState->enableState(GrDrawState::kCoverageDrawing_StateBit);
 
     // The scratch texture that we are drawing into can be substantially larger than the mask. Only
     // clear the part that we care about.
     fClipTarget->clear(&maskSpaceIBounds,
                        GrReducedClip::kAllIn_InitialState == initialState ? 0xffffffff : 0x00000000,
                        true,
                        result->asRenderTarget());
 
     // When we use the stencil in the below loop it is important to have this clip installed.
     // The second pass that zeros the stencil buffer renders the rect maskSpaceIBounds so the first
     // pass must not set values outside of this bounds or stencil values outside the rect won't be
     // cleared.
     GrDrawTarget::AutoClipRestore acr(fClipTarget, maskSpaceIBounds);
-    drawState->enableState(GrDrawState::kClip_StateBit);
+    SkAutoTUnref<GrTexture> temp;
 
-    SkAutoTUnref<GrTexture> temp;
     // walk through each clip element and perform its set op
     for (GrReducedClip::ElementList::Iter iter = elements.headIter(); iter.get(); iter.next()) {
         const Element* element = iter.get();
         SkRegion::Op op = element->getOp();
         bool invert = element->isInverseFilled();
+        if (invert || SkRegion::kIntersect_Op == op || SkRegion::kReverseDifference_Op == op) {
+            GrDrawState drawState(translate);
+            // We're drawing a coverage mask and want coverage to be run through the blend function.
+            drawState.enableState(GrDrawState::kCoverageDrawing_StateBit |
+                                  GrDrawState::kClip_StateBit);
 
-        if (invert || SkRegion::kIntersect_Op == op || SkRegion::kReverseDifference_Op == op) {
             GrPathRenderer* pr = NULL;
-            bool useTemp = !this->canStencilAndDrawElement(result, element, &pr);
+            bool useTemp = !this->canStencilAndDrawElement(&drawState, result, &pr, element);
             GrTexture* dst;
             // This is the bounds of the clip element in the space of the alpha-mask. The temporary
             // mask buffer can be substantially larger than the actually clip stack element. We
             // touch the minimum number of pixels necessary and use decal mode to combine it with
             // the accumulator.
             SkIRect maskSpaceElementIBounds;
 
             if (useTemp) {
                 if (invert) {
                     maskSpaceElementIBounds = maskSpaceIBounds;
                 } else {
                     SkRect elementBounds = element->getBounds();
                     elementBounds.offset(clipToMaskOffset);
                     elementBounds.roundOut(&maskSpaceElementIBounds);
                 }
 
                 if (!temp) {
                     temp.reset(this->createTempMask(maskSpaceIBounds.fRight,
                                                     maskSpaceIBounds.fBottom));
                     if (!temp) {
                         fAACache.reset();
                         return NULL;
                     }
                 }
                 dst = temp;
                 // clear the temp target and set blend to replace
                 fClipTarget->clear(&maskSpaceElementIBounds,
-                            invert ? 0xffffffff : 0x00000000,
-                            true,
-                            dst->asRenderTarget());
-                setup_boolean_blendcoeffs(drawState, SkRegion::kReplace_Op);
-
+                                   invert ? 0xffffffff : 0x00000000,
+                                   true,
+                                   dst->asRenderTarget());
+                setup_boolean_blendcoeffs(SkRegion::kReplace_Op, &drawState);
             } else {
                 // draw directly into the result with the stencil set to make the pixels affected
                 // by the clip shape be non-zero.
                 dst = result;
                 GR_STATIC_CONST_SAME_STENCIL(kStencilInElement,
                                              kReplace_StencilOp,
                                              kReplace_StencilOp,
                                              kAlways_StencilFunc,
                                              0xffff,
                                              0xffff,
                                              0xffff);
-                drawState->setStencil(kStencilInElement);
-                setup_boolean_blendcoeffs(drawState, op);
+                drawState.setStencil(kStencilInElement);
+                setup_boolean_blendcoeffs(op, &drawState);
             }
 
-            drawState->setAlpha(invert ? 0x00 : 0xff);
+            drawState.setAlpha(invert ? 0x00 : 0xff);
 
-            if (!this->drawElement(dst, element, pr)) {
+            // We have to backup the drawstate because the draw will consume ti

[bsalomon, 2014/11/14 21:51:02]

still true?

[joshualitt, 2014/11/14 23:25:40]

Unfortunately it is.  DrawElements may call into things which modify the
drawState.

