SkBitmap.cpp revision 92833f99b99f1f955c350f6f4f70acd3356a79a5 
1
2/*
3 * Copyright 2008 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#include "SkBitmap.h"
11#include "SkColorPriv.h"
12#include "SkDither.h"
13#include "SkFlattenable.h"
14#include "SkMallocPixelRef.h"
15#include "SkMask.h"
16#include "SkOrderedReadBuffer.h"
17#include "SkOrderedWriteBuffer.h"
18#include "SkPixelRef.h"
19#include "SkThread.h"
20#include "SkUnPreMultiply.h"
21#include "SkUtils.h"
22#include "SkPackBits.h"
23#include <new>
24
25SK_DEFINE_INST_COUNT(SkBitmap::Allocator)
26
27static bool isPos32Bits(const Sk64& value) {
28    return !value.isNeg() && value.is32();
29}
30
31struct MipLevel {
32    void*       fPixels;
33    uint32_t    fRowBytes;
34    uint32_t    fWidth, fHeight;
35};
36
37struct SkBitmap::MipMap : SkNoncopyable {
38    int32_t fRefCnt;
39    int     fLevelCount;
40//  MipLevel    fLevel[fLevelCount];
41//  Pixels[]
42
43    static MipMap* Alloc(int levelCount, size_t pixelSize) {
44        if (levelCount < 0) {
45            return NULL;
46        }
47        Sk64 size;
48        size.setMul(levelCount + 1, sizeof(MipLevel));
49        size.add(sizeof(MipMap));
50        size.add(SkToS32(pixelSize));
51        if (!isPos32Bits(size)) {
52            return NULL;
53        }
54        MipMap* mm = (MipMap*)sk_malloc_throw(size.get32());
55        mm->fRefCnt = 1;
56        mm->fLevelCount = levelCount;
57        return mm;
58    }
59
60    const MipLevel* levels() const { return (const MipLevel*)(this + 1); }
61    MipLevel* levels() { return (MipLevel*)(this + 1); }
62
63    const void* pixels() const { return levels() + fLevelCount; }
64    void* pixels() { return levels() + fLevelCount; }
65
66    void ref() {
67        if (SK_MaxS32 == sk_atomic_inc(&fRefCnt)) {
68            sk_throw();
69        }
70    }
71    void unref() {
72        SkASSERT(fRefCnt > 0);
73        if (sk_atomic_dec(&fRefCnt) == 1) {
74            sk_free(this);
75        }
76    }
77};
78
79///////////////////////////////////////////////////////////////////////////////
80///////////////////////////////////////////////////////////////////////////////
81
82SkBitmap::SkBitmap() {
83    sk_bzero(this, sizeof(*this));
84}
85
86SkBitmap::SkBitmap(const SkBitmap& src) {
87    SkDEBUGCODE(src.validate();)
88    sk_bzero(this, sizeof(*this));
89    *this = src;
90    SkDEBUGCODE(this->validate();)
91}
92
93SkBitmap::~SkBitmap() {
94    SkDEBUGCODE(this->validate();)
95    this->freePixels();
96}
97
98SkBitmap& SkBitmap::operator=(const SkBitmap& src) {
99    if (this != &src) {
100        this->freePixels();
101        memcpy(this, &src, sizeof(src));
102
103        // inc src reference counts
104        SkSafeRef(src.fPixelRef);
105        SkSafeRef(src.fMipMap);
106
107        // we reset our locks if we get blown away
108        fPixelLockCount = 0;
109
110        /*  The src could be in 3 states
111            1. no pixelref, in which case we just copy/ref the pixels/ctable
112            2. unlocked pixelref, pixels/ctable should be null
113            3. locked pixelref, we should lock the ref again ourselves
114        */
115        if (NULL == fPixelRef) {
116            // leave fPixels as it is
117            SkSafeRef(fColorTable); // ref the user's ctable if present
118        } else {    // we have a pixelref, so pixels/ctable reflect it
119            // ignore the values from the memcpy
120            fPixels = NULL;
121            fColorTable = NULL;
122            // Note that what to for genID is somewhat arbitrary. We have no
123            // way to track changes to raw pixels across multiple SkBitmaps.
124            // Would benefit from an SkRawPixelRef type created by
125            // setPixels.
126            // Just leave the memcpy'ed one but they'll get out of sync
127            // as soon either is modified.
128        }
129    }
130
131    SkDEBUGCODE(this->validate();)
132    return *this;
133}
134
135void SkBitmap::swap(SkBitmap& other) {
136    SkTSwap(fColorTable, other.fColorTable);
137    SkTSwap(fPixelRef, other.fPixelRef);
138    SkTSwap(fPixelRefOffset, other.fPixelRefOffset);
139    SkTSwap(fPixelLockCount, other.fPixelLockCount);
140    SkTSwap(fMipMap, other.fMipMap);
141    SkTSwap(fPixels, other.fPixels);
142    SkTSwap(fRowBytes, other.fRowBytes);
143    SkTSwap(fWidth, other.fWidth);
144    SkTSwap(fHeight, other.fHeight);
145    SkTSwap(fConfig, other.fConfig);
146    SkTSwap(fFlags, other.fFlags);
147    SkTSwap(fBytesPerPixel, other.fBytesPerPixel);
148
149    SkDEBUGCODE(this->validate();)
150}
151
152void SkBitmap::reset() {
153    this->freePixels();
154    sk_bzero(this, sizeof(*this));
155}
156
157int SkBitmap::ComputeBytesPerPixel(SkBitmap::Config config) {
158    int bpp;
159    switch (config) {
160        case kNo_Config:
161        case kA1_Config:
162            bpp = 0;   // not applicable
163            break;
164        case kA8_Config:
165        case kIndex8_Config:
166            bpp = 1;
167            break;
168        case kRGB_565_Config:
169        case kARGB_4444_Config:
170            bpp = 2;
171            break;
172        case kARGB_8888_Config:
173            bpp = 4;
174            break;
175        default:
176            SkDEBUGFAIL("unknown config");
177            bpp = 0;   // error
178            break;
179    }
180    return bpp;
181}
182
183size_t SkBitmap::ComputeRowBytes(Config c, int width) {
184    if (width < 0) {
185        return 0;
186    }
187
188    Sk64 rowBytes;
189    rowBytes.setZero();
190
191    switch (c) {
192        case kNo_Config:
193            break;
194        case kA1_Config:
195            rowBytes.set(width);
196            rowBytes.add(7);
197            rowBytes.shiftRight(3);
198            break;
199        case kA8_Config:
200        case kIndex8_Config:
201            rowBytes.set(width);
202            break;
203        case kRGB_565_Config:
204        case kARGB_4444_Config:
205            rowBytes.set(width);
206            rowBytes.shiftLeft(1);
207            break;
208        case kARGB_8888_Config:
209            rowBytes.set(width);
210            rowBytes.shiftLeft(2);
211            break;
212        default:
213            SkDEBUGFAIL("unknown config");
214            break;
215    }
216    return isPos32Bits(rowBytes) ? rowBytes.get32() : 0;
217}
218
219Sk64 SkBitmap::ComputeSize64(Config c, int width, int height) {
220    Sk64 size;
221    size.setMul(SkToS32(SkBitmap::ComputeRowBytes(c, width)), height);
222    return size;
223}
224
225size_t SkBitmap::ComputeSize(Config c, int width, int height) {
226    Sk64 size = SkBitmap::ComputeSize64(c, width, height);
227    return isPos32Bits(size) ? size.get32() : 0;
228}
229
230Sk64 SkBitmap::ComputeSafeSize64(Config config,
231                                 uint32_t width,
232                                 uint32_t height,
233                                 size_t rowBytes) {
234    Sk64 safeSize;
235    safeSize.setZero();
236    if (height > 0) {
237        // TODO: Handle the case where the return value from
238        // ComputeRowBytes is more than 31 bits.
