diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/core/SkBitmap.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/core/SkBitmap.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,1731 @@
+
+/*
+ * Copyright 2008 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#include "SkBitmap.h"
+#include "SkColorPriv.h"
+#include "SkDither.h"
+#include "SkFlattenable.h"
+#include "SkImagePriv.h"
+#include "SkMallocPixelRef.h"
+#include "SkMask.h"
+#include "SkReadBuffer.h"
+#include "SkWriteBuffer.h"
+#include "SkPixelRef.h"
+#include "SkThread.h"
+#include "SkUnPreMultiply.h"
+#include "SkUtils.h"
+#include "SkValidationUtils.h"
+#include "SkPackBits.h"
+#include <new>
+
+static bool reset_return_false(SkBitmap* bm) {
+    bm->reset();
+    return false;
+}
+
+struct MipLevel {
+    void*       fPixels;
+    uint32_t    fRowBytes;
+    uint32_t    fWidth, fHeight;
+};
+
+struct SkBitmap::MipMap : SkNoncopyable {
+    int32_t fRefCnt;
+    int     fLevelCount;
+//  MipLevel    fLevel[fLevelCount];
+//  Pixels[]
+
+    static MipMap* Alloc(int levelCount, size_t pixelSize) {
+        if (levelCount < 0) {
+            return NULL;
+        }
+        int64_t size = (levelCount + 1) * sizeof(MipLevel);
+        size += sizeof(MipMap) + pixelSize;
+        if (!sk_64_isS32(size)) {
+            return NULL;
+        }
+        MipMap* mm = (MipMap*)sk_malloc_throw(sk_64_asS32(size));
+        mm->fRefCnt = 1;
+        mm->fLevelCount = levelCount;
+        return mm;
+    }
+
+    const MipLevel* levels() const { return (const MipLevel*)(this + 1); }
+    MipLevel* levels() { return (MipLevel*)(this + 1); }
+
+    const void* pixels() const { return levels() + fLevelCount; }
+    void* pixels() { return levels() + fLevelCount; }
+
+    void ref() {
+        if (SK_MaxS32 == sk_atomic_inc(&fRefCnt)) {
+            sk_throw();
+        }
+    }
+    void unref() {
+        SkASSERT(fRefCnt > 0);
+        if (sk_atomic_dec(&fRefCnt) == 1) {
+            sk_free(this);
+        }
+    }
+};
+
+///////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
+
+SkBitmap::SkBitmap() {
+    sk_bzero(this, sizeof(*this));
+}
+
+SkBitmap::SkBitmap(const SkBitmap& src) {
+    SkDEBUGCODE(src.validate();)
+    sk_bzero(this, sizeof(*this));
+    *this = src;
+    SkDEBUGCODE(this->validate();)
+}
+
+SkBitmap::~SkBitmap() {
+    SkDEBUGCODE(this->validate();)
+    this->freePixels();
+}
+
+SkBitmap& SkBitmap::operator=(const SkBitmap& src) {
+    if (this != &src) {
+        this->freePixels();
+        memcpy(this, &src, sizeof(src));
+
+        // inc src reference counts
+        SkSafeRef(src.fPixelRef);
+        SkSafeRef(src.fMipMap);
+
+        // we reset our locks if we get blown away
+        fPixelLockCount = 0;
+
+        if (fPixelRef) {
+            // ignore the values from the memcpy
+            fPixels = NULL;
+            fColorTable = NULL;
+            // Note that what to for genID is somewhat arbitrary. We have no
+            // way to track changes to raw pixels across multiple SkBitmaps.
+            // Would benefit from an SkRawPixelRef type created by
+            // setPixels.
+            // Just leave the memcpy'ed one but they'll get out of sync
+            // as soon either is modified.
+        }
+    }
+
+    SkDEBUGCODE(this->validate();)
+    return *this;
+}
+
+void SkBitmap::swap(SkBitmap& other) {
+    SkTSwap(fColorTable, other.fColorTable);
+    SkTSwap(fPixelRef, other.fPixelRef);
+    SkTSwap(fPixelRefOrigin, other.fPixelRefOrigin);
+    SkTSwap(fPixelLockCount, other.fPixelLockCount);
+    SkTSwap(fMipMap, other.fMipMap);
+    SkTSwap(fPixels, other.fPixels);
+    SkTSwap(fInfo, other.fInfo);
+    SkTSwap(fRowBytes, other.fRowBytes);
+    SkTSwap(fFlags, other.fFlags);
+
+    SkDEBUGCODE(this->validate();)
+}
+
+void SkBitmap::reset() {
+    this->freePixels();
+    sk_bzero(this, sizeof(*this));
+}
+
+SkBitmap::Config SkBitmap::config() const {
+    return SkColorTypeToBitmapConfig(fInfo.colorType());
+}
+
+int SkBitmap::ComputeBytesPerPixel(SkBitmap::Config config) {
+    int bpp;
+    switch (config) {
+        case kNo_Config:
+            bpp = 0;   // not applicable
+            break;
+        case kA8_Config:
+        case kIndex8_Config:
+            bpp = 1;
+            break;
+        case kRGB_565_Config:
+        case kARGB_4444_Config:
+            bpp = 2;
+            break;
+        case kARGB_8888_Config:
+            bpp = 4;
+            break;
+        default:
+            SkDEBUGFAIL("unknown config");
+            bpp = 0;   // error
+            break;
+    }
+    return bpp;
+}
+
+size_t SkBitmap::ComputeRowBytes(Config c, int width) {
+    return SkColorTypeMinRowBytes(SkBitmapConfigToColorType(c), width);
+}
+
+int64_t SkBitmap::ComputeSize64(Config config, int width, int height) {
+    SkColorType ct = SkBitmapConfigToColorType(config);
+    int64_t rowBytes = sk_64_mul(SkColorTypeBytesPerPixel(ct), width);
+    return rowBytes * height;
+}
+
+size_t SkBitmap::ComputeSize(Config c, int width, int height) {
+    int64_t size = SkBitmap::ComputeSize64(c, width, height);
+    return sk_64_isS32(size) ? sk_64_asS32(size) : 0;
+}
+
+int64_t SkBitmap::ComputeSafeSize64(Config config,
+                                    uint32_t width,
+                                    uint32_t height,
+                                    size_t rowBytes) {
+    SkImageInfo info = SkImageInfo::Make(width, height,
+                                         SkBitmapConfigToColorType(config),
+                                         kPremul_SkAlphaType);
+    return info.getSafeSize64(rowBytes);
+}
+
+size_t SkBitmap::ComputeSafeSize(Config config,
+                                 uint32_t width,
+                                 uint32_t height,
+                                 size_t rowBytes) {
+    int64_t safeSize = ComputeSafeSize64(config, width, height, rowBytes);
+    int32_t safeSize32 = (int32_t)safeSize;
+
+    if (safeSize32 != safeSize) {
+        safeSize32 = 0;
+    }
+    return safeSize32;
+}
+
+void SkBitmap::getBounds(SkRect* bounds) const {
+    SkASSERT(bounds);
+    bounds->set(0, 0,
+                SkIntToScalar(fInfo.fWidth), SkIntToScalar(fInfo.fHeight));
+}
+
+void SkBitmap::getBounds(SkIRect* bounds) const {
+    SkASSERT(bounds);
