WebCore/html/CanvasPixelArray.h

/*
 * Copyright (C) 2008 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.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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 CanvasPixelArray_h
#define CanvasPixelArray_h

#include <wtf/MathExtras.h>
#include <wtf/PassRefPtr.h>
#include <wtf/RefCounted.h>
#include <wtf/Vector.h>

namespace WebCore {
    
    class CanvasPixelArray : public RefCounted<CanvasPixelArray> {
    public:
        static PassRefPtr<CanvasPixelArray> create(unsigned size);

        Vector<unsigned char>& data() { return m_data; }
        unsigned length() const { return m_data.size(); }

        void set(unsigned index, double value)
        {
            if (index >= m_data.size())
                return;
            if (!(value > 0)) // Clamp NaN to 0
                value = 0;
            else if (value > 255)
                value = 255;
            m_data[index] = static_cast<unsigned char>(value + 0.5);
        }

        bool get(unsigned index, unsigned char& result) const
        {
            if (index >= m_data.size())
                return false;
            result = m_data[index];
            return true;
        }

    private:
        CanvasPixelArray(unsigned size);
        Vector<unsigned char> m_data;
    };
    
} // namespace WebCore

#endif // CanvasPixelArray_h