239        safeSize.set(SkToS32(ComputeRowBytes(config, width)));
240        Sk64 sizeAllButLastRow;
241        sizeAllButLastRow.setMul(height - 1, SkToS32(rowBytes));
242        safeSize.add(sizeAllButLastRow);
243    }
244    SkASSERT(!safeSize.isNeg());
245    return safeSize;
246}
247
248size_t SkBitmap::ComputeSafeSize(Config config,
249                                 uint32_t width,
250                                 uint32_t height,
251                                 size_t rowBytes) {
252    Sk64 safeSize = ComputeSafeSize64(config, width, height, rowBytes);
253    return (safeSize.is32() ? safeSize.get32() : 0);
254}
255
256void SkBitmap::getBounds(SkRect* bounds) const {
257    SkASSERT(bounds);
258    bounds->set(0, 0,
259                SkIntToScalar(fWidth), SkIntToScalar(fHeight));
260}
261
262void SkBitmap::getBounds(SkIRect* bounds) const {
263    SkASSERT(bounds);
264    bounds->set(0, 0, fWidth, fHeight);
265}
266
267///////////////////////////////////////////////////////////////////////////////
268
269void SkBitmap::setConfig(Config c, int width, int height, size_t rowBytes) {
270    this->freePixels();
271
272    if ((width | height) < 0) {
273        goto err;
274    }
275
276    if (rowBytes == 0) {
277        rowBytes = SkBitmap::ComputeRowBytes(c, width);
278        if (0 == rowBytes && kNo_Config != c) {
279            goto err;
280        }
281    }
282
283    fConfig     = SkToU8(c);
284    fWidth      = width;
285    fHeight     = height;
286    fRowBytes   = SkToU32(rowBytes);
287
288    fBytesPerPixel = (uint8_t)ComputeBytesPerPixel(c);
289
290    SkDEBUGCODE(this->validate();)
291    return;
292
293    // if we got here, we had an error, so we reset the bitmap to empty
294err:
295    this->reset();
296}
297
298void SkBitmap::updatePixelsFromRef() const {
299    if (NULL != fPixelRef) {
300        if (fPixelLockCount > 0) {
301            SkASSERT(fPixelRef->isLocked());
302
303            void* p = fPixelRef->pixels();
304            if (NULL != p) {
305                p = (char*)p + fPixelRefOffset;
306            }
307            fPixels = p;
308            SkRefCnt_SafeAssign(fColorTable, fPixelRef->colorTable());
309        } else {
310            SkASSERT(0 == fPixelLockCount);
311            fPixels = NULL;
312            if (fColorTable) {
313                fColorTable->unref();
314                fColorTable = NULL;
315            }
316        }
317    }
318}
319
320SkPixelRef* SkBitmap::setPixelRef(SkPixelRef* pr, size_t offset) {
321    // do this first, we that we never have a non-zero offset with a null ref
322    if (NULL == pr) {
323        offset = 0;
324    }
325
326    if (fPixelRef != pr || fPixelRefOffset != offset) {
327        if (fPixelRef != pr) {
328            this->freePixels();
329            SkASSERT(NULL == fPixelRef);
330
331            SkSafeRef(pr);
332            fPixelRef = pr;
333        }
334        fPixelRefOffset = offset;
335        this->updatePixelsFromRef();
336    }
337
338    SkDEBUGCODE(this->validate();)
339    return pr;
340}
341
342void SkBitmap::lockPixels() const {
343    if (NULL != fPixelRef && 1 == ++fPixelLockCount) {
344        fPixelRef->lockPixels();
345        this->updatePixelsFromRef();
346    }
347    SkDEBUGCODE(this->validate();)
348}
349
350void SkBitmap::unlockPixels() const {
351    SkASSERT(NULL == fPixelRef || fPixelLockCount > 0);
352
353    if (NULL != fPixelRef && 0 == --fPixelLockCount) {
354        fPixelRef->unlockPixels();
355        this->updatePixelsFromRef();
356    }
357    SkDEBUGCODE(this->validate();)
358}
359
360bool SkBitmap::lockPixelsAreWritable() const {
361    return (fPixelRef) ? fPixelRef->lockPixelsAreWritable() : false;
362}
363
364void SkBitmap::setPixels(void* p, SkColorTable* ctable) {
365    if (NULL == p) {
366        this->setPixelRef(NULL, 0);
367        return;
368    }
369
370    Sk64 size = this->getSize64();
371    SkASSERT(!size.isNeg() && size.is32());
372
373    this->setPixelRef(new SkMallocPixelRef(p, size.get32(), ctable, false))->unref();
374    // since we're already allocated, we lockPixels right away
375    this->lockPixels();
376    SkDEBUGCODE(this->validate();)
377}
378
379bool SkBitmap::allocPixels(Allocator* allocator, SkColorTable* ctable) {
380    HeapAllocator stdalloc;
381
382    if (NULL == allocator) {
383        allocator = &stdalloc;
384    }
385    return allocator->allocPixelRef(this, ctable);
386}
387
388void SkBitmap::freePixels() {
389    // if we're gonna free the pixels, we certainly need to free the mipmap
390    this->freeMipMap();
391
392    if (fColorTable) {
393        fColorTable->unref();
394        fColorTable = NULL;
395    }
396
397    if (NULL != fPixelRef) {
398        if (fPixelLockCount > 0) {
399            fPixelRef->unlockPixels();
400        }
401        fPixelRef->unref();
402        fPixelRef = NULL;
403        fPixelRefOffset = 0;
404    }
405    fPixelLockCount = 0;
406    fPixels = NULL;
407}
408
409void SkBitmap::freeMipMap() {
410    if (fMipMap) {
411        fMipMap->unref();
412        fMipMap = NULL;
413    }
414}
415
416uint32_t SkBitmap::getGenerationID() const {
417    return (fPixelRef) ? fPixelRef->getGenerationID() : 0;
418}
419
420void SkBitmap::notifyPixelsChanged() const {
421    SkASSERT(!this->isImmutable());
422    if (fPixelRef) {
423        fPixelRef->notifyPixelsChanged();
424    }
425}
426
427GrTexture* SkBitmap::getTexture() const {
428    return fPixelRef ? fPixelRef->getTexture() : NULL;
429}
430
431///////////////////////////////////////////////////////////////////////////////
432
433/** We explicitly use the same allocator for our pixels that SkMask does,
434 so that we can freely assign memory allocated by one class to the other.
435 */
436bool SkBitmap::HeapAllocator::allocPixelRef(SkBitmap* dst,
437                                            SkColorTable* ctable) {
438    Sk64 size = dst->getSize64();
439    if (size.isNeg() || !size.is32()) {
440        return false;
441    }
442
443    void* addr = sk_malloc_flags(size.get32(), 0);  // returns NULL on failure
444    if (NULL == addr) {
445        return false;
446    }
447
448    dst->setPixelRef(new SkMallocPixelRef(addr, size.get32(), ctable))->unref();
449    // since we're already allocated, we lockPixels right away
450    dst->lockPixels();
451    return true;
452}
453
454///////////////////////////////////////////////////////////////////////////////
455
456size_t SkBitmap::getSafeSize() const {
457    // This is intended to be a size_t version of ComputeSafeSize64(), just
458    // faster. The computation is meant to be identical.
