1 /*
2 * Copyright 2012 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 "SkSurface_Base.h"
9 #include "SkImagePriv.h"
10 #include "SkCanvas.h"
11 #include "SkDevice.h"
12 #include "SkMallocPixelRef.h"
13
14 static const size_t kIgnoreRowBytesValue = (size_t)~0;
15
16 class SkSurface_Raster : public SkSurface_Base {
17 public:
18 static bool Valid(const SkImageInfo&, size_t rb = kIgnoreRowBytesValue);
19
20 SkSurface_Raster(const SkImageInfo&, void*, size_t rb);
21 SkSurface_Raster(const SkImageInfo&, SkPixelRef*, size_t rb);
22
23 virtual SkCanvas* onNewCanvas() SK_OVERRIDE;
24 virtual SkSurface* onNewSurface(const SkImageInfo&) SK_OVERRIDE;
25 virtual SkImage* onNewImageSnapshot() SK_OVERRIDE;
26 virtual void onDraw(SkCanvas*, SkScalar x, SkScalar y,
27 const SkPaint*) SK_OVERRIDE;
28 virtual void onCopyOnWrite(ContentChangeMode) SK_OVERRIDE;
29
30 private:
31 SkBitmap fBitmap;
32 bool fWeOwnThePixels;
33
34 typedef SkSurface_Base INHERITED;
35 };
36
37 ///////////////////////////////////////////////////////////////////////////////
38
Valid(const SkImageInfo & info,size_t rowBytes)39 bool SkSurface_Raster::Valid(const SkImageInfo& info, size_t rowBytes) {
40 static const size_t kMaxTotalSize = SK_MaxS32;
41
42 SkBitmap::Config config = SkImageInfoToBitmapConfig(info);
43
44 int shift = 0;
45 switch (config) {
46 case SkBitmap::kA8_Config:
47 shift = 0;
48 break;
49 case SkBitmap::kRGB_565_Config:
50 shift = 1;
51 break;
52 case SkBitmap::kARGB_8888_Config:
53 shift = 2;
54 break;
55 default:
56 return false;
57 }
58
59 // TODO: examine colorspace
60
61 if (kIgnoreRowBytesValue == rowBytes) {
62 return true;
63 }
64
65 uint64_t minRB = (uint64_t)info.fWidth << shift;
66 if (minRB > rowBytes) {
67 return false;
68 }
69
70 size_t alignedRowBytes = rowBytes >> shift << shift;
71 if (alignedRowBytes != rowBytes) {
72 return false;
73 }
74
75 uint64_t size = (uint64_t)info.fHeight * rowBytes;
76 if (size > kMaxTotalSize) {
77 return false;
78 }
79
80 return true;
81 }
82
SkSurface_Raster(const SkImageInfo & info,void * pixels,size_t rb)83 SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, void* pixels, size_t rb)
84 : INHERITED(info.fWidth, info.fHeight) {
85 SkBitmap::Config config = SkImageInfoToBitmapConfig(info);
86 fBitmap.setConfig(config, info.fWidth, info.fHeight, rb, info.fAlphaType);
87 fBitmap.setPixels(pixels);
88 fWeOwnThePixels = false; // We are "Direct"
89 }
90
SkSurface_Raster(const SkImageInfo & info,SkPixelRef * pr,size_t rb)91 SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, SkPixelRef* pr, size_t rb)
92 : INHERITED(info.fWidth, info.fHeight) {
93 SkBitmap::Config config = SkImageInfoToBitmapConfig(info);
94 fBitmap.setConfig(config, info.fWidth, info.fHeight, rb, info.fAlphaType);
95 fBitmap.setPixelRef(pr);
96 fWeOwnThePixels = true;
97
98 if (!SkAlphaTypeIsOpaque(info.fAlphaType)) {
99 fBitmap.eraseColor(SK_ColorTRANSPARENT);
100 }
101 }
102
onNewCanvas()103 SkCanvas* SkSurface_Raster::onNewCanvas() {
104 return SkNEW_ARGS(SkCanvas, (fBitmap));
105 }
106
onNewSurface(const SkImageInfo & info)107 SkSurface* SkSurface_Raster::onNewSurface(const SkImageInfo& info) {
108 return SkSurface::NewRaster(info);
109 }
110
onDraw(SkCanvas * canvas,SkScalar x,SkScalar y,const SkPaint * paint)111 void SkSurface_Raster::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y,
112 const SkPaint* paint) {
113 canvas->drawBitmap(fBitmap, x, y, paint);
114 }
115
onNewImageSnapshot()116 SkImage* SkSurface_Raster::onNewImageSnapshot() {
117 return SkNewImageFromBitmap(fBitmap, fWeOwnThePixels);
118 }
119
onCopyOnWrite(ContentChangeMode mode)120 void SkSurface_Raster::onCopyOnWrite(ContentChangeMode mode) {
121 // are we sharing pixelrefs with the image?
122 SkASSERT(NULL != this->getCachedImage());
123 if (SkBitmapImageGetPixelRef(this->getCachedImage()) == fBitmap.pixelRef()) {
124 SkASSERT(fWeOwnThePixels);
125 if (kDiscard_ContentChangeMode == mode) {
126 fBitmap.setPixelRef(NULL, 0);
127 fBitmap.allocPixels();
128 } else {
129 SkBitmap prev(fBitmap);
130 prev.deepCopyTo(&fBitmap, prev.config());
131 }
132 // Now fBitmap is a deep copy of itself (and therefore different from
133 // what is being used by the image. Next we update the canvas to use
134 // this as its backend, so we can't modify the image's pixels anymore.
135 SkASSERT(NULL != this->getCachedCanvas());
136 this->getCachedCanvas()->getDevice()->replaceBitmapBackendForRasterSurface(fBitmap);
137 }
138 }
139
140 ///////////////////////////////////////////////////////////////////////////////
141
NewRasterDirect(const SkImageInfo & info,void * pixels,size_t rowBytes)142 SkSurface* SkSurface::NewRasterDirect(const SkImageInfo& info, void* pixels, size_t rowBytes) {
143 if (!SkSurface_Raster::Valid(info, rowBytes)) {
144 return NULL;
145 }
146 if (NULL == pixels) {
147 return NULL;
148 }
149
150 return SkNEW_ARGS(SkSurface_Raster, (info, pixels, rowBytes));
151 }
152
NewRaster(const SkImageInfo & info)153 SkSurface* SkSurface::NewRaster(const SkImageInfo& info) {
154 if (!SkSurface_Raster::Valid(info)) {
155 return NULL;
156 }
157
158 SkAutoTUnref<SkPixelRef> pr(SkMallocPixelRef::NewAllocate(info, 0, NULL));
159 if (NULL == pr.get()) {
160 return NULL;
161 }
162 return SkNEW_ARGS(SkSurface_Raster, (info, pr, info.minRowBytes()));
163 }
164