src/core/SkRasterClip.cpp - skia - Git at Google

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "SkRasterClip.h"
 #include "SkPath.h"

 SkRasterClip::SkRasterClip(const SkRasterClip& src) {
     AUTO_RASTERCLIP_VALIDATE(src);

     fForceConservativeRects = src.fForceConservativeRects;
     fIsBW = src.fIsBW;
     if (fIsBW) {
         fBW = src.fBW;
     } else {
         fAA = src.fAA;
     }

     fIsEmpty = src.isEmpty();
     fIsRect = src.isRect();
     SkDEBUGCODE(this->validate();)
 }

 SkRasterClip::SkRasterClip(const SkIRect& bounds, bool forceConservativeRects) : fBW(bounds) {
     fForceConservativeRects = forceConservativeRects;
     fIsBW = true;
     fIsEmpty = this->computeIsEmpty();  // bounds might be empty, so compute
     fIsRect = !fIsEmpty;
     SkDEBUGCODE(this->validate();)
 }

 SkRasterClip::SkRasterClip(bool forceConservativeRects) {
     fForceConservativeRects = forceConservativeRects;
     fIsBW = true;
     fIsEmpty = true;
     fIsRect = false;
     SkDEBUGCODE(this->validate();)
 }

 SkRasterClip::~SkRasterClip() {
     SkDEBUGCODE(this->validate();)
 }

 bool SkRasterClip::isComplex() const {
     return fIsBW ? fBW.isComplex() : !fAA.isEmpty();
 }

 const SkIRect& SkRasterClip::getBounds() const {
     return fIsBW ? fBW.getBounds() : fAA.getBounds();
 }

 bool SkRasterClip::setEmpty() {
     AUTO_RASTERCLIP_VALIDATE(*this);

     fIsBW = true;
     fBW.setEmpty();
     fAA.setEmpty();
     fIsEmpty = true;
     fIsRect = false;
     return false;
 }

 bool SkRasterClip::setRect(const SkIRect& rect) {
     AUTO_RASTERCLIP_VALIDATE(*this);

     fIsBW = true;
     fAA.setEmpty();
     fIsRect = fBW.setRect(rect);
     fIsEmpty = !fIsRect;
     return fIsRect;
 }

 /////////////////////////////////////////////////////////////////////////////////////

 bool SkRasterClip::setConservativeRect(const SkRect& r, const SkIRect& clipR, bool isInverse) {
     SkIRect ir;
     r.roundOut(&ir);

     SkRegion::Op op;
     if (isInverse) {
         op = SkRegion::kDifference_Op;
     } else {
         op = SkRegion::kIntersect_Op;
     }
     fBW.setRect(clipR);
     fBW.op(ir, op);
     return this->updateCacheAndReturnNonEmpty();
 }

 /////////////////////////////////////////////////////////////////////////////////////

 enum MutateResult {
     kDoNothing_MutateResult,
     kReplaceClippedAgainstGlobalBounds_MutateResult,
     kContinue_MutateResult,
 };

 static MutateResult mutate_conservative_op(SkRegion::Op* op, bool inverseFilled) {
     if (inverseFilled) {
         switch (*op) {
             case SkRegion::kIntersect_Op:
             case SkRegion::kDifference_Op:
                 // These ops can only shrink the current clip. So leaving
                 // the clip unchanged conservatively respects the contract.
                 return kDoNothing_MutateResult;
             case SkRegion::kUnion_Op:
             case SkRegion::kReplace_Op:
             case SkRegion::kReverseDifference_Op:
             case SkRegion::kXOR_Op: {
                 // These ops can grow the current clip up to the extents of
                 // the input clip, which is inverse filled, so we just set
                 // the current clip to the device bounds.
                 *op = SkRegion::kReplace_Op;
                 return kReplaceClippedAgainstGlobalBounds_MutateResult;
             }
         }
     } else {
         // Not inverse filled
         switch (*op) {
             case SkRegion::kIntersect_Op:
             case SkRegion::kUnion_Op:
             case SkRegion::kReplace_Op:
                 return kContinue_MutateResult;
             case SkRegion::kDifference_Op:
                 // Difference can only shrink the current clip.
                 // Leaving clip unchanged conservatively fullfills the contract.
                 return kDoNothing_MutateResult;
             case SkRegion::kReverseDifference_Op:
                 // To reverse, we swap in the bounds with a replace op.
                 // As with difference, leave it unchanged.
                 *op = SkRegion::kReplace_Op;
                 return kContinue_MutateResult;
             case SkRegion::kXOR_Op:
                 // Be conservative, based on (A XOR B) always included in (A union B),
                 // which is always included in (bounds(A) union bounds(B))
                 *op = SkRegion::kUnion_Op;
                 return kContinue_MutateResult;
         }
     }
     SkFAIL("should not get here");
     return kDoNothing_MutateResult;
 }

