/*

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

 *

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

 * modification, are permitted provided that the following conditions

 * are met:

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

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

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

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

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

 *

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

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

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

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

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

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

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

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

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

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

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

 */

#ifndef WebGLBuffer_h

#define WebGLBuffer_h

#include "CanvasObject.h"

#include "ArrayBuffer.h"

#include <wtf/PassRefPtr.h>

#include <wtf/RefCounted.h>

namespace WebCore {

    class WebGLBuffer : public CanvasObject {

    public:

        virtual ~WebGLBuffer() { deleteObject(); }

        static PassRefPtr<WebGLBuffer> create(WebGLRenderingContext*);

        bool associateBufferData(int size);

        bool associateBufferData(ArrayBuffer* array);

        bool associateBufferData(ArrayBufferView* array);

        bool associateBufferSubData(long offset, ArrayBuffer* array);

        bool associateBufferSubData(long offset, ArrayBufferView* array);

        unsigned byteLength() const;

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

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

        // none has been set.

        long getCachedMaxIndex(unsigned long type);

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

        void setCachedMaxIndex(unsigned long type, long value);

        unsigned long getTarget() const { return m_target; }

        void setTarget(unsigned long);

    protected:

        WebGLBuffer(WebGLRenderingContext*);

        virtual void _deleteObject(Platform3DObject o);

    private:

        virtual bool isBuffer() const { return true; }

        unsigned long m_target;

        RefPtr<ArrayBuffer> m_elementArrayBuffer;

        unsigned m_byteLength;

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

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

        // entire buffer.

        // 

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

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

        // that size.

        struct MaxIndexCacheEntry {

            unsigned long type;

            long maxIndex;

        };

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

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

        // possibility of adding others.

        MaxIndexCacheEntry m_maxIndexCache[4];

        unsigned m_nextAvailableCacheEntry;

        // Clears all of the cached max indices.

        void clearCachedMaxIndices();

    };

} // namespace WebCore

#endif // WebGLBuffer_h