+    bounds->set(0, 0, fInfo.fWidth, fInfo.fHeight);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+static bool validate_alphaType(SkColorType colorType, SkAlphaType alphaType,
+                               SkAlphaType* canonical = NULL) {
+    switch (colorType) {
+        case kUnknown_SkColorType:
+            alphaType = kIgnore_SkAlphaType;
+            break;
+        case kAlpha_8_SkColorType:
+            if (kUnpremul_SkAlphaType == alphaType) {
+                alphaType = kPremul_SkAlphaType;
+            }
+            // fall-through
+        case kIndex_8_SkColorType:
+        case kARGB_4444_SkColorType:
+        case kRGBA_8888_SkColorType:
+        case kBGRA_8888_SkColorType:
+            if (kIgnore_SkAlphaType == alphaType) {
+                return false;
+            }
+            break;
+        case kRGB_565_SkColorType:
+            alphaType = kOpaque_SkAlphaType;
+            break;
+        default:
+            return false;
+    }
+    if (canonical) {
+        *canonical = alphaType;
+    }
+    return true;
+}
+
+bool SkBitmap::setConfig(const SkImageInfo& origInfo, size_t rowBytes) {
+    SkImageInfo info = origInfo;
+
+    if (!validate_alphaType(info.fColorType, info.fAlphaType,
+                            &info.fAlphaType)) {
+        return reset_return_false(this);
+    }
+
+    // require that rowBytes fit in 31bits
+    int64_t mrb = info.minRowBytes64();
+    if ((int32_t)mrb != mrb) {
+        return reset_return_false(this);
+    }
+    if ((int64_t)rowBytes != (int32_t)rowBytes) {
+        return reset_return_false(this);
+    }
+
+    if (info.width() < 0 || info.height() < 0) {
+        return reset_return_false(this);
+    }
+
+    if (kUnknown_SkColorType == info.colorType()) {
+        rowBytes = 0;
+    } else if (0 == rowBytes) {
+        rowBytes = (size_t)mrb;
+    } else if (rowBytes < info.minRowBytes()) {
+        return reset_return_false(this);
+    }
+
+    this->freePixels();
+
+    fInfo = info;
+    fRowBytes = SkToU32(rowBytes);
+    return true;
+}
+
+bool SkBitmap::setConfig(Config config, int width, int height, size_t rowBytes,
+                         SkAlphaType alphaType) {
+    SkColorType ct = SkBitmapConfigToColorType(config);
+    return this->setConfig(SkImageInfo::Make(width, height, ct, alphaType),
+                           rowBytes);
+}
+
+bool SkBitmap::setAlphaType(SkAlphaType alphaType) {
+    if (!validate_alphaType(fInfo.fColorType, alphaType, &alphaType)) {
+        return false;
+    }
+    if (fInfo.fAlphaType != alphaType) {
+        fInfo.fAlphaType = alphaType;
+        if (fPixelRef) {
+            fPixelRef->changeAlphaType(alphaType);
+        }
+    }
+    return true;
+}
+
+void SkBitmap::updatePixelsFromRef() const {
+    if (NULL != fPixelRef) {
+        if (fPixelLockCount > 0) {
+            SkASSERT(fPixelRef->isLocked());
+
+            void* p = fPixelRef->pixels();
+            if (NULL != p) {
+                p = (char*)p
+                    + fPixelRefOrigin.fY * fRowBytes
+                    + fPixelRefOrigin.fX * fInfo.bytesPerPixel();
+            }
+            fPixels = p;
+            fColorTable = fPixelRef->colorTable();
+        } else {
+            SkASSERT(0 == fPixelLockCount);
+            fPixels = NULL;
+            fColorTable = NULL;
+        }
+    }
+}
+
+static bool config_to_colorType(SkBitmap::Config config, SkColorType* ctOut) {
+    SkColorType ct;
+    switch (config) {
+        case SkBitmap::kA8_Config:
+            ct = kAlpha_8_SkColorType;
+            break;
+        case SkBitmap::kIndex8_Config:
+            ct = kIndex_8_SkColorType;
+            break;
+        case SkBitmap::kRGB_565_Config:
+            ct = kRGB_565_SkColorType;
+            break;
+        case SkBitmap::kARGB_4444_Config:
+            ct = kARGB_4444_SkColorType;
+            break;
+        case SkBitmap::kARGB_8888_Config:
+            ct = kPMColor_SkColorType;
+            break;
+        case SkBitmap::kNo_Config:
+        default:
+            return false;
+    }
+    if (ctOut) {
+        *ctOut = ct;
+    }
+    return true;
+}
+
+SkPixelRef* SkBitmap::setPixelRef(SkPixelRef* pr, int dx, int dy) {
+#ifdef SK_DEBUG
+    if (pr) {
+        SkImageInfo info;
+        if (this->asImageInfo(&info)) {
+            const SkImageInfo& prInfo = pr->info();
+            SkASSERT(info.fWidth <= prInfo.fWidth);
+            SkASSERT(info.fHeight <= prInfo.fHeight);
+            SkASSERT(info.fColorType == prInfo.fColorType);
+            switch (prInfo.fAlphaType) {
+                case kIgnore_SkAlphaType:
+                    SkASSERT(fInfo.fAlphaType == kIgnore_SkAlphaType);
+                    break;
+                case kOpaque_SkAlphaType:
+                case kPremul_SkAlphaType:
+                    SkASSERT(info.fAlphaType == kOpaque_SkAlphaType ||
+                             info.fAlphaType == kPremul_SkAlphaType);
+                    break;
+                case kUnpremul_SkAlphaType:
+                    SkASSERT(info.fAlphaType == kOpaque_SkAlphaType ||
+                             info.fAlphaType == kUnpremul_SkAlphaType);
+                    break;
+            }
+        }
+    }
+#endif
+
+    if (pr) {
+        const SkImageInfo& info = pr->info();
+        fPixelRefOrigin.set(SkPin32(dx, 0, info.fWidth),
+                            SkPin32(dy, 0, info.fHeight));
+    } else {
+        // ignore dx,dy if there is no pixelref
+        fPixelRefOrigin.setZero();
+    }
+
+    if (fPixelRef != pr) {
+        if (fPixelRef != pr) {
+            this->freePixels();
+            SkASSERT(NULL == fPixelRef);
+
+            SkSafeRef(pr);
+            fPixelRef = pr;
+        }
+        this->updatePixelsFromRef();
+    }
+
+    SkDEBUGCODE(this->validate();)
+    return pr;
+}
+
+void SkBitmap::lockPixels() const {
+    if (NULL != fPixelRef && 0 == sk_atomic_inc(&fPixelLockCount)) {
+        fPixelRef->lockPixels();
+        this->updatePixelsFromRef();
+    }
+    SkDEBUGCODE(this->validate();)
+}
+
+void SkBitmap::unlockPixels() const {
+    SkASSERT(NULL == fPixelRef || fPixelLockCount > 0);
+
+    if (NULL != fPixelRef && 1 == sk_atomic_dec(&fPixelLockCount)) {
+        fPixelRef->unlockPixels();
+        this->updatePixelsFromRef();
+    }
+    SkDEBUGCODE(this->validate();)