 bool SkRasterClip::setPath(const SkPath& path, const SkRegion& clip, bool doAA) {
     AUTO_RASTERCLIP_VALIDATE(*this);

     if (fForceConservativeRects) {
         return this->setConservativeRect(path.getBounds(), clip.getBounds(), path.isInverseFillType());
     }

     if (this->isBW() && !doAA) {
         (void)fBW.setPath(path, clip);
     } else {
         // TODO: since we are going to over-write fAA completely (aren't we?)
         // we should just clear our BW data (if any) and set fIsAA=true
         if (this->isBW()) {
             this->convertToAA();
         }
         (void)fAA.setPath(path, &clip, doAA);
     }
     return this->updateCacheAndReturnNonEmpty();
 }

 bool SkRasterClip::op(const SkPath& path, const SkISize& size, SkRegion::Op op, bool doAA) {
     // base is used to limit the size (and therefore memory allocation) of the
     // region that results from scan converting devPath.
     SkRegion base;

     if (fForceConservativeRects) {
         SkIRect ir;
         switch (mutate_conservative_op(&op, path.isInverseFillType())) {
             case kDoNothing_MutateResult:
                 return !this->isEmpty();
             case kReplaceClippedAgainstGlobalBounds_MutateResult:
                 ir = SkIRect::MakeSize(size);
                 break;
             case kContinue_MutateResult:
                 path.getBounds().roundOut(&ir);
                 break;
         }
         return this->op(ir, op);
     }

     if (SkRegion::kIntersect_Op == op) {
         // since we are intersect, we can do better (tighter) with currRgn's
         // bounds, than just using the device. However, if currRgn is complex,
         // our region blitter may hork, so we do that case in two steps.
         if (this->isRect()) {
             // FIXME: we should also be able to do this when this->isBW(),
             // but relaxing the test above triggers GM asserts in
             // SkRgnBuilder::blitH(). We need to investigate what's going on.
             return this->setPath(path, this->bwRgn(), doAA);
         } else {
             base.setRect(this->getBounds());
             SkRasterClip clip(fForceConservativeRects);
             clip.setPath(path, base, doAA);
             return this->op(clip, op);
         }
     } else {
         base.setRect(0, 0, size.width(), size.height());

         if (SkRegion::kReplace_Op == op) {
             return this->setPath(path, base, doAA);
         } else {
             SkRasterClip clip(fForceConservativeRects);
             clip.setPath(path, base, doAA);
             return this->op(clip, op);
         }
     }
 }

 bool SkRasterClip::setPath(const SkPath& path, const SkIRect& clip, bool doAA) {
     SkRegion tmp;
     tmp.setRect(clip);
     return this->setPath(path, tmp, doAA);
 }

 bool SkRasterClip::op(const SkIRect& rect, SkRegion::Op op) {
     AUTO_RASTERCLIP_VALIDATE(*this);

     fIsBW ? fBW.op(rect, op) : fAA.op(rect, op);
     return this->updateCacheAndReturnNonEmpty();
 }

 bool SkRasterClip::op(const SkRegion& rgn, SkRegion::Op op) {
     AUTO_RASTERCLIP_VALIDATE(*this);