459    return (fHeight ? ((fHeight - 1) * fRowBytes) +
460            ComputeRowBytes(getConfig(), fWidth): 0);
461}
462
463Sk64 SkBitmap::getSafeSize64() const {
464    return ComputeSafeSize64(getConfig(), fWidth, fHeight, fRowBytes);
465}
466
467bool SkBitmap::copyPixelsTo(void* const dst, size_t dstSize,
468                            size_t dstRowBytes, bool preserveDstPad) const {
469
470    if (0 == dstRowBytes) {
471        dstRowBytes = fRowBytes;
472    }
473
474    if (dstRowBytes < ComputeRowBytes(getConfig(), fWidth) ||
475        dst == NULL || (getPixels() == NULL && pixelRef() == NULL))
476        return false;
477
478    if (!preserveDstPad && static_cast<uint32_t>(dstRowBytes) == fRowBytes) {
479        size_t safeSize = getSafeSize();
480        if (safeSize > dstSize || safeSize == 0)
481            return false;
482        else {
483            SkAutoLockPixels lock(*this);
484            // This implementation will write bytes beyond the end of each row,
485            // excluding the last row, if the bitmap's stride is greater than
486            // strictly required by the current config.
487            memcpy(dst, getPixels(), safeSize);
488
489            return true;
490        }
491    } else {
492        // If destination has different stride than us, then copy line by line.
493        if (ComputeSafeSize(getConfig(), fWidth, fHeight, dstRowBytes) >
494            dstSize)
495            return false;
496        else {
497            // Just copy what we need on each line.
498            size_t rowBytes = ComputeRowBytes(getConfig(), fWidth);
499            SkAutoLockPixels lock(*this);
500            const uint8_t* srcP = reinterpret_cast<const uint8_t*>(getPixels());
501            uint8_t* dstP = reinterpret_cast<uint8_t*>(dst);
502            for (uint32_t row = 0; row < fHeight;
503                 row++, srcP += fRowBytes, dstP += dstRowBytes) {
504                memcpy(dstP, srcP, rowBytes);
505            }
506
507            return true;
508        }
509    }
510}
511
512///////////////////////////////////////////////////////////////////////////////
513
514bool SkBitmap::isImmutable() const {
515    return fPixelRef ? fPixelRef->isImmutable() :
516        fFlags & kImageIsImmutable_Flag;
517}
518
519void SkBitmap::setImmutable() {
520    if (fPixelRef) {
521        fPixelRef->setImmutable();
522    } else {
523        fFlags |= kImageIsImmutable_Flag;
524    }
525}
526
527bool SkBitmap::isOpaque() const {
528    switch (fConfig) {
529        case kNo_Config:
530            return true;
531
532        case kA1_Config:
533        case kA8_Config:
534        case kARGB_4444_Config:
535        case kARGB_8888_Config:
536            return (fFlags & kImageIsOpaque_Flag) != 0;
537
538        case kIndex8_Config: {
539            uint32_t flags = 0;
540
541            this->lockPixels();
542            // if lockPixels failed, we may not have a ctable ptr
543            if (fColorTable) {
544                flags = fColorTable->getFlags();
545            }
546            this->unlockPixels();
547
548            return (flags & SkColorTable::kColorsAreOpaque_Flag) != 0;
549        }
550
551        case kRGB_565_Config:
552            return true;
553
554        default:
555            SkDEBUGFAIL("unknown bitmap config pased to isOpaque");
556            return false;
557    }
558}
559
560void SkBitmap::setIsOpaque(bool isOpaque) {
561    /*  we record this regardless of fConfig, though it is ignored in
562        isOpaque() for configs that can't support per-pixel alpha.
563    */
564    if (isOpaque) {
565        fFlags |= kImageIsOpaque_Flag;
566    } else {
567        fFlags &= ~kImageIsOpaque_Flag;
568    }
569}
570
571bool SkBitmap::isVolatile() const {
572    return (fFlags & kImageIsVolatile_Flag) != 0;
573}
574
575void SkBitmap::setIsVolatile(bool isVolatile) {
576    if (isVolatile) {
577        fFlags |= kImageIsVolatile_Flag;
578    } else {
579        fFlags &= ~kImageIsVolatile_Flag;
580    }
581}
582
583void* SkBitmap::getAddr(int x, int y) const {
584    SkASSERT((unsigned)x < (unsigned)this->width());
585    SkASSERT((unsigned)y < (unsigned)this->height());
586
587    char* base = (char*)this->getPixels();
588    if (base) {
589        base += y * this->rowBytes();
590        switch (this->config()) {
591            case SkBitmap::kARGB_8888_Config:
592                base += x << 2;
593                break;
594            case SkBitmap::kARGB_4444_Config:
595            case SkBitmap::kRGB_565_Config:
596                base += x << 1;
597                break;
598            case SkBitmap::kA8_Config:
599            case SkBitmap::kIndex8_Config:
600                base += x;
601                break;
602            case SkBitmap::kA1_Config:
603                base += x >> 3;
604                break;
605            default:
606                SkDEBUGFAIL("Can't return addr for config");
607                base = NULL;
608                break;
609        }
610    }
611    return base;
612}
613
614SkColor SkBitmap::getColor(int x, int y) const {
615    SkASSERT((unsigned)x < (unsigned)this->width());
616    SkASSERT((unsigned)y < (unsigned)this->height());
617
618    switch (this->config()) {
619        case SkBitmap::kA1_Config: {
620            uint8_t* addr = this->getAddr1(x, y);
621            uint8_t mask = 1 << (7  - (x % 8));
622            if (addr[0] & mask) {
623                return SK_ColorBLACK;
624            } else {
625                return 0;
626            }
627        }
628        case SkBitmap::kA8_Config: {
629            uint8_t* addr = this->getAddr8(x, y);
630            return SkColorSetA(0, addr[0]);
631        }
632        case SkBitmap::kIndex8_Config: {
633            SkPMColor c = this->getIndex8Color(x, y);
634            return SkUnPreMultiply::PMColorToColor(c);
635        }
636        case SkBitmap::kRGB_565_Config: {
637            uint16_t* addr = this->getAddr16(x, y);
638            return SkPixel16ToColor(addr[0]);
639        }
640        case SkBitmap::kARGB_4444_Config: {
641            uint16_t* addr = this->getAddr16(x, y);
642            SkPMColor c = SkPixel4444ToPixel32(addr[0]);
643            return SkUnPreMultiply::PMColorToColor(c);
644        }
645        case SkBitmap::kARGB_8888_Config: {
646            uint32_t* addr = this->getAddr32(x, y);
647            return SkUnPreMultiply::PMColorToColor(addr[0]);
648        }
649        case kNo_Config:
650            SkASSERT(false);
651            return 0;
