1 /* 2 * Copyright 2011 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 GrRenderTarget_DEFINED 9 #define GrRenderTarget_DEFINED 10 11 #include "GrSurface.h" 12 #include "SkRect.h" 13 14 class GrCaps; 15 class GrRenderTargetOpList; 16 class GrRenderTargetPriv; 17 class GrStencilAttachment; 18 class GrBackendRenderTarget; 19 20 /** 21 * GrRenderTarget represents a 2D buffer of pixels that can be rendered to. 22 * A context's render target is set by setRenderTarget(). Render targets are 23 * created by a createTexture with the kRenderTarget_SurfaceFlag flag. 24 * Additionally, GrContext provides methods for creating GrRenderTargets 25 * that wrap externally created render targets. 26 */ 27 class GrRenderTarget : virtual public GrSurface { 28 public: alwaysClearStencil()29 virtual bool alwaysClearStencil() const { return false; } 30 31 // GrSurface overrides asRenderTarget()32 GrRenderTarget* asRenderTarget() override { return this; } asRenderTarget()33 const GrRenderTarget* asRenderTarget() const override { return this; } 34 35 // GrRenderTarget isStencilBufferMultisampled()36 bool isStencilBufferMultisampled() const { return fSampleCnt > 1; } 37 fsaaType()38 GrFSAAType fsaaType() const { 39 SkASSERT(fSampleCnt >= 1); 40 if (fSampleCnt <= 1) { 41 SkASSERT(!(fFlags & GrRenderTargetFlags::kMixedSampled)); 42 return GrFSAAType::kNone; 43 } 44 return (fFlags & GrRenderTargetFlags::kMixedSampled) ? GrFSAAType::kMixedSamples 45 : GrFSAAType::kUnifiedMSAA; 46 } 47 48 /** 49 * Returns the number of samples/pixel in the stencil buffer (Zero if non-MSAA). 50 */ numStencilSamples()51 int numStencilSamples() const { return fSampleCnt; } 52 53 /** 54 * Returns the number of samples/pixel in the color buffer (Zero if non-MSAA or mixed sampled). 55 */ numColorSamples()56 int numColorSamples() const { 57 return GrFSAAType::kMixedSamples == this->fsaaType() ? 1 : fSampleCnt; 58 } 59 60 /** 61 * Call to indicate the multisample contents were modified such that the 62 * render target needs to be resolved before it can be used as texture. Gr 63 * tracks this for its own drawing and thus this only needs to be called 64 * when the render target has been modified outside of Gr. This has no 65 * effect on wrapped backend render targets. 66 * 67 * @param rect a rect bounding the area needing resolve. NULL indicates 68 * the whole RT needs resolving. 69 */ 70 void flagAsNeedingResolve(const SkIRect* rect = nullptr); 71 72 /** 73 * Call to override the region that needs to be resolved. 74 */ 75 void overrideResolveRect(const SkIRect rect); 76 77 /** 78 * Call to indicate that GrRenderTarget was externally resolved. This may 79 * allow Gr to skip a redundant resolve step. 80 */ 81 void flagAsResolved(); 82 83 /** 84 * @return true if the GrRenderTarget requires MSAA resolving 85 */ needsResolve()86 bool needsResolve() const { return !fResolveRect.isEmpty(); } 87 88 /** 89 * Returns a rect bounding the region needing resolving. 90 */ getResolveRect()91 const SkIRect& getResolveRect() const { return fResolveRect; } 92 93 // a MSAA RT may require explicit resolving , it may auto-resolve (e.g. FBO 94 // 0 in GL), or be unresolvable because the client didn't give us the 95 // resolve destination. 96 enum ResolveType { 97 kCanResolve_ResolveType, 98 kAutoResolves_ResolveType, 99 kCantResolve_ResolveType, 100 }; 101 virtual ResolveType getResolveType() const = 0; 102 103 /** 104 * Return the native ID or handle to the rendertarget, depending on the 105 * platform. e.g. on OpenGL, return the FBO ID. 106 */ 107 virtual GrBackendObject getRenderTargetHandle() const = 0; 108 109 virtual GrBackendRenderTarget getBackendRenderTarget() const = 0; 110 111 // Checked when this object is asked to attach a stencil buffer. 112 virtual bool canAttemptStencilAttachment() const = 0; 113 114 // Provides access to functions that aren't part of the public API. 115 GrRenderTargetPriv renderTargetPriv(); 116 const GrRenderTargetPriv renderTargetPriv() const; 117 118 protected: 119 GrRenderTarget(GrGpu*, const GrSurfaceDesc&, 120 GrRenderTargetFlags = GrRenderTargetFlags::kNone, 121 GrStencilAttachment* = nullptr); 122 123 // override of GrResource 124 void onAbandon() override; 125 void onRelease() override; 126 127 private: 128 // Allows the backends to perform any additional work that is required for attaching a 129 // GrStencilAttachment. When this is called, the GrStencilAttachment has already been put onto 130 // the GrRenderTarget. This function must return false if any failures occur when completing the 131 // stencil attachment. 132 virtual bool completeStencilAttachment() = 0; 133 134 friend class GrRenderTargetPriv; 135 136 int fSampleCnt; 137 GrStencilAttachment* fStencilAttachment; 138 uint8_t fMultisampleSpecsID; 139 GrRenderTargetFlags fFlags; 140 141 SkIRect fResolveRect; 142 143 typedef GrSurface INHERITED; 144 }; 145 146 #endif 147