     if (fIsBW) {
         (void)fBW.op(rgn, op);
     } else {
         SkAAClip tmp;
         tmp.setRegion(rgn);
         (void)fAA.op(tmp, op);
     }
     return this->updateCacheAndReturnNonEmpty();
 }

 bool SkRasterClip::op(const SkRasterClip& clip, SkRegion::Op op) {
     AUTO_RASTERCLIP_VALIDATE(*this);
     clip.validate();

     if (this->isBW() && clip.isBW()) {
         (void)fBW.op(clip.fBW, op);
     } else {
         SkAAClip tmp;
         const SkAAClip* other;

         if (this->isBW()) {
             this->convertToAA();
         }
         if (clip.isBW()) {
             tmp.setRegion(clip.bwRgn());
             other = &tmp;
         } else {
             other = &clip.aaRgn();
         }
         (void)fAA.op(*other, op);
     }
     return this->updateCacheAndReturnNonEmpty();
 }

 /**
  *  Our antialiasing currently has a granularity of 1/4 of a pixel along each
  *  axis. Thus we can treat an axis coordinate as an integer if it differs
  *  from its nearest int by < half of that value (1.8 in this case).
  */
 static bool nearly_integral(SkScalar x) {
     static const SkScalar domain = SK_Scalar1 / 4;
     static const SkScalar halfDomain = domain / 2;

     x += halfDomain;
     return x - SkScalarFloorToScalar(x) < domain;
 }

 bool SkRasterClip::op(const SkRect& r, const SkISize& size, SkRegion::Op op, bool doAA) {
     AUTO_RASTERCLIP_VALIDATE(*this);

     if (fForceConservativeRects) {
         SkIRect ir;
         switch (mutate_conservative_op(&op, false)) {
             case kDoNothing_MutateResult:
                 return !this->isEmpty();
             case kReplaceClippedAgainstGlobalBounds_MutateResult:
                 ir = SkIRect::MakeSize(size);
                 break;
             case kContinue_MutateResult:
                 r.roundOut(&ir);
                 break;
         }
         return this->op(ir, op);
     }

     if (fIsBW && doAA) {
         // check that the rect really needs aa, or is it close enought to
         // integer boundaries that we can just treat it as a BW rect?
         if (nearly_integral(r.fLeft) && nearly_integral(r.fTop) &&
             nearly_integral(r.fRight) && nearly_integral(r.fBottom)) {
             doAA = false;
         }
     }

     if (fIsBW && !doAA) {
         SkIRect ir;
         r.round(&ir);
         (void)fBW.op(ir, op);
     } else {
         if (fIsBW) {
             this->convertToAA();
         }
         (void)fAA.op(r, op, doAA);
     }
     return this->updateCacheAndReturnNonEmpty();
 }

 void SkRasterClip::translate(int dx, int dy, SkRasterClip* dst) const {
     if (NULL == dst) {
         return;
     }

     AUTO_RASTERCLIP_VALIDATE(*this);

     if (this->isEmpty()) {
         dst->setEmpty();
         return;
     }
     if (0 == (dx | dy)) {
         *dst = *this;
         return;
     }

     dst->fIsBW = fIsBW;
     if (fIsBW) {
         fBW.translate(dx, dy, &dst->fBW);
         dst->fAA.setEmpty();
     } else {
         fAA.translate(dx, dy, &dst->fAA);
         dst->fBW.setEmpty();
     }
     dst->updateCacheAndReturnNonEmpty();
 }

 bool SkRasterClip::quickContains(const SkIRect& ir) const {
     return fIsBW ? fBW.quickContains(ir) : fAA.quickContains(ir);
 }

 ///////////////////////////////////////////////////////////////////////////////

 const SkRegion& SkRasterClip::forceGetBW() {
     AUTO_RASTERCLIP_VALIDATE(*this);

     if (!fIsBW) {
         fBW.setRect(fAA.getBounds());
     }
     return fBW;
 }

 void SkRasterClip::convertToAA() {
     AUTO_RASTERCLIP_VALIDATE(*this);

     SkASSERT(!fForceConservativeRects);

     SkASSERT(fIsBW);
     fAA.setRegion(fBW);
     fIsBW = false;

