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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 GrGpuGL;
     17 class GrGLTexture;
     18 class GrGLTexID;
     19 
     20 class GrGLRenderTarget : public GrRenderTarget {
     21 
     22 public:
     23     // set fTexFBOID to this value to indicate that it is multisampled but
     24     // Gr doesn't know how to resolve it.
     25     enum { kUnresolvableFBOID = 0 };
     26 
     27     struct Desc {
     28         GrGLuint      fRTFBOID;
     29         GrGLuint      fTexFBOID;
     30         GrGLuint      fMSColorRenderbufferID;
     31         bool          fIsWrapped;
     32         GrPixelConfig fConfig;
     33         int           fSampleCnt;
     34     };
     35 
     36     // creates a GrGLRenderTarget associated with a texture
     37     GrGLRenderTarget(GrGpuGL*          gpu,
     38                      const Desc&       desc,
     39                      const GrGLIRect&  viewport,
     40                      GrGLTexID*        texID,
     41                      GrGLTexture*      texture);
     42 
     43     // creates an independent GrGLRenderTarget
     44     GrGLRenderTarget(GrGpuGL*          gpu,
     45                      const Desc&       desc,
     46                      const GrGLIRect&  viewport);
     47 
     48     virtual ~GrGLRenderTarget() { this->release(); }
     49 
     50     void setViewport(const GrGLIRect& rect) { fViewport = rect; }
     51     const GrGLIRect& getViewport() const { return fViewport; }
     52 
     53     // The following two functions return the same ID when a
     54     // texture/render target is multisampled, and different IDs when
     55     // it is.
     56     // FBO ID used to render into
     57     GrGLuint renderFBOID() const { return fRTFBOID; }
     58     // FBO ID that has texture ID attached.
     59     GrGLuint textureFBOID() const { return fTexFBOID; }
     60 
     61     // override of GrRenderTarget
     62     virtual GrBackendObject getRenderTargetHandle() const {
     63         return this->renderFBOID();
     64     }
     65     virtual GrBackendObject getRenderTargetResolvedHandle() const {
     66         return this->textureFBOID();
     67     }
     68     virtual ResolveType getResolveType() const {
     69 
     70         if (!this->isMultisampled() ||
     71             fRTFBOID == fTexFBOID) {
     72             // catches FBO 0 and non MSAA case
     73             return kAutoResolves_ResolveType;
     74         } else if (kUnresolvableFBOID == fTexFBOID) {
     75             return kCantResolve_ResolveType;
     76         } else {
     77             return kCanResolve_ResolveType;
     78         }
     79     }
     80 
     81 protected:
     82     // override of GrResource
     83     virtual void onAbandon() SK_OVERRIDE;
     84     virtual void onRelease() SK_OVERRIDE;
     85 
     86 private:
     87     GrGLuint      fRTFBOID;
     88     GrGLuint      fTexFBOID;
     89 
     90     GrGLuint      fMSColorRenderbufferID;
     91 
     92     // when we switch to this render target we want to set the viewport to
     93     // only render to to content area (as opposed to the whole allocation) and
     94     // we want the rendering to be at top left (GL has origin in bottom left)
     95     GrGLIRect fViewport;
     96 
     97     // non-NULL if this RT was created by Gr with an associated GrGLTexture.
     98     GrGLTexID* fTexIDObj;
     99 
    100     void init(const Desc& desc, const GrGLIRect& viewport, GrGLTexID* texID);
    101 
    102     typedef GrRenderTarget INHERITED;
    103 };
    104 
    105 #endif
    106