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      1 /*
      2  * Copyright 2012 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 GrSurface_DEFINED
     10 #define GrSurface_DEFINED
     11 
     12 #include "GrTypes.h"
     13 #include "GrResource.h"
     14 #include "SkRect.h"
     15 
     16 class GrTexture;
     17 class GrRenderTarget;
     18 struct SkImageInfo;
     19 
     20 class GrSurface : public GrResource {
     21 public:
     22     SK_DECLARE_INST_COUNT(GrSurface);
     23 
     24     /**
     25      * Retrieves the width of the surface.
     26      *
     27      * @return the width in texels
     28      */
     29     int width() const { return fDesc.fWidth; }
     30 
     31     /**
     32      * Retrieves the height of the surface.
     33      *
     34      * @return the height in texels
     35      */
     36     int height() const { return fDesc.fHeight; }
     37 
     38     /**
     39      * Helper that gets the width and height of the surface as a bounding rectangle.
     40      */
     41     void getBoundsRect(SkRect* rect) const { rect->setWH(SkIntToScalar(this->width()),
     42                                                          SkIntToScalar(this->height())); }
     43 
     44     GrSurfaceOrigin origin() const {
     45         SkASSERT(kTopLeft_GrSurfaceOrigin == fDesc.fOrigin || kBottomLeft_GrSurfaceOrigin == fDesc.fOrigin);
     46         return fDesc.fOrigin;
     47     }
     48 
     49     /**
     50      * Retrieves the pixel config specified when the surface was created.
     51      * For render targets this can be kUnknown_GrPixelConfig
     52      * if client asked us to render to a target that has a pixel
     53      * config that isn't equivalent with one of our configs.
     54      */
     55     GrPixelConfig config() const { return fDesc.fConfig; }
     56 
     57     /**
     58      * Return the descriptor describing the surface
     59      */
     60     const GrTextureDesc& desc() const { return fDesc; }
     61 
     62     void asImageInfo(SkImageInfo*) const;
     63 
     64     /**
     65      * @return the texture associated with the surface, may be NULL.
     66      */
     67     virtual GrTexture* asTexture() = 0;
     68     virtual const GrTexture* asTexture() const = 0;
     69 
     70     /**
     71      * @return the render target underlying this surface, may be NULL.
     72      */
     73     virtual GrRenderTarget* asRenderTarget() = 0;
     74     virtual const GrRenderTarget* asRenderTarget() const = 0;
     75 
     76     /**
     77      * Checks whether this GrSurface refers to the same GPU object as other. This
     78      * catches the case where a GrTexture and GrRenderTarget refer to the same
     79      * GPU memory.
     80      */
     81     bool isSameAs(const GrSurface* other) const {
     82         const GrRenderTarget* thisRT = this->asRenderTarget();
     83         if (NULL != thisRT) {
     84             return thisRT == other->asRenderTarget();
     85         } else {
     86             const GrTexture* thisTex = this->asTexture();
     87             SkASSERT(NULL != thisTex); // We must be one or the other
     88             return thisTex == other->asTexture();
     89         }
     90     }
     91 
     92     /**
     93      * Reads a rectangle of pixels from the surface.
     94      * @param left          left edge of the rectangle to read (inclusive)
     95      * @param top           top edge of the rectangle to read (inclusive)
     96      * @param width         width of rectangle to read in pixels.
     97      * @param height        height of rectangle to read in pixels.
     98      * @param config        the pixel config of the destination buffer
     99      * @param buffer        memory to read the rectangle into.
    100      * @param rowBytes      number of bytes between consecutive rows. Zero means rows are tightly
    101      *                      packed.
    102      * @param pixelOpsFlags See the GrContext::PixelOpsFlags enum.
    103      *
    104      * @return true if the read succeeded, false if not. The read can fail because of an unsupported
    105      *              pixel config.
    106      */
    107     virtual bool readPixels(int left, int top, int width, int height,
    108                             GrPixelConfig config,
    109                             void* buffer,
    110                             size_t rowBytes = 0,
    111                             uint32_t pixelOpsFlags = 0) = 0;
    112 
    113     /**
    114      * Copy the src pixels [buffer, rowbytes, pixelconfig] into the surface at the specified
    115      * rectangle.
    116      * @param left          left edge of the rectangle to write (inclusive)
    117      * @param top           top edge of the rectangle to write (inclusive)
    118      * @param width         width of rectangle to write in pixels.
    119      * @param height        height of rectangle to write in pixels.
    120      * @param config        the pixel config of the source buffer
    121      * @param buffer        memory to read the rectangle from.
    122      * @param rowBytes      number of bytes between consecutive rows. Zero means rows are tightly
    123      *                      packed.
    124      * @param pixelOpsFlags See the GrContext::PixelOpsFlags enum.
    125      */
    126     virtual void writePixels(int left, int top, int width, int height,
    127                              GrPixelConfig config,
    128                              const void* buffer,
    129                              size_t rowBytes = 0,
    130                              uint32_t pixelOpsFlags = 0) = 0;
    131 
    132     /**
    133      * Write the contents of the surface to a PNG. Returns true if successful.
    134      * @param filename      Full path to desired file
    135      */
    136     bool savePixels(const char* filename);
    137 
    138 protected:
    139     GrSurface(GrGpu* gpu, bool isWrapped, const GrTextureDesc& desc)
    140     : INHERITED(gpu, isWrapped)
    141     , fDesc(desc) {
    142     }
    143 
    144     GrTextureDesc fDesc;
    145 
    146 private:
    147     typedef GrResource INHERITED;
    148 };
    149 
    150 #endif // GrSurface_DEFINED
    151