     // since we are being explicitly asked to convert-to-aa, we pass false so we don't "optimize"
     // ourselves back to BW.
     (void)this->updateCacheAndReturnNonEmpty(false);
 }

 #ifdef SK_DEBUG
 void SkRasterClip::validate() const {
     // can't ever assert that fBW is empty, since we may have called forceGetBW
     if (fIsBW) {
         SkASSERT(fAA.isEmpty());
     }

     fBW.validate();
     fAA.validate();

     SkASSERT(this->computeIsEmpty() == fIsEmpty);
     SkASSERT(this->computeIsRect() == fIsRect);
 }
 #endif

 ///////////////////////////////////////////////////////////////////////////////

 SkAAClipBlitterWrapper::SkAAClipBlitterWrapper() {
     SkDEBUGCODE(fClipRgn = NULL;)
     SkDEBUGCODE(fBlitter = NULL;)
 }

 SkAAClipBlitterWrapper::SkAAClipBlitterWrapper(const SkRasterClip& clip,
                                                SkBlitter* blitter) {
     this->init(clip, blitter);
 }

 SkAAClipBlitterWrapper::SkAAClipBlitterWrapper(const SkAAClip* aaclip,
                                                SkBlitter* blitter) {
     SkASSERT(blitter);
     SkASSERT(aaclip);
     fBWRgn.setRect(aaclip->getBounds());
     fAABlitter.init(blitter, aaclip);
     // now our return values
     fClipRgn = &fBWRgn;
     fBlitter = &fAABlitter;
 }

 void SkAAClipBlitterWrapper::init(const SkRasterClip& clip, SkBlitter* blitter) {
     SkASSERT(blitter);
     if (clip.isBW()) {
         fClipRgn = &clip.bwRgn();
         fBlitter = blitter;
     } else {
         const SkAAClip& aaclip = clip.aaRgn();
         fBWRgn.setRect(aaclip.getBounds());
         fAABlitter.init(blitter, &aaclip);
         // now our return values
         fClipRgn = &fBWRgn;
         fBlitter = &fAABlitter;
     }
 }
	/*
	* Copyright 2010 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "SkRasterClip.h"
	#include "SkPath.h"

	SkRasterClip::SkRasterClip(const SkRasterClip& src) {
	AUTO_RASTERCLIP_VALIDATE(src);

	fForceConservativeRects = src.fForceConservativeRects;
	fIsBW = src.fIsBW;
	if (fIsBW) {
	fBW = src.fBW;
	} else {
	fAA = src.fAA;
	}

	fIsEmpty = src.isEmpty();
	fIsRect = src.isRect();
	SkDEBUGCODE(this->validate();)
	}

	SkRasterClip::SkRasterClip(const SkIRect& bounds, bool forceConservativeRects) : fBW(bounds) {
	fForceConservativeRects = forceConservativeRects;
	fIsBW = true;
	fIsEmpty = this->computeIsEmpty(); // bounds might be empty, so compute
	fIsRect = !fIsEmpty;
	SkDEBUGCODE(this->validate();)
	}

	SkRasterClip::SkRasterClip(bool forceConservativeRects) {
	fForceConservativeRects = forceConservativeRects;
	fIsBW = true;
	fIsEmpty = true;
	fIsRect = false;
	SkDEBUGCODE(this->validate();)
	}

	SkRasterClip::~SkRasterClip() {
	SkDEBUGCODE(this->validate();)
	}

	bool SkRasterClip::isComplex() const {
	return fIsBW ? fBW.isComplex() : !fAA.isEmpty();
	}

	const SkIRect& SkRasterClip::getBounds() const {
	return fIsBW ? fBW.getBounds() : fAA.getBounds();
	}

	bool SkRasterClip::setEmpty() {
	AUTO_RASTERCLIP_VALIDATE(*this);

	fIsBW = true;
	fBW.setEmpty();
	fAA.setEmpty();
	fIsEmpty = true;
	fIsRect = false;
	return false;
	}

	bool SkRasterClip::setRect(const SkIRect& rect) {
	AUTO_RASTERCLIP_VALIDATE(*this);

	fIsBW = true;
	fAA.setEmpty();
	fIsRect = fBW.setRect(rect);
	fIsEmpty = !fIsRect;
	return fIsRect;
	}

