SkMallocPixelRef.cpp revision 3e89524e747b513986abfeeea00b6fac79593f26 
1/*
2 * Copyright 2011 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "SkMallocPixelRef.h"
9#include "SkBitmap.h"
10#include "SkFlattenableBuffers.h"
11
12static bool check_info(const SkImageInfo& info, SkColorTable* ctable) {
13    if (info.fWidth < 0 ||
14        info.fHeight < 0 ||
15        (unsigned)info.fColorType > (unsigned)kLastEnum_SkColorType ||
16        (unsigned)info.fAlphaType > (unsigned)kLastEnum_SkAlphaType)
17    {
18        return false;
19    }
20
21    // these seem like good checks, but currently we have (at least) tests
22    // that expect the pixelref to succeed even when there is a mismatch
23    // with colortables. fix?
24#if 0
25    if (kIndex8_SkColorType == info.fColorType && NULL == ctable) {
26        return false;
27    }
28    if (kIndex8_SkColorType != info.fColorType && NULL != ctable) {
29        return false;
30    }
31#endif
32    return true;
33}
34
35SkMallocPixelRef* SkMallocPixelRef::NewDirect(const SkImageInfo& info,
36                                              void* addr,
37                                              size_t rowBytes,
38                                              SkColorTable* ctable) {
39    if (!check_info(info, ctable)) {
40        return NULL;
41    }
42    return SkNEW_ARGS(SkMallocPixelRef, (info, addr, rowBytes, ctable, false));
43}
44
45SkMallocPixelRef* SkMallocPixelRef::NewAllocate(const SkImageInfo& info,
46                                                size_t requestedRowBytes,
47                                                SkColorTable* ctable) {
48    if (!check_info(info, ctable)) {
49        return NULL;
50    }
51
52    int32_t minRB = info.minRowBytes();
53    if (minRB < 0) {
54        return NULL;    // allocation will be too large
55    }
56    if (requestedRowBytes > 0 && (int32_t)requestedRowBytes < minRB) {
57        return NULL;    // cannot meet requested rowbytes
58    }
59
60    int32_t rowBytes;
61    if (requestedRowBytes) {
62        rowBytes = requestedRowBytes;
63    } else {
64        rowBytes = minRB;
65    }
66
67    Sk64 bigSize;
68    bigSize.setMul(info.fHeight, rowBytes);
69    if (!bigSize.is32()) {
70        return NULL;
71    }
72
73    size_t size = bigSize.get32();
74    void* addr = sk_malloc_flags(size, 0);
75    if (NULL == addr) {
76        return NULL;
77    }
78
79    return SkNEW_ARGS(SkMallocPixelRef, (info, addr, rowBytes, ctable, true));
80}
81
82///////////////////////////////////////////////////////////////////////////////
83
84SkMallocPixelRef::SkMallocPixelRef(const SkImageInfo& info, void* storage,
85                                   size_t rowBytes, SkColorTable* ctable,
86                                   bool ownsPixels)
87    : SkPixelRef(info)
88    , fOwnPixels(ownsPixels)
89{
90    SkASSERT(check_info(info, ctable));
91    SkASSERT(rowBytes >= info.minRowBytes());
92
93    if (kIndex8_SkColorType != info.fColorType) {
94        ctable = NULL;
95    }
96
97    fStorage = storage;
98    fCTable = ctable;
99    fRB = rowBytes;
100    SkSafeRef(ctable);
101
102    this->setPreLocked(fStorage, fRB, fCTable);
103}
104
105SkMallocPixelRef::~SkMallocPixelRef() {
106    SkSafeUnref(fCTable);
107    if (fOwnPixels) {
108        sk_free(fStorage);
109    }
110}
111
112bool SkMallocPixelRef::onNewLockPixels(LockRec* rec) {
113    rec->fPixels = fStorage;
114    rec->fRowBytes = fRB;
115    rec->fColorTable = fCTable;
116    return true;
117}
118
119void SkMallocPixelRef::onUnlockPixels() {
120    // nothing to do
121}
122
123size_t SkMallocPixelRef::getAllocatedSizeInBytes() const {
124    return this->info().getSafeSize(fRB);
125}
126
127void SkMallocPixelRef::flatten(SkFlattenableWriteBuffer& buffer) const {
128    this->INHERITED::flatten(buffer);
129
130    buffer.write32(fRB);
131
132    // TODO: replace this bulk write with a chunky one that can trim off any
133    // trailing bytes on each scanline (in case rowbytes > width*size)
134    size_t size = this->info().getSafeSize(fRB);
135    buffer.writeByteArray(fStorage, size);
136    buffer.writeBool(fCTable != NULL);
137    if (fCTable) {
138        fCTable->writeToBuffer(buffer);
139    }
140}
141
142SkMallocPixelRef::SkMallocPixelRef(SkFlattenableReadBuffer& buffer)
143    : INHERITED(buffer, NULL)
144    , fOwnPixels(true)
145{
146    fRB = buffer.read32();
147    size_t size = this->info().getSafeSize(fRB);
148    fStorage = sk_malloc_throw(size);
149    buffer.readByteArray(fStorage, size);
150    if (buffer.readBool()) {
151        fCTable = SkNEW_ARGS(SkColorTable, (buffer));
152    } else {
153        fCTable = NULL;
154    }
155
156    this->setPreLocked(fStorage, fRB, fCTable);
157}
158