1 /*
2  * Copyright 2015 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 GrResourceProvider_DEFINED
9 #define GrResourceProvider_DEFINED
10 
11 #include "GrBuffer.h"
12 #include "GrGpu.h"
13 #include "GrPathRange.h"
14 
15 class GrPath;
16 class GrRenderTarget;
17 class GrSingleOwner;
18 class GrStencilAttachment;
19 class GrStyle;
20 class SkDescriptor;
21 class SkPath;
22 class SkTypeface;
23 
24 /**
25  * A factory for arbitrary resource types. This class is intended for use within the Gr code base.
26  *
27  * Some members force callers to make a flags (pendingIO) decision. This can be relaxed once
28  * https://bug.skia.org/4156 is fixed.
29  */
30 class GrResourceProvider {
31 public:
32     GrResourceProvider(GrGpu* gpu, GrResourceCache* cache, GrSingleOwner* owner);
33 
findAndRefTByUniqueKey(const GrUniqueKey & key)34     template <typename T> T* findAndRefTByUniqueKey(const GrUniqueKey& key) {
35         return static_cast<T*>(this->findAndRefResourceByUniqueKey(key));
36     }
37 
38     ///////////////////////////////////////////////////////////////////////////
39     // Textures
40 
41     /**
42      * Creates a new texture in the resource cache and returns it. The caller owns a
43      * ref on the returned texture which must be balanced by a call to unref.
44      *
45      * @param desc          Description of the texture properties.
46      * @param budgeted      Does the texture count against the resource cache budget?
47      * @param texels        A contiguous array of mipmap levels
48      * @param mipLevelCount The amount of elements in the texels array
49      */
50     GrTexture* createMipMappedTexture(const GrSurfaceDesc& desc, SkBudgeted budgeted,
51                                       const GrMipLevel* texels, int mipLevelCount,
52                                       uint32_t flags = 0,
53                                       SkDestinationSurfaceColorMode mipColorMode =
54                                                         SkDestinationSurfaceColorMode::kLegacy);
55 
56     /**
57      * This function is a shim which creates a SkTArray<GrMipLevel> of size 1.
58      * It then calls createTexture with that SkTArray.
59      *
60      * @param srcData   Pointer to the pixel values (optional).
61      * @param rowBytes  The number of bytes between rows of the texture. Zero
62      *                  implies tightly packed rows. For compressed pixel configs, this
63      *                  field is ignored.
64      */
65     GrTexture* createTexture(const GrSurfaceDesc& desc, SkBudgeted budgeted, const void* srcData,
66                              size_t rowBytes, uint32_t flags = 0);
67 
68     /** Shortcut for creating a texture with no initial data to upload. */
69     GrTexture* createTexture(const GrSurfaceDesc& desc, SkBudgeted budgeted, uint32_t flags = 0) {
70         return this->createTexture(desc, budgeted, nullptr, 0, flags);
71     }
72 
73     /** Assigns a unique key to the texture. The texture will be findable via this key using
74     findTextureByUniqueKey(). If an existing texture has this key, it's key will be removed. */
75     void assignUniqueKeyToProxy(const GrUniqueKey& key, GrTextureProxy*);
76 
77     /** Finds a texture by unique key. If the texture is found it is ref'ed and returned. */
78     sk_sp<GrTextureProxy> findProxyByUniqueKey(const GrUniqueKey& key);
79 
80     /**
81      * Finds a texture that approximately matches the descriptor. Will be at least as large in width
82      * and height as desc specifies. If desc specifies that the texture should be a render target
83      * then result will be a render target. Format and sample count will always match the request.
84      * The contents of the texture are undefined. The caller owns a ref on the returned texture and
85      * must balance with a call to unref.
86      */
87     GrTexture* createApproxTexture(const GrSurfaceDesc&, uint32_t flags);
88 
89     ///////////////////////////////////////////////////////////////////////////
90     // Wrapped Backend Surfaces
91 
92     /**
93      * Wraps an existing texture with a GrTexture object.
94      *
95      * OpenGL: if the object is a texture Gr may change its GL texture params
96      *         when it is drawn.
97      *
98      * @return GrTexture object or NULL on failure.