+}
+
+bool SkBitmap::lockPixelsAreWritable() const {
+    return (fPixelRef) ? fPixelRef->lockPixelsAreWritable() : false;
+}
+
+void SkBitmap::setPixels(void* p, SkColorTable* ctable) {
+    if (NULL == p) {
+        this->setPixelRef(NULL);
+        return;
+    }
+
+    SkImageInfo info;
+    if (!this->asImageInfo(&info)) {
+        this->setPixelRef(NULL);
+        return;
+    }
+
+    SkPixelRef* pr = SkMallocPixelRef::NewDirect(info, p, fRowBytes, ctable);
+    if (NULL == pr) {
+        this->setPixelRef(NULL);
+        return;
+    }
+
+    this->setPixelRef(pr)->unref();
+
+    // since we're already allocated, we lockPixels right away
+    this->lockPixels();
+    SkDEBUGCODE(this->validate();)
+}
+
+bool SkBitmap::allocPixels(Allocator* allocator, SkColorTable* ctable) {
+    HeapAllocator stdalloc;
+
+    if (NULL == allocator) {
+        allocator = &stdalloc;
+    }
+    return allocator->allocPixelRef(this, ctable);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+bool SkBitmap::allocPixels(const SkImageInfo& info, SkPixelRefFactory* factory,
+                           SkColorTable* ctable) {
+    if (kIndex_8_SkColorType == info.fColorType && NULL == ctable) {
+        return reset_return_false(this);
+    }
+    if (!this->setConfig(info)) {
+        return reset_return_false(this);
+    }
+
+    SkMallocPixelRef::PRFactory defaultFactory;
+    if (NULL == factory) {
+        factory = &defaultFactory;
+    }
+
+    SkPixelRef* pr = factory->create(info, ctable);
+    if (NULL == pr) {
+        return reset_return_false(this);
+    }
+    this->setPixelRef(pr)->unref();
+
+    // TODO: lockPixels could/should return bool or void*/NULL
+    this->lockPixels();
+    if (NULL == this->getPixels()) {
+        return reset_return_false(this);
+    }
+    return true;
+}
+
+bool SkBitmap::installPixels(const SkImageInfo& info, void* pixels, size_t rb,
+                             void (*releaseProc)(void* addr, void* context),
+                             void* context) {
+    if (!this->setConfig(info, rb)) {
+        this->reset();
+        return false;
+    }
+
+    SkPixelRef* pr = SkMallocPixelRef::NewWithProc(info, rb, NULL, pixels,
+                                                   releaseProc, context);
+    if (!pr) {
+        this->reset();
+        return false;
+    }
+
+    this->setPixelRef(pr)->unref();
+
+    // since we're already allocated, we lockPixels right away
+    this->lockPixels();
+    SkDEBUGCODE(this->validate();)
+    return true;
+}
+
+bool SkBitmap::installMaskPixels(const SkMask& mask) {
+    if (SkMask::kA8_Format != mask.fFormat) {
+        this->reset();
+        return false;
+    }
+    return this->installPixels(SkImageInfo::MakeA8(mask.fBounds.width(),
+                                                   mask.fBounds.height()),
+                               mask.fImage, mask.fRowBytes);
+}
+
+bool SkBitmap::allocConfigPixels(Config config, int width, int height,
+                                 bool isOpaque) {
+    SkColorType ct;
+    if (!config_to_colorType(config, &ct)) {
+        return false;
+    }
+
+    SkAlphaType at = isOpaque ? kOpaque_SkAlphaType : kPremul_SkAlphaType;
+    return this->allocPixels(SkImageInfo::Make(width, height, ct, at));
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+void SkBitmap::freePixels() {
+    // if we're gonna free the pixels, we certainly need to free the mipmap
+    this->freeMipMap();
+
+    if (NULL != fPixelRef) {
+        if (fPixelLockCount > 0) {
+            fPixelRef->unlockPixels();
+        }
+        fPixelRef->unref();
+        fPixelRef = NULL;
+        fPixelRefOrigin.setZero();
+    }
+    fPixelLockCount = 0;
+    fPixels = NULL;
+    fColorTable = NULL;
+}
+
+void SkBitmap::freeMipMap() {
+    if (fMipMap) {
+        fMipMap->unref();
+        fMipMap = NULL;
+    }
+}
+
+uint32_t SkBitmap::getGenerationID() const {
+    return (fPixelRef) ? fPixelRef->getGenerationID() : 0;
+}
+
+void SkBitmap::notifyPixelsChanged() const {
+    SkASSERT(!this->isImmutable());
+    if (fPixelRef) {
+        fPixelRef->notifyPixelsChanged();
+    }
+}
+
+GrTexture* SkBitmap::getTexture() const {
+    return fPixelRef ? fPixelRef->getTexture() : NULL;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+/** We explicitly use the same allocator for our pixels that SkMask does,
+ so that we can freely assign memory allocated by one class to the other.
+ */
+bool SkBitmap::HeapAllocator::allocPixelRef(SkBitmap* dst,
+                                            SkColorTable* ctable) {
+    SkImageInfo info;
+    if (!dst->asImageInfo(&info)) {
+//        SkDebugf("unsupported config for info %d\n", dst->config());
+        return false;
+    }
+
+    SkPixelRef* pr = SkMallocPixelRef::NewAllocate(info, dst->rowBytes(),
+                                                   ctable);
+    if (NULL == pr) {
+        return false;
+    }
+
+    dst->setPixelRef(pr)->unref();
+    // since we're already allocated, we lockPixels right away
+    dst->lockPixels();
+    return true;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+bool SkBitmap::copyPixelsTo(void* const dst, size_t dstSize,
+                            size_t dstRowBytes, bool preserveDstPad) const {
+
+    if (0 == dstRowBytes) {
+        dstRowBytes = fRowBytes;
+    }
+
+    if (dstRowBytes < fInfo.minRowBytes() ||
+        dst == NULL || (getPixels() == NULL && pixelRef() == NULL)) {
+        return false;
+    }
+
+    if (!preserveDstPad && static_cast<uint32_t>(dstRowBytes) == fRowBytes) {
+        size_t safeSize = this->getSafeSize();
+        if (safeSize > dstSize || safeSize == 0)
+            return false;
+        else {
+            SkAutoLockPixels lock(*this);
+            // This implementation will write bytes beyond the end of each row,
+            // excluding the last row, if the bitmap's stride is greater than
+            // strictly required by the current config.
+            memcpy(dst, getPixels(), safeSize);
+
+            return true;
+        }
+    } else {
+        // If destination has different stride than us, then copy line by line.
+        if (fInfo.getSafeSize(dstRowBytes) > dstSize) {
+            return false;
+        } else {
+            // Just copy what we need on each line.