652    }
653    SkASSERT(false);  // Not reached.
654    return 0;
655}
656
657bool SkBitmap::ComputeIsOpaque(const SkBitmap& bm) {
658    SkAutoLockPixels alp(bm);
659    if (!bm.getPixels()) {
660        return false;
661    }
662
663    const int height = bm.height();
664    const int width = bm.width();
665
666    switch (bm.config()) {
667        case SkBitmap::kA1_Config: {
668            // TODO
669        } break;
670        case SkBitmap::kA8_Config: {
671            unsigned a = 0xFF;
672            for (int y = 0; y < height; ++y) {
673                const uint8_t* row = bm.getAddr8(0, y);
674                for (int x = 0; x < width; ++x) {
675                    a &= row[x];
676                }
677                if (0xFF != a) {
678                    return false;
679                }
680            }
681            return true;
682        } break;
683        case SkBitmap::kIndex8_Config: {
684            SkAutoLockColors alc(bm);
685            const SkPMColor* table = alc.colors();
686            if (!table) {
687                return false;
688            }
689            SkPMColor c = (SkPMColor)~0;
690            for (int i = bm.getColorTable()->count() - 1; i >= 0; --i) {
691                c &= table[i];
692            }
693            return 0xFF == SkGetPackedA32(c);
694        } break;
695        case SkBitmap::kRGB_565_Config:
696            return true;
697            break;
698        case SkBitmap::kARGB_4444_Config: {
699            unsigned c = 0xFFFF;
700            for (int y = 0; y < height; ++y) {
701                const SkPMColor16* row = bm.getAddr16(0, y);
702                for (int x = 0; x < width; ++x) {
703                    c &= row[x];
704                }
705                if (0xF != SkGetPackedA4444(c)) {
706                    return false;
707                }
708            }
709            return true;
710        } break;
711        case SkBitmap::kARGB_8888_Config: {
712            SkPMColor c = (SkPMColor)~0;
713            for (int y = 0; y < height; ++y) {
714                const SkPMColor* row = bm.getAddr32(0, y);
715                for (int x = 0; x < width; ++x) {
716                    c &= row[x];
717                }
718                if (0xFF != SkGetPackedA32(c)) {
719                    return false;
720                }
721            }
722            return true;
723        }
724        default:
725            break;
726    }
727    return false;
728}
729
730
731///////////////////////////////////////////////////////////////////////////////
732///////////////////////////////////////////////////////////////////////////////
733
734static uint16_t pack_8888_to_4444(unsigned a, unsigned r, unsigned g, unsigned b) {
735    unsigned pixel = (SkA32To4444(a) << SK_A4444_SHIFT) |
736                     (SkR32To4444(r) << SK_R4444_SHIFT) |
737                     (SkG32To4444(g) << SK_G4444_SHIFT) |
738                     (SkB32To4444(b) << SK_B4444_SHIFT);
739    return SkToU16(pixel);
740}
741
742void SkBitmap::internalErase(const SkIRect& area,
743                             U8CPU a, U8CPU r, U8CPU g, U8CPU b) const {
744#ifdef SK_DEBUG
745    SkDEBUGCODE(this->validate();)
746    SkASSERT(!area.isEmpty());
747    {
748        SkIRect total = { 0, 0, this->width(), this->height() };
749        SkASSERT(total.contains(area));
750    }
751#endif
752
753    if (kNo_Config == fConfig || kIndex8_Config == fConfig) {
754        return;
755    }
756
757    SkAutoLockPixels alp(*this);
758    // perform this check after the lock call
759    if (!this->readyToDraw()) {
760        return;
761    }
762
763    int height = area.height();
764    const int width = area.width();
765    const int rowBytes = fRowBytes;
766
767    // make rgb premultiplied
768    if (255 != a) {
769        r = SkAlphaMul(r, a);
770        g = SkAlphaMul(g, a);
771        b = SkAlphaMul(b, a);
772    }
773
774    switch (fConfig) {
775        case kA1_Config: {
776            uint8_t* p = this->getAddr1(area.fLeft, area.fTop);
777            const int left = area.fLeft >> 3;
778            const int right = area.fRight >> 3;
779
780            int middle = right - left - 1;
781
782            uint8_t leftMask = 0xFF >> (area.fLeft & 7);
783            uint8_t rightMask = ~(0xFF >> (area.fRight & 7));
784            if (left == right) {
785                leftMask &= rightMask;
786                rightMask = 0;
787            }
788
789            a = (a >> 7) ? 0xFF : 0;
790            while (--height >= 0) {
791                uint8_t* startP = p;
792
793                *p = (*p & ~leftMask) | (a & leftMask);
794                p++;
795                if (middle > 0) {
796                    memset(p, a, middle);
797                    p += middle;
798                }
799                if (rightMask) {
800                    *p = (*p & ~rightMask) | (a & rightMask);
801                }
802
803                p = startP + rowBytes;
804            }
805            break;
806        }
807        case kA8_Config: {
808            uint8_t* p = this->getAddr8(area.fLeft, area.fTop);
809            while (--height >= 0) {
810                memset(p, a, width);
811                p += rowBytes;
812            }
813            break;
814        }
815        case kARGB_4444_Config:
816        case kRGB_565_Config: {
817            uint16_t* p = this->getAddr16(area.fLeft, area.fTop);;
818            uint16_t v;
819
820            if (kARGB_4444_Config == fConfig) {
821                v = pack_8888_to_4444(a, r, g, b);
822            } else {
823                v = SkPackRGB16(r >> (8 - SK_R16_BITS),
824                                g >> (8 - SK_G16_BITS),
825                                b >> (8 - SK_B16_BITS));
826            }
827            while (--height >= 0) {
828                sk_memset16(p, v, width);
829                p = (uint16_t*)((char*)p + rowBytes);
830            }
831            break;
832        }
833        case kARGB_8888_Config: {
834            uint32_t* p = this->getAddr32(area.fLeft, area.fTop);
835            uint32_t  v = SkPackARGB32(a, r, g, b);
836
837            while (--height >= 0) {
838                sk_memset32(p, v, width);
839                p = (uint32_t*)((char*)p + rowBytes);
840            }
841            break;
842        }
843    }
844
845    this->notifyPixelsChanged();
846}
847
848void SkBitmap::eraseARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b) const {
849    SkIRect area = { 0, 0, this->width(), this->height() };
850    if (!area.isEmpty()) {
851        this->internalErase(area, a, r, g, b);
852    }
853}
854
855void SkBitmap::eraseArea(const SkIRect& rect, SkColor c) const {
856    SkIRect area = { 0, 0, this->width(), this->height() };
857    if (area.intersect(rect)) {
858        this->internalErase(area, SkColorGetA(c), SkColorGetR(c),
859                            SkColorGetG(c), SkColorGetB(c));
860    }
861}
862
863//////////////////////////////////////////////////////////////////////////////////////
864//////////////////////////////////////////////////////////////////////////////////////
865
866#define SUB_OFFSET_FAILURE  ((size_t)-1)
867
868/**
869 *  Based on the Config and rowBytes() of bm, return the offset into an SkPixelRef of the pixel at
870 *  (x, y).
871 *  Note that the SkPixelRef does not need to be set yet. deepCopyTo takes advantage of this fact.
872 *  Also note that (x, y) may be outside the range of (0 - width(), 0 - height()), so long as it is
873 *  within the bounds of the SkPixelRef being used.
874 */
875static size_t get_sub_offset(const SkBitmap& bm, int x, int y) {
876    switch (bm.getConfig()) {
877        case SkBitmap::kA8_Config:
878        case SkBitmap:: kIndex8_Config:
879            // x is fine as is for the calculation
880            break;
881
882        case SkBitmap::kRGB_565_Config:
883        case SkBitmap::kARGB_4444_Config:
884            x <<= 1;
885            break;
886
887        case SkBitmap::kARGB_8888_Config:
888            x <<= 2;
889            break;
890
891        case SkBitmap::kNo_Config:
892        case SkBitmap::kA1_Config:
893        default:
894            return SUB_OFFSET_FAILURE;
895    }
896    return y * bm.rowBytes() + x;
897}
898
899/**
900 *  Using the pixelRefOffset(), rowBytes(), and Config of bm, determine the (x, y) coordinate of the
901 *  upper left corner of bm relative to its SkPixelRef.
902 *  x and y must be non-NULL.
