The Tor Browser: gfx/skia/trunk/include/gpu/GrContext.h@6474c204b198 (annotated)

gfx/skia/trunk/include/gpu/GrContext.h@6474c204b198 (annotated)

gfx/skia/trunk/include/gpu/GrContext.h

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef GrContext_DEFINED
 #define GrContext_DEFINED
 #include "GrClipData.h"
 #include "GrColor.h"
 #include "GrPaint.h"
 #include "GrPathRendererChain.h"
 #include "GrPoint.h"
 #include "GrRenderTarget.h"
 #include "GrTexture.h"
 #include "SkMatrix.h"
 #include "SkTypes.h"
 class GrAARectRenderer;
 class GrAutoScratchTexture;
 class GrDrawState;
 class GrDrawTarget;
 class GrEffect;
 class GrFontCache;
 class GrGpu;
 class GrIndexBuffer;
 class GrIndexBufferAllocPool;
 class GrInOrderDrawBuffer;
 class GrOvalRenderer;
 class GrPath;
 class GrPathRenderer;
 class GrResourceEntry;
 class GrResourceCache;
 class GrStencilBuffer;
 class GrTestTarget;
 class GrTextureParams;
 class GrVertexBuffer;
 class GrVertexBufferAllocPool;
 class GrSoftwarePathRenderer;
 class SkStrokeRec;
 class SK_API GrContext : public SkRefCnt {
 public:
     SK_DECLARE_INST_COUNT(GrContext)
     /**
      * Creates a GrContext for a backend context.
      */
     static GrContext* Create(GrBackend, GrBackendContext);
     virtual ~GrContext();
     /**
      * The GrContext normally assumes that no outsider is setting state
      * within the underlying 3D API's context/device/whatever. This call informs
      * the context that the state was modified and it should resend. Shouldn't
      * be called frequently for good performance.
      * The flag bits, state, is dpendent on which backend is used by the
      * context, either GL or D3D (possible in future).
      */
     void resetContext(uint32_t state = kAll_GrBackendState);
     /**
      * Callback function to allow classes to cleanup on GrContext destruction.
      * The 'info' field is filled in with the 'info' passed to addCleanUp.
      */
     typedef void (*PFCleanUpFunc)(const GrContext* context, void* info);
     /**
      * Add a function to be called from within GrContext's destructor.
      * This gives classes a chance to free resources held on a per context basis.
      * The 'info' parameter will be stored and passed to the callback function.
      */
     void addCleanUp(PFCleanUpFunc cleanUp, void* info) {
         CleanUpData* entry = fCleanUpData.push();
         entry->fFunc = cleanUp;
         entry->fInfo = info;
     }
     /**
      * Abandons all GPU resources, assumes 3D API state is unknown. Call this
      * if you have lost the associated GPU context, and thus internal texture,
      * buffer, etc. references/IDs are now invalid. Should be called even when
      * GrContext is no longer going to be used for two reasons:
      *  1) ~GrContext will not try to free the objects in the 3D API.
      *  2) If you've created GrResources that outlive the GrContext they will
      *     be marked as invalid (GrResource::isValid()) and won't attempt to
      *     free their underlying resource in the 3D API.
      * Content drawn since the last GrContext::flush() may be lost.
      */
     void contextLost();
     /**
      * Similar to contextLost, but makes no attempt to reset state.
      * Use this method when GrContext destruction is pending, but
      * the graphics context is destroyed first.
      */
     void contextDestroyed();
     /**
      * Frees GPU created by the context. Can be called to reduce GPU memory
      * pressure.
      */
     void freeGpuResources();
     /**
      * Returns the number of bytes of GPU memory hosted by the texture cache.
      */
     size_t getGpuTextureCacheBytes() const;
     ///////////////////////////////////////////////////////////////////////////
     // Textures
     /**
      * Creates a new entry, based on the specified key and texture and returns it. The caller owns a
      * ref on the returned texture which must be balanced by a call to unref.
      *
      * @param params    The texture params used to draw a texture may help determine
      *                  the cache entry used. (e.g. different versions may exist
      *                  for different wrap modes on GPUs with limited NPOT
      *                  texture support). NULL implies clamp wrap modes.
      * @param desc      Description of the texture properties.
      * @param cacheID Cache-specific properties (e.g., texture gen ID)
      * @param srcData   Pointer to the pixel values.
      * @param rowBytes  The number of bytes between rows of the texture. Zero
      *                  implies tightly packed rows.
      * @param cacheKey  (optional) If non-NULL, we'll write the cache key we used to cacheKey.
