michael@0: 
michael@0: /*
michael@0:  * Copyright 2011 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: 
michael@0: #ifndef GrGeometryBuffer_DEFINED
michael@0: #define GrGeometryBuffer_DEFINED
michael@0: 
michael@0: #include "GrResource.h"
michael@0: 
michael@0: class GrGpu;
michael@0: 
michael@0: /**
michael@0:  * Parent class for vertex and index buffers
michael@0:  */
michael@0: class GrGeometryBuffer : public GrResource {
michael@0: public:
michael@0:     SK_DECLARE_INST_COUNT(GrGeometryBuffer);
michael@0: 
michael@0:     /**
michael@0:      *Retrieves whether the buffer was created with the dynamic flag
michael@0:      *
michael@0:      * @return true if the buffer was created with the dynamic flag
michael@0:      */
michael@0:     bool dynamic() const { return fDynamic; }
michael@0: 
michael@0:     /**
michael@0:      * Returns true if the buffer is a wrapper around a CPU array. If true it
michael@0:      * indicates that lock will always succeed and will be free.
michael@0:      */
michael@0:     bool isCPUBacked() const { return fCPUBacked; }
michael@0: 
michael@0:     /**
michael@0:      * Locks the buffer to be written by the CPU.
michael@0:      *
michael@0:      * The previous content of the buffer is invalidated. It is an error
michael@0:      * to draw from the buffer while it is locked. It is an error to call lock
michael@0:      * on an already locked buffer. It may fail if the backend doesn't support
michael@0:      * locking the buffer. If the buffer is CPU backed then it will always
michael@0:      * succeed and is a free operation. Must be matched by an unlock() call.
michael@0:      * Currently only one lock at a time is supported (no nesting of
michael@0:      * lock/unlock).
michael@0:      *
michael@0:      * @return a pointer to the data or NULL if the lock fails.
michael@0:      */
michael@0:     virtual void* lock() = 0;
michael@0: 
michael@0:     /**
michael@0:      * Returns the same ptr that lock() returned at time of lock or NULL if the
michael@0:      * is not locked.
michael@0:      *
michael@0:      * @return ptr to locked buffer data or undefined if buffer is not locked.
michael@0:      */
michael@0:     virtual void* lockPtr() const = 0;
michael@0: 
michael@0:     /**
michael@0:      * Unlocks the buffer.
michael@0:      *
michael@0:      * The pointer returned by the previous lock call will no longer be valid.
michael@0:      */
michael@0:     virtual void unlock() = 0;
michael@0: 
michael@0:     /**
michael@0:      Queries whether the buffer has been locked.
michael@0: 
michael@0:      @return true if the buffer is locked, false otherwise.
michael@0:      */
michael@0:     virtual bool isLocked() const = 0;
michael@0: 
michael@0:     /**
michael@0:      * Updates the buffer data.
michael@0:      *
michael@0:      * The size of the buffer will be preserved. The src data will be
michael@0:      * placed at the beginning of the buffer and any remaining contents will
michael@0:      * be undefined.
michael@0:      *
michael@0:      * @return returns true if the update succeeds, false otherwise.
michael@0:      */
michael@0:     virtual bool updateData(const void* src, size_t srcSizeInBytes) = 0;
michael@0: 
michael@0:     // GrResource overrides
michael@0:     virtual size_t sizeInBytes() const { return fSizeInBytes; }
michael@0: 
michael@0: protected:
michael@0:     GrGeometryBuffer(GrGpu* gpu, bool isWrapped, size_t sizeInBytes, bool dynamic, bool cpuBacked)
michael@0:         : INHERITED(gpu, isWrapped)
michael@0:         , fSizeInBytes(sizeInBytes)
michael@0:         , fDynamic(dynamic)
michael@0:         , fCPUBacked(cpuBacked) {}
michael@0: 
michael@0: private:
michael@0:     size_t   fSizeInBytes;
michael@0:     bool     fDynamic;
michael@0:     bool     fCPUBacked;
michael@0: 
michael@0:     typedef GrResource INHERITED;
michael@0: };
michael@0: 
michael@0: #endif