+            size_t rowBytes = fInfo.minRowBytes();
+            SkAutoLockPixels lock(*this);
+            const uint8_t* srcP = reinterpret_cast<const uint8_t*>(getPixels());
+            uint8_t* dstP = reinterpret_cast<uint8_t*>(dst);
+            for (int row = 0; row < fInfo.fHeight;
+                 row++, srcP += fRowBytes, dstP += dstRowBytes) {
+                memcpy(dstP, srcP, rowBytes);
+            }
+
+            return true;
+        }
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+bool SkBitmap::isImmutable() const {
+    return fPixelRef ? fPixelRef->isImmutable() :
+        fFlags & kImageIsImmutable_Flag;
+}
+
+void SkBitmap::setImmutable() {
+    if (fPixelRef) {
+        fPixelRef->setImmutable();
+    } else {
+        fFlags |= kImageIsImmutable_Flag;
+    }
+}
+
+bool SkBitmap::isVolatile() const {
+    return (fFlags & kImageIsVolatile_Flag) != 0;
+}
+
+void SkBitmap::setIsVolatile(bool isVolatile) {
+    if (isVolatile) {
+        fFlags |= kImageIsVolatile_Flag;
+    } else {
+        fFlags &= ~kImageIsVolatile_Flag;
+    }
+}
+
+void* SkBitmap::getAddr(int x, int y) const {
+    SkASSERT((unsigned)x < (unsigned)this->width());
+    SkASSERT((unsigned)y < (unsigned)this->height());
+
+    char* base = (char*)this->getPixels();
+    if (base) {
+        base += y * this->rowBytes();
+        switch (this->colorType()) {
+            case kRGBA_8888_SkColorType:
+            case kBGRA_8888_SkColorType:
+                base += x << 2;
+                break;
+            case kARGB_4444_SkColorType:
+            case kRGB_565_SkColorType:
+                base += x << 1;
+                break;
+            case kAlpha_8_SkColorType:
+            case kIndex_8_SkColorType:
+                base += x;
+                break;
+            default:
+                SkDEBUGFAIL("Can't return addr for config");
+                base = NULL;
+                break;
+        }
+    }
+    return base;
+}
+
+SkColor SkBitmap::getColor(int x, int y) const {
+    SkASSERT((unsigned)x < (unsigned)this->width());
+    SkASSERT((unsigned)y < (unsigned)this->height());
+
+    switch (this->config()) {
+        case SkBitmap::kA8_Config: {
+            uint8_t* addr = this->getAddr8(x, y);
+            return SkColorSetA(0, addr[0]);
+        }
+        case SkBitmap::kIndex8_Config: {
+            SkPMColor c = this->getIndex8Color(x, y);
+            return SkUnPreMultiply::PMColorToColor(c);
+        }
+        case SkBitmap::kRGB_565_Config: {
+            uint16_t* addr = this->getAddr16(x, y);
+            return SkPixel16ToColor(addr[0]);
+        }
+        case SkBitmap::kARGB_4444_Config: {
+            uint16_t* addr = this->getAddr16(x, y);
+            SkPMColor c = SkPixel4444ToPixel32(addr[0]);
+            return SkUnPreMultiply::PMColorToColor(c);
+        }
+        case SkBitmap::kARGB_8888_Config: {
+            uint32_t* addr = this->getAddr32(x, y);
+            return SkUnPreMultiply::PMColorToColor(addr[0]);
+        }
+        case kNo_Config:
+        default:
+            SkASSERT(false);
+            return 0;
+    }
+    SkASSERT(false);  // Not reached.
+    return 0;
+}
+
+bool SkBitmap::ComputeIsOpaque(const SkBitmap& bm) {
+    SkAutoLockPixels alp(bm);
+    if (!bm.getPixels()) {
+        return false;
+    }
+
+    const int height = bm.height();
+    const int width = bm.width();
+
+    switch (bm.config()) {
+        case SkBitmap::kA8_Config: {
+            unsigned a = 0xFF;
+            for (int y = 0; y < height; ++y) {
+                const uint8_t* row = bm.getAddr8(0, y);
+                for (int x = 0; x < width; ++x) {
+                    a &= row[x];
+                }
+                if (0xFF != a) {
+                    return false;
+                }
+            }
+            return true;
+        } break;
+        case SkBitmap::kIndex8_Config: {
+            SkAutoLockColors alc(bm);
+            const SkPMColor* table = alc.colors();
+            if (!table) {
+                return false;
+            }
+            SkPMColor c = (SkPMColor)~0;
+            for (int i = bm.getColorTable()->count() - 1; i >= 0; --i) {
+                c &= table[i];
+            }
+            return 0xFF == SkGetPackedA32(c);
+        } break;
+        case SkBitmap::kRGB_565_Config:
+            return true;
+            break;
+        case SkBitmap::kARGB_4444_Config: {
+            unsigned c = 0xFFFF;
+            for (int y = 0; y < height; ++y) {
+                const SkPMColor16* row = bm.getAddr16(0, y);
+                for (int x = 0; x < width; ++x) {
+                    c &= row[x];
+                }
+                if (0xF != SkGetPackedA4444(c)) {
+                    return false;
+                }
+            }
+            return true;
+        } break;
+        case SkBitmap::kARGB_8888_Config: {
+            SkPMColor c = (SkPMColor)~0;
+            for (int y = 0; y < height; ++y) {
+                const SkPMColor* row = bm.getAddr32(0, y);
+                for (int x = 0; x < width; ++x) {
+                    c &= row[x];
+                }
+                if (0xFF != SkGetPackedA32(c)) {
+                    return false;
+                }
+            }
+            return true;
+        }
+        default:
+            break;
+    }
+    return false;
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
+
+static uint16_t pack_8888_to_4444(unsigned a, unsigned r, unsigned g, unsigned b) {
+    unsigned pixel = (SkA32To4444(a) << SK_A4444_SHIFT) |
+                     (SkR32To4444(r) << SK_R4444_SHIFT) |
+                     (SkG32To4444(g) << SK_G4444_SHIFT) |
+                     (SkB32To4444(b) << SK_B4444_SHIFT);
+    return SkToU16(pixel);
+}
+
+void SkBitmap::internalErase(const SkIRect& area,
+                             U8CPU a, U8CPU r, U8CPU g, U8CPU b) const {
+#ifdef SK_DEBUG
+    SkDEBUGCODE(this->validate();)
+    SkASSERT(!area.isEmpty());
+    {
+        SkIRect total = { 0, 0, this->width(), this->height() };
+        SkASSERT(total.contains(area));
+    }
+#endif
+
+    switch (fInfo.colorType()) {
+        case kUnknown_SkColorType:
+        case kIndex_8_SkColorType:
+            return; // can't erase
+        default:
+            break;
+    }
+
+    SkAutoLockPixels alp(*this);
+    // perform this check after the lock call
+    if (!this->readyToDraw()) {
+        return;
+    }
+
+    int height = area.height();
+    const int width = area.width();
+    const int rowBytes = fRowBytes;
+
+    // make rgb premultiplied
+    if (255 != a) {
+        r = SkAlphaMul(r, a);
+        g = SkAlphaMul(g, a);
+        b = SkAlphaMul(b, a);
+    }
+
+    switch (this->colorType()) {
+        case kAlpha_8_SkColorType: {
+            uint8_t* p = this->getAddr8(area.fLeft, area.fTop);
+            while (--height >= 0) {
+                memset(p, a, width);
+                p += rowBytes;
+            }
+            break;
+        }
+        case kARGB_4444_SkColorType:
+        case kRGB_565_SkColorType: {
+            uint16_t* p = this->getAddr16(area.fLeft, area.fTop);;
+            uint16_t v;
+
+            if (kARGB_4444_SkColorType == this->colorType()) {
+                v = pack_8888_to_4444(a, r, g, b);
+            } else {
+                v = SkPackRGB16(r >> (8 - SK_R16_BITS),
+                                g >> (8 - SK_G16_BITS),
+                                b >> (8 - SK_B16_BITS));
+            }
+            while (--height >= 0) {
+                sk_memset16(p, v, width);
+                p = (uint16_t*)((char*)p + rowBytes);
+            }
+            break;
+        }
+        case kPMColor_SkColorType: {
+            // what to do about BGRA or RGBA (which ever is != PMColor ?
+            // for now we don't support them.