      */
     GrTexture* createTexture(const GrTextureParams* params,
                              const GrTextureDesc& desc,
                              const GrCacheID& cacheID,
                              void* srcData,
                              size_t rowBytes,
                              GrResourceKey* cacheKey = NULL);
     /**
      * Search for an entry based on key and dimensions. If found, ref it and return it. The return
      * value will be NULL if not found. The caller must balance with a call to unref.
      *
      *  @param desc     Description of the texture properties.
      *  @param cacheID Cache-specific properties (e.g., texture gen ID)
      *  @param params   The texture params used to draw a texture may help determine
      *                  the cache entry used. (e.g. different versions may exist
      *                  for different wrap modes on GPUs with limited NPOT
      *                  texture support). NULL implies clamp wrap modes.
      */
     GrTexture* findAndRefTexture(const GrTextureDesc& desc,
                                  const GrCacheID& cacheID,
                                  const GrTextureParams* params);
     /**
      * Determines whether a texture is in the cache. If the texture is found it
      * will not be locked or returned. This call does not affect the priority of
      * the texture for deletion.
      */
     bool isTextureInCache(const GrTextureDesc& desc,
                           const GrCacheID& cacheID,
                           const GrTextureParams* params) const;
     /**
      * Enum that determines how closely a returned scratch texture must match
      * a provided GrTextureDesc.
      */
     enum ScratchTexMatch {
         /**
          * Finds a texture that exactly matches the descriptor.
          */
         kExact_ScratchTexMatch,
         /**
          * Finds a texture that approximately matches the descriptor. Will be
          * at least as large in width and height as desc specifies. If desc
          * specifies that texture is a render target then result will be a
          * render target. If desc specifies a render target and doesn't set the
          * no stencil flag then result will have a stencil. Format and aa level
          * will always match.
          */
         kApprox_ScratchTexMatch
     };
     /**
      * Returns a texture matching the desc. It's contents are unknown. Subsequent
      * requests with the same descriptor are not guaranteed to return the same
      * texture. The same texture is guaranteed not be returned again until it is
      * unlocked. Call must be balanced with an unlockTexture() call. The caller
      * owns a ref on the returned texture and must balance with a call to unref.
      *
      * Textures created by createAndLockTexture() hide the complications of
      * tiling non-power-of-two textures on APIs that don't support this (e.g.
      * unextended GLES2). Tiling a NPOT texture created by lockScratchTexture on
      * such an API will create gaps in the tiling pattern. This includes clamp
      * mode. (This may be addressed in a future update.)
      */
     GrTexture* lockAndRefScratchTexture(const GrTextureDesc&, ScratchTexMatch match);
     /**
      *  When done with an entry, call unlockScratchTexture(entry) on it, which returns
      *  it to the cache, where it may be purged. This does not unref the texture.
      */
     void unlockScratchTexture(GrTexture* texture);
     /**
      * This method should be called whenever a GrTexture is unreffed or
      * switched from exclusive to non-exclusive. This
      * gives the resource cache a chance to discard unneeded textures.
      * Note: this entry point will be removed once totally ref-driven
      * cache maintenance is implemented
      */
     void purgeCache();
     /**
      * Purge all the unlocked resources from the cache.
      * This entry point is mainly meant for timing texture uploads
      * and is not defined in normal builds of Skia.
      */
     void purgeAllUnlockedResources();
     /**
      * Creates a texture that is outside the cache. Does not count against
      * cache's budget.
      */
     GrTexture* createUncachedTexture(const GrTextureDesc& desc,
                                      void* srcData,
                                      size_t rowBytes);
     /**
      * Returns true if the specified use of an indexed texture is supported.
      * Support may depend upon whether the texture params indicate that the
      * texture will be tiled. Passing NULL for the texture params indicates
      * clamp mode.
      */
     bool supportsIndex8PixelConfig(const GrTextureParams*,
                                    int width,
                                    int height) const;
     /**
      *  Return the current texture cache limits.
      *
      *  @param maxTextures If non-null, returns maximum number of textures that
      *                     can be held in the cache.
      *  @param maxTextureBytes If non-null, returns maximum number of bytes of
      *                         texture memory that can be held in the cache.
      */
     void getTextureCacheLimits(int* maxTextures, size_t* maxTextureBytes) const;
     /**
      *  Specify the texture cache limits. If the current cache exceeds either
      *  of these, it will be purged (LRU) to keep the cache within these limits.
      *
      *  @param maxTextures The maximum number of textures that can be held in
      *                     the cache.
      *  @param maxTextureBytes The maximum number of bytes of texture memory
      *                         that can be held in the cache.
      */
     void setTextureCacheLimits(int maxTextures, size_t maxTextureBytes);
     /**
      *  Return the max width or height of a texture supported by the current GPU.
