GrGeometryBuffer.h revision 7fa18762e0ab64c3473df3aab0c2bfd6fabd8831 
1
2/*
3 * Copyright 2011 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#ifndef GrGeometryBuffer_DEFINED
11#define GrGeometryBuffer_DEFINED
12
13#include "GrResource.h"
14
15class GrGpu;
16
17/**
18 * Parent class for vertex and index buffers
19 */
20class GrGeometryBuffer : public GrResource {
21public:
22    SK_DECLARE_INST_COUNT(GrGeometryBuffer);
23
24    /**
25     *Retrieves whether the buffer was created with the dynamic flag
26     *
27     * @return true if the buffer was created with the dynamic flag
28     */
29    bool dynamic() const { return fDynamic; }
30
31    /**
32     * Locks the buffer to be written by the CPU.
33     *
34     * The previous content of the buffer is invalidated. It is an error
35     * to draw from the buffer while it is locked. It is an error to call lock
36     * on an already locked buffer.
37     *
38     * @return a pointer to the data or NULL if the lock fails.
39     */
40    virtual void* lock() = 0;
41
42    /**
43     * Returns the same ptr that lock() returned at time of lock or NULL if the
44     * is not locked.
45     *
46     * @return ptr to locked buffer data or undefined if buffer is not locked.
47     */
48    virtual void* lockPtr() const = 0;
49
50    /**
51     * Unlocks the buffer.
52     *
53     * The pointer returned by the previous lock call will no longer be valid.
54     */
55    virtual void unlock() = 0;
56
57    /**
58     Queries whether the buffer has been locked.
59
60     @return true if the buffer is locked, false otherwise.
61     */
62    virtual bool isLocked() const = 0;
63
64    /**
65     * Updates the buffer data.
66     *
67     * The size of the buffer will be preserved. The src data will be
68     * placed at the begining of the buffer and any remaining contents will
69     * be undefined.
70     *
71     * @return returns true if the update succeeds, false otherwise.
72     */
73    virtual bool updateData(const void* src, size_t srcSizeInBytes) = 0;
74
75    // GrResource overrides
76    virtual size_t sizeInBytes() const { return fSizeInBytes; }
77
78protected:
79    GrGeometryBuffer(GrGpu* gpu, size_t sizeInBytes, bool dynamic)
80        : INHERITED(gpu)
81        , fSizeInBytes(sizeInBytes)
82        , fDynamic(dynamic) {}
83
84private:
85    size_t   fSizeInBytes;
86    bool     fDynamic;
87
88    typedef GrResource INHERITED;
89};
90
91#endif
92