+            uint32_t* p = this->getAddr32(area.fLeft, area.fTop);
+            uint32_t  v = SkPackARGB32(a, r, g, b);
+
+            while (--height >= 0) {
+                sk_memset32(p, v, width);
+                p = (uint32_t*)((char*)p + rowBytes);
+            }
+            break;
+        }
+        default:
+            return; // no change, so don't call notifyPixelsChanged()
+    }
+
+    this->notifyPixelsChanged();
+}
+
+void SkBitmap::eraseARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b) const {
+    SkIRect area = { 0, 0, this->width(), this->height() };
+    if (!area.isEmpty()) {
+        this->internalErase(area, a, r, g, b);
+    }
+}
+
+void SkBitmap::eraseArea(const SkIRect& rect, SkColor c) const {
+    SkIRect area = { 0, 0, this->width(), this->height() };
+    if (area.intersect(rect)) {
+        this->internalErase(area, SkColorGetA(c), SkColorGetR(c),
+                            SkColorGetG(c), SkColorGetB(c));
+    }
+}
+
+//////////////////////////////////////////////////////////////////////////////////////
+//////////////////////////////////////////////////////////////////////////////////////
+
+bool SkBitmap::extractSubset(SkBitmap* result, const SkIRect& subset) const {
+    SkDEBUGCODE(this->validate();)
+
+    if (NULL == result || NULL == fPixelRef) {
+        return false;   // no src pixels
+    }
+
+    SkIRect srcRect, r;
+    srcRect.set(0, 0, this->width(), this->height());
+    if (!r.intersect(srcRect, subset)) {
+        return false;   // r is empty (i.e. no intersection)
+    }
+
+    if (fPixelRef->getTexture() != NULL) {
+        // Do a deep copy
+        SkPixelRef* pixelRef = fPixelRef->deepCopy(this->config(), &subset);
+        if (pixelRef != NULL) {
+            SkBitmap dst;
+            dst.setConfig(this->config(), subset.width(), subset.height(), 0,
+                          this->alphaType());
+            dst.setIsVolatile(this->isVolatile());
+            dst.setPixelRef(pixelRef)->unref();
+            SkDEBUGCODE(dst.validate());
+            result->swap(dst);
+            return true;
+        }
+    }
+
+    // If the upper left of the rectangle was outside the bounds of this SkBitmap, we should have
+    // exited above.
+    SkASSERT(static_cast<unsigned>(r.fLeft) < static_cast<unsigned>(this->width()));
+    SkASSERT(static_cast<unsigned>(r.fTop) < static_cast<unsigned>(this->height()));
+
+    SkBitmap dst;
+    dst.setConfig(this->config(), r.width(), r.height(), this->rowBytes(),
+                  this->alphaType());
+    dst.setIsVolatile(this->isVolatile());
+
+    if (fPixelRef) {
+        SkIPoint origin = fPixelRefOrigin;
+        origin.fX += r.fLeft;
+        origin.fY += r.fTop;
+        // share the pixelref with a custom offset
+        dst.setPixelRef(fPixelRef, origin);
+    }
+    SkDEBUGCODE(dst.validate();)
+
+    // we know we're good, so commit to result
+    result->swap(dst);
+    return true;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+#include "SkCanvas.h"
+#include "SkPaint.h"
+
+bool SkBitmap::canCopyTo(SkColorType dstColorType) const {
+    if (this->colorType() == kUnknown_SkColorType) {
+        return false;
+    }
+
+    bool sameConfigs = (this->colorType() == dstColorType);
+    switch (dstColorType) {
+        case kAlpha_8_SkColorType:
+        case kRGB_565_SkColorType:
+        case kPMColor_SkColorType:
+            break;
+        case kIndex_8_SkColorType:
+            if (!sameConfigs) {
+                return false;
+            }
+            break;
+        case kARGB_4444_SkColorType:
+            return sameConfigs || kPMColor_SkColorType == this->colorType();
+        default:
+            return false;
+    }
+    return true;
+}
+
+bool SkBitmap::copyTo(SkBitmap* dst, SkColorType dstColorType,
+                      Allocator* alloc) const {
+    if (!this->canCopyTo(dstColorType)) {
+        return false;
+    }
+
+    // if we have a texture, first get those pixels
+    SkBitmap tmpSrc;
+    const SkBitmap* src = this;
+
+    if (fPixelRef) {
+        SkIRect subset;
+        subset.setXYWH(fPixelRefOrigin.fX, fPixelRefOrigin.fY,
+                       fInfo.width(), fInfo.height());
+        if (fPixelRef->readPixels(&tmpSrc, &subset)) {
+            SkASSERT(tmpSrc.width() == this->width());
+            SkASSERT(tmpSrc.height() == this->height());
+
+            // did we get lucky and we can just return tmpSrc?
+            if (tmpSrc.colorType() == dstColorType && NULL == alloc) {
+                dst->swap(tmpSrc);
+                // If the result is an exact copy, clone the gen ID.
+                if (dst->pixelRef() && dst->pixelRef()->info() == fPixelRef->info()) {
+                    dst->pixelRef()->cloneGenID(*fPixelRef);
+                }
+                return true;
+            }
+
+            // fall through to the raster case
+            src = &tmpSrc;
+        }
+    }
+
+    // we lock this now, since we may need its colortable
+    SkAutoLockPixels srclock(*src);
+    if (!src->readyToDraw()) {
+        return false;
+    }
+
+    // The only way to be readyToDraw is if fPixelRef is non NULL.
+    SkASSERT(fPixelRef != NULL);
+
+    SkImageInfo dstInfo = src->info();
+    dstInfo.fColorType = dstColorType;
+
+    SkBitmap tmpDst;
+    if (!tmpDst.setConfig(dstInfo)) {
+        return false;
+    }
+
+    // allocate colortable if srcConfig == kIndex8_Config
+    SkAutoTUnref<SkColorTable> ctable;
+    if (dstColorType == kIndex_8_SkColorType) {
+        // TODO: can we just ref() the src colortable? Is it reentrant-safe?
+        ctable.reset(SkNEW_ARGS(SkColorTable, (*src->getColorTable())));
+    }
+    if (!tmpDst.allocPixels(alloc, ctable)) {
+        return false;
+    }
+
+    if (!tmpDst.readyToDraw()) {
+        // allocator/lock failed
+        return false;
+    }
+
+    // pixelRef must be non NULL or tmpDst.readyToDraw() would have
+    // returned false.
+    SkASSERT(tmpDst.pixelRef() != NULL);
+
+    /* do memcpy for the same configs cases, else use drawing
+    */
+    if (src->colorType() == dstColorType) {
+        if (tmpDst.getSize() == src->getSize()) {
+            memcpy(tmpDst.getPixels(), src->getPixels(), src->getSafeSize());
+            SkPixelRef* pixelRef = tmpDst.pixelRef();
+
+            // In order to reach this point, we know that the width, config and
+            // rowbytes of the SkPixelRefs are the same, but it is possible for
+            // the heights to differ, if this SkBitmap's height is a subset of
+            // fPixelRef. Only if the SkPixelRefs' heights match are we
+            // guaranteed that this is an exact copy, meaning we should clone
+            // the genID.
+            if (pixelRef->info().fHeight == fPixelRef->info().fHeight) {
+                // TODO: what to do if the two infos match, BUT
+                // fPixelRef is premul and pixelRef is opaque?