[bsalomon, 2014/11/17 14:41:16]

Oh that makes sense. lgtm

+            GrDrawState backupDrawState = drawState;
+
+            if (!this->drawElement(&drawState, dst, element, pr)) {
                 fAACache.reset();
                 return NULL;
             }
 
             if (useTemp) {
                 // Now draw into the accumulator using the real operation and the temp buffer as a
                 // texture
-                this->mergeMask(result,
+                this->mergeMask(&backupDrawState,
+                                result,
                                 temp,
                                 op,
                                 maskSpaceIBounds,
                                 maskSpaceElementIBounds);
             } else {
                 // Draw to the exterior pixels (those with a zero stencil value).
-                drawState->setAlpha(invert ? 0xff : 0x00);
+                backupDrawState.setAlpha(invert ? 0xff : 0x00);
                 GR_STATIC_CONST_SAME_STENCIL(kDrawOutsideElement,
                                              kZero_StencilOp,
                                              kZero_StencilOp,
                                              kEqual_StencilFunc,
                                              0xffff,
                                              0x0000,
                                              0xffff);
-                drawState->setStencil(kDrawOutsideElement);
-                fClipTarget->drawSimpleRect(clipSpaceIBounds);
-                drawState->disableStencil();
+                backupDrawState.setStencil(kDrawOutsideElement);
+                fClipTarget->drawSimpleRect(&backupDrawState, clipSpaceIBounds);
             }
         } else {
+            GrDrawState drawState(translate);
+            drawState.enableState(GrDrawState::kCoverageDrawing_StateBit |
+                                  GrDrawState::kClip_StateBit);
+
             // all the remaining ops can just be directly draw into the accumulation buffer
-            drawState->setAlpha(0xff);
-            setup_boolean_blendcoeffs(drawState, op);
-            this->drawElement(result, element);
+            drawState.setAlpha(0xff);
+            setup_boolean_blendcoeffs(op, &drawState);
+            this->drawElement(&drawState, result, element);
         }
     }
 
     fCurrClipMaskType = kAlpha_ClipMaskType;
     return result;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Create a 1-bit clip mask in the stencil buffer. 'devClipBounds' are in device
 // (as opposed to canvas) coordinates
-bool GrClipMaskManager::createStencilClipMask(int32_t elementsGenID,
+bool GrClipMaskManager::createStencilClipMask(GrRenderTarget* rt,
+                                              int32_t elementsGenID,
                                               GrReducedClip::InitialState initialState,
                                               const GrReducedClip::ElementList& elements,
                                               const SkIRect& clipSpaceIBounds,
                                               const SkIPoint& clipSpaceToStencilOffset) {
-
     SkASSERT(kNone_ClipMaskType == fCurrClipMaskType);
-
-    GrDrawState* drawState = fClipTarget->drawState();
-    SkASSERT(drawState->isClipState());
-
-    GrRenderTarget* rt = drawState->getRenderTarget();
     SkASSERT(rt);
 
     // TODO: dynamically attach a SB when needed.
     GrStencilBuffer* stencilBuffer = rt->getStencilBuffer();
     if (NULL == stencilBuffer) {
         return false;
     }
 
     if (stencilBuffer->mustRenderClip(elementsGenID, clipSpaceIBounds, clipSpaceToStencilOffset)) {
         stencilBuffer->setLastClip(elementsGenID, clipSpaceIBounds, clipSpaceToStencilOffset);
-
         // Set the matrix so that rendered clip elements are transformed from clip to stencil space.
         SkVector translate = {
             SkIntToScalar(clipSpaceToStencilOffset.fX),
             SkIntToScalar(clipSpaceToStencilOffset.fY)
         };
         SkMatrix matrix;
         matrix.setTranslate(translate);
-        GrDrawTarget::AutoGeometryAndStatePush agasp(fClipTarget, GrDrawTarget::kReset_ASRInit,
-                                                     &matrix);
-        drawState = fClipTarget->drawState();
-
-        drawState->setRenderTarget(rt);
 
         // We set the current clip to the bounds so that our recursive draws are scissored to them.
         SkIRect stencilSpaceIBounds(clipSpaceIBounds);
         stencilSpaceIBounds.offset(clipSpaceToStencilOffset);
         GrDrawTarget::AutoClipRestore acr(fClipTarget, stencilSpaceIBounds);
-        drawState->enableState(GrDrawState::kClip_StateBit);
-
-#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));
 
         fClipTarget->clearStencilClip(stencilSpaceIBounds,
                                       GrReducedClip::kAllIn_InitialState == initialState,
                                       rt);
 
