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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 class SkSurface_Raster : public SkSurface_Base {
15 public:
16     SkSurface_Raster(const SkImageInfo&, void*, size_t rb,
17                      void (*releaseProc)(void* pixels, void* context), void* context,
18                      const SkSurfaceProps*);
19     SkSurface_Raster(const SkImageInfo& info, sk_sp<SkPixelRef>, const SkSurfaceProps*);
20 
21     SkCanvas* onNewCanvas() override;
22     sk_sp<SkSurface> onNewSurface(const SkImageInfo&) override;
23     sk_sp<SkImage> onNewImageSnapshot() override;
24     void onDraw(SkCanvas*, SkScalar x, SkScalar y, const SkPaint*) override;
25     void onCopyOnWrite(ContentChangeMode) override;
26     void onRestoreBackingMutability() override;
27 
28 private:
29     SkBitmap    fBitmap;
30     size_t      fRowBytes;
31     bool        fWeOwnThePixels;
32 
33     typedef SkSurface_Base INHERITED;
34 };
35 
36 ///////////////////////////////////////////////////////////////////////////////
37 
SkSurfaceValidateRasterInfo(const SkImageInfo & info,size_t rowBytes)38 bool SkSurfaceValidateRasterInfo(const SkImageInfo& info, size_t rowBytes) {
39     if (info.isEmpty()) {
40         return false;
41     }
42 
43     static const size_t kMaxTotalSize = SK_MaxS32;
44 
45     // TODO(mtklein,brianosman): revisit all these color space decisions
46     switch (info.colorType()) {
47         case kAlpha_8_SkColorType:
48         case kGray_8_SkColorType:
49         case kRGB_565_SkColorType:
50         case kARGB_4444_SkColorType:
51         case kRGB_888x_SkColorType:
52         case kRGBA_1010102_SkColorType:
53         case kRGB_101010x_SkColorType:
54             if (info.colorSpace()) {
55                 return false;
56             }
57             break;
58 
59         case kRGBA_8888_SkColorType:
60         case kBGRA_8888_SkColorType:
61             if (info.colorSpace() && !info.colorSpace()->gammaCloseToSRGB()) {
62                 return false;
63             }
64             break;
65         case kRGBA_F16_SkColorType:
66             if (info.colorSpace() && (!info.colorSpace()->gammaIsLinear())) {
67                 return false;
68             }
69             break;
70         default:
71             return false;
72     }
73 
74     if (kIgnoreRowBytesValue == rowBytes) {
75         return true;
76     }
77 
78     int shift = SkColorTypeShiftPerPixel(info.colorType());
79 
80     uint64_t minRB = (uint64_t)info.width() << shift;
81     if (minRB > rowBytes) {
82         return false;
83     }
84 
85     size_t alignedRowBytes = rowBytes >> shift << shift;
86     if (alignedRowBytes != rowBytes) {
87         return false;
88     }
89 
90     uint64_t size = sk_64_mul(info.height(), rowBytes);
91     if (size > kMaxTotalSize) {
92         return false;
93     }
94 
95     return true;
96 }
97 
SkSurface_Raster(const SkImageInfo & info,void * pixels,size_t rb,void (* releaseProc)(void * pixels,void * context),void * context,const SkSurfaceProps * props)98 SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, void* pixels, size_t rb,
99                                    void (*releaseProc)(void* pixels, void* context), void* context,
100                                    const SkSurfaceProps* props)
101     : INHERITED(info, props)
102 {
103     fBitmap.installPixels(info, pixels, rb, releaseProc, context);
104     fRowBytes = 0;              // don't need to track the rowbytes
105     fWeOwnThePixels = false;    // We are "Direct"
106 }
107 
SkSurface_Raster(const SkImageInfo & info,sk_sp<SkPixelRef> pr,const SkSurfaceProps * props)108 SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, sk_sp<SkPixelRef> pr,
109                                    const SkSurfaceProps* props)
110     : INHERITED(pr->width(), pr->height(), props)
111 {
112     fBitmap.setInfo(info, pr->rowBytes());
113     fRowBytes = pr->rowBytes(); // we track this, so that subsequent re-allocs will match
114     fBitmap.setPixelRef(std::move(pr), 0, 0);
115     fWeOwnThePixels = true;
116 }
117 
onNewCanvas()118 SkCanvas* SkSurface_Raster::onNewCanvas() { return new SkCanvas(fBitmap, this->props()); }
119 
onNewSurface(const SkImageInfo & info)120 sk_sp<SkSurface> SkSurface_Raster::onNewSurface(const SkImageInfo& info) {
121     return SkSurface::MakeRaster(info, &this->props());
122 }
123 
onDraw(SkCanvas * canvas,SkScalar x,SkScalar y,const SkPaint * paint)124 void SkSurface_Raster::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y,
125                               const SkPaint* paint) {
126     canvas->drawBitmap(fBitmap, x, y, paint);
127 }
128 
onNewImageSnapshot()129 sk_sp<SkImage> SkSurface_Raster::onNewImageSnapshot() {
130     SkCopyPixelsMode cpm = kIfMutable_SkCopyPixelsMode;
131     if (fWeOwnThePixels) {
132         // SkImage_raster requires these pixels are immutable for its full lifetime.
