1
2 /*
3 * Copyright 2011 Google Inc.
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 #include "SkFlipPixelRef.h"
9 #include "SkFlattenable.h"
10 #include "SkRegion.h"
11
SkFlipPixelRef(SkBitmap::Config config,int width,int height)12 SkFlipPixelRef::SkFlipPixelRef(SkBitmap::Config config, int width, int height)
13 : fFlipper(width, height) {
14 fConfig = config;
15 fSize = SkBitmap::ComputeSize(config, width, height);
16 fStorage = sk_malloc_throw(fSize << 1);
17 fPage0 = fStorage;
18 fPage1 = (char*)fStorage + fSize;
19 }
20
~SkFlipPixelRef()21 SkFlipPixelRef::~SkFlipPixelRef() {
22 sk_free(fStorage);
23 }
24
beginUpdate(SkBitmap * device)25 const SkRegion& SkFlipPixelRef::beginUpdate(SkBitmap* device) {
26 void* writeAddr;
27 const void* readAddr;
28 this->getFrontBack(&readAddr, &writeAddr);
29
30 device->setConfig(fConfig, fFlipper.width(), fFlipper.height());
31 device->setPixels(writeAddr);
32
33 SkRegion copyBits;
34 const SkRegion& dirty = fFlipper.update(©Bits);
35
36 SkFlipPixelRef::CopyBitsFromAddr(*device, copyBits, readAddr);
37 return dirty;
38 }
39
endUpdate()40 void SkFlipPixelRef::endUpdate() {
41 this->swapPages();
42 }
43
44 ///////////////////////////////////////////////////////////////////////////////
45
onLockPixels(SkColorTable ** ct)46 void* SkFlipPixelRef::onLockPixels(SkColorTable** ct) {
47 fMutex.acquire();
48 *ct = NULL;
49 return fPage0;
50 }
51
onUnlockPixels()52 void SkFlipPixelRef::onUnlockPixels() {
53 fMutex.release();
54 }
55
swapPages()56 void SkFlipPixelRef::swapPages() {
57 fMutex.acquire();
58 SkTSwap<void*>(fPage0, fPage1);
59 this->notifyPixelsChanged();
60 fMutex.release();
61 }
62
63 ///////////////////////////////////////////////////////////////////////////////
64
copyRect(const SkBitmap & dst,const SkIRect & rect,const void * srcAddr,int shift)65 static void copyRect(const SkBitmap& dst, const SkIRect& rect,
66 const void* srcAddr, int shift) {
67 const size_t offset = rect.fTop * dst.rowBytes() + (rect.fLeft << shift);
68 char* dstP = static_cast<char*>(dst.getPixels()) + offset;
69 const char* srcP = static_cast<const char*>(srcAddr) + offset;
70 const size_t rb = dst.rowBytes();
71 const size_t bytes = rect.width() << shift;
72
73 int height = rect.height();
74 while (--height >= 0) {
75 memcpy(dstP, srcP, bytes);
76 dstP += rb;
77 srcP += rb;
78 }
79 }
80
getShift(SkBitmap::Config config)81 static int getShift(SkBitmap::Config config) {
82 switch (config) {
83 case SkBitmap::kARGB_8888_Config:
84 return 2;
85 case SkBitmap::kRGB_565_Config:
86 case SkBitmap::kARGB_4444_Config:
87 return 1;
88 case SkBitmap::kIndex8_Config:
89 case SkBitmap::kA8_Config:
90 return 0;
91 default:
92 return -1; // signal not supported
93 }
94 }
95
CopyBitsFromAddr(const SkBitmap & dst,const SkRegion & clip,const void * srcAddr)96 void SkFlipPixelRef::CopyBitsFromAddr(const SkBitmap& dst, const SkRegion& clip,
97 const void* srcAddr) {
98 const int shift = getShift(dst.config());
99 if (shift < 0) {
100 return;
101 }
102
103 const SkIRect bounds = {0, 0, dst.width(), dst.height()};
104 SkRegion::Cliperator iter(clip, bounds);
105
106 while (!iter.done()) {
107 copyRect(dst, iter.rect(), srcAddr, shift);
108 iter.next();
109 }
110 }
111