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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 "include/core/SkBitmap.h"
9 #include "include/core/SkCanvas.h"
10 #include "include/core/SkCapabilities.h"
11 #include "include/core/SkImageInfo.h"
12 #include "include/core/SkMallocPixelRef.h"
13 #include "include/core/SkPixelRef.h"
14 #include "include/core/SkRect.h"
15 #include "include/core/SkRefCnt.h"
16 #include "include/core/SkSamplingOptions.h"
17 #include "include/core/SkScalar.h"
18 #include "include/core/SkSurface.h"
19 #include "include/private/base/SkAssert.h"
20 #include "include/private/base/SkMath.h"
21 #include "src/core/SkDevice.h"
22 #include "src/core/SkImageInfoPriv.h"
23 #include "src/core/SkImagePriv.h"
24 #include "src/core/SkSurfacePriv.h"
25 #include "src/image/SkSurface_Base.h"
26 
27 #include <cstdint>
28 #include <cstring>
29 #include <utility>
30 
31 class SkImage;
32 class SkPaint;
33 class SkPixmap;
34 class SkSurfaceProps;
35 
36 class SkSurface_Raster : public SkSurface_Base {
37 public:
38     SkSurface_Raster(const SkImageInfo&, void*, size_t rb,
39                      void (*releaseProc)(void* pixels, void* context), void* context,
40                      const SkSurfaceProps*);
41     SkSurface_Raster(const SkImageInfo& info, sk_sp<SkPixelRef>, const SkSurfaceProps*);
42 
imageInfo() const43     SkImageInfo imageInfo() const override { return fBitmap.info(); }
44 
45     SkCanvas* onNewCanvas() override;
46     sk_sp<SkSurface> onNewSurface(const SkImageInfo&) override;
47     sk_sp<SkImage> onNewImageSnapshot(const SkIRect* subset) override;
48     void onWritePixels(const SkPixmap&, int x, int y) override;
49     void onDraw(SkCanvas*, SkScalar, SkScalar, const SkSamplingOptions&, const SkPaint*) override;
50     bool onCopyOnWrite(ContentChangeMode) override;
51     void onRestoreBackingMutability() override;
52     sk_sp<const SkCapabilities> onCapabilities() override;
53 
54 private:
55     SkBitmap    fBitmap;
56     bool        fWeOwnThePixels;
57 
58     using INHERITED = SkSurface_Base;
59 };
60 
61 ///////////////////////////////////////////////////////////////////////////////
62 
SkSurfaceValidateRasterInfo(const SkImageInfo & info,size_t rowBytes)63 bool SkSurfaceValidateRasterInfo(const SkImageInfo& info, size_t rowBytes) {
64     if (!SkImageInfoIsValid(info)) {
65         return false;
66     }
67 
68     if (kIgnoreRowBytesValue == rowBytes) {
69         return true;
70     }
71 
72     if (!info.validRowBytes(rowBytes)) {
73         return false;
74     }
75 
76     uint64_t size = sk_64_mul(info.height(), rowBytes);
77     static const size_t kMaxTotalSize = SK_MaxS32;
78     if (size > kMaxTotalSize) {
79         return false;
80     }
81 
82     return true;
83 }
84 
SkSurface_Raster(const SkImageInfo & info,void * pixels,size_t rb,void (* releaseProc)(void * pixels,void * context),void * context,const SkSurfaceProps * props)85 SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, void* pixels, size_t rb,
86                                    void (*releaseProc)(void* pixels, void* context), void* context,
87                                    const SkSurfaceProps* props)
88     : INHERITED(info, props)
89 {
90     fBitmap.installPixels(info, pixels, rb, releaseProc, context);
91     fWeOwnThePixels = false;    // We are "Direct"
92 }
93 
SkSurface_Raster(const SkImageInfo & info,sk_sp<SkPixelRef> pr,const SkSurfaceProps * props)94 SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, sk_sp<SkPixelRef> pr,
95                                    const SkSurfaceProps* props)
96     : INHERITED(pr->width(), pr->height(), props)
97 {
98     fBitmap.setInfo(info, pr->rowBytes());
99     fBitmap.setPixelRef(std::move(pr), 0, 0);
100     fWeOwnThePixels = true;
101 }
102 
onNewCanvas()103 SkCanvas* SkSurface_Raster::onNewCanvas() { return new SkCanvas(fBitmap, this->props()); }
104 
onNewSurface(const SkImageInfo & info)105 sk_sp<SkSurface> SkSurface_Raster::onNewSurface(const SkImageInfo& info) {
106     return SkSurface::MakeRaster(info, &this->props());
107 }
108 
onDraw(SkCanvas * canvas,SkScalar x,SkScalar y,const SkSamplingOptions & sampling,const SkPaint * paint)109 void SkSurface_Raster::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y,
110                               const SkSamplingOptions& sampling, const SkPaint* paint) {
111     canvas->drawImage(fBitmap.asImage().get(), x, y, sampling, paint);
112 }
113 
onNewImageSnapshot(const SkIRect * subset)114 sk_sp<SkImage> SkSurface_Raster::onNewImageSnapshot(const SkIRect* subset) {
115     if (subset) {
116         SkASSERT(SkIRect::MakeWH(fBitmap.width(), fBitmap.height()).contains(*subset));
117         SkBitmap dst;
118         dst.allocPixels(fBitmap.info().makeDimensions(subset->size()));
119         SkAssertResult(fBitmap.readPixels(dst.pixmap(), subset->left(), subset->top()));
120         dst.setImmutable(); // key, so MakeFromBitmap doesn't make a copy of the buffer
121         return dst.asImage();
122     }
123 
124     SkCopyPixelsMode cpm = kIfMutable_SkCopyPixelsMode;
125     if (fWeOwnThePixels) {
126         // SkImage_raster requires these pixels are immutable for its full lifetime.