903 */
904bool get_upper_left_from_offset(SkBitmap::Config config, size_t offset, size_t rowBytes,
905                                   int32_t* x, int32_t* y);
906bool get_upper_left_from_offset(SkBitmap::Config config, size_t offset, size_t rowBytes,
907                                   int32_t* x, int32_t* y) {
908    SkASSERT(x != NULL && y != NULL);
909    if (0 == offset) {
910        *x = *y = 0;
911        return true;
912    }
913    // Use integer division to find the correct y position.
914    *y = SkToS32(offset / rowBytes);
915    // The remainder will be the x position, after we reverse get_sub_offset.
916    *x = SkToS32(offset % rowBytes);
917    switch (config) {
918        case SkBitmap::kA8_Config:
919            // Fall through.
920        case SkBitmap::kIndex8_Config:
921            // x is unmodified
922            break;
923
924        case SkBitmap::kRGB_565_Config:
925            // Fall through.
926        case SkBitmap::kARGB_4444_Config:
927            *x >>= 1;
928            break;
929
930        case SkBitmap::kARGB_8888_Config:
931            *x >>= 2;
932            break;
933
934        case SkBitmap::kNo_Config:
935            // Fall through.
936        case SkBitmap::kA1_Config:
937            // Fall through.
938        default:
939            return false;
940    }
941    return true;
942}
943
944static bool get_upper_left_from_offset(const SkBitmap& bm, int32_t* x, int32_t* y) {
945    return get_upper_left_from_offset(bm.config(), bm.pixelRefOffset(), bm.rowBytes(), x, y);
946}
947
948bool SkBitmap::extractSubset(SkBitmap* result, const SkIRect& subset) const {
949    SkDEBUGCODE(this->validate();)
950
951    if (NULL == result || NULL == fPixelRef) {
952        return false;   // no src pixels
953    }
954
955    SkIRect srcRect, r;
956    srcRect.set(0, 0, this->width(), this->height());
957    if (!r.intersect(srcRect, subset)) {
958        return false;   // r is empty (i.e. no intersection)
959    }
960
961    if (fPixelRef->getTexture() != NULL) {
962        // Do a deep copy
963        SkPixelRef* pixelRef = fPixelRef->deepCopy(this->config(), &subset);
964        if (pixelRef != NULL) {
965            SkBitmap dst;
966            dst.setConfig(this->config(), subset.width(), subset.height());
967            dst.setIsVolatile(this->isVolatile());
968            dst.setIsOpaque(this->isOpaque());
969            dst.setPixelRef(pixelRef)->unref();
970            SkDEBUGCODE(dst.validate());
971            result->swap(dst);
972            return true;
973        }
974    }
975
976    // If the upper left of the rectangle was outside the bounds of this SkBitmap, we should have
977    // exited above.
978    SkASSERT(static_cast<unsigned>(r.fLeft) < static_cast<unsigned>(this->width()));
979    SkASSERT(static_cast<unsigned>(r.fTop) < static_cast<unsigned>(this->height()));
980
981    size_t offset = get_sub_offset(*this, r.fLeft, r.fTop);
982    if (SUB_OFFSET_FAILURE == offset) {
983        return false;   // config not supported
984    }
985
986    SkBitmap dst;
987    dst.setConfig(this->config(), r.width(), r.height(), this->rowBytes());
988    dst.setIsVolatile(this->isVolatile());
989    dst.setIsOpaque(this->isOpaque());
990
991    if (fPixelRef) {
992        // share the pixelref with a custom offset
993        dst.setPixelRef(fPixelRef, fPixelRefOffset + offset);
994    }
995    SkDEBUGCODE(dst.validate();)
996
997    // we know we're good, so commit to result
998    result->swap(dst);
999    return true;
1000}
1001
1002///////////////////////////////////////////////////////////////////////////////
1003
1004#include "SkCanvas.h"
1005#include "SkPaint.h"
1006
1007bool SkBitmap::canCopyTo(Config dstConfig) const {
1008    if (this->getConfig() == kNo_Config) {
1009        return false;
1010    }
1011
1012    bool sameConfigs = (this->config() == dstConfig);
1013    switch (dstConfig) {
1014        case kA8_Config:
1015        case kRGB_565_Config:
1016        case kARGB_8888_Config:
1017            break;
1018        case kA1_Config:
1019        case kIndex8_Config:
1020        case kARGB_4444_Config:
1021            if (!sameConfigs) {
1022                return false;
1023            }
1024            break;
1025        default:
1026            return false;
1027    }
1028
1029    // do not copy src if srcConfig == kA1_Config while dstConfig != kA1_Config
1030    if (this->getConfig() == kA1_Config && !sameConfigs) {
1031        return false;
1032    }
1033
1034    return true;
1035}
1036
1037bool SkBitmap::copyTo(SkBitmap* dst, Config dstConfig, Allocator* alloc) const {
1038    if (!this->canCopyTo(dstConfig)) {
1039        return false;
1040    }
1041
1042    // if we have a texture, first get those pixels
1043    SkBitmap tmpSrc;
1044    const SkBitmap* src = this;
1045
1046    if (fPixelRef) {
1047        SkIRect subset;
1048        if (get_upper_left_from_offset(*this, &subset.fLeft, &subset.fTop)) {
1049            subset.fRight = subset.fLeft + fWidth;
1050            subset.fBottom = subset.fTop + fHeight;
1051            if (fPixelRef->readPixels(&tmpSrc, &subset)) {
1052                SkASSERT(tmpSrc.width() == this->width());
1053                SkASSERT(tmpSrc.height() == this->height());
1054
1055                // did we get lucky and we can just return tmpSrc?
1056                if (tmpSrc.config() == dstConfig && NULL == alloc) {
1057                    dst->swap(tmpSrc);
1058                    if (dst->pixelRef() && this->config() == dstConfig) {
1059                        dst->pixelRef()->fGenerationID = fPixelRef->getGenerationID();
1060                    }
1061                    return true;
1062                }
1063
1064                // fall through to the raster case
1065                src = &tmpSrc;
1066            }
1067        }
1068    }
1069
1070    // we lock this now, since we may need its colortable
1071    SkAutoLockPixels srclock(*src);
1072    if (!src->readyToDraw()) {
1073        return false;
1074    }
1075
1076    SkBitmap tmpDst;
1077    tmpDst.setConfig(dstConfig, src->width(), src->height());
1078
1079    // allocate colortable if srcConfig == kIndex8_Config
1080    SkColorTable* ctable = (dstConfig == kIndex8_Config) ?
1081    new SkColorTable(*src->getColorTable()) : NULL;
1082    SkAutoUnref au(ctable);
1083    if (!tmpDst.allocPixels(alloc, ctable)) {
1084        return false;
1085    }
1086
1087    if (!tmpDst.readyToDraw()) {
1088        // allocator/lock failed
1089        return false;
1090    }
1091
1092    /* do memcpy for the same configs cases, else use drawing
1093    */
1094    if (src->config() == dstConfig) {
1095        if (tmpDst.getSize() == src->getSize()) {
1096            memcpy(tmpDst.getPixels(), src->getPixels(), src->getSafeSize());
1097            SkPixelRef* pixelRef = tmpDst.pixelRef();
1098            if (pixelRef != NULL) {
1099                pixelRef->fGenerationID = this->getGenerationID();
1100            }
1101        } else {
1102            const char* srcP = reinterpret_cast<const char*>(src->getPixels());
1103            char* dstP = reinterpret_cast<char*>(tmpDst.getPixels());
1104            // to be sure we don't read too much, only copy our logical pixels
1105            size_t bytesToCopy = tmpDst.width() * tmpDst.bytesPerPixel();
1106            for (int y = 0; y < tmpDst.height(); y++) {
1107                memcpy(dstP, srcP, bytesToCopy);
1108                srcP += src->rowBytes();
1109                dstP += tmpDst.rowBytes();
1110            }
1111        }
1112    } else {
1113        // if the src has alpha, we have to clear the dst first
1114        if (!src->isOpaque()) {
1115            tmpDst.eraseColor(SK_ColorTRANSPARENT);
1116        }
1117
1118        SkCanvas canvas(tmpDst);
1119        SkPaint  paint;
1120
1121        paint.setDither(true);
1122        canvas.drawBitmap(*src, 0, 0, &paint);
1123    }
1124
1125    tmpDst.setIsOpaque(src->isOpaque());
1126
1127    dst->swap(tmpDst);
1128    return true;
1129}
1130
1131bool SkBitmap::deepCopyTo(SkBitmap* dst, Config dstConfig) const {
1132    if (!this->canCopyTo(dstConfig)) {
1133        return false;
1134    }
1135
1136    // If we have a PixelRef, and it supports deep copy, use it.