      */
     int getMaxTextureSize() const;
     /**
      *  Temporarily override the true max texture size. Note: an override
      *  larger then the true max texture size will have no effect.
      *  This entry point is mainly meant for testing texture size dependent
      *  features and is only available if defined outside of Skia (see
      *  bleed GM.
      */
     void setMaxTextureSizeOverride(int maxTextureSizeOverride);
     ///////////////////////////////////////////////////////////////////////////
     // Render targets
     /**
      * Sets the render target.
      * @param target    the render target to set.
      */
     void setRenderTarget(GrRenderTarget* target) {
         fRenderTarget.reset(SkSafeRef(target));
     }
     /**
      * Gets the current render target.
      * @return the currently bound render target.
      */
     const GrRenderTarget* getRenderTarget() const { return fRenderTarget.get(); }
     GrRenderTarget* getRenderTarget() { return fRenderTarget.get(); }
     GrAARectRenderer* getAARectRenderer() { return fAARectRenderer; }
     /**
      * Can the provided configuration act as a color render target?
      */
     bool isConfigRenderable(GrPixelConfig config, bool withMSAA) const;
     /**
      * Return the max width or height of a render target supported by the
      * current GPU.
      */
     int getMaxRenderTargetSize() const;
     /**
      * Returns the max sample count for a render target. It will be 0 if MSAA
      * is not supported.
      */
     int getMaxSampleCount() const;
     /**
      * Returns the recommended sample count for a render target when using this
      * context.
      *
      * @param  config the configuration of the render target.
      * @param  dpi the display density in dots per inch.
      *
      * @return sample count that should be perform well and have good enough
      *         rendering quality for the display. Alternatively returns 0 if
      *         MSAA is not supported or recommended to be used by default.
      */
     int getRecommendedSampleCount(GrPixelConfig config, SkScalar dpi) const;
     ///////////////////////////////////////////////////////////////////////////
     // Backend Surfaces
     /**
      * Wraps an existing texture with a GrTexture object.
      *
      * OpenGL: if the object is a texture Gr may change its GL texture params
      *         when it is drawn.
      *
      * @param  desc     description of the object to create.
      *
      * @return GrTexture object or NULL on failure.
      */
     GrTexture* wrapBackendTexture(const GrBackendTextureDesc& desc);
     /**
      * Wraps an existing render target with a GrRenderTarget object. It is
      * similar to wrapBackendTexture but can be used to draw into surfaces
      * that are not also textures (e.g. FBO 0 in OpenGL, or an MSAA buffer that
      * the client will resolve to a texture).
      *
      * @param  desc     description of the object to create.
      *
      * @return GrTexture object or NULL on failure.
      */
      GrRenderTarget* wrapBackendRenderTarget(const GrBackendRenderTargetDesc& desc);
     ///////////////////////////////////////////////////////////////////////////
     // Matrix state
     /**
      * Gets the current transformation matrix.
      * @return the current matrix.
      */
     const SkMatrix& getMatrix() const { return fViewMatrix; }
     /**
      * Sets the transformation matrix.
      * @param m the matrix to set.
      */
     void setMatrix(const SkMatrix& m) { fViewMatrix = m; }
     /**
      * Sets the current transformation matrix to identity.
      */
     void setIdentityMatrix() { fViewMatrix.reset(); }
     /**
      * Concats the current matrix. The passed matrix is applied before the
      * current matrix.
      * @param m the matrix to concat.
      */
     void concatMatrix(const SkMatrix& m) { fViewMatrix.preConcat(m); }
     ///////////////////////////////////////////////////////////////////////////
     // Clip state
     /**
      * Gets the current clip.
      * @return the current clip.
      */
     const GrClipData* getClip() const { return fClip; }
     /**
      * Sets the clip.
      * @param clipData  the clip to set.
      */
     void setClip(const GrClipData* clipData) { fClip = clipData; }
     ///////////////////////////////////////////////////////////////////////////
     // Draws
     /**
      * Clear the entire or rect of the render target, ignoring any clips.
      * @param rect  the rect to clear or the whole thing if rect is NULL.
      * @param color the color to clear to.
      * @param canIgnoreRect allows partial clears to be converted to whole
      *                      clears on platforms for which that is cheap
      * @param target if non-NULL, the render target to clear otherwise clear
      *               the current render target
      */
     void clear(const SkIRect* rect, GrColor color, bool canIgnoreRect,
                GrRenderTarget* target = NULL);
     /**
      *  Draw everywhere (respecting the clip) with the paint.
      */
     void drawPaint(const GrPaint& paint);
     /**
      *  Draw the rect using a paint.
      *  @param paint        describes how to color pixels.
      *  @param stroke       the stroke information (width, join, cap).
