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 #ifndef SkSurface_Base_DEFINED
9 #define SkSurface_Base_DEFINED
10
11 #include "include/core/SkCanvas.h"
12 #include "include/core/SkImage.h"
13 #include "include/core/SkRefCnt.h"
14 #include "include/core/SkSamplingOptions.h"
15 #include "include/core/SkScalar.h"
16 #include "include/core/SkSurface.h"
17 #include "include/core/SkTypes.h"
18
19 #include <cstdint>
20 #include <memory>
21
22 class GrBackendSemaphore;
23 class GrBackendTexture;
24 class GrRecordingContext;
25 class SkCapabilities;
26 class SkColorSpace;
27 class SkPaint;
28 class SkPixmap;
29 class GrSurfaceCharacterization;
30 class SkSurfaceProps;
31 enum GrSurfaceOrigin : int;
32 enum SkYUVColorSpace : int;
33 namespace skgpu { namespace graphite { class Recorder; } }
34 struct SkIRect;
35 struct SkISize;
36 struct SkImageInfo;
37
38 class SkSurface_Base : public SkSurface {
39 public:
40 SkSurface_Base(int width, int height, const SkSurfaceProps*);
41 SkSurface_Base(const SkImageInfo&, const SkSurfaceProps*);
42 ~SkSurface_Base() override;
43
44 // From SkSurface.h
replaceBackendTexture(const GrBackendTexture &,GrSurfaceOrigin,ContentChangeMode,TextureReleaseProc,ReleaseContext)45 bool replaceBackendTexture(const GrBackendTexture&,
46 GrSurfaceOrigin,
47 ContentChangeMode,
48 TextureReleaseProc,
49 ReleaseContext) override {
50 return false;
51 }
52
53 enum class Type {
54 kNull, // intentionally associating 0 with a null canvas
55 kGanesh,
56 kGraphite,
57 kRaster,
58 };
59
60 // TODO(kjlubick) Android directly subclasses SkSurface_Base for tests, so we
61 // cannot make this a pure virtual. They seem to want a surface that is spy-able
62 // or mockable, so maybe we should provide something like that.
type()63 virtual Type type() const { return Type::kNull; }
64
65 // True for surfaces instantiated by pixels in CPU memory
isRasterBacked()66 bool isRasterBacked() const { return this->type() == Type::kRaster; }
67 // True for surfaces instantiated by Ganesh in GPU memory
isGaneshBacked()68 bool isGaneshBacked() const { return this->type() == Type::kGanesh; }
69 // True for surfaces instantiated by Graphite in GPU memory
isGraphiteBacked()70 bool isGraphiteBacked() const { return this->type() == Type::kGraphite; }
71
72 virtual GrRecordingContext* onGetRecordingContext() const;
73 virtual skgpu::graphite::Recorder* onGetRecorder() const;
74
75 /**
76 * Allocate a canvas that will draw into this surface. We will cache this
77 * canvas, to return the same object to the caller multiple times. We
78 * take ownership, and will call unref() on the canvas when we go out of
79 * scope.
80 */
81 virtual SkCanvas* onNewCanvas() = 0;
82
83 virtual sk_sp<SkSurface> onNewSurface(const SkImageInfo&) = 0;
84
85 /**
86 * Allocate an SkImage that represents the current contents of the surface.
87 * This needs to be able to outlive the surface itself (if need be), and
88 * must faithfully represent the current contents, even if the surface
89 * is changed after this called (e.g. it is drawn to via its canvas).
90 *
91 * If a subset is specified, the the impl must make a copy, rather than try to wait
92 * on copy-on-write.
93 */
94 virtual sk_sp<SkImage> onNewImageSnapshot(const SkIRect* subset = nullptr) { return nullptr; }
95
onMakeTemporaryImage()96 virtual sk_sp<SkImage> onMakeTemporaryImage() { return this->makeImageSnapshot(); }
97
98 virtual void onWritePixels(const SkPixmap&, int x, int y) = 0;
99
100 /**
101 * Default implementation does a rescale/read and then calls the callback.
102 */
103 virtual void onAsyncRescaleAndReadPixels(const SkImageInfo&,
104 const SkIRect srcRect,
105 RescaleGamma,
106 RescaleMode,
107 ReadPixelsCallback,
108 ReadPixelsContext);
109 /**
110 * Default implementation does a rescale/read/yuv conversion and then calls the callback.