         // walk through each clip element and perform its set op
         // with the existing clip.
         for (GrReducedClip::ElementList::Iter iter(elements.headIter()); iter.get(); iter.next()) {
             const Element* element = iter.get();
             bool fillInverted = false;
             // enabled at bottom of loop
             fClipMode = kIgnoreClip_StencilClipMode;
-            // if the target is MSAA then we want MSAA enabled when the clip is soft
-            if (rt->isMultisampled()) {
-                drawState->setState(GrDrawState::kHWAntialias_StateBit, element->isAA());
-            }
 
             // This will be used to determine whether the clip shape can be rendered into the
             // stencil with arbitrary stencil settings.
             GrPathRenderer::StencilSupport stencilSupport;
 
             SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
-
             SkRegion::Op op = element->getOp();
 
             GrPathRenderer* pr = NULL;
             SkPath clipPath;
             if (Element::kRect_Type == element->getType()) {
                 stencilSupport = GrPathRenderer::kNoRestriction_StencilSupport;
                 fillInverted = false;
             } else {
                 element->asPath(&clipPath);
                 fillInverted = clipPath.isInverseFillType();
                 if (fillInverted) {
                     clipPath.toggleInverseFillType();
                 }
-                pr = this->getContext()->getPathRenderer(clipPath,
+                // TODO not sure which drawstate this should be
+                GrDrawState drawState;
+                drawState.setRenderTarget(rt);
+                pr = this->getContext()->getPathRenderer(fClipTarget,
+                                                         &drawState,
+                                                         clipPath,
                                                          stroke,
-                                                         fClipTarget,
                                                          false,
                                                          GrPathRendererChain::kStencilOnly_DrawType,
                                                          &stencilSupport);
                 if (NULL == pr) {
                     return false;
                 }
             }
 
             int passes;
             GrStencilSettings stencilSettings[GrStencilSettings::kMaxStencilClipPasses];
 
             bool canRenderDirectToStencil =
                 GrPathRenderer::kNoRestriction_StencilSupport == stencilSupport;
             bool canDrawDirectToClip; // Given the renderer, the element,
                                       // fill rule, and set operation can
                                       // we render the element directly to
                                       // stencil bit used for clipping.
             canDrawDirectToClip = GrStencilSettings::GetClipPasses(op,
                                                                    canRenderDirectToStencil,
                                                                    clipBit,
                                                                    fillInverted,
                                                                    &passes,
                                                                    stencilSettings);
 
             // draw the element to the client stencil bits if necessary
             if (!canDrawDirectToClip) {
+                GrDrawState drawState(matrix);
+                drawState.setRenderTarget(rt);
+                drawState.enableState(GrDrawState::kClip_StateBit);
+#if !VISUALIZE_COMPLEX_CLIP
+                drawState.enableState(GrDrawState::kNoColorWrites_StateBit);
+#endif
+                // if the target is MSAA then we want MSAA enabled when the clip is soft
+                if (rt->isMultisampled()) {
+                    drawState.setState(GrDrawState::kHWAntialias_StateBit, element->isAA());
+                }
+
                 GR_STATIC_CONST_SAME_STENCIL(gDrawToStencil,
                                              kIncClamp_StencilOp,
                                              kIncClamp_StencilOp,
                                              kAlways_StencilFunc,
                                              0xffff,
                                              0x0000,
                                              0xffff);
                 SET_RANDOM_COLOR
                 if (Element::kRect_Type == element->getType()) {
-                    *drawState->stencil() = gDrawToStencil;
-                    fClipTarget->drawSimpleRect(element->getRect());
+                    *drawState.stencil() = gDrawToStencil;
+                    fClipTarget->drawSimpleRect(&drawState, element->getRect());
                 } else {
                     if (!clipPath.isEmpty()) {
+                        GrDrawTarget::AutoGeometryPush agp(fClipTarget);
                         if (canRenderDirectToStencil) {
-                            *drawState->stencil() = gDrawToStencil;
-                            pr->drawPath(clipPath, stroke, fClipTarget, false);
+                            *drawState.stencil() = gDrawToStencil;
+                            pr->drawPath(fClipTarget, &drawState, clipPath, stroke, false);
                         } else {
-                            pr->stencilPath(clipPath, stroke, fClipTarget);
+                            pr->stencilPath(fClipTarget, &drawState, clipPath, stroke);
                         }
                     }
                 }
             }
 