	/////////////////////////////////////////////////////////////////////////////////////

	bool SkRasterClip::setConservativeRect(const SkRect& r, const SkIRect& clipR, bool isInverse) {
	SkIRect ir;
	r.roundOut(&ir);

	SkRegion::Op op;
	if (isInverse) {
	op = SkRegion::kDifference_Op;
	} else {
	op = SkRegion::kIntersect_Op;
	}
	fBW.setRect(clipR);
	fBW.op(ir, op);
	return this->updateCacheAndReturnNonEmpty();
	}

	/////////////////////////////////////////////////////////////////////////////////////

	enum MutateResult {
	kDoNothing_MutateResult,
	kReplaceClippedAgainstGlobalBounds_MutateResult,
	kContinue_MutateResult,
	};

	static MutateResult mutate_conservative_op(SkRegion::Op* op, bool inverseFilled) {
	if (inverseFilled) {
	switch (*op) {
	case SkRegion::kIntersect_Op:
	case SkRegion::kDifference_Op:
	// These ops can only shrink the current clip. So leaving
	// the clip unchanged conservatively respects the contract.
	return kDoNothing_MutateResult;
	case SkRegion::kUnion_Op:
	case SkRegion::kReplace_Op:
	case SkRegion::kReverseDifference_Op:
	case SkRegion::kXOR_Op: {
	// These ops can grow the current clip up to the extents of
	// the input clip, which is inverse filled, so we just set
	// the current clip to the device bounds.
	*op = SkRegion::kReplace_Op;
	return kReplaceClippedAgainstGlobalBounds_MutateResult;
	}
	}
	} else {
	// Not inverse filled
	switch (*op) {
	case SkRegion::kIntersect_Op:
	case SkRegion::kUnion_Op:
	case SkRegion::kReplace_Op:
	return kContinue_MutateResult;
	case SkRegion::kDifference_Op:
	// Difference can only shrink the current clip.
	// Leaving clip unchanged conservatively fullfills the contract.
	return kDoNothing_MutateResult;
	case SkRegion::kReverseDifference_Op:
	// To reverse, we swap in the bounds with a replace op.
	// As with difference, leave it unchanged.
	*op = SkRegion::kReplace_Op;
	return kContinue_MutateResult;
	case SkRegion::kXOR_Op:
	// Be conservative, based on (A XOR B) always included in (A union B),
	// which is always included in (bounds(A) union bounds(B))
	*op = SkRegion::kUnion_Op;
	return kContinue_MutateResult;
	}
	}
	SkFAIL("should not get here");
	return kDoNothing_MutateResult;
	}

	bool SkRasterClip::setPath(const SkPath& path, const SkRegion& clip, bool doAA) {
	AUTO_RASTERCLIP_VALIDATE(*this);

	if (fForceConservativeRects) {
	return this->setConservativeRect(path.getBounds(), clip.getBounds(), path.isInverseFillType());
	}

	if (this->isBW() && !doAA) {
	(void)fBW.setPath(path, clip);
	} else {
	// TODO: since we are going to over-write fAA completely (aren't we?)
	// we should just clear our BW data (if any) and set fIsAA=true
	if (this->isBW()) {
	this->convertToAA();
	}
	(void)fAA.setPath(path, &clip, doAA);
	}
	return this->updateCacheAndReturnNonEmpty();
	}

	bool SkRasterClip::op(const SkPath& path, const SkISize& size, SkRegion::Op op, bool doAA) {
	// base is used to limit the size (and therefore memory allocation) of the
	// region that results from scan converting devPath.
	SkRegion base;

	if (fForceConservativeRects) {
	SkIRect ir;
	switch (mutate_conservative_op(&op, path.isInverseFillType())) {
	case kDoNothing_MutateResult:
	return !this->isEmpty();
	case kReplaceClippedAgainstGlobalBounds_MutateResult:
	ir = SkIRect::MakeSize(size);
	break;
	case kContinue_MutateResult:
	path.getBounds().roundOut(&ir);
	break;
	}
	return this->op(ir, op);
	}

