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(SkPixelRef*);
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 int shift = 0;
43 switch (info.fColorType) {
44 case kAlpha_8_SkColorType:
45 shift = 0;
46 break;
47 case kRGB_565_SkColorType:
48 shift = 1;
49 break;
50 case kN32_SkColorType:
51 shift = 2;
52 break;
53 default:
54 return false;
55 }
56
57 if (kIgnoreRowBytesValue == rowBytes) {
58 return true;
59 }
60
61 uint64_t minRB = (uint64_t)info.fWidth << shift;
62 if (minRB > rowBytes) {
63 return false;
64 }
65
66 size_t alignedRowBytes = rowBytes >> shift << shift;
67 if (alignedRowBytes != rowBytes) {
68 return false;
69 }
70
71 uint64_t size = sk_64_mul(info.fHeight, rowBytes);
72 if (size > kMaxTotalSize) {
73 return false;
74 }
75
76 return true;
77 }
78
SkSurface_Raster(const SkImageInfo & info,void * pixels,size_t rb)79 SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, void* pixels, size_t rb)
80 : INHERITED(info)
81 {
82 fBitmap.installPixels(info, pixels, rb);
83 fWeOwnThePixels = false; // We are "Direct"
84 }
85
SkSurface_Raster(SkPixelRef * pr)86 SkSurface_Raster::SkSurface_Raster(SkPixelRef* pr)
87 : INHERITED(pr->info().fWidth, pr->info().fHeight)
88 {
89 const SkImageInfo& info = pr->info();
90
91 fBitmap.setInfo(info, info.minRowBytes());
92 fBitmap.setPixelRef(pr);
93 fWeOwnThePixels = true;
94
95 if (!info.isOpaque()) {
96 fBitmap.eraseColor(SK_ColorTRANSPARENT);
97 }
98 }
99
onNewCanvas()100 SkCanvas* SkSurface_Raster::onNewCanvas() {
101 return SkNEW_ARGS(SkCanvas, (fBitmap));
102 }
103
onNewSurface(const SkImageInfo & info)104 SkSurface* SkSurface_Raster::onNewSurface(const SkImageInfo& info) {
105 return SkSurface::NewRaster(info);
106 }
107
onDraw(SkCanvas * canvas,SkScalar x,SkScalar y,const SkPaint * paint)108 void SkSurface_Raster::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y,
109 const SkPaint* paint) {
110 canvas->drawBitmap(fBitmap, x, y, paint);
111 }
112
onNewImageSnapshot()113 SkImage* SkSurface_Raster::onNewImageSnapshot() {
114 return SkNewImageFromBitmap(fBitmap, fWeOwnThePixels);
115 }
116
onCopyOnWrite(ContentChangeMode mode)117 void SkSurface_Raster::onCopyOnWrite(ContentChangeMode mode) {
118 // are we sharing pixelrefs with the image?
119 SkASSERT(NULL != this->getCachedImage());
120 if (SkBitmapImageGetPixelRef(this->getCachedImage()) == fBitmap.pixelRef()) {
121 SkASSERT(fWeOwnThePixels);
122 if (kDiscard_ContentChangeMode == mode) {
123 fBitmap.setPixelRef(NULL);
124 fBitmap.allocPixels();
125 } else {
126 SkBitmap prev(fBitmap);
127 prev.deepCopyTo(&fBitmap);
128 }
129 // Now fBitmap is a deep copy of itself (and therefore different from
130 // what is being used by the image. Next we update the canvas to use
131 // this as its backend, so we can't modify the image's pixels anymore.
132 SkASSERT(NULL != this->getCachedCanvas());
133 this->getCachedCanvas()->getDevice()->replaceBitmapBackendForRasterSurface(fBitmap);
134 }
135 }
136
137 ///////////////////////////////////////////////////////////////////////////////
138
NewRasterDirect(const SkImageInfo & info,void * pixels,size_t rowBytes)139 SkSurface* SkSurface::NewRasterDirect(const SkImageInfo& info, void* pixels, size_t rowBytes) {
140 if (!SkSurface_Raster::Valid(info, rowBytes)) {
141 return NULL;
142 }
143 if (NULL == pixels) {
144 return NULL;
145 }
146
147 return SkNEW_ARGS(SkSurface_Raster, (info, pixels, rowBytes));
148 }
149
NewRaster(const SkImageInfo & info)150 SkSurface* SkSurface::NewRaster(const SkImageInfo& info) {
151 if (!SkSurface_Raster::Valid(info)) {
152 return NULL;
153 }
154
155 SkAutoTUnref<SkPixelRef> pr(SkMallocPixelRef::NewAllocate(info, 0, NULL));
156 if (NULL == pr.get()) {
157 return NULL;
158 }
159 return SkNEW_ARGS(SkSurface_Raster, (pr));
160 }
161