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1 /*
2  * Copyright 2013 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 #ifndef SkImageGenerator_DEFINED
9 #define SkImageGenerator_DEFINED
10 
11 #include "include/core/SkBitmap.h"
12 #include "include/core/SkColor.h"
13 #include "include/core/SkImage.h"
14 #include "include/core/SkImageInfo.h"
15 #include "include/core/SkYUVAPixmaps.h"
16 
17 class GrRecordingContext;
18 class GrSurfaceProxyView;
19 class GrSamplerState;
20 class SkBitmap;
21 class SkData;
22 class SkMatrix;
23 class SkPaint;
24 class SkPicture;
25 
26 enum class GrImageTexGenPolicy : int;
27 
28 class SK_API SkImageGenerator {
29 public:
30     /**
31      *  The PixelRef which takes ownership of this SkImageGenerator
32      *  will call the image generator's destructor.
33      */
~SkImageGenerator()34     virtual ~SkImageGenerator() { }
35 
uniqueID()36     uint32_t uniqueID() const { return fUniqueID; }
37 
38     /**
39      *  Return a ref to the encoded (i.e. compressed) representation
40      *  of this data.
41      *
42      *  If non-NULL is returned, the caller is responsible for calling
43      *  unref() on the data when it is finished.
44      */
refEncodedData()45     sk_sp<SkData> refEncodedData() {
46         return this->onRefEncodedData();
47     }
48 
49     /**
50      *  Return the ImageInfo associated with this generator.
51      */
getInfo()52     const SkImageInfo& getInfo() const { return fInfo; }
53 
54     /**
55      *  Can this generator be used to produce images that will be drawable to the specified context
56      *  (or to CPU, if context is nullptr)?
57      */
isValid(GrRecordingContext * context)58     bool isValid(GrRecordingContext* context) const {
59         return this->onIsValid(context);
60     }
61 
62     /**
63      *  Decode into the given pixels, a block of memory of size at
64      *  least (info.fHeight - 1) * rowBytes + (info.fWidth *
65      *  bytesPerPixel)
66      *
67      *  Repeated calls to this function should give the same results,
68      *  allowing the PixelRef to be immutable.
69      *
70      *  @param info A description of the format
71      *         expected by the caller.  This can simply be identical
72      *         to the info returned by getInfo().
73      *
74      *         This contract also allows the caller to specify
75      *         different output-configs, which the implementation can
76      *         decide to support or not.
77      *
78      *         A size that does not match getInfo() implies a request
79      *         to scale. If the generator cannot perform this scale,
80      *         it will return false.
81      *
82      *  @return true on success.
83      */
84     bool getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes);
85 
getPixels(const SkPixmap & pm)86     bool getPixels(const SkPixmap& pm) {
87         return this->getPixels(pm.info(), pm.writable_addr(), pm.rowBytes());
88     }
89 
90     /**
91      *  If decoding to YUV is supported, this returns true. Otherwise, this
92      *  returns false and the caller will ignore output parameter yuvaPixmapInfo.
93      *
94      * @param  supportedDataTypes Indicates the data type/planar config combinations that are
95      *                            supported by the caller. If the generator supports decoding to
96      *                            YUV(A), but not as a type in supportedDataTypes, this method
97      *                            returns false.
98      *  @param yuvaPixmapInfo Output parameter that specifies the planar configuration, subsampling,
99      *                        orientation, chroma siting, plane color types, and row bytes.
100      */
101     bool queryYUVAInfo(const SkYUVAPixmapInfo::SupportedDataTypes& supportedDataTypes,
102                        SkYUVAPixmapInfo* yuvaPixmapInfo) const;
103 
104     /**
105      *  Returns true on success and false on failure.
106      *  This always attempts to perform a full decode. To get the planar
107      *  configuration without decoding use queryYUVAInfo().
108      *
109      *  @param yuvaPixmaps  Contains preallocated pixmaps configured according to a successful call
110      *                      to queryYUVAInfo().
111      */
112     bool getYUVAPlanes(const SkYUVAPixmaps& yuvaPixmaps);
113 
114 #if SK_SUPPORT_GPU
115     /**
116      *  If the generator can natively/efficiently return its pixels as a GPU image (backed by a
117      *  texture) this will return that image. If not, this will return NULL.
118      *
119      *  This routine also supports retrieving only a subset of the pixels. That subset is specified
120      *  by the following rectangle:
121      *
122      *      subset = SkIRect::MakeXYWH(origin.x(), origin.y(), info.width(), info.height())
123      *
124      *  If subset is not contained inside the generator's bounds, this returns false.