	if (SkRegion::kIntersect_Op == op) {
	// since we are intersect, we can do better (tighter) with currRgn's
	// bounds, than just using the device. However, if currRgn is complex,
	// our region blitter may hork, so we do that case in two steps.
	if (this->isRect()) {
	// FIXME: we should also be able to do this when this->isBW(),
	// but relaxing the test above triggers GM asserts in
	// SkRgnBuilder::blitH(). We need to investigate what's going on.
	return this->setPath(path, this->bwRgn(), doAA);
	} else {
	base.setRect(this->getBounds());
	SkRasterClip clip(fForceConservativeRects);
	clip.setPath(path, base, doAA);
	return this->op(clip, op);
	}
	} else {
	base.setRect(0, 0, size.width(), size.height());

	if (SkRegion::kReplace_Op == op) {
	return this->setPath(path, base, doAA);
	} else {
	SkRasterClip clip(fForceConservativeRects);
	clip.setPath(path, base, doAA);
	return this->op(clip, op);
	}
	}
	}

	bool SkRasterClip::setPath(const SkPath& path, const SkIRect& clip, bool doAA) {
	SkRegion tmp;
	tmp.setRect(clip);
	return this->setPath(path, tmp, doAA);
	}

	bool SkRasterClip::op(const SkIRect& rect, SkRegion::Op op) {
	AUTO_RASTERCLIP_VALIDATE(*this);

	fIsBW ? fBW.op(rect, op) : fAA.op(rect, op);
	return this->updateCacheAndReturnNonEmpty();
	}

	bool SkRasterClip::op(const SkRegion& rgn, SkRegion::Op op) {
	AUTO_RASTERCLIP_VALIDATE(*this);

	if (fIsBW) {
	(void)fBW.op(rgn, op);
	} else {
	SkAAClip tmp;
	tmp.setRegion(rgn);
	(void)fAA.op(tmp, op);
	}
	return this->updateCacheAndReturnNonEmpty();
	}

	bool SkRasterClip::op(const SkRasterClip& clip, SkRegion::Op op) {
	AUTO_RASTERCLIP_VALIDATE(*this);
	clip.validate();

	if (this->isBW() && clip.isBW()) {
	(void)fBW.op(clip.fBW, op);
	} else {
	SkAAClip tmp;
	const SkAAClip* other;

	if (this->isBW()) {
	this->convertToAA();
	}
	if (clip.isBW()) {
	tmp.setRegion(clip.bwRgn());
	other = &tmp;
	} else {
	other = &clip.aaRgn();
	}
	(void)fAA.op(*other, op);
	}
	return this->updateCacheAndReturnNonEmpty();
	}

	/**
	* Our antialiasing currently has a granularity of 1/4 of a pixel along each
	* axis. Thus we can treat an axis coordinate as an integer if it differs
	* from its nearest int by < half of that value (1.8 in this case).
	*/
	static bool nearly_integral(SkScalar x) {
	static const SkScalar domain = SK_Scalar1 / 4;
	static const SkScalar halfDomain = domain / 2;

	x += halfDomain;
	return x - SkScalarFloorToScalar(x) < domain;
	}

	bool SkRasterClip::op(const SkRect& r, const SkISize& size, SkRegion::Op op, bool doAA) {
	AUTO_RASTERCLIP_VALIDATE(*this);

	if (fForceConservativeRects) {
	SkIRect ir;
	switch (mutate_conservative_op(&op, false)) {
	case kDoNothing_MutateResult:
	return !this->isEmpty();
	case kReplaceClippedAgainstGlobalBounds_MutateResult:
	ir = SkIRect::MakeSize(size);
	break;
	case kContinue_MutateResult:
	r.roundOut(&ir);
	break;
	}
	return this->op(ir, op);
	}

