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 void (*releaseProc)(void* pixels, void* context), void* context,
22 const SkSurfaceProps*);
23 SkSurface_Raster(SkPixelRef*, const SkSurfaceProps*);
24
25 virtual SkCanvas* onNewCanvas() SK_OVERRIDE;
26 virtual SkSurface* onNewSurface(const SkImageInfo&) SK_OVERRIDE;
27 virtual SkImage* onNewImageSnapshot() SK_OVERRIDE;
28 virtual void onDraw(SkCanvas*, SkScalar x, SkScalar y,
29 const SkPaint*) SK_OVERRIDE;
30 virtual void onCopyOnWrite(ContentChangeMode) SK_OVERRIDE;
31
32 private:
33 SkBitmap fBitmap;
34 bool fWeOwnThePixels;
35
36 typedef SkSurface_Base INHERITED;
37 };
38
39 ///////////////////////////////////////////////////////////////////////////////
40
Valid(const SkImageInfo & info,size_t rowBytes)41 bool SkSurface_Raster::Valid(const SkImageInfo& info, size_t rowBytes) {
42 static const size_t kMaxTotalSize = SK_MaxS32;
43
44 int shift = 0;
45 switch (info.colorType()) {
46 case kAlpha_8_SkColorType:
47 shift = 0;
48 break;
49 case kRGB_565_SkColorType:
50 shift = 1;
51 break;
52 case kN32_SkColorType:
53 shift = 2;
54 break;
55 default:
56 return false;
57 }
58
59 if (kIgnoreRowBytesValue == rowBytes) {
60 return true;
61 }
62
63 uint64_t minRB = (uint64_t)info.width() << shift;
64 if (minRB > rowBytes) {
65 return false;
66 }
67
68 size_t alignedRowBytes = rowBytes >> shift << shift;
69 if (alignedRowBytes != rowBytes) {
70 return false;
71 }
72
73 uint64_t size = sk_64_mul(info.height(), rowBytes);
74 if (size > kMaxTotalSize) {
75 return false;
76 }
77
78 return true;
79 }
80
SkSurface_Raster(const SkImageInfo & info,void * pixels,size_t rb,void (* releaseProc)(void * pixels,void * context),void * context,const SkSurfaceProps * props)81 SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, void* pixels, size_t rb,
82 void (*releaseProc)(void* pixels, void* context), void* context,
83 const SkSurfaceProps* props)
84 : INHERITED(info, props)
85 {
86 fBitmap.installPixels(info, pixels, rb, NULL, releaseProc, context);
87 fWeOwnThePixels = false; // We are "Direct"
88 }
89
SkSurface_Raster(SkPixelRef * pr,const SkSurfaceProps * props)90 SkSurface_Raster::SkSurface_Raster(SkPixelRef* pr, const SkSurfaceProps* props)
91 : INHERITED(pr->info().width(), pr->info().height(), props)
92 {
93 const SkImageInfo& info = pr->info();
94
95 fBitmap.setInfo(info, info.minRowBytes());
96 fBitmap.setPixelRef(pr);
97 fWeOwnThePixels = true;
98
99 if (!info.isOpaque()) {
100 fBitmap.eraseColor(SK_ColorTRANSPARENT);
101 }
102 }
103
onNewCanvas()104 SkCanvas* SkSurface_Raster::onNewCanvas() {
105 return SkNEW_ARGS(SkCanvas, (fBitmap, this->props()));
106 }
107
onNewSurface(const SkImageInfo & info)108 SkSurface* SkSurface_Raster::onNewSurface(const SkImageInfo& info) {
109 return SkSurface::NewRaster(info);
110 }
111
onDraw(SkCanvas * canvas,SkScalar x,SkScalar y,const SkPaint * paint)112 void SkSurface_Raster::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y,
113 const SkPaint* paint) {
114 canvas->drawBitmap(fBitmap, x, y, paint);
115 }
116
onNewImageSnapshot()117 SkImage* SkSurface_Raster::onNewImageSnapshot() {
118 return SkNewImageFromBitmap(fBitmap, fWeOwnThePixels);
119 }
120
onCopyOnWrite(ContentChangeMode mode)121 void SkSurface_Raster::onCopyOnWrite(ContentChangeMode mode) {
122 // are we sharing pixelrefs with the image?
123 SkASSERT(this->getCachedImage());
124 if (SkBitmapImageGetPixelRef(this->getCachedImage()) == fBitmap.pixelRef()) {
125 SkASSERT(fWeOwnThePixels);
126 if (kDiscard_ContentChangeMode == mode) {
127 fBitmap.setPixelRef(NULL);
128 fBitmap.allocPixels();
129 } else {
130 SkBitmap prev(fBitmap);
131 prev.deepCopyTo(&fBitmap);
132 }
133 // Now fBitmap is a deep copy of itself (and therefore different from
134 // what is being used by the image. Next we update the canvas to use
135 // this as its backend, so we can't modify the image's pixels anymore.
136 SkASSERT(this->getCachedCanvas());
137 this->getCachedCanvas()->getDevice()->replaceBitmapBackendForRasterSurface(fBitmap);
138 }
139 }
140
141 ///////////////////////////////////////////////////////////////////////////////
142
NewRasterDirectReleaseProc(const SkImageInfo & info,void * pixels,size_t rb,void (* releaseProc)(void * pixels,void * context),void * context,const SkSurfaceProps * props)143 SkSurface* SkSurface::NewRasterDirectReleaseProc(const SkImageInfo& info, void* pixels, size_t rb,
144 void (*releaseProc)(void* pixels, void* context),
145 void* context, const SkSurfaceProps* props) {
146 if (NULL == releaseProc) {
147 context = NULL;
148 }
149 if (!SkSurface_Raster::Valid(info, rb)) {
150 return NULL;
151 }
152 if (NULL == pixels) {
153 return NULL;
154 }
155
156 return SkNEW_ARGS(SkSurface_Raster, (info, pixels, rb, releaseProc, context, props));
157 }
158
NewRasterDirect(const SkImageInfo & info,void * pixels,size_t rowBytes,const SkSurfaceProps * props)159 SkSurface* SkSurface::NewRasterDirect(const SkImageInfo& info, void* pixels, size_t rowBytes,
160 const SkSurfaceProps* props) {
161 return NewRasterDirectReleaseProc(info, pixels, rowBytes, NULL, NULL, props);
162 }
163
NewRaster(const SkImageInfo & info,const SkSurfaceProps * props)164 SkSurface* SkSurface::NewRaster(const SkImageInfo& info, const SkSurfaceProps* props) {
165 if (!SkSurface_Raster::Valid(info)) {
166 return NULL;
167 }
168
169 SkAutoTUnref<SkPixelRef> pr(SkMallocPixelRef::NewAllocate(info, 0, NULL));
170 if (NULL == pr.get()) {
171 return NULL;
172 }
173 return SkNEW_ARGS(SkSurface_Raster, (pr, props));
174 }
175