      *                      If stroke == NULL, then the rect is filled.
      *                      Otherwise, if stroke width == 0, then the stroke
      *                      is always a single pixel thick, else the rect is
      *                      mitered/beveled stroked based on stroke width.
      *  @param matrix       Optional matrix applied to the rect. Applied before
      *                      context's matrix or the paint's matrix.
      *  The rects coords are used to access the paint (through texture matrix)
      */
     void drawRect(const GrPaint& paint,
                   const SkRect&,
                   const SkStrokeRec* stroke = NULL,
                   const SkMatrix* matrix = NULL);
     /**
      * Maps a rect of local coordinates onto the a rect of destination
      * coordinates. Each rect can optionally be transformed. The localRect
      * is stretched over the dstRect. The dstRect is transformed by the
      * context's matrix. Additional optional matrices for both rects can be
      * provided by parameters.
      *
      * @param paint         describes how to color pixels.
      * @param dstRect       the destination rect to draw.
      * @param localRect     rect of local coordinates to be mapped onto dstRect
      * @param dstMatrix     Optional matrix to transform dstRect. Applied before context's matrix.
      * @param localMatrix   Optional matrix to transform localRect.
      */
     void drawRectToRect(const GrPaint& paint,
                         const SkRect& dstRect,
                         const SkRect& localRect,
                         const SkMatrix* dstMatrix = NULL,
                         const SkMatrix* localMatrix = NULL);
     /**
      *  Draw a roundrect using a paint.
      *
      *  @param paint        describes how to color pixels.
      *  @param rrect        the roundrect to draw
      *  @param stroke       the stroke information (width, join, cap)
      */
     void drawRRect(const GrPaint& paint,
                    const SkRRect& rrect,
                    const SkStrokeRec& stroke);
     /**
      * Draws a path.
      *
      * @param paint         describes how to color pixels.
      * @param path          the path to draw
      * @param stroke        the stroke information (width, join, cap)
      */
     void drawPath(const GrPaint& paint, const SkPath& path, const SkStrokeRec& stroke);
     /**
      * Draws vertices with a paint.
      *
      * @param   paint           describes how to color pixels.
      * @param   primitiveType   primitives type to draw.
      * @param   vertexCount     number of vertices.
      * @param   positions       array of vertex positions, required.
      * @param   texCoords       optional array of texture coordinates used
      *                          to access the paint.
      * @param   colors          optional array of per-vertex colors, supercedes
      *                          the paint's color field.
      * @param   indices         optional array of indices. If NULL vertices
      *                          are drawn non-indexed.
      * @param   indexCount      if indices is non-null then this is the
      *                          number of indices.
      */
     void drawVertices(const GrPaint& paint,
                       GrPrimitiveType primitiveType,
                       int vertexCount,
                       const GrPoint positions[],
                       const GrPoint texs[],
                       const GrColor colors[],
                       const uint16_t indices[],
                       int indexCount);
     /**
      * Draws an oval.
      *
      * @param paint         describes how to color pixels.
      * @param oval          the bounding rect of the oval.
      * @param stroke        the stroke information (width, style)
      */
     void drawOval(const GrPaint& paint,
                   const SkRect& oval,
                   const SkStrokeRec& stroke);
     ///////////////////////////////////////////////////////////////////////////
     // Misc.
     /**
      * Flags that affect flush() behavior.
      */
     enum FlushBits {
         /**
          * A client may reach a point where it has partially rendered a frame
          * through a GrContext that it knows the user will never see. This flag
          * causes the flush to skip submission of deferred content to the 3D API
          * during the flush.
          */
         kDiscard_FlushBit                    = 0x2,
     };
     /**
      * Call to ensure all drawing to the context has been issued to the
      * underlying 3D API.
      * @param flagsBitfield     flags that control the flushing behavior. See
      *                          FlushBits.
      */
     void flush(int flagsBitfield = 0);
    /**
     * These flags can be used with the read/write pixels functions below.
     */
     enum PixelOpsFlags {
         /** The GrContext will not be flushed. This means that the read or write may occur before
             previous draws have executed. */
         kDontFlush_PixelOpsFlag = 0x1,
         /** The src for write or dst read is unpremultiplied. This is only respected if both the
             config src and dst configs are an RGBA/BGRA 8888 format. */
         kUnpremul_PixelOpsFlag  = 0x2,
     };
     /**
      * Reads a rectangle of pixels from a render target.
      * @param target        the render target to read from. NULL means the current render target.
      * @param left          left edge of the rectangle to read (inclusive)
      * @param top           top edge of the rectangle to read (inclusive)
      * @param width         width of rectangle to read in pixels.
      * @param height        height of rectangle to read in pixels.