	if (fIsBW && doAA) {
	// check that the rect really needs aa, or is it close enought to
	// integer boundaries that we can just treat it as a BW rect?
	if (nearly_integral(r.fLeft) && nearly_integral(r.fTop) &&
	nearly_integral(r.fRight) && nearly_integral(r.fBottom)) {
	doAA = false;
	}
	}

	if (fIsBW && !doAA) {
	SkIRect ir;
	r.round(&ir);
	(void)fBW.op(ir, op);
	} else {
	if (fIsBW) {
	this->convertToAA();
	}
	(void)fAA.op(r, op, doAA);
	}
	return this->updateCacheAndReturnNonEmpty();
	}

	void SkRasterClip::translate(int dx, int dy, SkRasterClip* dst) const {
	if (NULL == dst) {
	return;
	}

	AUTO_RASTERCLIP_VALIDATE(*this);

	if (this->isEmpty()) {
	dst->setEmpty();
	return;
	}
	if (0 == (dx \| dy)) {
	dst = this;
	return;
	}

	dst->fIsBW = fIsBW;
	if (fIsBW) {
	fBW.translate(dx, dy, &dst->fBW);
	dst->fAA.setEmpty();
	} else {
	fAA.translate(dx, dy, &dst->fAA);
	dst->fBW.setEmpty();
	}
	dst->updateCacheAndReturnNonEmpty();
	}

	bool SkRasterClip::quickContains(const SkIRect& ir) const {
	return fIsBW ? fBW.quickContains(ir) : fAA.quickContains(ir);
	}

	///////////////////////////////////////////////////////////////////////////////

	const SkRegion& SkRasterClip::forceGetBW() {
	AUTO_RASTERCLIP_VALIDATE(*this);

	if (!fIsBW) {
	fBW.setRect(fAA.getBounds());
	}
	return fBW;
	}

	void SkRasterClip::convertToAA() {
	AUTO_RASTERCLIP_VALIDATE(*this);

	SkASSERT(!fForceConservativeRects);

	SkASSERT(fIsBW);
	fAA.setRegion(fBW);
	fIsBW = false;

	// since we are being explicitly asked to convert-to-aa, we pass false so we don't "optimize"
	// ourselves back to BW.
	(void)this->updateCacheAndReturnNonEmpty(false);
	}

	#ifdef SK_DEBUG
	void SkRasterClip::validate() const {
	// can't ever assert that fBW is empty, since we may have called forceGetBW
	if (fIsBW) {
	SkASSERT(fAA.isEmpty());
	}

	fBW.validate();
	fAA.validate();

	SkASSERT(this->computeIsEmpty() == fIsEmpty);
	SkASSERT(this->computeIsRect() == fIsRect);
	}
	#endif

	///////////////////////////////////////////////////////////////////////////////

	SkAAClipBlitterWrapper::SkAAClipBlitterWrapper() {
	SkDEBUGCODE(fClipRgn = NULL;)
	SkDEBUGCODE(fBlitter = NULL;)
	}

	SkAAClipBlitterWrapper::SkAAClipBlitterWrapper(const SkRasterClip& clip,
	SkBlitter* blitter) {
	this->init(clip, blitter);
	}

	SkAAClipBlitterWrapper::SkAAClipBlitterWrapper(const SkAAClip* aaclip,
	SkBlitter* blitter) {
	SkASSERT(blitter);
	SkASSERT(aaclip);
	fBWRgn.setRect(aaclip->getBounds());
	fAABlitter.init(blitter, aaclip);
	// now our return values
	fClipRgn = &fBWRgn;
	fBlitter = &fAABlitter;
	}

	void SkAAClipBlitterWrapper::init(const SkRasterClip& clip, SkBlitter* blitter) {
	SkASSERT(blitter);
	if (clip.isBW()) {
	fClipRgn = &clip.bwRgn();
	fBlitter = blitter;
	} else {
	const SkAAClip& aaclip = clip.aaRgn();
	fBWRgn.setRect(aaclip.getBounds());
	fAABlitter.init(blitter, &aaclip);
	// now our return values
	fClipRgn = &fBWRgn;
	fBlitter = &fAABlitter;
	}
	}