             // now we modify the clip bit by rendering either the clip
             // element directly or a bounding rect of the entire clip.
             fClipMode = kModifyClip_StencilClipMode;
             for (int p = 0; p < passes; ++p) {
-                *drawState->stencil() = stencilSettings[p];
+                GrDrawState drawState(matrix);
+                // if the target is MSAA then we want MSAA enabled when the clip is soft
+                if (rt->isMultisampled()) {
+                    drawState.setState(GrDrawState::kHWAntialias_StateBit, element->isAA());
+                }
+
+                drawState.setRenderTarget(rt);
+                drawState.enableState(GrDrawState::kClip_StateBit);
+#if !VISUALIZE_COMPLEX_CLIP
+                drawState.enableState(GrDrawState::kNoColorWrites_StateBit);
+#endif
+
+                *drawState.stencil() = stencilSettings[p];
+
                 if (canDrawDirectToClip) {
                     if (Element::kRect_Type == element->getType()) {
                         SET_RANDOM_COLOR
-                        fClipTarget->drawSimpleRect(element->getRect());
+                        fClipTarget->drawSimpleRect(&drawState, element->getRect());
                     } else {
                         SET_RANDOM_COLOR
-                        pr->drawPath(clipPath, stroke, fClipTarget, false);
+                        GrDrawTarget::AutoGeometryPush agp(fClipTarget);
+                        pr->drawPath(fClipTarget, &drawState, clipPath, stroke, false);
                     }
                 } else {
                     SET_RANDOM_COLOR
                     // The view matrix is setup to do clip space -> stencil space translation, so
                     // draw rect in clip space.
-                    fClipTarget->drawSimpleRect(SkRect::Make(clipSpaceIBounds));
+                    fClipTarget->drawSimpleRect(&drawState, SkRect::Make(clipSpaceIBounds));
                 }
             }
         }
     }
     // set this last because recursive draws may overwrite it back to kNone.
     SkASSERT(kNone_ClipMaskType == fCurrClipMaskType);
     fCurrClipMaskType = kStencil_ClipMaskType;
     fClipMode = kRespectClip_StencilClipMode;
     return true;
 }
 
-
 // mapping of clip-respecting stencil funcs to normal stencil funcs
 // mapping depends on whether stencil-clipping is in effect.
 static const GrStencilFunc
     gSpecialToBasicStencilFunc[2][kClipStencilFuncCount] = {
     {// Stencil-Clipping is DISABLED,  we are effectively always inside the clip
         // In the Clip Funcs
         kAlways_StencilFunc,          // kAlwaysIfInClip_StencilFunc
         kEqual_StencilFunc,           // kEqualIfInClip_StencilFunc
         kLess_StencilFunc,            // kLessIfInClip_StencilFunc
         kLEqual_StencilFunc,          // kLEqualIfInClip_StencilFunc
@@ skipping 32 matching lines @@
         kKeep_StencilOp,
         kKeep_StencilOp,
         kAlwaysIfInClip_StencilFunc,
         0x0000,
         0x0000,
         0x0000);
     return *GR_CONST_STENCIL_SETTINGS_PTR_FROM_STRUCT_PTR(&gSettings);
 }
 }
 
-void GrClipMaskManager::setDrawStateStencil(GrDrawState::AutoRestoreStencil* ars) {
+void GrClipMaskManager::setDrawStateStencil(GrDrawState* drawState,
+                                            GrDrawState::AutoRestoreStencil* ars) {
     // We make two copies of the StencilSettings here (except in the early
     // exit scenario. One copy from draw state to the stack var. Then another
     // from the stack var to the gpu. We could make this class hold a ptr to
     // GrGpu's fStencilSettings and eliminate the stack copy here.
 
-    const GrDrawState& drawState = fClipTarget->getDrawState();
-
     // use stencil for clipping if clipping is enabled and the clip
     // has been written into the stencil.
+    GrStencilSettings settings;
 
-    GrStencilSettings settings;
     // The GrGpu client may not be using the stencil buffer but we may need to
     // enable it in order to respect a stencil clip.
-    if (drawState.getStencil().isDisabled()) {
+    if (drawState->getStencil().isDisabled()) {
         if (GrClipMaskManager::kRespectClip_StencilClipMode == fClipMode) {
             settings = basic_apply_stencil_clip_settings();
         } else {
             return;
         }
     } else {
-        settings = drawState.getStencil();
+        settings = drawState->getStencil();
     }
 