      * @param config        the pixel config of the destination buffer
      * @param buffer        memory to read the rectangle into.
      * @param rowBytes      number of bytes bewtween consecutive rows. Zero means rows are tightly
      *                      packed.
      * @param pixelOpsFlags see PixelOpsFlags enum above.
      *
      * @return true if the read succeeded, false if not. The read can fail because of an unsupported
      *         pixel config or because no render target is currently set and NULL was passed for
      *         target.
      */
     bool readRenderTargetPixels(GrRenderTarget* target,
                                 int left, int top, int width, int height,
                                 GrPixelConfig config, void* buffer,
                                 size_t rowBytes = 0,
                                 uint32_t pixelOpsFlags = 0);
     /**
      * Copy the src pixels [buffer, row bytes, pixel config] into a render target at the specified
      * rectangle.
      * @param target        the render target to write into. NULL means the current render target.
      * @param left          left edge of the rectangle to write (inclusive)
      * @param top           top edge of the rectangle to write (inclusive)
      * @param width         width of rectangle to write in pixels.
      * @param height        height of rectangle to write in pixels.
      * @param config        the pixel config of the source buffer
      * @param buffer        memory to read the rectangle from.
      * @param rowBytes      number of bytes between consecutive rows. Zero means rows are tightly
      *                      packed.
      * @param pixelOpsFlags see PixelOpsFlags enum above.
      *
      * @return true if the write succeeded, false if not. The write can fail because of an
      *         unsupported combination of target and pixel configs.
      */
     bool writeRenderTargetPixels(GrRenderTarget* target,
                                  int left, int top, int width, int height,
                                  GrPixelConfig config, const void* buffer,
                                  size_t rowBytes = 0,
                                  uint32_t pixelOpsFlags = 0);
     /**
      * Reads a rectangle of pixels from a texture.
      * @param texture       the texture to read from.
      * @param left          left edge of the rectangle to read (inclusive)
      * @param top           top edge of the rectangle to read (inclusive)
      * @param width         width of rectangle to read in pixels.
      * @param height        height of rectangle to read in pixels.
      * @param config        the pixel config of the destination buffer
      * @param buffer        memory to read the rectangle into.
      * @param rowBytes      number of bytes between consecutive rows. Zero means rows are tightly
      *                      packed.
      * @param pixelOpsFlags see PixelOpsFlags enum above.
      *
      * @return true if the read succeeded, false if not. The read can fail because of an unsupported
      *         pixel config.
      */
     bool readTexturePixels(GrTexture* texture,
                            int left, int top, int width, int height,
                            GrPixelConfig config, void* buffer,
                            size_t rowBytes = 0,
                            uint32_t pixelOpsFlags = 0);
     /**
      * Writes a rectangle of pixels to a texture.
      * @param texture       the render target to read from.
      * @param left          left edge of the rectangle to write (inclusive)
      * @param top           top edge of the rectangle to write (inclusive)
      * @param width         width of rectangle to write in pixels.
      * @param height        height of rectangle to write in pixels.
      * @param config        the pixel config of the source buffer
      * @param buffer        memory to read pixels from
      * @param rowBytes      number of bytes between consecutive rows. Zero
      *                      means rows are tightly packed.
      * @param pixelOpsFlags see PixelOpsFlags enum above.
      * @return true if the write succeeded, false if not. The write can fail because of an
      *         unsupported combination of texture and pixel configs.
      */
     bool writeTexturePixels(GrTexture* texture,
                             int left, int top, int width, int height,
                             GrPixelConfig config, const void* buffer,
                             size_t rowBytes,
                             uint32_t pixelOpsFlags = 0);
     /**
      * Copies a rectangle of texels from src to dst. The size of dst is the size of the rectangle
      * copied and topLeft is the position of the rect in src. The rectangle is clipped to src's
      * bounds.
      * @param src           the texture to copy from.
      * @param dst           the render target to copy to.
      * @param topLeft       the point in src that will be copied to the top-left of dst. If NULL,
      *                      (0, 0) will be used.
      */
     void copyTexture(GrTexture* src, GrRenderTarget* dst, const SkIPoint* topLeft = NULL);
     /**
      * Resolves a render target that has MSAA. The intermediate MSAA buffer is
      * down-sampled to the associated GrTexture (accessible via
      * GrRenderTarget::asTexture()). Any pending draws to the render target will
      * be executed before the resolve.
      *
      * This is only necessary when a client wants to access the object directly
      * using the backend API directly. GrContext will detect when it must
      * perform a resolve to a GrTexture used as the source of a draw or before
      * reading pixels back from a GrTexture or GrRenderTarget.