+                // skipping assert for now
+                // https://code.google.com/p/skia/issues/detail?id=2012
+//                SkASSERT(pixelRef->info() == fPixelRef->info());
+                SkASSERT(pixelRef->info().fWidth == fPixelRef->info().fWidth);
+                SkASSERT(pixelRef->info().fColorType == fPixelRef->info().fColorType);
+                pixelRef->cloneGenID(*fPixelRef);
+            }
+        } else {
+            const char* srcP = reinterpret_cast<const char*>(src->getPixels());
+            char* dstP = reinterpret_cast<char*>(tmpDst.getPixels());
+            // to be sure we don't read too much, only copy our logical pixels
+            size_t bytesToCopy = tmpDst.width() * tmpDst.bytesPerPixel();
+            for (int y = 0; y < tmpDst.height(); y++) {
+                memcpy(dstP, srcP, bytesToCopy);
+                srcP += src->rowBytes();
+                dstP += tmpDst.rowBytes();
+            }
+        }
+    } else if (kARGB_4444_SkColorType == dstColorType
+               && kPMColor_SkColorType == src->colorType()) {
+        SkASSERT(src->height() == tmpDst.height());
+        SkASSERT(src->width() == tmpDst.width());
+        for (int y = 0; y < src->height(); ++y) {
+            SkPMColor16* SK_RESTRICT dstRow = (SkPMColor16*) tmpDst.getAddr16(0, y);
+            SkPMColor* SK_RESTRICT srcRow = (SkPMColor*) src->getAddr32(0, y);
+            DITHER_4444_SCAN(y);
+            for (int x = 0; x < src->width(); ++x) {
+                dstRow[x] = SkDitherARGB32To4444(srcRow[x],
+                                                 DITHER_VALUE(x));
+            }
+        }
+    } else {
+        // Always clear the dest in case one of the blitters accesses it
+        // TODO: switch the allocation of tmpDst to call sk_calloc_throw
+        tmpDst.eraseColor(SK_ColorTRANSPARENT);
+
+        SkCanvas canvas(tmpDst);
+        SkPaint  paint;
+
+        paint.setDither(true);
+        canvas.drawBitmap(*src, 0, 0, &paint);
+    }
+
+    dst->swap(tmpDst);
+    return true;
+}
+
+bool SkBitmap::deepCopyTo(SkBitmap* dst) const {
+    const SkBitmap::Config dstConfig = this->config();
+    const SkColorType dstCT = SkBitmapConfigToColorType(dstConfig);
+
+    if (!this->canCopyTo(dstCT)) {
+        return false;
+    }
+
+    // If we have a PixelRef, and it supports deep copy, use it.
+    // Currently supported only by texture-backed bitmaps.
+    if (fPixelRef) {
+        SkPixelRef* pixelRef = fPixelRef->deepCopy(dstConfig);
+        if (pixelRef) {
+            uint32_t rowBytes;
+            if (this->colorType() == dstCT) {
+                // Since there is no subset to pass to deepCopy, and deepCopy
+                // succeeded, the new pixel ref must be identical.
+                SkASSERT(fPixelRef->info() == pixelRef->info());
+                pixelRef->cloneGenID(*fPixelRef);
+                // Use the same rowBytes as the original.
+                rowBytes = fRowBytes;
+            } else {
+                // With the new config, an appropriate fRowBytes will be computed by setConfig.
+                rowBytes = 0;
+            }
+
+            SkImageInfo info = fInfo;
+            info.fColorType = dstCT;
+            if (!dst->setConfig(info, rowBytes)) {
+                return false;
+            }
+            dst->setPixelRef(pixelRef, fPixelRefOrigin)->unref();
+            return true;
+        }
+    }
+
+    if (this->getTexture()) {
+        return false;
+    } else {
+        return this->copyTo(dst, dstCT, NULL);
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
+
+static void downsampleby2_proc32(SkBitmap* dst, int x, int y,
+                                 const SkBitmap& src) {
+    x <<= 1;
+    y <<= 1;
+    const SkPMColor* p = src.getAddr32(x, y);
+    const SkPMColor* baseP = p;
+    SkPMColor c, ag, rb;
+
+    c = *p; ag = (c >> 8) & 0xFF00FF; rb = c & 0xFF00FF;
+    if (x < src.width() - 1) {
+        p += 1;
+    }
+    c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF;
+
+    p = baseP;
+    if (y < src.height() - 1) {
+        p += src.rowBytes() >> 2;
+    }
+    c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF;
+    if (x < src.width() - 1) {
+        p += 1;
+    }
+    c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF;
+
+    *dst->getAddr32(x >> 1, y >> 1) =
+        ((rb >> 2) & 0xFF00FF) | ((ag << 6) & 0xFF00FF00);
+}
+
+static inline uint32_t expand16(U16CPU c) {
+    return (c & ~SK_G16_MASK_IN_PLACE) | ((c & SK_G16_MASK_IN_PLACE) << 16);
+}
+
+// returns dirt in the top 16bits, but we don't care, since we only
+// store the low 16bits.
+static inline U16CPU pack16(uint32_t c) {
+    return (c & ~SK_G16_MASK_IN_PLACE) | ((c >> 16) & SK_G16_MASK_IN_PLACE);
+}
+
+static void downsampleby2_proc16(SkBitmap* dst, int x, int y,
+                                 const SkBitmap& src) {
+    x <<= 1;
+    y <<= 1;
+    const uint16_t* p = src.getAddr16(x, y);
+    const uint16_t* baseP = p;
+    SkPMColor       c;
+
+    c = expand16(*p);
+    if (x < src.width() - 1) {
+        p += 1;
+    }
+    c += expand16(*p);
+
+    p = baseP;
+    if (y < src.height() - 1) {
+        p += src.rowBytes() >> 1;
+    }
+    c += expand16(*p);
+    if (x < src.width() - 1) {
+        p += 1;
+    }
+    c += expand16(*p);
+
+    *dst->getAddr16(x >> 1, y >> 1) = (uint16_t)pack16(c >> 2);
+}
+
+static uint32_t expand4444(U16CPU c) {
+    return (c & 0xF0F) | ((c & ~0xF0F) << 12);
+}
+
+static U16CPU collaps4444(uint32_t c) {
+    return (c & 0xF0F) | ((c >> 12) & ~0xF0F);
+}
+
+static void downsampleby2_proc4444(SkBitmap* dst, int x, int y,
+                                   const SkBitmap& src) {
+    x <<= 1;
+    y <<= 1;
+    const uint16_t* p = src.getAddr16(x, y);
+    const uint16_t* baseP = p;
+    uint32_t        c;
+
+    c = expand4444(*p);
+    if (x < src.width() - 1) {
+        p += 1;
+    }
+    c += expand4444(*p);
+
+    p = baseP;
+    if (y < src.height() - 1) {
+        p += src.rowBytes() >> 1;
+    }
+    c += expand4444(*p);
+    if (x < src.width() - 1) {
+        p += 1;
+    }
+    c += expand4444(*p);
+
+    *dst->getAddr16(x >> 1, y >> 1) = (uint16_t)collaps4444(c >> 2);
+}
+
+void SkBitmap::buildMipMap(bool forceRebuild) {
+    if (forceRebuild)
+        this->freeMipMap();
+    else if (fMipMap)
+        return; // we're already built
+
+    SkASSERT(NULL == fMipMap);
+
+    void (*proc)(SkBitmap* dst, int x, int y, const SkBitmap& src);
+
+    const SkBitmap::Config config = this->config();
+
+    switch (config) {
+        case kARGB_8888_Config:
+            proc = downsampleby2_proc32;
+            break;
+        case kRGB_565_Config:
+            proc = downsampleby2_proc16;
+            break;
+        case kARGB_4444_Config:
+            proc = downsampleby2_proc4444;
+            break;
+        case kIndex8_Config:
+        case kA8_Config:
+        default:
+            return; // don't build mipmaps for these configs
+    }
+
+    SkAutoLockPixels alp(*this);
+    if (!this->readyToDraw()) {
+        return;
+    }
+
+    // whip through our loop to compute the exact size needed
+    size_t  size = 0;
+    int     maxLevels = 0;
+    {
+        int width = this->width();
+        int height = this->height();
+        for (;;) {
+            width >>= 1;
+            height >>= 1;
+            if (0 == width || 0 == height) {
+                break;
+            }
+            size += ComputeRowBytes(config, width) * height;
+            maxLevels += 1;
+        }
+    }
+
+    // nothing to build
+    if (0 == maxLevels) {
+        return;
+    }
+
+    SkBitmap srcBM(*this);
+    srcBM.lockPixels();
+    if (!srcBM.readyToDraw()) {
+        return;
+    }
+
+    MipMap* mm = MipMap::Alloc(maxLevels, size);
+    if (NULL == mm) {
+        return;
+    }
+
+    MipLevel*   level = mm->levels();
+    uint8_t*    addr = (uint8_t*)mm->pixels();
+    int         width = this->width();
+    int         height = this->height();
+    uint32_t    rowBytes;
+    SkBitmap    dstBM;
+
+    for (int i = 0; i < maxLevels; i++) {
+        width >>= 1;
+        height >>= 1;
+        rowBytes = SkToU32(ComputeRowBytes(config, width));
+
+        level[i].fPixels   = addr;
+        level[i].fWidth    = width;
+        level[i].fHeight   = height;
+        level[i].fRowBytes = rowBytes;
+
+        dstBM.setConfig(config, width, height, rowBytes);
+        dstBM.setPixels(addr);
+
+        srcBM.lockPixels();
+        for (int y = 0; y < height; y++) {
+            for (int x = 0; x < width; x++) {
+                proc(&dstBM, x, y, srcBM);
+            }
+        }
+        srcBM.unlockPixels();
+
+        srcBM = dstBM;
+        addr += height * rowBytes;
+    }
+    SkASSERT(addr == (uint8_t*)mm->pixels() + size);
+    fMipMap = mm;
+}
+
+bool SkBitmap::hasMipMap() const {
+    return fMipMap != NULL;
+}
+
+int SkBitmap::extractMipLevel(SkBitmap* dst, SkFixed sx, SkFixed sy) {
+    if (NULL == fMipMap) {
+        return 0;
+    }
+
+    int level = ComputeMipLevel(sx, sy) >> 16;
+    SkASSERT(level >= 0);
+    if (level <= 0) {
+        return 0;
+    }
+
+    if (level >= fMipMap->fLevelCount) {
+        level = fMipMap->fLevelCount - 1;
+    }
+    if (dst) {
+        const MipLevel& mip = fMipMap->levels()[level - 1];
+        dst->setConfig((SkBitmap::Config)this->config(),
+                       mip.fWidth, mip.fHeight, mip.fRowBytes);
+        dst->setPixels(mip.fPixels);
+    }
+    return level;
+}
+
+SkFixed SkBitmap::ComputeMipLevel(SkFixed sx, SkFixed sy) {
+    sx = SkAbs32(sx);
+    sy = SkAbs32(sy);
+    if (sx < sy) {
+        sx = sy;
+    }
+    if (sx < SK_Fixed1) {
+        return 0;
+    }
+    int clz = SkCLZ(sx);
+    SkASSERT(clz >= 1 && clz <= 15);
+    return SkIntToFixed(15 - clz) + ((unsigned)(sx << (clz + 1)) >> 16);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+static bool GetBitmapAlpha(const SkBitmap& src, uint8_t* SK_RESTRICT alpha,
+                           int alphaRowBytes) {
+    SkASSERT(alpha != NULL);
+    SkASSERT(alphaRowBytes >= src.width());
+
+    SkBitmap::Config config = src.config();
+    int              w = src.width();
+    int              h = src.height();
+    size_t           rb = src.rowBytes();
+
+    SkAutoLockPixels alp(src);
+    if (!src.readyToDraw()) {
+        // zero out the alpha buffer and return
+        while (--h >= 0) {
+            memset(alpha, 0, w);
+            alpha += alphaRowBytes;
+        }
+        return false;
+    }
+
+    if (SkBitmap::kA8_Config == config && !src.isOpaque()) {
+        const uint8_t* s = src.getAddr8(0, 0);
+        while (--h >= 0) {
+            memcpy(alpha, s, w);
+            s += rb;
+            alpha += alphaRowBytes;
+        }
+    } else if (SkBitmap::kARGB_8888_Config == config && !src.isOpaque()) {
+        const SkPMColor* SK_RESTRICT s = src.getAddr32(0, 0);
+        while (--h >= 0) {
+            for (int x = 0; x < w; x++) {
+                alpha[x] = SkGetPackedA32(s[x]);
+            }
+            s = (const SkPMColor*)((const char*)s + rb);
+            alpha += alphaRowBytes;
+        }
+    } else if (SkBitmap::kARGB_4444_Config == config && !src.isOpaque()) {
+        const SkPMColor16* SK_RESTRICT s = src.getAddr16(0, 0);
+        while (--h >= 0) {
+            for (int x = 0; x < w; x++) {
+                alpha[x] = SkPacked4444ToA32(s[x]);
+            }
+            s = (const SkPMColor16*)((const char*)s + rb);
+            alpha += alphaRowBytes;
+        }
+    } else if (SkBitmap::kIndex8_Config == config && !src.isOpaque()) {
+        SkColorTable* ct = src.getColorTable();
+        if (ct) {
+            const SkPMColor* SK_RESTRICT table = ct->lockColors();
+            const uint8_t* SK_RESTRICT s = src.getAddr8(0, 0);
+            while (--h >= 0) {
+                for (int x = 0; x < w; x++) {
+                    alpha[x] = SkGetPackedA32(table[s[x]]);
+                }
+                s += rb;
+                alpha += alphaRowBytes;
+            }
+            ct->unlockColors();
+        }
+    } else {    // src is opaque, so just fill alpha[] with 0xFF
+        memset(alpha, 0xFF, h * alphaRowBytes);
+    }
+    return true;
+}
+
+#include "SkPaint.h"
+#include "SkMaskFilter.h"
+#include "SkMatrix.h"
+
+bool SkBitmap::extractAlpha(SkBitmap* dst, const SkPaint* paint,
+                            Allocator *allocator, SkIPoint* offset) const {
+    SkDEBUGCODE(this->validate();)
+
+    SkBitmap    tmpBitmap;
+    SkMatrix    identity;
+    SkMask      srcM, dstM;
+
+    srcM.fBounds.set(0, 0, this->width(), this->height());
+    srcM.fRowBytes = SkAlign4(this->width());
+    srcM.fFormat = SkMask::kA8_Format;
+
+    SkMaskFilter* filter = paint ? paint->getMaskFilter() : NULL;
+
+    // compute our (larger?) dst bounds if we have a filter
+    if (NULL != filter) {
+        identity.reset();
+        srcM.fImage = NULL;
+        if (!filter->filterMask(&dstM, srcM, identity, NULL)) {
+            goto NO_FILTER_CASE;
+        }
+        dstM.fRowBytes = SkAlign4(dstM.fBounds.width());
+    } else {
+    NO_FILTER_CASE:
+        tmpBitmap.setConfig(SkBitmap::kA8_Config, this->width(), this->height(),
+                       srcM.fRowBytes);
+        if (!tmpBitmap.allocPixels(allocator, NULL)) {
+            // Allocation of pixels for alpha bitmap failed.