     // TODO: dynamically attach a stencil buffer
     int stencilBits = 0;
-    GrStencilBuffer* stencilBuffer = drawState.getRenderTarget()->getStencilBuffer();
+    GrStencilBuffer* stencilBuffer = drawState->getRenderTarget()->getStencilBuffer();
     if (stencilBuffer) {
         stencilBits = stencilBuffer->bits();
     }
 
     SkASSERT(fClipTarget->caps()->stencilWrapOpsSupport() || !settings.usesWrapOp());
     SkASSERT(fClipTarget->caps()->twoSidedStencilSupport() || !settings.isTwoSided());
     this->adjustStencilParams(&settings, fClipMode, stencilBits);
-    ars->set(fClipTarget->drawState());
-    fClipTarget->drawState()->setStencil(settings);
+    ars->set(drawState);
+    drawState->setStencil(settings);
 }
 
 void GrClipMaskManager::adjustStencilParams(GrStencilSettings* settings,
                                             StencilClipMode mode,
                                             int stencilBitCnt) {
     SkASSERT(stencilBitCnt > 0);
 
     if (kModifyClip_StencilClipMode == mode) {
         // We assume that this clip manager itself is drawing to the GrGpu and
         // has already setup the correct values.
@@ skipping 84 matching lines @@
 
     // The mask texture may be larger than necessary. We round out the clip space bounds and pin
     // the top left corner of the resulting rect to the top left of the texture.
     SkIRect maskSpaceIBounds = SkIRect::MakeWH(clipSpaceIBounds.width(), clipSpaceIBounds.height());
 
     GrSWMaskHelper helper(this->getContext());
 
     SkMatrix matrix;
     matrix.setTranslate(SkIntToScalar(-clipSpaceIBounds.fLeft),
                         SkIntToScalar(-clipSpaceIBounds.fTop));
+
     helper.init(maskSpaceIBounds, &matrix, false);
-
     helper.clear(GrReducedClip::kAllIn_InitialState == initialState ? 0xFF : 0x00);
-
     SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
 
     for (GrReducedClip::ElementList::Iter iter(elements.headIter()) ; iter.get(); iter.next()) {
-
         const Element* element = iter.get();
         SkRegion::Op op = element->getOp();
 
         if (SkRegion::kIntersect_Op == op || SkRegion::kReverseDifference_Op == op) {
             // Intersect and reverse difference require modifying pixels outside of the geometry
             // that is being "drawn". In both cases we erase all the pixels outside of the geometry
             // but leave the pixels inside the geometry alone. For reverse difference we invert all
             // the pixels before clearing the ones outside the geometry.
             if (SkRegion::kReverseDifference_Op == op) {
                 SkRect temp = SkRect::Make(clipSpaceIBounds);
                 // invert the entire scene
                 helper.draw(temp, SkRegion::kXOR_Op, false, 0xFF);
             }
-
             SkPath clipPath;
             element->asPath(&clipPath);
             clipPath.toggleInverseFillType();
             helper.draw(clipPath, stroke, SkRegion::kReplace_Op, element->isAA(), 0x00);
-
             continue;
         }
 
         // The other ops (union, xor, diff) only affect pixels inside
         // the geometry so they can just be drawn normally
         if (Element::kRect_Type == element->getType()) {
             helper.draw(element->getRect(), op, element->isAA(), 0xFF);
         } else {
             SkPath path;
             element->asPath(&path);
@@ skipping 16 matching lines @@
 ////////////////////////////////////////////////////////////////////////////////
 void GrClipMaskManager::purgeResources() {
     fAACache.purgeResources();
 }
 
 void GrClipMaskManager::setClipTarget(GrClipTarget* clipTarget) {
     fClipTarget = clipTarget;
     fAACache.setContext(clipTarget->getContext());
 }
 
-void GrClipMaskManager::adjustPathStencilParams(GrStencilSettings* settings) {
-    const GrDrawState& drawState = fClipTarget->getDrawState();
-
+void GrClipMaskManager::adjustPathStencilParams(const GrStencilBuffer* stencilBuffer,
+                                                GrStencilSettings* settings) {
     // TODO: dynamically attach a stencil buffer
-    int stencilBits = 0;
-    GrStencilBuffer* stencilBuffer = drawState.getRenderTarget()->getStencilBuffer();
     if (stencilBuffer) {
-        stencilBits = stencilBuffer->bits();
+        int stencilBits = stencilBuffer->bits();
         this->adjustStencilParams(settings, fClipMode, stencilBits);
     }
 }