      */
     void resolveRenderTarget(GrRenderTarget* target);
 #ifdef SK_DEVELOPER
     void dumpFontCache() const;
 #endif
     ///////////////////////////////////////////////////////////////////////////
     // Helpers
     class AutoRenderTarget : public ::SkNoncopyable {
     public:
         AutoRenderTarget(GrContext* context, GrRenderTarget* target) {
             fPrevTarget = context->getRenderTarget();
             SkSafeRef(fPrevTarget);
             context->setRenderTarget(target);
             fContext = context;
         }
         AutoRenderTarget(GrContext* context) {
             fPrevTarget = context->getRenderTarget();
             SkSafeRef(fPrevTarget);
             fContext = context;
         }
         ~AutoRenderTarget() {
             if (NULL != fContext) {
                 fContext->setRenderTarget(fPrevTarget);
             }
             SkSafeUnref(fPrevTarget);
         }
     private:
         GrContext*      fContext;
         GrRenderTarget* fPrevTarget;
     };
     /**
      * Save/restore the view-matrix in the context. It can optionally adjust a paint to account
      * for a coordinate system change. Here is an example of how the paint param can be used:
      *
      * A GrPaint is setup with GrEffects. The stages will have access to the pre-matrix source
      * geometry positions when the draw is executed. Later on a decision is made to transform the
      * geometry to device space on the CPU. The effects now need to know that the space in which
      * the geometry will be specified has changed.
      *
      * Note that when restore is called (or in the destructor) the context's matrix will be
      * restored. However, the paint will not be restored. The caller must make a copy of the
      * paint if necessary. Hint: use SkTCopyOnFirstWrite if the AutoMatrix is conditionally
      * initialized.
      */
     class AutoMatrix : public ::SkNoncopyable {
     public:
         AutoMatrix() : fContext(NULL) {}
         ~AutoMatrix() { this->restore(); }
         /**
          * Initializes by pre-concat'ing the context's current matrix with the preConcat param.
          */
         void setPreConcat(GrContext* context, const SkMatrix& preConcat, GrPaint* paint = NULL) {
             SkASSERT(NULL != context);
             this->restore();
             fContext = context;
             fMatrix = context->getMatrix();
             this->preConcat(preConcat, paint);
         }
         /**
          * Sets the context's matrix to identity. Returns false if the inverse matrix is required to
          * update a paint but the matrix cannot be inverted.
          */
         bool setIdentity(GrContext* context, GrPaint* paint = NULL) {
             SkASSERT(NULL != context);
             this->restore();
             if (NULL != paint) {
                 if (!paint->localCoordChangeInverse(context->getMatrix())) {
                     return false;
                 }
             }
             fMatrix = context->getMatrix();
             fContext = context;
             context->setIdentityMatrix();
             return true;
         }
         /**
          * Replaces the context's matrix with a new matrix. Returns false if the inverse matrix is
          * required to update a paint but the matrix cannot be inverted.
          */
         bool set(GrContext* context, const SkMatrix& newMatrix, GrPaint* paint = NULL) {
             if (NULL != paint) {
                 if (!this->setIdentity(context, paint)) {
                     return false;
                 }
                 this->preConcat(newMatrix, paint);
             } else {
                 this->restore();
                 fContext = context;
                 fMatrix = context->getMatrix();
                 context->setMatrix(newMatrix);
             }
             return true;
         }
         /**
          * If this has been initialized then the context's matrix will be further updated by
          * pre-concat'ing the preConcat param. The matrix that will be restored remains unchanged.
          * The paint is assumed to be relative to the context's matrix at the time this call is
          * made, not the matrix at the time AutoMatrix was first initialized. In other words, this
          * performs an incremental update of the paint.
          */
         void preConcat(const SkMatrix& preConcat, GrPaint* paint = NULL) {
             if (NULL != paint) {
                 paint->localCoordChange(preConcat);
             }
             fContext->concatMatrix(preConcat);
         }
         /**
          * Returns false if never initialized or the inverse matrix was required to update a paint
          * but the matrix could not be inverted.
          */
         bool succeeded() const { return NULL != fContext; }
         /**
          * If this has been initialized then the context's original matrix is restored.