1137    // Currently supported only by texture-backed bitmaps.
1138    if (fPixelRef) {
1139        SkPixelRef* pixelRef = fPixelRef->deepCopy(dstConfig);
1140        if (pixelRef) {
1141            uint32_t rowBytes;
1142            if (dstConfig == fConfig) {
1143                pixelRef->fGenerationID = fPixelRef->getGenerationID();
1144                // Use the same rowBytes as the original.
1145                rowBytes = fRowBytes;
1146            } else {
1147                // With the new config, an appropriate fRowBytes will be computed by setConfig.
1148                rowBytes = 0;
1149            }
1150            dst->setConfig(dstConfig, fWidth, fHeight, rowBytes);
1151
1152            size_t pixelRefOffset;
1153            if (0 == fPixelRefOffset || dstConfig == fConfig) {
1154                // Use the same offset as the original.
1155                pixelRefOffset = fPixelRefOffset;
1156            } else {
1157                // Find the correct offset in the new config. This needs to be done after calling
1158                // setConfig so dst's fConfig and fRowBytes have been set properly.
1159                int32_t x, y;
1160                if (!get_upper_left_from_offset(*this, &x, &y)) {
1161                    return false;
1162                }
1163                pixelRefOffset = get_sub_offset(*dst, x, y);
1164                if (SUB_OFFSET_FAILURE == pixelRefOffset) {
1165                    return false;
1166                }
1167            }
1168            dst->setPixelRef(pixelRef, pixelRefOffset)->unref();
1169            return true;
1170        }
1171    }
1172
1173    if (this->getTexture()) {
1174        return false;
1175    } else {
1176        return this->copyTo(dst, dstConfig, NULL);
1177    }
1178}
1179
1180///////////////////////////////////////////////////////////////////////////////
1181///////////////////////////////////////////////////////////////////////////////
1182
1183static void downsampleby2_proc32(SkBitmap* dst, int x, int y,
1184                                 const SkBitmap& src) {
1185    x <<= 1;
1186    y <<= 1;
1187    const SkPMColor* p = src.getAddr32(x, y);
1188    const SkPMColor* baseP = p;
1189    SkPMColor c, ag, rb;
1190
1191    c = *p; ag = (c >> 8) & 0xFF00FF; rb = c & 0xFF00FF;
1192    if (x < src.width() - 1) {
1193        p += 1;
1194    }
1195    c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF;
1196
1197    p = baseP;
1198    if (y < src.height() - 1) {
1199        p += src.rowBytes() >> 2;
1200    }
1201    c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF;
1202    if (x < src.width() - 1) {
1203        p += 1;
1204    }
1205    c = *p; ag += (c >> 8) & 0xFF00FF; rb += c & 0xFF00FF;
1206
1207    *dst->getAddr32(x >> 1, y >> 1) =
1208        ((rb >> 2) & 0xFF00FF) | ((ag << 6) & 0xFF00FF00);
1209}
1210
1211static inline uint32_t expand16(U16CPU c) {
1212    return (c & ~SK_G16_MASK_IN_PLACE) | ((c & SK_G16_MASK_IN_PLACE) << 16);
1213}
1214
1215// returns dirt in the top 16bits, but we don't care, since we only
1216// store the low 16bits.
1217static inline U16CPU pack16(uint32_t c) {
1218    return (c & ~SK_G16_MASK_IN_PLACE) | ((c >> 16) & SK_G16_MASK_IN_PLACE);
1219}
1220
1221static void downsampleby2_proc16(SkBitmap* dst, int x, int y,
1222                                 const SkBitmap& src) {
1223    x <<= 1;
1224    y <<= 1;
1225    const uint16_t* p = src.getAddr16(x, y);
1226    const uint16_t* baseP = p;
1227    SkPMColor       c;
1228
1229    c = expand16(*p);
1230    if (x < src.width() - 1) {
1231        p += 1;
1232    }
1233    c += expand16(*p);
1234
1235    p = baseP;
1236    if (y < src.height() - 1) {
1237        p += src.rowBytes() >> 1;
1238    }
1239    c += expand16(*p);
1240    if (x < src.width() - 1) {
1241        p += 1;
1242    }
1243    c += expand16(*p);
1244
1245    *dst->getAddr16(x >> 1, y >> 1) = (uint16_t)pack16(c >> 2);
1246}
1247
1248static uint32_t expand4444(U16CPU c) {
1249    return (c & 0xF0F) | ((c & ~0xF0F) << 12);
1250}
1251
1252static U16CPU collaps4444(uint32_t c) {
1253    return (c & 0xF0F) | ((c >> 12) & ~0xF0F);
1254}
1255
1256static void downsampleby2_proc4444(SkBitmap* dst, int x, int y,
1257                                   const SkBitmap& src) {
1258    x <<= 1;
1259    y <<= 1;
1260    const uint16_t* p = src.getAddr16(x, y);
1261    const uint16_t* baseP = p;
1262    uint32_t        c;
1263
1264    c = expand4444(*p);
1265    if (x < src.width() - 1) {
1266        p += 1;
1267    }
1268    c += expand4444(*p);
1269
1270    p = baseP;
1271    if (y < src.height() - 1) {
1272        p += src.rowBytes() >> 1;
1273    }
1274    c += expand4444(*p);
1275    if (x < src.width() - 1) {
1276        p += 1;
1277    }
1278    c += expand4444(*p);
1279
1280    *dst->getAddr16(x >> 1, y >> 1) = (uint16_t)collaps4444(c >> 2);
1281}
1282
1283void SkBitmap::buildMipMap(bool forceRebuild) {
1284    if (forceRebuild)
1285        this->freeMipMap();
1286    else if (fMipMap)
1287        return; // we're already built
1288
1289    SkASSERT(NULL == fMipMap);
1290
1291    void (*proc)(SkBitmap* dst, int x, int y, const SkBitmap& src);
1292
1293    const SkBitmap::Config config = this->getConfig();
1294
1295    switch (config) {
1296        case kARGB_8888_Config:
1297            proc = downsampleby2_proc32;
1298            break;
1299        case kRGB_565_Config:
1300            proc = downsampleby2_proc16;
1301            break;
1302        case kARGB_4444_Config:
1303            proc = downsampleby2_proc4444;
1304            break;
1305        case kIndex8_Config:
1306        case kA8_Config:
1307        default:
1308            return; // don't build mipmaps for these configs
1309    }
1310
1311    SkAutoLockPixels alp(*this);
1312    if (!this->readyToDraw()) {
1313        return;
1314    }
1315
1316    // whip through our loop to compute the exact size needed
1317    size_t  size = 0;
1318    int     maxLevels = 0;
1319    {
1320        int width = this->width();
1321        int height = this->height();
1322        for (;;) {
1323            width >>= 1;
1324            height >>= 1;
1325            if (0 == width || 0 == height) {
1326                break;
1327            }
1328            size += ComputeRowBytes(config, width) * height;
1329            maxLevels += 1;
1330        }
1331    }
1332
1333    // nothing to build
1334    if (0 == maxLevels) {
