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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 "GrGLIRect.h"
     13 #include "GrRenderTarget.h"
     14 #include "SkScalar.h"
     15 
     16 class GrGLGpu;
     17 
     18 class GrGLRenderTarget : public GrRenderTarget {
     19 public:
     20     // set fTexFBOID to this value to indicate that it is multisampled but
     21     // Gr doesn't know how to resolve it.
     22     enum { kUnresolvableFBOID = 0 };
     23 
     24     struct IDDesc {
     25         GrGLuint                    fRTFBOID;
     26         GrGLuint                    fTexFBOID;
     27         GrGLuint                    fMSColorRenderbufferID;
     28         GrGpuResource::LifeCycle    fLifeCycle;
     29     };
     30 
     31     GrGLRenderTarget(GrGLGpu*, const GrSurfaceDesc&, const IDDesc&);
     32 
     33     void setViewport(const GrGLIRect& rect) { fViewport = rect; }
     34     const GrGLIRect& getViewport() const { return fViewport; }
     35 
     36     // The following two functions return the same ID when a
     37     // texture/render target is multisampled, and different IDs when
     38     // it is.
     39     // FBO ID used to render into
     40     GrGLuint renderFBOID() const { return fRTFBOID; }
     41     // FBO ID that has texture ID attached.
     42     GrGLuint textureFBOID() const { return fTexFBOID; }
     43 
     44     // override of GrRenderTarget
     45     ResolveType getResolveType() const override {
     46         if (!this->isMultisampled() ||
     47             fRTFBOID == fTexFBOID) {
     48             // catches FBO 0 and non MSAA case
     49             return kAutoResolves_ResolveType;
     50         } else if (kUnresolvableFBOID == fTexFBOID) {
     51             return kCantResolve_ResolveType;
     52         } else {
     53             return kCanResolve_ResolveType;
     54         }
     55     }
     56 
     57     /** When we don't own the FBO ID we don't attempt to modify its attachments. */
     58     bool canAttemptStencilAttachment() const override { return !fIsWrapped; }
     59 
     60 protected:
     61     // The public constructor registers this object with the cache. However, only the most derived
     62     // class should register with the cache. This constructor does not do the registration and
     63     // rather moves that burden onto the derived class.
     64     enum Derived { kDerived };
     65     GrGLRenderTarget(GrGLGpu*, const GrSurfaceDesc&, const IDDesc&, Derived);
     66 
     67     void init(const GrSurfaceDesc&, const IDDesc&);
     68 
     69     void onAbandon() override;
     70     void onRelease() override;
     71 
     72     // In protected because subclass GrGLTextureRenderTarget calls this version.
     73     size_t onGpuMemorySize() const override;
     74 
     75 private:
     76     GrGLuint      fRTFBOID;
     77     GrGLuint      fTexFBOID;
     78     GrGLuint      fMSColorRenderbufferID;
     79 
     80     // We track this separately from GrGpuResource because this may be both a texture and a render
     81     // target, and the texture may be wrapped while the render target is not.
     82     bool fIsWrapped;
     83 
     84     // when we switch to this render target we want to set the viewport to
     85     // only render to content area (as opposed to the whole allocation) and
     86     // we want the rendering to be at top left (GL has origin in bottom left)
     87     GrGLIRect fViewport;
     88 
     89     // onGpuMemorySize() needs to know the VRAM footprint of the FBO(s). However, abandon and
     90     // release zero out the IDs and the cache needs to know the size even after those actions.
     91     size_t fGpuMemorySize;
     92 
     93     typedef GrRenderTarget INHERITED;
     94 };
     95 
     96 #endif
     97