1 /*

     2  * Copyright (C) 2009 Apple Inc. All rights reserved.

     3  *

     4  * Redistribution and use in source and binary forms, with or without

     5  * modification, are permitted provided that the following conditions

     6  * are met:

     7  * 1. Redistributions of source code must retain the above copyright

     8  *    notice, this list of conditions and the following disclaimer.

     9  * 2. Redistributions in binary form must reproduce the above copyright

    10  *    notice, this list of conditions and the following disclaimer in the

    11  *    documentation and/or other materials provided with the distribution.

    12  *

    13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY

    14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

    16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR

    17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

    18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

    19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

    20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

    21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

    22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

    23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

    24  */

    25 

    26 #ifndef WebGLBuffer_h

    27 #define WebGLBuffer_h

    28 

    29 #include "CanvasObject.h"

    30 #include "ArrayBuffer.h"

    31 

    32 #include <wtf/PassRefPtr.h>

    33 #include <wtf/RefCounted.h>

    34 

    35 namespace WebCore {

    36     

    37     class WebGLBuffer : public CanvasObject {

    38     public:

    39         virtual ~WebGLBuffer() { deleteObject(); }

    40         

    41         static PassRefPtr<WebGLBuffer> create(WebGLRenderingContext*);

    42 

    43         bool associateBufferData(int size);

    44         bool associateBufferData(ArrayBuffer* array);

    45         bool associateBufferData(ArrayBufferView* array);

    46         bool associateBufferSubData(long offset, ArrayBuffer* array);

    47         bool associateBufferSubData(long offset, ArrayBufferView* array);

    48         

    49         unsigned byteLength() const;

    50         const ArrayBuffer* elementArrayBuffer() const { return m_elementArrayBuffer.get(); }

    51                         

    52         // Gets the cached max index for the given type. Returns -1 if

    53         // none has been set.

    54         long getCachedMaxIndex(unsigned long type);

    55         // Sets the cached max index for the given type.

    56         void setCachedMaxIndex(unsigned long type, long value);

    57 

    58         unsigned long getTarget() const { return m_target; }

    59         void setTarget(unsigned long);

    60 

    61     protected:

    62         WebGLBuffer(WebGLRenderingContext*);

    63 

    64         virtual void _deleteObject(Platform3DObject o);

    65     

    66     private:

    67         virtual bool isBuffer() const { return true; }

    68 

    69         unsigned long m_target;

    70 

    71         RefPtr<ArrayBuffer> m_elementArrayBuffer;

    72         unsigned m_byteLength;

    73 

    74         // Optimization for index validation. For each type of index

    75         // (i.e., UNSIGNED_SHORT), cache the maximum index in the

    76         // entire buffer.

    77         // 

    78         // This is sufficient to eliminate a lot of work upon each

    79         // draw call as long as all bound array buffers are at least

    80         // that size.

    81         struct MaxIndexCacheEntry {

    82             unsigned long type;

    83             long maxIndex;

    84         };

    85         // OpenGL ES 2.0 only has two valid index types (UNSIGNED_BYTE

    86         // and UNSIGNED_SHORT), but might as well leave open the

    87         // possibility of adding others.

    88         MaxIndexCacheEntry m_maxIndexCache[4];

    89         unsigned m_nextAvailableCacheEntry;

    90 

    91         // Clears all of the cached max indices.

    92         void clearCachedMaxIndices();

    93     };

    94     

    95 } // namespace WebCore

    96 

    97 #endif // WebGLBuffer_h