1335        return;
1336    }
1337
1338    SkBitmap srcBM(*this);
1339    srcBM.lockPixels();
1340    if (!srcBM.readyToDraw()) {
1341        return;
1342    }
1343
1344    MipMap* mm = MipMap::Alloc(maxLevels, size);
1345    if (NULL == mm) {
1346        return;
1347    }
1348
1349    MipLevel*   level = mm->levels();
1350    uint8_t*    addr = (uint8_t*)mm->pixels();
1351    int         width = this->width();
1352    int         height = this->height();
1353    uint32_t    rowBytes;
1354    SkBitmap    dstBM;
1355
1356    for (int i = 0; i < maxLevels; i++) {
1357        width >>= 1;
1358        height >>= 1;
1359        rowBytes = SkToU32(ComputeRowBytes(config, width));
1360
1361        level[i].fPixels   = addr;
1362        level[i].fWidth    = width;
1363        level[i].fHeight   = height;
1364        level[i].fRowBytes = rowBytes;
1365
1366        dstBM.setConfig(config, width, height, rowBytes);
1367        dstBM.setPixels(addr);
1368
1369        srcBM.lockPixels();
1370        for (int y = 0; y < height; y++) {
1371            for (int x = 0; x < width; x++) {
1372                proc(&dstBM, x, y, srcBM);
1373            }
1374        }
1375        srcBM.unlockPixels();
1376
1377        srcBM = dstBM;
1378        addr += height * rowBytes;
1379    }
1380    SkASSERT(addr == (uint8_t*)mm->pixels() + size);
1381    fMipMap = mm;
1382}
1383
1384bool SkBitmap::hasMipMap() const {
1385    return fMipMap != NULL;
1386}
1387
1388int SkBitmap::extractMipLevel(SkBitmap* dst, SkFixed sx, SkFixed sy) {
1389    if (NULL == fMipMap) {
1390        return 0;
1391    }
1392
1393    int level = ComputeMipLevel(sx, sy) >> 16;
1394    SkASSERT(level >= 0);
1395    if (level <= 0) {
1396        return 0;
1397    }
1398
1399    if (level >= fMipMap->fLevelCount) {
1400        level = fMipMap->fLevelCount - 1;
1401    }
1402    if (dst) {
1403        const MipLevel& mip = fMipMap->levels()[level - 1];
1404        dst->setConfig((SkBitmap::Config)this->config(),
1405                       mip.fWidth, mip.fHeight, mip.fRowBytes);
1406        dst->setPixels(mip.fPixels);
1407    }
1408    return level;
1409}
1410
1411SkFixed SkBitmap::ComputeMipLevel(SkFixed sx, SkFixed sy) {
1412    sx = SkAbs32(sx);
1413    sy = SkAbs32(sy);
1414    if (sx < sy) {
1415        sx = sy;
1416    }
1417    if (sx < SK_Fixed1) {
1418        return 0;
1419    }
1420    int clz = SkCLZ(sx);
1421    SkASSERT(clz >= 1 && clz <= 15);
1422    return SkIntToFixed(15 - clz) + ((unsigned)(sx << (clz + 1)) >> 16);
1423}
1424
1425///////////////////////////////////////////////////////////////////////////////
1426
1427static bool GetBitmapAlpha(const SkBitmap& src, uint8_t* SK_RESTRICT alpha,
1428                           int alphaRowBytes) {
1429    SkASSERT(alpha != NULL);
1430    SkASSERT(alphaRowBytes >= src.width());
1431
1432    SkBitmap::Config config = src.getConfig();
1433    int              w = src.width();
1434    int              h = src.height();
1435    size_t           rb = src.rowBytes();
1436
1437    SkAutoLockPixels alp(src);
1438    if (!src.readyToDraw()) {
1439        // zero out the alpha buffer and return
1440        while (--h >= 0) {
1441            memset(alpha, 0, w);
1442            alpha += alphaRowBytes;
1443        }
1444        return false;
1445    }
1446
1447    if (SkBitmap::kA8_Config == config && !src.isOpaque()) {
1448        const uint8_t* s = src.getAddr8(0, 0);
1449        while (--h >= 0) {
1450            memcpy(alpha, s, w);
1451            s += rb;
1452            alpha += alphaRowBytes;
1453        }
1454    } else if (SkBitmap::kARGB_8888_Config == config && !src.isOpaque()) {
1455        const SkPMColor* SK_RESTRICT s = src.getAddr32(0, 0);
1456        while (--h >= 0) {
1457            for (int x = 0; x < w; x++) {
1458                alpha[x] = SkGetPackedA32(s[x]);
1459            }
1460            s = (const SkPMColor*)((const char*)s + rb);
1461            alpha += alphaRowBytes;
1462        }
1463    } else if (SkBitmap::kARGB_4444_Config == config && !src.isOpaque()) {
1464        const SkPMColor16* SK_RESTRICT s = src.getAddr16(0, 0);
1465        while (--h >= 0) {
1466            for (int x = 0; x < w; x++) {
1467                alpha[x] = SkPacked4444ToA32(s[x]);
1468            }
1469            s = (const SkPMColor16*)((const char*)s + rb);
1470            alpha += alphaRowBytes;
1471        }
1472    } else if (SkBitmap::kIndex8_Config == config && !src.isOpaque()) {
1473        SkColorTable* ct = src.getColorTable();
1474        if (ct) {
1475            const SkPMColor* SK_RESTRICT table = ct->lockColors();
1476            const uint8_t* SK_RESTRICT s = src.getAddr8(0, 0);
1477            while (--h >= 0) {
1478                for (int x = 0; x < w; x++) {
1479                    alpha[x] = SkGetPackedA32(table[s[x]]);
1480                }
1481                s += rb;
1482                alpha += alphaRowBytes;
1483            }
1484            ct->unlockColors(false);
1485        }
1486    } else {    // src is opaque, so just fill alpha[] with 0xFF
1487        memset(alpha, 0xFF, h * alphaRowBytes);
1488    }
1489    return true;
1490}
1491
1492#include "SkPaint.h"
1493#include "SkMaskFilter.h"
1494#include "SkMatrix.h"
1495
1496bool SkBitmap::extractAlpha(SkBitmap* dst, const SkPaint* paint,
1497                            Allocator *allocator, SkIPoint* offset) const {
1498    SkDEBUGCODE(this->validate();)
1499
1500    SkBitmap    tmpBitmap;
1501    SkMatrix    identity;
1502    SkMask      srcM, dstM;
1503
1504    srcM.fBounds.set(0, 0, this->width(), this->height());
1505    srcM.fRowBytes = SkAlign4(this->width());
1506    srcM.fFormat = SkMask::kA8_Format;
1507
1508    SkMaskFilter* filter = paint ? paint->getMaskFilter() : NULL;
1509
1510    // compute our (larger?) dst bounds if we have a filter
1511    if (NULL != filter) {
1512        identity.reset();
1513        srcM.fImage = NULL;
1514        if (!filter->filterMask(&dstM, srcM, identity, NULL)) {
1515            goto NO_FILTER_CASE;
1516        }
1517        dstM.fRowBytes = SkAlign4(dstM.fBounds.width());
1518    } else {
1519    NO_FILTER_CASE:
1520        tmpBitmap.setConfig(SkBitmap::kA8_Config, this->width(), this->height(),
1521                       srcM.fRowBytes);
1522        if (!tmpBitmap.allocPixels(allocator, NULL)) {
1523            // Allocation of pixels for alpha bitmap failed.