          */
         void restore() {
             if (NULL != fContext) {
                 fContext->setMatrix(fMatrix);
                 fContext = NULL;
             }
         }
     private:
         GrContext*  fContext;
         SkMatrix    fMatrix;
     };
     class AutoClip : public ::SkNoncopyable {
     public:
         // This enum exists to require a caller of the constructor to acknowledge that the clip will
         // initially be wide open. It also could be extended if there are other desirable initial
         // clip states.
         enum InitialClip {
             kWideOpen_InitialClip,
         };
         AutoClip(GrContext* context, InitialClip initialState)
         : fContext(context) {
             SkASSERT(kWideOpen_InitialClip == initialState);
             fNewClipData.fClipStack = &fNewClipStack;
             fOldClip = context->getClip();
             context->setClip(&fNewClipData);
         }
         AutoClip(GrContext* context, const SkRect& newClipRect)
         : fContext(context)
         , fNewClipStack(newClipRect) {
             fNewClipData.fClipStack = &fNewClipStack;
             fOldClip = fContext->getClip();
             fContext->setClip(&fNewClipData);
         }
         ~AutoClip() {
             if (NULL != fContext) {
                 fContext->setClip(fOldClip);
             }
         }
     private:
         GrContext*        fContext;
         const GrClipData* fOldClip;
         SkClipStack       fNewClipStack;
         GrClipData        fNewClipData;
     };
     class AutoWideOpenIdentityDraw {
     public:
         AutoWideOpenIdentityDraw(GrContext* ctx, GrRenderTarget* rt)
             : fAutoClip(ctx, AutoClip::kWideOpen_InitialClip)
             , fAutoRT(ctx, rt) {
             fAutoMatrix.setIdentity(ctx);
             // should never fail with no paint param.
             SkASSERT(fAutoMatrix.succeeded());
         }
     private:
         AutoClip fAutoClip;
         AutoRenderTarget fAutoRT;
         AutoMatrix fAutoMatrix;
     };
     ///////////////////////////////////////////////////////////////////////////
     // Functions intended for internal use only.
     GrGpu* getGpu() { return fGpu; }
     const GrGpu* getGpu() const { return fGpu; }
     GrFontCache* getFontCache() { return fFontCache; }
     GrDrawTarget* getTextTarget();
     const GrIndexBuffer* getQuadIndexBuffer() const;
     // Called by tests that draw directly to the context via GrDrawTarget
     void getTestTarget(GrTestTarget*);
     /**
      * Stencil buffers add themselves to the cache using addStencilBuffer. findStencilBuffer is
      * called to check the cache for a SB that matches an RT's criteria.
      */
     void addStencilBuffer(GrStencilBuffer* sb);
     GrStencilBuffer* findStencilBuffer(int width, int height, int sampleCnt);
     GrPathRenderer* getPathRenderer(
                     const SkPath& path,
                     const SkStrokeRec& stroke,
                     const GrDrawTarget* target,
                     bool allowSW,
                     GrPathRendererChain::DrawType drawType = GrPathRendererChain::kColor_DrawType,
                     GrPathRendererChain::StencilSupport* stencilSupport = NULL);
 #if GR_CACHE_STATS
     void printCacheStats() const;
 #endif
 private:
     // Used to indicate whether a draw should be performed immediately or queued in fDrawBuffer.
     enum BufferedDraw {
         kYes_BufferedDraw,
         kNo_BufferedDraw,
     };
     BufferedDraw fLastDrawWasBuffered;
     GrGpu*                          fGpu;
     SkMatrix                        fViewMatrix;
     SkAutoTUnref<GrRenderTarget>    fRenderTarget;
     const GrClipData*               fClip;  // TODO: make this ref counted
     GrDrawState*                    fDrawState;
     GrResourceCache*                fTextureCache;
     GrFontCache*                    fFontCache;
     GrPathRendererChain*            fPathRendererChain;
     GrSoftwarePathRenderer*         fSoftwarePathRenderer;
     GrVertexBufferAllocPool*        fDrawBufferVBAllocPool;
     GrIndexBufferAllocPool*         fDrawBufferIBAllocPool;
     GrInOrderDrawBuffer*            fDrawBuffer;
     // Set by OverbudgetCB() to request that GrContext flush before exiting a draw.
     bool                            fFlushToReduceCacheSize;
     GrAARectRenderer*               fAARectRenderer;
     GrOvalRenderer*                 fOvalRenderer;
     bool                            fDidTestPMConversions;
     int                             fPMToUPMConversion;
     int                             fUPMToPMConversion;
     struct CleanUpData {
         PFCleanUpFunc fFunc;
         void*         fInfo;
     };
     SkTDArray<CleanUpData>          fCleanUpData;
     int                             fMaxTextureSizeOverride;
     GrContext(); // init must be called after the constructor.
     bool init(GrBackend, GrBackendContext);
     void setupDrawBuffer();
     class AutoRestoreEffects;
     class AutoCheckFlush;
     /// Sets the paint and returns the target to draw into. The paint can be NULL in which case the
     /// draw state is left unmodified.
