1 /* 2 * Copyright 2019 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 GrVkSecondaryCBDrawContext_DEFINED 9 #define GrVkSecondaryCBDrawContext_DEFINED 10 11 #include "SkTypes.h" 12 #include "SkRefCnt.h" 13 14 class GrBackendSemaphore; 15 class GrContext; 16 struct GrVkDrawableInfo; 17 class SkCanvas; 18 class SkDeferredDisplayList; 19 class SkGpuDevice; 20 struct SkImageInfo; 21 class SkSurfaceCharacterization; 22 class SkSurfaceProps; 23 24 /** 25 * This class is a private header that is intended to only be used inside of Chromium. This requires 26 * Chromium to burrow in and include this specifically since it is not part of skia's public include 27 * directory. 28 */ 29 30 /** 31 * This class is used to draw into an external Vulkan secondary command buffer that is imported 32 * by the client. The secondary command buffer that gets imported must already have had begin called 33 * on it with VK_COMMAND_BUFFER_USAGE_RENDER_PASS_CONTINUE_BIT. Thus any draws to the imported 34 * command buffer cannot require changing the render pass. This requirement means that certain types 35 * of draws will not be supported when using a GrVkSecondaryCBDrawContext. This includes: 36 * Draws that require a dst copy for blending will be dropped 37 * Text draws will be dropped (these may require intermediate uploads of text data) 38 * Read and Write pixels will not work 39 * Any other draw that requires a copy will fail (this includes using backdrop filter with save 40 * layer). 41 * Stenciling is also disabled, but that should not restrict any actual draws from working. 42 * 43 * While using a GrVkSecondaryCBDrawContext, the client can also draw into normal SkSurfaces and 44 * then draw those SkSufaces (as SkImages) into the GrVkSecondaryCBDrawContext. If any of the 45 * previously mentioned unsupported draws are needed by the client, they can draw them into an 46 * offscreen surface, and then draw that into the GrVkSecondaryCBDrawContext. 47 * 48 * After all drawing to the GrVkSecondaryCBDrawContext has been done, the client must call flush() 49 * on the GrVkSecondaryCBDrawContext to actually fill in the secondary VkCommandBuffer with the 50 * draws. 51 * 52 * Additionally, the client must keep the GrVkSecondaryCBDrawContext alive until the secondary 53 * VkCommandBuffer has been submitted and all work finished on the GPU. Before deleting the 54 * GrVkSecondaryCBDrawContext, the client must call releaseResources() so that Skia can cleanup 55 * any internal objects that were created for the draws into the secondary command buffer. 56 */ 57 class SK_API GrVkSecondaryCBDrawContext : public SkRefCnt { 58 public: 59 static sk_sp<GrVkSecondaryCBDrawContext> Make(GrContext*, const SkImageInfo&, 60 const GrVkDrawableInfo&, 61 const SkSurfaceProps* props); 62 63 ~GrVkSecondaryCBDrawContext() override; 64 65 SkCanvas* getCanvas(); 66 67 // Records all the draws to the imported secondary command buffer and sets any dependent 68 // offscreen draws to the GPU. 69 void flush(); 70 71 /** Inserts a list of GPU semaphores that Skia will have the driver wait on before executing 72 commands for this secondary CB. The wait semaphores will get added to the VkCommandBuffer 73 owned by this GrContext when flush() is called, and not the command buffer which the 74 Secondary CB is from. This will guarantee that the driver waits on the semaphores before 75 the secondary command buffer gets executed. Skia will take ownership of the underlying 76 semaphores and delete them once they have been signaled and waited on. If this call returns 77 false, then the GPU back-end will not wait on any passed in semaphores, and the client will 78 still own the semaphores. 79 80 @param numSemaphores size of waitSemaphores array 81 @param waitSemaphores array of semaphore containers 82 @return true if GPU is waiting on semaphores 83 */ 84 bool wait(int numSemaphores, const GrBackendSemaphore waitSemaphores[]); 85 86 // This call will release all resources held by the draw context. The client must call 87 // releaseResources() before deleting the drawing context. However, the resources also include 88 // any Vulkan resources that were created and used for draws. Therefore the client must only 89 // call releaseResources() after submitting the secondary command buffer, and waiting for it to 90 // finish on the GPU. If it is called earlier then some vulkan objects may be deleted while they 91 // are still in use by the GPU. 92 void releaseResources(); 93 94 // TODO: Fill out these calls to support DDL 95 bool characterize(SkSurfaceCharacterization* characterization) const; 96 bool draw(SkDeferredDisplayList* deferredDisplayList); 97 98 private: 99 explicit GrVkSecondaryCBDrawContext(sk_sp<SkGpuDevice>); 100 101 sk_sp<SkGpuDevice> fDevice; 102 std::unique_ptr<SkCanvas> fCachedCanvas; 103 104 typedef SkRefCnt INHERITED; 105 }; 106 107 #endif 108