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/SkDeferredDisplayList.h"
13#include "include/core/SkSurface.h"
14#include "src/core/SkImagePriv.h"
15#include "src/core/SkSurfacePriv.h"
16
17class SkSurface_Base : public SkSurface {
18public:
19 SkSurface_Base(int width, int height, const SkSurfaceProps*);
20 SkSurface_Base(const SkImageInfo&, const SkSurfaceProps*);
21 ~SkSurface_Base() override;
22
23 virtual GrContext* onGetContext_deprecated();
24 virtual GrRecordingContext* onGetRecordingContext();
25
26 virtual GrBackendTexture onGetBackendTexture(BackendHandleAccess);
27 virtual GrBackendRenderTarget onGetBackendRenderTarget(BackendHandleAccess);
28 virtual bool onReplaceBackendTexture(const GrBackendTexture&,
29 GrSurfaceOrigin,
30 ContentChangeMode,
31 TextureReleaseProc,
32 ReleaseContext);
33 /**
34 * Allocate a canvas that will draw into this surface. We will cache this
35 * canvas, to return the same object to the caller multiple times. We
36 * take ownership, and will call unref() on the canvas when we go out of
37 * scope.
38 */
39 virtual SkCanvas* onNewCanvas() = 0;
40
41 virtual sk_sp<SkSurface> onNewSurface(const SkImageInfo&) = 0;
42
43 /**
44 * Allocate an SkImage that represents the current contents of the surface.
45 * This needs to be able to outlive the surface itself (if need be), and
46 * must faithfully represent the current contents, even if the surface
47 * is changed after this called (e.g. it is drawn to via its canvas).
48 *
49 * If a subset is specified, the the impl must make a copy, rather than try to wait
50 * on copy-on-write.
51 */
52 virtual sk_sp<SkImage> onNewImageSnapshot(const SkIRect* subset = nullptr) { return nullptr; }
53
54 virtual void onWritePixels(const SkPixmap&, int x, int y) = 0;
55
56 /**
57 * Default implementation does a rescale/read and then calls the callback.
58 */
59 virtual void onAsyncRescaleAndReadPixels(const SkImageInfo&,
60 const SkIRect& srcRect,
61 RescaleGamma,
62 SkFilterQuality,
63 ReadPixelsCallback,
64 ReadPixelsContext);
65 /**
66 * Default implementation does a rescale/read/yuv conversion and then calls the callback.
67 */
68 virtual void onAsyncRescaleAndReadPixelsYUV420(SkYUVColorSpace,
69 sk_sp<SkColorSpace> dstColorSpace,
70 const SkIRect& srcRect,
71 const SkISize& dstSize,
72 RescaleGamma,
73 SkFilterQuality,
74 ReadPixelsCallback,
75 ReadPixelsContext);
76
77 /**
78 * Default implementation:
79 *
80 * image = this->newImageSnapshot();
81 * if (image) {
82 * image->draw(canvas, ...);
83 * image->unref();
84 * }
85 */
86 virtual void onDraw(SkCanvas*, SkScalar x, SkScalar y, const SkPaint*);
87
88 /**
89 * Called as a performance hint when the Surface is allowed to make it's contents
90 * undefined.
91 */
92 virtual void onDiscard() {}
93
94 /**
95 * If the surface is about to change, we call this so that our subclass
96 * can optionally fork their backend (copy-on-write) in case it was
97 * being shared with the cachedImage.
98 */
99 virtual void onCopyOnWrite(ContentChangeMode) = 0;
100
101 /**
102 * Signal the surface to remind its backing store that it's mutable again.
103 * Called only when we _didn't_ copy-on-write; we assume the copies start mutable.
104 */
105 virtual void onRestoreBackingMutability() {}
106
107 /**
108 * Issue any pending surface IO to the current backend 3D API and resolve any surface MSAA.
109 * Inserts the requested number of semaphores for the gpu to signal when work is complete on the
110 * gpu and inits the array of GrBackendSemaphores with the signaled semaphores.
111 */
112 virtual GrSemaphoresSubmitted onFlush(BackendSurfaceAccess access, const GrFlushInfo&,
113 const GrBackendSurfaceMutableState*) {
114 return GrSemaphoresSubmitted::kNo;
115 }
116
117 /**
118 * Caused the current backend 3D API to wait on the passed in semaphores before executing new
119 * commands on the gpu. Any previously submitting commands will not be blocked by these
120 * semaphores.
121 */
122 virtual bool onWait(int numSemaphores, const GrBackendSemaphore* waitSemaphores,
123 bool deleteSemaphoresAfterWait) {
124 return false;
125 }
126
127 virtual bool onCharacterize(SkSurfaceCharacterization*) const { return false; }
128 virtual bool onIsCompatible(const SkSurfaceCharacterization&) const { return false; }
129 virtual bool onDraw(sk_sp<const SkDeferredDisplayList>) { return false; }
130
131 inline SkCanvas* getCachedCanvas();
132 inline sk_sp<SkImage> refCachedImage();
133
134 bool hasCachedImage() const { return fCachedImage != nullptr; }
135
136 // called by SkSurface to compute a new genID
137 uint32_t newGenerationID();
138
139private:
140 std::unique_ptr<SkCanvas> fCachedCanvas;
141 sk_sp<SkImage> fCachedImage;
142
143 void aboutToDraw(ContentChangeMode mode);
144
145 // Returns true if there is an outstanding image-snapshot, indicating that a call to aboutToDraw
146 // would trigger a copy-on-write.
147 bool outstandingImageSnapshot() const;
148
149 friend class SkCanvas;
150 friend class SkSurface;
151
152 typedef SkSurface INHERITED;
153};
154
155SkCanvas* SkSurface_Base::getCachedCanvas() {
156 if (nullptr == fCachedCanvas) {
157 fCachedCanvas = std::unique_ptr<SkCanvas>(this->onNewCanvas());
158 if (fCachedCanvas) {
159 fCachedCanvas->setSurfaceBase(this);
160 }
161 }
162 return fCachedCanvas.get();
163}
164
165sk_sp<SkImage> SkSurface_Base::refCachedImage() {
166 if (fCachedImage) {
167 return fCachedImage;
168 }
169
170 fCachedImage = this->onNewImageSnapshot();
171
172 SkASSERT(!fCachedCanvas || fCachedCanvas->getSurfaceBase() == this);
173 return fCachedImage;
174}
175
176#endif
177