     GrDrawTarget* prepareToDraw(const GrPaint*, BufferedDraw, AutoRestoreEffects*, AutoCheckFlush*);
     void internalDrawPath(GrDrawTarget* target, bool useAA, const SkPath& path,
                           const SkStrokeRec& stroke);
     GrTexture* createResizedTexture(const GrTextureDesc& desc,
                                     const GrCacheID& cacheID,
                                     void* srcData,
                                     size_t rowBytes,
                                     bool filter);
     // Needed so GrTexture's returnToCache helper function can call
     // addExistingTextureToCache
     friend class GrTexture;
     friend class GrStencilAndCoverPathRenderer;
     // Add an existing texture to the texture cache. This is intended solely
     // for use with textures released from an GrAutoScratchTexture.
     void addExistingTextureToCache(GrTexture* texture);
     /**
      * These functions create premul <-> unpremul effects if it is possible to generate a pair
      * of effects that make a readToUPM->writeToPM->readToUPM cycle invariant. Otherwise, they
      * return NULL.
      */
     const GrEffectRef* createPMToUPMEffect(GrTexture* texture,
                                            bool swapRAndB,
                                            const SkMatrix& matrix);
     const GrEffectRef* createUPMToPMEffect(GrTexture* texture,
                                            bool swapRAndB,
                                            const SkMatrix& matrix);
     /**
      *  This callback allows the resource cache to callback into the GrContext
      *  when the cache is still overbudget after a purge.
      */
     static bool OverbudgetCB(void* data);
     /** Creates a new gpu path, based on the specified path and stroke and returns it.
      * The caller owns a ref on the returned path which must be balanced by a call to unref.
      *
      * @param skPath the path geometry.
      * @param stroke the path stroke.
      * @return a new path or NULL if the operation is not supported by the backend.
      */
     GrPath* createPath(const SkPath& skPath, const SkStrokeRec& stroke);
     typedef SkRefCnt INHERITED;
 };
 /**
  * Gets and locks a scratch texture from a descriptor using either exact or approximate criteria.
  * Unlocks texture in the destructor.
  */
 class GrAutoScratchTexture : public ::SkNoncopyable {
 public:
     GrAutoScratchTexture()
         : fContext(NULL)
         , fTexture(NULL) {
     }
     GrAutoScratchTexture(GrContext* context,
                          const GrTextureDesc& desc,
                          GrContext::ScratchTexMatch match = GrContext::kApprox_ScratchTexMatch)
       : fContext(NULL)
       , fTexture(NULL) {
       this->set(context, desc, match);
     }
     ~GrAutoScratchTexture() {
         this->reset();
     }
     void reset() {
         if (NULL != fContext && NULL != fTexture) {
             fContext->unlockScratchTexture(fTexture);
             fTexture->unref();
             fTexture = NULL;
         }
     }
     /*
      * When detaching a texture we do not unlock it in the texture cache but
      * we do set the returnToCache flag. In this way the texture remains
      * "locked" in the texture cache until it is freed and recycled in
      * GrTexture::internal_dispose. In reality, the texture has been removed
      * from the cache (because this is in AutoScratchTexture) and by not
      * calling unlockScratchTexture we simply don't re-add it. It will be
      * reattached in GrTexture::internal_dispose.
      *
      * Note that the caller is assumed to accept and manage the ref to the
      * returned texture.
      */
     GrTexture* detach() {
         if (NULL == fTexture) {
             return NULL;
         }
         GrTexture* texture = fTexture;
         fTexture = NULL;
         // This GrAutoScratchTexture has a ref from lockAndRefScratchTexture, which we give up now.
         // The cache also has a ref which we are lending to the caller of detach(). When the caller
         // lets go of the ref and the ref count goes to 0 internal_dispose will see this flag is
         // set and re-ref the texture, thereby restoring the cache's ref.
         SkASSERT(texture->getRefCnt() > 1);
         texture->setFlag((GrTextureFlags) GrTexture::kReturnToCache_FlagBit);
         texture->unref();
         SkASSERT(NULL != texture->getCacheEntry());
         return texture;
     }
     GrTexture* set(GrContext* context,
                    const GrTextureDesc& desc,
                    GrContext::ScratchTexMatch match = GrContext::kApprox_ScratchTexMatch) {
         this->reset();
         fContext = context;
         if (NULL != fContext) {
             fTexture = fContext->lockAndRefScratchTexture(desc, match);
             if (NULL == fTexture) {
                 fContext = NULL;
             }
             return fTexture;
         } else {
             return NULL;
         }
     }
     GrTexture* texture() { return fTexture; }
 private:
     GrContext*                    fContext;
     GrTexture*                    fTexture;
 };
 #endif

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gfx/skia/trunk/include/gpu/GrContext.h@6474c204b198 (annotated)

gfx/skia/trunk/include/gpu/GrContext.h