127         // We'll undo this via onRestoreBackingMutability() if we can avoid the COW.
128         if (SkPixelRef* pr = fBitmap.pixelRef()) {
129             pr->setTemporarilyImmutable();
130         }
131     } else {
132         cpm = kAlways_SkCopyPixelsMode;
133     }
134 
135     // Our pixels are in memory, so read access on the snapshot SkImage could be cheap.
136     // Lock the shared pixel ref to ensure peekPixels() is usable.
137     return SkMakeImageFromRasterBitmap(fBitmap, cpm);
138 }
139 
onWritePixels(const SkPixmap & src,int x,int y)140 void SkSurface_Raster::onWritePixels(const SkPixmap& src, int x, int y) {
141     fBitmap.writePixels(src, x, y);
142 }
143 
onRestoreBackingMutability()144 void SkSurface_Raster::onRestoreBackingMutability() {
145     SkASSERT(!this->hasCachedImage());  // Shouldn't be any snapshots out there.
146     if (SkPixelRef* pr = fBitmap.pixelRef()) {
147         pr->restoreMutability();
148     }
149 }
150 
onCopyOnWrite(ContentChangeMode mode)151 bool SkSurface_Raster::onCopyOnWrite(ContentChangeMode mode) {
152     // are we sharing pixelrefs with the image?
153     sk_sp<SkImage> cached(this->refCachedImage());
154     SkASSERT(cached);
155     if (SkBitmapImageGetPixelRef(cached.get()) == fBitmap.pixelRef()) {
156         SkASSERT(fWeOwnThePixels);
157         if (kDiscard_ContentChangeMode == mode) {
158             if (!fBitmap.tryAllocPixels()) {
159                 return false;
160             }
161         } else {
162             SkBitmap prev(fBitmap);
163             if (!fBitmap.tryAllocPixels()) {
164                 return false;
165             }
166             SkASSERT(prev.info() == fBitmap.info());
167             SkASSERT(prev.rowBytes() == fBitmap.rowBytes());
168             memcpy(fBitmap.getPixels(), prev.getPixels(), fBitmap.computeByteSize());
169         }
170 
171         // Now fBitmap is a deep copy of itself (and therefore different from
172         // what is being used by the image. Next we update the canvas to use
173         // this as its backend, so we can't modify the image's pixels anymore.
174         SkASSERT(this->getCachedCanvas());
175         this->getCachedCanvas()->baseDevice()->replaceBitmapBackendForRasterSurface(fBitmap);
176     }
177     return true;
178 }
179 
onCapabilities()180 sk_sp<const SkCapabilities> SkSurface_Raster::onCapabilities() {
181     return SkCapabilities::RasterBackend();
182 }
183 
184 ///////////////////////////////////////////////////////////////////////////////
185 
MakeRasterDirectReleaseProc(const SkImageInfo & info,void * pixels,size_t rb,void (* releaseProc)(void * pixels,void * context),void * context,const SkSurfaceProps * props)186 sk_sp<SkSurface> SkSurface::MakeRasterDirectReleaseProc(const SkImageInfo& info, void* pixels,
187         size_t rb, void (*releaseProc)(void* pixels, void* context), void* context,
188         const SkSurfaceProps* props) {
189     if (nullptr == releaseProc) {
190         context = nullptr;
191     }
192     if (!SkSurfaceValidateRasterInfo(info, rb)) {
193         return nullptr;
194     }
195     if (nullptr == pixels) {
196         return nullptr;
197     }
198 
199     return sk_make_sp<SkSurface_Raster>(info, pixels, rb, releaseProc, context, props);
200 }
201 
MakeRasterDirect(const SkImageInfo & info,void * pixels,size_t rowBytes,const SkSurfaceProps * props)202 sk_sp<SkSurface> SkSurface::MakeRasterDirect(const SkImageInfo& info, void* pixels, size_t rowBytes,
203                                              const SkSurfaceProps* props) {
204     return MakeRasterDirectReleaseProc(info, pixels, rowBytes, nullptr, nullptr, props);
205 }
206 
MakeRaster(const SkImageInfo & info,size_t rowBytes,const SkSurfaceProps * props)207 sk_sp<SkSurface> SkSurface::MakeRaster(const SkImageInfo& info, size_t rowBytes,
208                                        const SkSurfaceProps* props) {
209     if (!SkSurfaceValidateRasterInfo(info)) {
210         return nullptr;
211     }
212 
213     sk_sp<SkPixelRef> pr = SkMallocPixelRef::MakeAllocate(info, rowBytes);
214     if (!pr) {
215         return nullptr;
216     }
217     if (rowBytes) {
218         SkASSERT(pr->rowBytes() == rowBytes);
219     }
220     return sk_make_sp<SkSurface_Raster>(info, std::move(pr), props);
221 }
222 
MakeRasterN32Premul(int width,int height,const SkSurfaceProps * surfaceProps)223 sk_sp<SkSurface> SkSurface::MakeRasterN32Premul(int width, int height,
224                                                 const SkSurfaceProps* surfaceProps) {
225     return MakeRaster(SkImageInfo::MakeN32Premul(width, height), surfaceProps);
226 }
227