1524            SkDebugf("extractAlpha failed to allocate (%d,%d) alpha bitmap\n",
1525                    tmpBitmap.width(), tmpBitmap.height());
1526            return false;
1527        }
1528        GetBitmapAlpha(*this, tmpBitmap.getAddr8(0, 0), srcM.fRowBytes);
1529        if (offset) {
1530            offset->set(0, 0);
1531        }
1532        tmpBitmap.swap(*dst);
1533        return true;
1534    }
1535    srcM.fImage = SkMask::AllocImage(srcM.computeImageSize());
1536    SkAutoMaskFreeImage srcCleanup(srcM.fImage);
1537
1538    GetBitmapAlpha(*this, srcM.fImage, srcM.fRowBytes);
1539    if (!filter->filterMask(&dstM, srcM, identity, NULL)) {
1540        goto NO_FILTER_CASE;
1541    }
1542    SkAutoMaskFreeImage dstCleanup(dstM.fImage);
1543
1544    tmpBitmap.setConfig(SkBitmap::kA8_Config, dstM.fBounds.width(),
1545                   dstM.fBounds.height(), dstM.fRowBytes);
1546    if (!tmpBitmap.allocPixels(allocator, NULL)) {
1547        // Allocation of pixels for alpha bitmap failed.
1548        SkDebugf("extractAlpha failed to allocate (%d,%d) alpha bitmap\n",
1549                tmpBitmap.width(), tmpBitmap.height());
1550        return false;
1551    }
1552    memcpy(tmpBitmap.getPixels(), dstM.fImage, dstM.computeImageSize());
1553    if (offset) {
1554        offset->set(dstM.fBounds.fLeft, dstM.fBounds.fTop);
1555    }
1556    SkDEBUGCODE(tmpBitmap.validate();)
1557
1558    tmpBitmap.swap(*dst);
1559    return true;
1560}
1561
1562///////////////////////////////////////////////////////////////////////////////
1563
1564enum {
1565    SERIALIZE_PIXELTYPE_NONE,
1566    SERIALIZE_PIXELTYPE_REF_DATA
1567};
1568
1569void SkBitmap::flatten(SkFlattenableWriteBuffer& buffer) const {
1570    buffer.writeInt(fWidth);
1571    buffer.writeInt(fHeight);
1572    buffer.writeInt(fRowBytes);
1573    buffer.writeInt(fConfig);
1574    buffer.writeBool(this->isOpaque());
1575
1576    if (fPixelRef) {
1577        if (fPixelRef->getFactory()) {
1578            buffer.writeInt(SERIALIZE_PIXELTYPE_REF_DATA);
1579            buffer.writeUInt(SkToU32(fPixelRefOffset));
1580            buffer.writeFlattenable(fPixelRef);
1581            return;
1582        }
1583        // if we get here, we can't record the pixels
1584        buffer.writeInt(SERIALIZE_PIXELTYPE_NONE);
1585    } else {
1586        buffer.writeInt(SERIALIZE_PIXELTYPE_NONE);
1587    }
1588}
1589
1590void SkBitmap::unflatten(SkFlattenableReadBuffer& buffer) {
1591    this->reset();
1592
1593    int width = buffer.readInt();
1594    int height = buffer.readInt();
1595    int rowBytes = buffer.readInt();
1596    int config = buffer.readInt();
1597
1598    this->setConfig((Config)config, width, height, rowBytes);
1599    this->setIsOpaque(buffer.readBool());
1600
1601    int reftype = buffer.readInt();
1602    switch (reftype) {
1603        case SERIALIZE_PIXELTYPE_REF_DATA: {
1604            size_t offset = buffer.readUInt();
1605            SkPixelRef* pr = buffer.readFlattenableT<SkPixelRef>();
1606            SkSafeUnref(this->setPixelRef(pr, offset));
1607            break;
1608        }
1609        case SERIALIZE_PIXELTYPE_NONE:
1610            break;
1611        default:
1612            SkDEBUGFAIL("unrecognized pixeltype in serialized data");
1613            sk_throw();
1614    }
1615}
1616
1617///////////////////////////////////////////////////////////////////////////////
1618
1619SkBitmap::RLEPixels::RLEPixels(int width, int height) {
1620    fHeight = height;
1621    fYPtrs = (uint8_t**)sk_malloc_throw(height * sizeof(uint8_t*));
1622    sk_bzero(fYPtrs, height * sizeof(uint8_t*));
1623}
1624
1625SkBitmap::RLEPixels::~RLEPixels() {
1626    sk_free(fYPtrs);
1627}
1628
1629///////////////////////////////////////////////////////////////////////////////
1630
1631#ifdef SK_DEBUG
1632void SkBitmap::validate() const {
1633    SkASSERT(fConfig < kConfigCount);
1634    SkASSERT(fRowBytes >= (unsigned)ComputeRowBytes((Config)fConfig, fWidth));
1635    uint8_t allFlags = kImageIsOpaque_Flag | kImageIsVolatile_Flag | kImageIsImmutable_Flag;
1636#ifdef SK_BUILD_FOR_ANDROID
1637    allFlags |= kHasHardwareMipMap_Flag;
1638#endif
1639    SkASSERT(fFlags <= allFlags);
1640    SkASSERT(fPixelLockCount >= 0);
1641    SkASSERT(NULL == fColorTable || (unsigned)fColorTable->getRefCnt() < 10000);
1642    SkASSERT((uint8_t)ComputeBytesPerPixel((Config)fConfig) == fBytesPerPixel);
1643
1644#if 0   // these asserts are not thread-correct, so disable for now
1645    if (fPixelRef) {
1646        if (fPixelLockCount > 0) {
1647            SkASSERT(fPixelRef->isLocked());
1648        } else {
1649            SkASSERT(NULL == fPixels);
1650            SkASSERT(NULL == fColorTable);
1651        }
1652    }
1653#endif
1654}
1655#endif
1656
1657#ifdef SK_DEVELOPER
1658void SkBitmap::toString(SkString* str) const {
1659
1660    static const char* gConfigNames[kConfigCount] = {
1661        "NONE", "A1", "A8", "INDEX8", "565", "4444", "8888"
1662    };
1663
1664    str->appendf("bitmap: ((%d, %d) %s", this->width(), this->height(),
1665                 gConfigNames[this->config()]);
1666
1667    str->append(" (");
1668    if (this->isOpaque()) {
1669        str->append("opaque");
1670    } else {
1671        str->append("transparent");
1672    }
1673    if (this->isImmutable()) {
1674        str->append(", immutable");
1675    } else {
1676        str->append(", not-immutable");
1677    }
1678    str->append(")");
1679
1680    SkPixelRef* pr = this->pixelRef();
1681    if (NULL == pr) {
1682        // show null or the explicit pixel address (rare)
1683        str->appendf(" pixels:%p", this->getPixels());
1684    } else {
1685        const char* uri = pr->getURI();
1686        if (NULL != uri) {
1687            str->appendf(" uri:\"%s\"", uri);
1688        } else {
1689            str->appendf(" pixelref:%p", pr);
1690        }
1691    }
1692
1693    str->append(")");
1694}
1695#endif
1696