111 */
112 virtual void onAsyncRescaleAndReadPixelsYUV420(SkYUVColorSpace,
113 bool readAlpha,
114 sk_sp<SkColorSpace> dstColorSpace,
115 SkIRect srcRect,
116 SkISize dstSize,
117 RescaleGamma,
118 RescaleMode,
119 ReadPixelsCallback,
120 ReadPixelsContext);
121
122 /**
123 * Default implementation:
124 *
125 * image = this->newImageSnapshot();
126 * if (image) {
127 * image->draw(canvas, ...);
128 * image->unref();
129 * }
130 */
131 virtual void onDraw(SkCanvas*, SkScalar x, SkScalar y, const SkSamplingOptions&,const SkPaint*);
132
133 /**
134 * Called as a performance hint when the Surface is allowed to make it's contents
135 * undefined.
136 */
onDiscard()137 virtual void onDiscard() {}
138
139 /**
140 * If the surface is about to change, we call this so that our subclass
141 * can optionally fork their backend (copy-on-write) in case it was
142 * being shared with the cachedImage.
143 *
144 * Returns false if the backing cannot be un-shared.
145 */
146 [[nodiscard]] virtual bool onCopyOnWrite(ContentChangeMode) = 0;
147
148 /**
149 * Signal the surface to remind its backing store that it's mutable again.
150 * Called only when we _didn't_ copy-on-write; we assume the copies start mutable.
151 */
onRestoreBackingMutability()152 virtual void onRestoreBackingMutability() {}
153
154 /**
155 * Caused the current backend 3D API to wait on the passed in semaphores before executing new
156 * commands on the gpu. Any previously submitting commands will not be blocked by these
157 * semaphores.
158 */
onWait(int numSemaphores,const GrBackendSemaphore * waitSemaphores,bool deleteSemaphoresAfterWait)159 virtual bool onWait(int numSemaphores, const GrBackendSemaphore* waitSemaphores,
160 bool deleteSemaphoresAfterWait) {
161 return false;
162 }
163
onCharacterize(GrSurfaceCharacterization *)164 virtual bool onCharacterize(GrSurfaceCharacterization*) const { return false; }
onIsCompatible(const GrSurfaceCharacterization &)165 virtual bool onIsCompatible(const GrSurfaceCharacterization&) const { return false; }
166
167 // TODO: Remove this (make it pure virtual) after updating Android (which has a class derived
168 // from SkSurface_Base).
169 virtual sk_sp<const SkCapabilities> onCapabilities();
170
171 inline SkCanvas* getCachedCanvas();
172 inline sk_sp<SkImage> refCachedImage();
173
hasCachedImage()174 bool hasCachedImage() const { return fCachedImage != nullptr; }
175
176 // called by SkSurface to compute a new genID
177 uint32_t newGenerationID();
178
179 private:
180 std::unique_ptr<SkCanvas> fCachedCanvas = nullptr;
181 sk_sp<SkImage> fCachedImage = nullptr;
182
183 // Returns false if drawing should not take place (allocation failure).
184 [[nodiscard]] bool aboutToDraw(ContentChangeMode mode);
185
186 // Returns true if there is an outstanding image-snapshot, indicating that a call to aboutToDraw
187 // would trigger a copy-on-write.
188 bool outstandingImageSnapshot() const;
189
190 friend class SkCanvas;
191 friend class SkSurface;
192 };
193
getCachedCanvas()194 SkCanvas* SkSurface_Base::getCachedCanvas() {
195 if (nullptr == fCachedCanvas) {
196 fCachedCanvas = std::unique_ptr<SkCanvas>(this->onNewCanvas());
197 if (fCachedCanvas) {
198 fCachedCanvas->setSurfaceBase(this);
199 }
200 }
201 return fCachedCanvas.get();
202 }
203
refCachedImage()204 sk_sp<SkImage> SkSurface_Base::refCachedImage() {
205 if (fCachedImage) {
206 return fCachedImage;
207 }
208
209 fCachedImage = this->onNewImageSnapshot();
210
211 SkASSERT(!fCachedCanvas || fCachedCanvas->getSurfaceBase() == this);
212 return fCachedImage;
213 }
214
asSB(SkSurface * surface)215 static inline SkSurface_Base* asSB(SkSurface* surface) {
216 return static_cast<SkSurface_Base*>(surface);
217 }
218
asConstSB(const SkSurface * surface)219 static inline const SkSurface_Base* asConstSB(const SkSurface* surface) {
220 return static_cast<const SkSurface_Base*>(surface);
221 }
222
223 #endif
224