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      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 
      9 #ifndef GrGLRenderTarget_DEFINED
     10 #define GrGLRenderTarget_DEFINED
     11 
     12 #include "GrBackendSurface.h"
     13 #include "GrGLIRect.h"
     14 #include "GrRenderTarget.h"
     15 #include "SkScalar.h"
     16 
     17 class GrGLCaps;
     18 class GrGLGpu;
     19 class GrGLStencilAttachment;
     20 
     21 class GrGLRenderTarget : public GrRenderTarget {
     22 public:
     23     bool alwaysClearStencil() const override { return 0 == fRTFBOID; }
     24 
     25     // set fTexFBOID to this value to indicate that it is multisampled but
     26     // Gr doesn't know how to resolve it.
     27     enum { kUnresolvableFBOID = 0 };
     28 
     29     struct IDDesc {
     30         GrGLuint                   fRTFBOID;
     31         GrBackendObjectOwnership   fRTFBOOwnership;
     32         GrGLuint                   fTexFBOID;
     33         GrGLuint                   fMSColorRenderbufferID;
     34         bool                       fIsMixedSampled;
     35     };
     36 
     37     static sk_sp<GrGLRenderTarget> MakeWrapped(GrGLGpu*,
     38                                                const GrSurfaceDesc&,
     39                                                const IDDesc&,
     40                                                int stencilBits);
     41 
     42     void setViewport(const GrGLIRect& rect) { fViewport = rect; }
     43     const GrGLIRect& getViewport() const { return fViewport; }
     44 
     45     // The following two functions return the same ID when a texture/render target is not
     46     // multisampled, and different IDs when it is multisampled.
     47     // FBO ID used to render into
     48     GrGLuint renderFBOID() const { return fRTFBOID; }
     49     // FBO ID that has texture ID attached.
     50     GrGLuint textureFBOID() const { return fTexFBOID; }
     51 
     52     // override of GrRenderTarget
     53     ResolveType getResolveType() const override {
     54         if (GrFSAAType::kUnifiedMSAA != this->fsaaType() || fRTFBOID == fTexFBOID) {
     55             // catches FBO 0 and non unified-MSAA case
     56             return kAutoResolves_ResolveType;
     57         } else if (kUnresolvableFBOID == fTexFBOID) {
     58             return kCantResolve_ResolveType;
     59         } else {
     60             return kCanResolve_ResolveType;
     61         }
     62     }
     63 
     64     GrBackendObject getRenderTargetHandle() const override { return fRTFBOID; }
     65 
     66     GrBackendRenderTarget getBackendRenderTarget() const override;
     67 
     68     bool canAttemptStencilAttachment() const override;
     69 
     70     // GrGLRenderTarget overrides dumpMemoryStatistics so it can log its texture and renderbuffer
     71     // components seperately.
     72     void dumpMemoryStatistics(SkTraceMemoryDump* traceMemoryDump) const override;
     73 
     74 protected:
     75     // Constructor for subclasses.
     76     GrGLRenderTarget(GrGLGpu*, const GrSurfaceDesc&, const IDDesc&);
     77 
     78     void init(const GrSurfaceDesc&, const IDDesc&);
     79 
     80     void onAbandon() override;
     81     void onRelease() override;
     82 
     83     int numSamplesOwnedPerPixel() const { return fNumSamplesOwnedPerPixel; }
     84 
     85 private:
     86     // Constructor for instances wrapping backend objects.
     87     GrGLRenderTarget(GrGLGpu*, const GrSurfaceDesc&, const IDDesc&, GrGLStencilAttachment*);
     88 
     89     static GrRenderTargetFlags ComputeFlags(const GrGLCaps&, const IDDesc&);
     90 
     91     GrGLGpu* getGLGpu() const;
     92     bool completeStencilAttachment() override;
     93 
     94     size_t onGpuMemorySize() const override;
     95 
     96     int msaaSamples() const;
     97     // The number total number of samples, including both MSAA and resolve texture samples.
     98     int totalSamples() const;
     99 
    100     GrGLuint    fRTFBOID;
    101     GrGLuint    fTexFBOID;
    102     GrGLuint    fMSColorRenderbufferID;
    103 
    104     GrBackendObjectOwnership fRTFBOOwnership;
    105 
    106     // when we switch to this render target we want to set the viewport to
    107     // only render to content area (as opposed to the whole allocation) and
    108     // we want the rendering to be at top left (GL has origin in bottom left)
    109     GrGLIRect   fViewport;
    110 
    111     // The RenderTarget needs to be able to report its VRAM footprint even after abandon and
    112     // release have potentially zeroed out the IDs (e.g., so the cache can reset itself). Since
    113     // the IDs are just required for the computation in totalSamples we cache that result here.
    114     int         fNumSamplesOwnedPerPixel;
    115 
    116     typedef GrRenderTarget INHERITED;
    117 };
    118 
    119 #endif
    120