133         // We'll undo this via onRestoreBackingMutability() if we can avoid the COW.
134         if (SkPixelRef* pr = fBitmap.pixelRef()) {
135             pr->setTemporarilyImmutable();
136         }
137     } else {
138         cpm = kAlways_SkCopyPixelsMode;
139     }
140 
141     // Our pixels are in memory, so read access on the snapshot SkImage could be cheap.
142     // Lock the shared pixel ref to ensure peekPixels() is usable.
143     return SkMakeImageFromRasterBitmap(fBitmap, cpm);
144 }
145 
onRestoreBackingMutability()146 void SkSurface_Raster::onRestoreBackingMutability() {
147     SkASSERT(!this->hasCachedImage());  // Shouldn't be any snapshots out there.
148     if (SkPixelRef* pr = fBitmap.pixelRef()) {
149         pr->restoreMutability();
150     }
151 }
152 
onCopyOnWrite(ContentChangeMode mode)153 void SkSurface_Raster::onCopyOnWrite(ContentChangeMode mode) {
154     // are we sharing pixelrefs with the image?
155     sk_sp<SkImage> cached(this->refCachedImage());
156     SkASSERT(cached);
157     if (SkBitmapImageGetPixelRef(cached.get()) == fBitmap.pixelRef()) {
158         SkASSERT(fWeOwnThePixels);
159         if (kDiscard_ContentChangeMode == mode) {
160             fBitmap.allocPixels();
161         } else {
162             SkBitmap prev(fBitmap);
163             fBitmap.allocPixels();
164             SkASSERT(prev.info() == fBitmap.info());
165             SkASSERT(prev.rowBytes() == fBitmap.rowBytes());
166             memcpy(fBitmap.getPixels(), prev.getPixels(), fBitmap.computeByteSize());
167         }
168         SkASSERT(fBitmap.rowBytes() == fRowBytes);  // be sure we always use the same value
169 
170         // Now fBitmap is a deep copy of itself (and therefore different from
171         // what is being used by the image. Next we update the canvas to use
172         // this as its backend, so we can't modify the image's pixels anymore.
173         SkASSERT(this->getCachedCanvas());
174         this->getCachedCanvas()->getDevice()->replaceBitmapBackendForRasterSurface(fBitmap);
175     }
176 }
177 
178 ///////////////////////////////////////////////////////////////////////////////
179 
MakeRasterDirectReleaseProc(const SkImageInfo & info,void * pixels,size_t rb,void (* releaseProc)(void * pixels,void * context),void * context,const SkSurfaceProps * props)180 sk_sp<SkSurface> SkSurface::MakeRasterDirectReleaseProc(const SkImageInfo& info, void* pixels,
181         size_t rb, void (*releaseProc)(void* pixels, void* context), void* context,
182         const SkSurfaceProps* props) {
183     if (nullptr == releaseProc) {
184         context = nullptr;
185     }
186     if (!SkSurfaceValidateRasterInfo(info, rb)) {
187         return nullptr;
188     }
189     if (nullptr == pixels) {
190         return nullptr;
191     }
192 
193     return sk_make_sp<SkSurface_Raster>(info, pixels, rb, releaseProc, context, props);
194 }
195 
MakeRasterDirect(const SkImageInfo & info,void * pixels,size_t rowBytes,const SkSurfaceProps * props)196 sk_sp<SkSurface> SkSurface::MakeRasterDirect(const SkImageInfo& info, void* pixels, size_t rowBytes,
197                                              const SkSurfaceProps* props) {
198     return MakeRasterDirectReleaseProc(info, pixels, rowBytes, nullptr, nullptr, props);
199 }
200 
MakeRaster(const SkImageInfo & info,size_t rowBytes,const SkSurfaceProps * props)201 sk_sp<SkSurface> SkSurface::MakeRaster(const SkImageInfo& info, size_t rowBytes,
202                                        const SkSurfaceProps* props) {
203     if (!SkSurfaceValidateRasterInfo(info)) {
204         return nullptr;
205     }
206 
207     sk_sp<SkPixelRef> pr = SkMallocPixelRef::MakeZeroed(info, rowBytes);
208     if (!pr) {
209         return nullptr;
210     }
211     if (rowBytes) {
212         SkASSERT(pr->rowBytes() == rowBytes);
213     }
214     return sk_make_sp<SkSurface_Raster>(info, std::move(pr), props);
215 }
216