| /* |
| * Copyright 2017 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| #ifndef GrBackendTextureImageGenerator_DEFINED |
| #define GrBackendTextureImageGenerator_DEFINED |
| |
| #include "include/core/SkImageGenerator.h" |
| #include "include/gpu/GrBackendSurface.h" |
| #include "include/gpu/GrDirectContext.h" |
| #include "include/private/GrResourceKey.h" |
| #include "include/private/SkMutex.h" |
| #include "src/gpu/GrTexture.h" |
| |
| class GrSemaphore; |
| |
| /* |
| * This ImageGenerator is used to wrap a texture in one GrContext and can then be used as a source |
| * in another GrContext. It holds onto a semaphore which the producing GrContext will signal and the |
| * consuming GrContext will wait on before using the texture. Only one GrContext can ever be used |
| * as a consumer (this is mostly because Vulkan can't allow multiple things to wait on the same |
| * semaphore). |
| * |
| * In practice, this capability is used by clients to create backend-specific texture resources in |
| * one thread (with, say, GrContext-A) and then ship them over to another GrContext (say, |
| * GrContext-B) which will then use the texture as a source for draws. GrContext-A uses the |
| * semaphore to notify GrContext-B when the shared texture is ready to use. |
| */ |
| class GrBackendTextureImageGenerator : public SkImageGenerator { |
| public: |
| static std::unique_ptr<SkImageGenerator> Make(sk_sp<GrTexture>, GrSurfaceOrigin, |
| std::unique_ptr<GrSemaphore>, SkColorType, |
| SkAlphaType, sk_sp<SkColorSpace>); |
| |
| ~GrBackendTextureImageGenerator() override; |
| |
| protected: |
| bool onIsValid(GrRecordingContext* context) const override { |
| if (context && context->abandoned()) { |
| return false; |
| } |
| return true; |
| } |
| |
| GrSurfaceProxyView onGenerateTexture(GrRecordingContext*, const SkImageInfo&, const SkIPoint&, |
| GrMipmapped mipMapped, GrImageTexGenPolicy) override; |
| |
| private: |
| GrBackendTextureImageGenerator(const SkImageInfo& info, |
| GrTexture*, |
| GrSurfaceOrigin, |
| GrDirectContext::DirectContextID owningContextID, |
| std::unique_ptr<GrSemaphore>, |
| const GrBackendTexture&); |
| |
| static void ReleaseRefHelper_TextureReleaseProc(void* ctx); |
| |
| class RefHelper : public SkNVRefCnt<RefHelper> { |
| public: |
| RefHelper(GrTexture*, |
| GrDirectContext::DirectContextID owningContextID, |
| std::unique_ptr<GrSemaphore>); |
| |
| ~RefHelper(); |
| |
| GrTexture* fOriginalTexture; |
| GrDirectContext::DirectContextID fOwningContextID; |
| |
| // We use this key so that we don't rewrap the GrBackendTexture in a GrTexture for each |
| // proxy created from this generator for a particular borrowing context. |
| GrUniqueKey fBorrowedTextureKey; |
| // There is no ref associated with this pointer. We rely on our atomic bookkeeping with the |
| // context ID to know when this pointer is valid and safe to use. This is used to make sure |
| // all uses of the wrapped texture are finished on the borrowing context before we open |
| // this back up to other contexts. In general a ref to this release proc is owned by all |
| // proxies and gpu uses of the backend texture. |
| GrRefCntedCallback* fBorrowingContextReleaseProc; |
| GrDirectContext::DirectContextID fBorrowingContextID; |
| |
| std::unique_ptr<GrSemaphore> fSemaphore; |
| }; |
| |
| RefHelper* fRefHelper; |
| // This Mutex is used to guard the borrowing of the texture to one GrContext at a time as well |
| // as the creation of the fBorrowingContextReleaseProc. The latter happening if two threads with |
| // the same consuming GrContext try to generate a texture at the same time. |
| SkMutex fBorrowingMutex; |
| |
| GrBackendTexture fBackendTexture; |
| GrSurfaceOrigin fSurfaceOrigin; |
| |
| using INHERITED = SkImageGenerator; |
| }; |
| #endif // GrBackendTextureImageGenerator_DEFINED |