125      *
126      *      whole = SkIRect::MakeWH(getInfo().width(), getInfo().height())
127      *      if (!whole.contains(subset)) {
128      *          return false;
129      *      }
130      *
131      *  Regarding the GrRecordingContext parameter:
132      *
133      *  It must be non-NULL. The generator should only succeed if:
134      *  - its internal context is the same
135      *  - it can somehow convert its texture into one that is valid for the provided context.
136      *
137      *  If the willNeedMipMaps flag is true, the generator should try to create a TextureProxy that
138      *  at least has the mip levels allocated and the base layer filled in. If this is not possible,
139      *  the generator is allowed to return a non mipped proxy, but this will have some additional
140      *  overhead in later allocating mips and copying of the base layer.
141      *
142      *  GrImageTexGenPolicy determines whether or not a new texture must be created (and its budget
143      *  status) or whether this may (but is not required to) return a pre-existing texture that is
144      *  retained by the generator (kDraw).
145      */
146     GrSurfaceProxyView generateTexture(GrRecordingContext*, const SkImageInfo& info,
147                                        const SkIPoint& origin, GrMipmapped, GrImageTexGenPolicy);
148 
149 #endif
150 
151     /**
152      *  If the default image decoder system can interpret the specified (encoded) data, then
153      *  this returns a new ImageGenerator for it. Otherwise this returns NULL. Either way
154      *  the caller is still responsible for managing their ownership of the data.
155      */
156     static std::unique_ptr<SkImageGenerator> MakeFromEncoded(sk_sp<SkData>);
157 
158     /** Return a new image generator backed by the specified picture.  If the size is empty or
159      *  the picture is NULL, this returns NULL.
160      *  The optional matrix and paint arguments are passed to drawPicture() at rasterization
161      *  time.
162      */
163     static std::unique_ptr<SkImageGenerator> MakeFromPicture(const SkISize&, sk_sp<SkPicture>,
164                                                              const SkMatrix*, const SkPaint*,
165                                                              SkImage::BitDepth,
166                                                              sk_sp<SkColorSpace>);
167 
168 protected:
169     static constexpr int kNeedNewImageUniqueID = 0;
170 
171     SkImageGenerator(const SkImageInfo& info, uint32_t uniqueId = kNeedNewImageUniqueID);
172 
onRefEncodedData()173     virtual sk_sp<SkData> onRefEncodedData() { return nullptr; }
174     struct Options {};
onGetPixels(const SkImageInfo &,void *,size_t,const Options &)175     virtual bool onGetPixels(const SkImageInfo&, void*, size_t, const Options&) { return false; }
onIsValid(GrRecordingContext *)176     virtual bool onIsValid(GrRecordingContext*) const { return true; }
onQueryYUVAInfo(const SkYUVAPixmapInfo::SupportedDataTypes &,SkYUVAPixmapInfo *)177     virtual bool onQueryYUVAInfo(const SkYUVAPixmapInfo::SupportedDataTypes&,
178                                  SkYUVAPixmapInfo*) const { return false; }
onGetYUVAPlanes(const SkYUVAPixmaps &)179     virtual bool onGetYUVAPlanes(const SkYUVAPixmaps&) { return false; }
180 #if SK_SUPPORT_GPU
181     // returns nullptr
182     virtual GrSurfaceProxyView onGenerateTexture(GrRecordingContext*, const SkImageInfo&,
183                                                  const SkIPoint&, GrMipmapped, GrImageTexGenPolicy);
184 #endif
185 
186 private:
187     const SkImageInfo fInfo;
188     const uint32_t fUniqueID;
189 
190     friend class SkImage_Lazy;
191 
192     // This is our default impl, which may be different on different platforms.
193     // It is called from NewFromEncoded() after it has checked for any runtime factory.
194     // The SkData will never be NULL, as that will have been checked by NewFromEncoded.
195     static std::unique_ptr<SkImageGenerator> MakeFromEncodedImpl(sk_sp<SkData>);
196 
197     SkImageGenerator(SkImageGenerator&&) = delete;
198     SkImageGenerator(const SkImageGenerator&) = delete;
199     SkImageGenerator& operator=(SkImageGenerator&&) = delete;
200     SkImageGenerator& operator=(const SkImageGenerator&) = delete;
201 };
202 
203 #endif  // SkImageGenerator_DEFINED
204