99      */
100     sk_sp<GrTexture> wrapBackendTexture(const GrBackendTextureDesc& desc,
101                                         GrWrapOwnership = kBorrow_GrWrapOwnership);
102 
103     /**
104      * Wraps an existing render target with a GrRenderTarget object. It is
105      * similar to wrapBackendTexture but can be used to draw into surfaces
106      * that are not also textures (e.g. FBO 0 in OpenGL, or an MSAA buffer that
107      * the client will resolve to a texture). Currently wrapped render targets
108      * always use the kBorrow_GrWrapOwnership semantics.
109      *
110      * @return GrRenderTarget object or NULL on failure.
111      */
112     sk_sp<GrRenderTarget> wrapBackendRenderTarget(const GrBackendRenderTargetDesc& desc);
113 
114     static const int kMinScratchTextureSize;
115 
116     /**
117      * Either finds and refs, or creates an index buffer for instanced drawing with a specific
118      * pattern if the index buffer is not found. If the return is non-null, the caller owns
119      * a ref on the returned GrBuffer.
120      *
121      * @param pattern     the pattern of indices to repeat
122      * @param patternSize size in bytes of the pattern
123      * @param reps        number of times to repeat the pattern
124      * @param vertCount   number of vertices the pattern references
125      * @param key         Key to be assigned to the index buffer.
126      *
127      * @return The index buffer if successful, otherwise nullptr.
128      */
findOrCreateInstancedIndexBuffer(const uint16_t * pattern,int patternSize,int reps,int vertCount,const GrUniqueKey & key)129     const GrBuffer* findOrCreateInstancedIndexBuffer(const uint16_t* pattern,
130                                                      int patternSize,
131                                                      int reps,
132                                                      int vertCount,
133                                                      const GrUniqueKey& key) {
134         if (GrBuffer* buffer = this->findAndRefTByUniqueKey<GrBuffer>(key)) {
135             return buffer;
136         }
137         return this->createInstancedIndexBuffer(pattern, patternSize, reps, vertCount, key);
138     }
139 
140     /**
141      * Returns an index buffer that can be used to render quads.
142      * Six indices per quad: 0, 1, 2, 0, 2, 3, etc.
143      * The max number of quads is the buffer's index capacity divided by 6.
144      * Draw with kTriangles_GrPrimitiveType
145      * @ return the quad index buffer
146      */
refQuadIndexBuffer()147     const GrBuffer* refQuadIndexBuffer() {
148         if (GrBuffer* buffer =
149             this->findAndRefTByUniqueKey<GrBuffer>(fQuadIndexBufferKey)) {
150             return buffer;
151         }
152         return this->createQuadIndexBuffer();
153     }
154 
155     /**
156      * Factories for GrPath and GrPathRange objects. It's an error to call these if path rendering
157      * is not supported.
158      */
159     GrPath* createPath(const SkPath&, const GrStyle&);
160     GrPathRange* createPathRange(GrPathRange::PathGenerator*, const GrStyle&);
161     GrPathRange* createGlyphs(const SkTypeface*, const SkScalerContextEffects&,
162                               const SkDescriptor*, const GrStyle&);
163 
164     /** These flags govern which scratch resources we are allowed to return */
165     enum Flags {
166         kExact_Flag           = 0x1,
167 
168         /** If the caller intends to do direct reads/writes to/from the CPU then this flag must be
169          *  set when accessing resources during a GrOpList flush. This includes the execution of
170          *  GrOp objects. The reason is that these memory operations are done immediately and
171          *  will occur out of order WRT the operations being flushed.
172          *  Make this automatic: https://bug.skia.org/4156
173          */
174         kNoPendingIO_Flag     = 0x2,
175 
176         kNoCreate_Flag        = 0x4,
177 
178         /** Normally the caps may indicate a preference for client-side buffers. Set this flag when
179          *  creating a buffer to guarantee it resides in GPU memory.
180          */
181         kRequireGpuMemory_Flag = 0x8,
182     };
183 
184     /**
185      * Returns a buffer.
186      *
187      * @param size            minimum size of buffer to return.
188      * @param intendedType    hint to the graphics subsystem about what the buffer will be used for.
189      * @param GrAccessPattern hint to the graphics subsystem about how the data will be accessed.
190      * @param flags           see Flags enum.
191      * @param data            optional data with which to initialize the buffer.
192      *
193      * @return the buffer if successful, otherwise nullptr.
