1#include "SkFlipPixelRef.h"
2#include "SkFlattenable.h"
3#include "SkRegion.h"
4
5SkFlipPixelRef::SkFlipPixelRef(SkBitmap::Config config, int width, int height)
6: fFlipper(width, height) {
7    fConfig = config;
8    fSize = SkBitmap::ComputeSize(config, width, height);
9    fStorage = sk_malloc_throw(fSize << 1);
10    fPage0 = fStorage;
11    fPage1 = (char*)fStorage + fSize;
12}
13
14SkFlipPixelRef::~SkFlipPixelRef() {
15    sk_free(fStorage);
16}
17
18const SkRegion& SkFlipPixelRef::beginUpdate(SkBitmap* device) {
19    void*       writeAddr;
20    const void* readAddr;
21    this->getFrontBack(&readAddr, &writeAddr);
22
23    device->setConfig(fConfig, fFlipper.width(), fFlipper.height());
24    device->setPixels(writeAddr);
25
26    SkRegion    copyBits;
27    const SkRegion& dirty = fFlipper.update(&copyBits);
28
29    SkFlipPixelRef::CopyBitsFromAddr(*device, copyBits, readAddr);
30    return dirty;
31}
32
33void SkFlipPixelRef::endUpdate() {
34    this->swapPages();
35}
36
37///////////////////////////////////////////////////////////////////////////////
38
39void* SkFlipPixelRef::onLockPixels(SkColorTable** ct) {
40    fMutex.acquire();
41    *ct = NULL;
42    return fPage0;
43}
44
45void SkFlipPixelRef::onUnlockPixels() {
46    fMutex.release();
47}
48
49void SkFlipPixelRef::swapPages() {
50    fMutex.acquire();
51    SkTSwap<void*>(fPage0, fPage1);
52    this->notifyPixelsChanged();
53    fMutex.release();
54}
55
56void SkFlipPixelRef::flatten(SkFlattenableWriteBuffer& buffer) const {
57    this->INHERITED::flatten(buffer);
58
59    buffer.write32(fSize);
60    // only need to write page0
61    buffer.writePad(fPage0, fSize);
62}
63
64SkFlipPixelRef::SkFlipPixelRef(SkFlattenableReadBuffer& buffer)
65        : INHERITED(buffer, NULL) {
66    fSize = buffer.readU32();
67    fStorage = sk_malloc_throw(fSize << 1);
68    fPage0 = fStorage;
69    fPage1 = (char*)fStorage + fSize;
70    buffer.read(fPage0, fSize);
71}
72
73SkPixelRef* SkFlipPixelRef::Create(SkFlattenableReadBuffer& buffer) {
74    return SkNEW_ARGS(SkFlipPixelRef, (buffer));
75}
76
77static SkPixelRef::Registrar::Registrar reg("SkFlipPixelRef",
78                                            SkFlipPixelRef::Create);
79
80///////////////////////////////////////////////////////////////////////////////
81
82static void copyRect(const SkBitmap& dst, const SkIRect& rect,
83                     const void* srcAddr, int shift) {
84    const size_t offset = rect.fTop * dst.rowBytes() + (rect.fLeft << shift);
85    char* dstP = static_cast<char*>(dst.getPixels()) + offset;
86    const char* srcP = static_cast<const char*>(srcAddr) + offset;
87    const size_t rb = dst.rowBytes();
88    const size_t bytes = rect.width() << shift;
89
90    int height = rect.height();
91    while (--height >= 0) {
92        memcpy(dstP, srcP, bytes);
93        dstP += rb;
94        srcP += rb;
95    }
96}
97
98static int getShift(SkBitmap::Config config) {
99    switch (config) {
100        case SkBitmap::kARGB_8888_Config:
101            return 2;
102        case SkBitmap::kRGB_565_Config:
103        case SkBitmap::kARGB_4444_Config:
104            return 1;
105        case SkBitmap::kIndex8_Config:
106        case SkBitmap::kA8_Config:
107            return 0;
108        default:
109            return -1;  // signal not supported
110    }
111}
112
113void SkFlipPixelRef::CopyBitsFromAddr(const SkBitmap& dst, const SkRegion& clip,
114                                      const void* srcAddr) {
115    const int shift = getShift(dst.config());
116    if (shift < 0) {
117        return;
118    }
119
120    const SkIRect bounds = {0, 0, dst.width(), dst.height()};
121    SkRegion::Cliperator iter(clip, bounds);
122
123    while (!iter.done()) {
124        copyRect(dst, iter.rect(), srcAddr, shift);
125        iter.next();
126    }
127}
128
129