+            SkDebugf("extractAlpha failed to allocate (%d,%d) alpha bitmap\n",
+                    tmpBitmap.width(), tmpBitmap.height());
+            return false;
+        }
+        GetBitmapAlpha(*this, tmpBitmap.getAddr8(0, 0), srcM.fRowBytes);
+        if (offset) {
+            offset->set(0, 0);
+        }
+        tmpBitmap.swap(*dst);
+        return true;
+    }
+    srcM.fImage = SkMask::AllocImage(srcM.computeImageSize());
+    SkAutoMaskFreeImage srcCleanup(srcM.fImage);
+
+    GetBitmapAlpha(*this, srcM.fImage, srcM.fRowBytes);
+    if (!filter->filterMask(&dstM, srcM, identity, NULL)) {
+        goto NO_FILTER_CASE;
+    }
+    SkAutoMaskFreeImage dstCleanup(dstM.fImage);
+
+    tmpBitmap.setConfig(SkBitmap::kA8_Config, dstM.fBounds.width(),
+                   dstM.fBounds.height(), dstM.fRowBytes);
+    if (!tmpBitmap.allocPixels(allocator, NULL)) {
+        // Allocation of pixels for alpha bitmap failed.
+        SkDebugf("extractAlpha failed to allocate (%d,%d) alpha bitmap\n",
+                tmpBitmap.width(), tmpBitmap.height());
+        return false;
+    }
+    memcpy(tmpBitmap.getPixels(), dstM.fImage, dstM.computeImageSize());
+    if (offset) {
+        offset->set(dstM.fBounds.fLeft, dstM.fBounds.fTop);
+    }
+    SkDEBUGCODE(tmpBitmap.validate();)
+
+    tmpBitmap.swap(*dst);
+    return true;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+enum {
+    SERIALIZE_PIXELTYPE_NONE,
+    SERIALIZE_PIXELTYPE_REF_DATA
+};
+
+void SkBitmap::flatten(SkWriteBuffer& buffer) const {
+    fInfo.flatten(buffer);
+    buffer.writeInt(fRowBytes);
+
+    if (fPixelRef) {
+        if (fPixelRef->getFactory()) {
+            buffer.writeInt(SERIALIZE_PIXELTYPE_REF_DATA);
+            buffer.writeInt(fPixelRefOrigin.fX);
+            buffer.writeInt(fPixelRefOrigin.fY);
+            buffer.writeFlattenable(fPixelRef);
+            return;
+        }
+        // if we get here, we can't record the pixels
+        buffer.writeInt(SERIALIZE_PIXELTYPE_NONE);
+    } else {
+        buffer.writeInt(SERIALIZE_PIXELTYPE_NONE);
+    }
+}
+
+void SkBitmap::unflatten(SkReadBuffer& buffer) {
+    this->reset();
+
+    SkImageInfo info;
+    info.unflatten(buffer);
+    size_t rowBytes = buffer.readInt();
+    if (!buffer.validate((info.width() >= 0) && (info.height() >= 0) &&
+                         SkColorTypeIsValid(info.fColorType) &&
+                         SkAlphaTypeIsValid(info.fAlphaType) &&
+                         validate_alphaType(info.fColorType, info.fAlphaType) &&
+                         info.validRowBytes(rowBytes))) {
+        return;
+    }
+
+    bool configIsValid = this->setConfig(info, rowBytes);
+    buffer.validate(configIsValid);
+
+    int reftype = buffer.readInt();
+    if (buffer.validate((SERIALIZE_PIXELTYPE_REF_DATA == reftype) ||
+                        (SERIALIZE_PIXELTYPE_NONE == reftype))) {
+        switch (reftype) {
+            case SERIALIZE_PIXELTYPE_REF_DATA: {
+                SkIPoint origin;
+                origin.fX = buffer.readInt();
+                origin.fY = buffer.readInt();
+                size_t offset = origin.fY * rowBytes + origin.fX * info.bytesPerPixel();
+                SkPixelRef* pr = buffer.readPixelRef();
+                if (!buffer.validate((NULL == pr) ||
+                       (pr->getAllocatedSizeInBytes() >= (offset + this->getSafeSize())))) {
+                    origin.setZero();
+                }
+                SkSafeUnref(this->setPixelRef(pr, origin));
+                break;
+            }
+            case SERIALIZE_PIXELTYPE_NONE:
+                break;
+            default:
+                SkDEBUGFAIL("unrecognized pixeltype in serialized data");
+                sk_throw();
+        }
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+SkBitmap::RLEPixels::RLEPixels(int width, int height) {
+    fHeight = height;
+    fYPtrs = (uint8_t**)sk_calloc_throw(height * sizeof(uint8_t*));
+}
+
+SkBitmap::RLEPixels::~RLEPixels() {
+    sk_free(fYPtrs);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+#ifdef SK_DEBUG
+void SkBitmap::validate() const {
+    fInfo.validate();
+
+    // ImageInfo may not require this, but Bitmap ensures that opaque-only
+    // colorTypes report opaque for their alphatype
+    if (kRGB_565_SkColorType == fInfo.colorType()) {
+        SkASSERT(kOpaque_SkAlphaType == fInfo.alphaType());
+    }
+
+    SkASSERT(fInfo.validRowBytes(fRowBytes));
+    uint8_t allFlags = kImageIsOpaque_Flag | kImageIsVolatile_Flag | kImageIsImmutable_Flag;
+#ifdef SK_BUILD_FOR_ANDROID
+    allFlags |= kHasHardwareMipMap_Flag;
+#endif
+    SkASSERT(fFlags <= allFlags);
+    SkASSERT(fPixelLockCount >= 0);
+
+    if (fPixels) {
+        SkASSERT(fPixelRef);
+        SkASSERT(fPixelLockCount > 0);
+        SkASSERT(fPixelRef->isLocked());
+        SkASSERT(fPixelRef->rowBytes() == fRowBytes);
+        SkASSERT(fPixelRefOrigin.fX >= 0);
+        SkASSERT(fPixelRefOrigin.fY >= 0);
+        SkASSERT(fPixelRef->info().width() >= (int)this->width() + fPixelRefOrigin.fX);
+        SkASSERT(fPixelRef->info().fHeight >= (int)this->height() + fPixelRefOrigin.fY);
+        SkASSERT(fPixelRef->rowBytes() >= fInfo.minRowBytes());
+    } else {
+        SkASSERT(NULL == fColorTable);
+    }
+}
+#endif
+
+#ifndef SK_IGNORE_TO_STRING
+void SkBitmap::toString(SkString* str) const {
+
+    static const char* gConfigNames[kConfigCount] = {
+        "NONE", "A8", "INDEX8", "565", "4444", "8888"
+    };
+
+    str->appendf("bitmap: ((%d, %d) %s", this->width(), this->height(),
+                 gConfigNames[this->config()]);
+
+    str->append(" (");
+    if (this->isOpaque()) {
+        str->append("opaque");
+    } else {
+        str->append("transparent");
+    }
+    if (this->isImmutable()) {
+        str->append(", immutable");
+    } else {
+        str->append(", not-immutable");
+    }
+    str->append(")");
+
+    SkPixelRef* pr = this->pixelRef();
+    if (NULL == pr) {
+        // show null or the explicit pixel address (rare)
+        str->appendf(" pixels:%p", this->getPixels());
+    } else {
+        const char* uri = pr->getURI();
+        if (NULL != uri) {
+            str->appendf(" uri:\"%s\"", uri);
+        } else {
+            str->appendf(" pixelref:%p", pr);
+        }
+    }
+
+    str->append(")");
+}
+#endif
+
+///////////////////////////////////////////////////////////////////////////////
+
+#ifdef SK_DEBUG
+void SkImageInfo::validate() const {
+    SkASSERT(fWidth >= 0);
+    SkASSERT(fHeight >= 0);
+    SkASSERT(SkColorTypeIsValid(fColorType));
+    SkASSERT(SkAlphaTypeIsValid(fAlphaType));
+}
+#endif