194      */
195     GrBuffer* createBuffer(size_t size, GrBufferType intendedType, GrAccessPattern, uint32_t flags,
196                            const void* data = nullptr);
197 
198 
199     /**
200      * If passed in render target already has a stencil buffer, return it. Otherwise attempt to
201      * attach one.
202      */
203     GrStencilAttachment* attachStencilAttachment(GrRenderTarget* rt);
204 
205      /**
206       * Wraps an existing texture with a GrRenderTarget object. This is useful when the provided
207       * texture has a format that cannot be textured from by Skia, but we want to raster to it.
208       *
209       * The texture is wrapped as borrowed. The texture object will not be freed once the
210       * render target is destroyed.
211       *
212       * @return GrRenderTarget object or NULL on failure.
213       */
214      sk_sp<GrRenderTarget> wrapBackendTextureAsRenderTarget(const GrBackendTextureDesc& desc);
215 
216     /**
217      * Assigns a unique key to a resource. If the key is associated with another resource that
218      * association is removed and replaced by this resource.
219      */
220     void assignUniqueKeyToResource(const GrUniqueKey&, GrGpuResource*);
221 
222     /**
223      * Finds a resource in the cache, based on the specified key. This is intended for use in
224      * conjunction with addResourceToCache(). The return value will be NULL if not found. The
225      * caller must balance with a call to unref().
226      */
227     GrGpuResource* findAndRefResourceByUniqueKey(const GrUniqueKey&);
228 
229     sk_sp<GrSemaphore> SK_WARN_UNUSED_RESULT makeSemaphore();
230 
231     // Takes the GrSemaphore and sets the ownership of the semaphore to the GrGpu object used by
232     // this class. This call is only used when passing a GrSemaphore from one context to another.
233     void takeOwnershipOfSemaphore(sk_sp<GrSemaphore>);
234     // Takes the GrSemaphore and resets the ownership of the semaphore so that it is not owned by
235     // any GrGpu. A follow up call to takeOwnershipofSemaphore must be made so that the underlying
236     // semaphore can be deleted. This call is only used when passing a GrSemaphore from one context
237     // to another.
238     void releaseOwnershipOfSemaphore(sk_sp<GrSemaphore>);
239 
abandon()240     void abandon() {
241         fCache = nullptr;
242         fGpu = nullptr;
243     }
244 
245     // 'Proxy' is about to be used as a texture src. This query can be used to determine if
246     // it is going to need a texture domain.
247     static bool IsFunctionallyExact(GrTextureProxy* proxy);
248 
caps()249     const GrCaps* caps() const { return fCaps.get(); }
250 
251 private:
252     GrTexture* internalCreateApproxTexture(const GrSurfaceDesc& desc, uint32_t scratchTextureFlags);
253 
254     GrTexture* findAndRefTextureByUniqueKey(const GrUniqueKey& key);
assignUniqueKeyToTexture(const GrUniqueKey & key,GrTexture * texture)255     void assignUniqueKeyToTexture(const GrUniqueKey& key, GrTexture* texture) {
256         SkASSERT(key.isValid());
257         this->assignUniqueKeyToResource(key, texture);
258     }
259 
260     GrTexture* refScratchTexture(const GrSurfaceDesc&, uint32_t scratchTextureFlags);
261 
cache()262     GrResourceCache* cache() { return fCache; }
cache()263     const GrResourceCache* cache() const { return fCache; }
264 
gpu()265     GrGpu* gpu() { return fGpu; }
gpu()266     const GrGpu* gpu() const { return fGpu; }
267 
isAbandoned()268     bool isAbandoned() const {
269         SkASSERT(SkToBool(fGpu) == SkToBool(fCache));
270         return !SkToBool(fCache);
271     }
272 
273     const GrBuffer* createInstancedIndexBuffer(const uint16_t* pattern,
274                                                int patternSize,
275                                                int reps,
276                                                int vertCount,
277                                                const GrUniqueKey& key);
278 
279     const GrBuffer* createQuadIndexBuffer();
280 
281     GrResourceCache*    fCache;
282     GrGpu*              fGpu;
283     sk_sp<const GrCaps> fCaps;
284     GrUniqueKey         fQuadIndexBufferKey;
285 
286     // In debug builds we guard against improper thread handling
287     SkDEBUGCODE(mutable GrSingleOwner* fSingleOwner;)
288 };
289 
290 #endif
291